• Expedition to Europa

    From Joe Gwinn@21:1/5 to All on Thu Jun 27 14:39:33 2024
    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    But ever since NASA’s Voyager flybys in 1979 and the flagship
    1995-2003 Galileo mission to Jupiter, scientists have assembled an
    increasingly convincing body of evidence that beneath Europa's frozen
    surface lies a massive saltwater ocean containing 2-3 times the water
    in all the oceans on Earth.

    Scientists suspect that Europa’s sea, which lies about 60 mi. beneath
    the surface, remains liquid due to the heat of tidal flexing as
    Jupiter’s gravity stretches and squeezes the moon. Europa, with a
    diameter of about 1,900 mi.—slightly smaller than Earth’s Moon—circles
    Jupiter every 3.5 days. Like Earth’s Moon, Europa is tidally locked,
    resulting in one hemisphere always facing Jupiter. Tidal forces on
    Europa are about 1,000 times stronger than the Moon’s effect on Earth.

    Europa’s surface is young—just 40-90 million years old— but its inner
    ocean is believed to have existed for billions of years, long enough
    for the chemistry of life to evolve. And while there is no evidence of
    life on Europa, scientists suggest the moon may have environments
    similar to Earth’s deep-ocean hydrothermal vents, where unique
    ecosystems thrive despite extreme temperatures and pressures, toxic
    minerals and no sunlight.

    Observations by NASA’s Hubble Space Telescope in 2012 and 2014 also
    suggest water from inside Europa may intermittently vent into space as
    plumes, similar to what the Cassini spacecraft has observed on
    Saturn’s moon Endeladus. Astronomers estimate Europa’s plumes rise
    about 125 mi. into space before raining material back down onto the
    moon’s surface.

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general
    idea of "random but inevitable" theories of Abiogenesis.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Joe Gwinn on Thu Jun 27 14:17:13 2024
    On 6/27/2024 11:39 AM, Joe Gwinn wrote:
    But ever since NASA’s Voyager flybys in 1979 and the flagship
    1995-2003 Galileo mission to Jupiter, scientists have assembled an increasingly convincing body of evidence that beneath Europa's frozen
    surface lies a massive saltwater ocean containing 2-3 times the water
    in all the oceans on Earth.

    IIRC, didn't Clarke pose the same possibility a few (4) decades back in one
    of the "2001" sequels: "All these worlds are yours -- except Europa..."

    Scientists suspect that Europa’s sea, which lies about 60 mi. beneath
    the surface, remains liquid due to the heat of tidal flexing as
    Jupiter’s gravity stretches and squeezes the moon. Europa, with a
    diameter of about 1,900 mi.—slightly smaller than Earth’s Moon—circles Jupiter every 3.5 days. Like Earth’s Moon, Europa is tidally locked, resulting in one hemisphere always facing Jupiter. Tidal forces on
    Europa are about 1,000 times stronger than the Moon’s effect on Earth.

    Europa’s surface is young—just 40-90 million years old— but its inner ocean is believed to have existed for billions of years, long enough
    for the chemistry of life to evolve. And while there is no evidence of
    life on Europa, scientists suggest the moon may have environments
    similar to Earth’s deep-ocean hydrothermal vents, where unique
    ecosystems thrive despite extreme temperatures and pressures, toxic
    minerals and no sunlight.

    Observations by NASA’s Hubble Space Telescope in 2012 and 2014 also
    suggest water from inside Europa may intermittently vent into space as plumes, similar to what the Cassini spacecraft has observed on
    Saturn’s moon Endeladus. Astronomers estimate Europa’s plumes rise
    about 125 mi. into space before raining material back down onto the
    moon’s surface.

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe. It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to Carlos E.R. on Fri Jun 28 01:56:16 2024
    Carlos E.R. <robin_listas@es.invalid> wrote:
    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?



    Jupiter’s magnetosphere. See e.g. <https://www.science.org/doi/10.1126/sciadv.abd1204>

    Cheers

    Phil Hobbs

    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to robin_listas@es.invalid on Thu Jun 27 18:41:19 2024
    On Fri, 28 Jun 2024 03:22:04 +0200, "Carlos E.R."
    <robin_listas@es.invalid> wrote:

    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?

    Our sun is friendly. The universe is deadly.

    It's a miracle that Earth is shielded.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Carlos E.R.@21:1/5 to Joe Gwinn on Fri Jun 28 03:22:04 2024
    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?


    --
    Cheers, Carlos.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeff Layman@21:1/5 to john larkin on Fri Jun 28 08:01:48 2024
    On 28/06/2024 02:41, john larkin wrote:
    On Fri, 28 Jun 2024 03:22:04 +0200, "Carlos E.R."
    <robin_listas@es.invalid> wrote:

    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?

    Our sun is friendly. The universe is deadly.

    It's a miracle that Earth is shielded.

    Indeed. It's a point often ignored by exoplanet life-seekers. It's one
    thing to find suitable conditions which might create life, it's another
    thing entirely to find conditions which could sustain life. Take this
    very recent review on Gliese 12 b: <https://ras.ac.uk/news-and-press/news/rare-exo-venus-earth-temperature-discovered>

    Note this comment:
    "..."Although we don't yet know whether it possesses an atmosphere,
    we've been thinking of it as an exo-Venus, with similar size and energy received from its star as our planetary neighbour in the solar system."

    An important factor in retaining an atmosphere is the storminess of its
    star. Red dwarfs tend to be magnetically active, resulting in frequent, powerful X-ray flares.

    However, analyses by both teams conclude that Gliese 12 shows no signs
    of such extreme behaviour, raising hopes that Gliese 12 b's atmosphere
    may still be intact."

    So a red dwarf tends to have frequent powerful x-ray flares, yet the
    only comment is that there were no signs of this extreme behaviour.
    Firstly, how can it be "extreme" if it's frequent, and how long have
    they been observing this star anyway? Secondly, did nobody consider what
    an x-ray flare would do to any life which might have formed on the
    planet? Never mind the planet's surface temperature and presence - or
    not - of an atmosphere. A blast of x-rays and probably other radiation
    isn't exactly know for its life-sustaining properties.

    And that's even supposing a red dwarf would be capable of providing
    "suitable" radiation levels capable of supporting an earth-like planet
    in the first place. See: <https://ras.ac.uk/news-and-press/research-highlights/earth-biospheres-other-planets-may-be-rare>

    --
    Jeff

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Carlos E.R.@21:1/5 to Phil Hobbs on Fri Jun 28 15:36:43 2024
    On 2024-06-28 03:56, Phil Hobbs wrote:
    Carlos E.R. <robin_listas@es.invalid> wrote:
    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?



    Jupiter’s magnetosphere. See e.g. <https://www.science.org/doi/10.1126/sciadv.abd1204>


    Ah.


    (Although the article doesn't mention Europa)

    --
    Cheers, Carlos.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to pcdhSpamMeSenseless@electrooptical. on Fri Jun 28 11:26:45 2024
    On Fri, 28 Jun 2024 01:56:16 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    Carlos E.R. <robin_listas@es.invalid> wrote:
    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?



    Jupiter’s magnetosphere. See e.g. ><https://www.science.org/doi/10.1126/sciadv.abd1204>

    Also plus radioactive elements in Europa's iron core and surrounding
    ocean.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to jeroen@nospam.please on Fri Jun 28 11:03:22 2024
    On Fri, 28 Jun 2024 20:01:20 +0200, Jeroen Belleman
    <jeroen@nospam.please> wrote:

    On 6/28/24 09:01, Jeff Layman wrote:
    On 28/06/2024 02:41, john larkin wrote:
    On Fri, 28 Jun 2024 03:22:04 +0200, "Carlos E.R."
    <robin_listas@es.invalid> wrote:

    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures >>>>> on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?

    Our sun is friendly. The universe is deadly.

    It's a miracle that Earth is shielded.

    Indeed. It's a point often ignored by exoplanet life-seekers. It's one
    thing to find suitable conditions which might create life, it's another
    thing entirely to find conditions which could sustain life. Take this
    very recent review on Gliese 12 b:
    <https://ras.ac.uk/news-and-press/news/rare-exo-venus-earth-temperature-discovered>

    Note this comment:
    "..."Although we don't yet know whether it possesses an atmosphere,
    we've been thinking of it as an exo-Venus, with similar size and energy
    received from its star as our planetary neighbour in the solar system."

    An important factor in retaining an atmosphere is the storminess of its
    star. Red dwarfs tend to be magnetically active, resulting in frequent,
    powerful X-ray flares.

    However, analyses by both teams conclude that Gliese 12 shows no signs
    of such extreme behaviour, raising hopes that Gliese 12 b's atmosphere
    may still be intact."

    So a red dwarf tends to have frequent powerful x-ray flares, yet the
    only comment is that there were no signs of this extreme behaviour.
    Firstly, how can it be "extreme" if it's frequent, and how long have
    they been observing this star anyway? Secondly, did nobody consider what
    an x-ray flare would do to any life which might have formed on the
    planet? Never mind the planet's surface temperature and presence - or
    not - of an atmosphere. A blast of x-rays and probably other radiation
    isn't exactly know for its life-sustaining properties.

    And that's even supposing a red dwarf would be capable of providing
    "suitable" radiation levels capable of supporting an earth-like planet
    in the first place. See:
    <https://ras.ac.uk/news-and-press/research-highlights/earth-biospheres-other-planets-may-be-rare>


    Oh well. Earth has a toxic, oxidizing atmosphere, with free oxygen and
    worse, ozone. And yet life thrives.

    Earth wants to burn down most of the stuff that we build.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Jeff Layman on Fri Jun 28 20:01:20 2024
    On 6/28/24 09:01, Jeff Layman wrote:
    On 28/06/2024 02:41, john larkin wrote:
    On Fri, 28 Jun 2024 03:22:04 +0200, "Carlos E.R."
    <robin_listas@es.invalid> wrote:

    On 2024-06-27 20:39, Joe Gwinn wrote:

    Excerpted from Aviation Week, June 3-16 2024, page 38:

    Located more than five times farther away from the Sun than Earth,
    Europa seems an unlikely place to look for life. Surface temperatures
    on the ice-shrouded moon of Jupiter average |-260F, and radiation
    levels are high enough to kill a human being in one day.

    Being that far from the sun, where comes that radiation from?

    Our sun is friendly. The universe is deadly.

    It's a miracle that Earth is shielded.

    Indeed. It's a point often ignored by exoplanet life-seekers. It's one
    thing to find suitable conditions which might create life, it's another
    thing entirely to find conditions which could sustain life. Take this
    very recent review on Gliese 12 b: <https://ras.ac.uk/news-and-press/news/rare-exo-venus-earth-temperature-discovered>

    Note this comment:
    "..."Although we don't yet know whether it possesses an atmosphere,
    we've been thinking of it as an exo-Venus, with similar size and energy received from its star as our planetary neighbour in the solar system."

    An important factor in retaining an atmosphere is the storminess of its
    star. Red dwarfs tend to be magnetically active, resulting in frequent, powerful X-ray flares.

    However, analyses by both teams conclude that Gliese 12 shows no signs
    of such extreme behaviour, raising hopes that Gliese 12 b's atmosphere
    may still be intact."

    So a red dwarf tends to have frequent powerful x-ray flares, yet the
    only comment is that there were no signs of this extreme behaviour.
    Firstly, how can it be "extreme" if it's frequent, and how long have
    they been observing this star anyway? Secondly, did nobody consider what
    an x-ray flare would do to any life which might have formed on the
    planet? Never mind the planet's surface temperature and presence - or
    not - of an atmosphere. A blast of x-rays and probably other radiation
    isn't exactly know for its life-sustaining properties.

    And that's even supposing a red dwarf would be capable of providing "suitable" radiation levels capable of supporting an earth-like planet
    in the first place. See: <https://ras.ac.uk/news-and-press/research-highlights/earth-biospheres-other-planets-may-be-rare>


    Oh well. Earth has a toxic, oxidizing atmosphere, with free oxygen and
    worse, ozone. And yet life thrives.

    Don't take all these "extreme" conditions too seriously. What seems
    extreme for us may be balmy for them. That is, if there is a 'them';
    We have yet to find any.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to bitrex on Sat Jun 29 01:14:35 2024
    On 6/29/2024 1:08 AM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core.



    My guess: The Universe is mammoth, the technological and energy
    requirements of even short-distance interstellar travel are immense, the lifespan of technological civilizations is highly time-limited before
    such a civilization destroys itself, technological civilizations are
    very rare to begin with, and no technological civilization ever survives
    long enough to attempt it.

    I call this the "vexation and vanity" theory; by the time an intelligent species is sufficiently intelligent to even conceive of the concept of interstellar flight as plausible, the degree of collective insanity
    required to think these thoughts in the first place already ensures its destruction.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From bitrex@21:1/5 to Don Y on Sat Jun 29 01:08:27 2024
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core.



    My guess: The Universe is mammoth, the technological and energy
    requirements of even short-distance interstellar travel are immense, the lifespan of technological civilizations is highly time-limited before
    such a civilization destroys itself, technological civilizations are
    very rare to begin with, and no technological civilization ever survives
    long enough to attempt it.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to bitrex on Sat Jun 29 04:04:11 2024
    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core.

    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of technological civilizations is highly time-limited before such a civilization destroys itself, technological civilizations are very rare to begin with, and no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to *detect* our presence (given that we seem to make no attempt at "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some interesting takes on the Fermi paradox.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to blockedofcourse@foo.invalid on Sat Jun 29 11:35:47 2024
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has
    existed for something like four billion years, it supports the general >>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core.

    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >*detect* our presence (given that we seem to make no attempt at "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Joe Gwinn on Sat Jun 29 10:11:39 2024
    On 6/29/2024 8:35 AM, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>> existed for something like four billion years, it supports the general >>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >> interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to All on Sat Jun 29 11:26:56 2024
    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>> existed for something like four billion years, it supports the general >>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>*detect* our presence (given that we seem to make no attempt at "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >>interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to
    visit us.

    A very advanced robot might.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jeroen Belleman@21:1/5 to Don Y on Sat Jun 29 20:25:03 2024
    On 6/29/24 19:11, Don Y wrote:
    On 6/29/2024 8:35 AM, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>> existed for something like four billion years, it supports the
    general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for >>>>> me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its
    core.

    My guess: The Universe is mammoth, the technological and energy
    requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a
    civilization
    destroys itself, technological civilizations are very rare to begin
    with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at
    "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_
    gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?



    I think we aren't nearly as conspicuous as you think we are. The
    deep space probes are tiny. There is not the slightest chance of
    finding them without knowing exactly where to look. The very
    presence of earth itself is barely noticeable beyond a few
    lightyears.

    Jeroen Belleman

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Carlos E.R.@21:1/5 to Joe Gwinn on Sat Jun 29 20:45:27 2024
    On 2024-06-29 17:35, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>> existed for something like four billion years, it supports the general >>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >> interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    But why can we not detect them, by radio or something? Surely we would
    have seen them already.

    It is not about visiting.


    --
    Cheers, Carlos.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Phil Hobbs@21:1/5 to All on Sat Jun 29 18:41:07 2024
    john larkin <jlarkin_highland_tech> wrote:
    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>> existed for something like four billion years, it supports the general >>>>>> idea of "random but inevitable"˙theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.˙ It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at "hiding") >>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >>> interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to
    visit us.

    A very advanced robot might.



    https://memory-alpha.fandom.com/wiki/V%27ger

    Cheers

    Phil Hobbs


    --
    Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to pcdhSpamMeSenseless@electrooptical. on Sat Jun 29 13:14:36 2024
    On Sat, 29 Jun 2024 18:41:07 -0000 (UTC), Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> wrote:

    john larkin <jlarkin_highland_tech> wrote:
    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>>> existed for something like four billion years, it supports the general >>>>>>> idea of "random but inevitable"?ies of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole >>>>>> notion behind an "empty" universe.? a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of >>>>> technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it. >>>>
    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>> *detect* our presence (given that we seem to make no attempt at "hiding") >>>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to
    visit us.

    A very advanced robot might.



    https://memory-alpha.fandom.com/wiki/V%27ger

    Cheers

    Phil Hobbs

    and

    https://en.wikipedia.org/wiki/Berserker_(novel_series)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Clive Arthur@21:1/5 to Joe Gwinn on Sat Jun 29 21:31:45 2024
    On 29/06/2024 16:35, Joe Gwinn wrote:

    <snipped>

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    The old ones are the best...

    https://www.mit.edu/people/dpolicar/writing/prose/text/thinkingMeat.html

    --
    Cheers
    Clive

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to robin_listas@es.invalid on Sat Jun 29 13:16:38 2024
    On Sat, 29 Jun 2024 20:45:27 +0200, "Carlos E.R."
    <robin_listas@es.invalid> wrote:

    On 2024-06-29 17:35, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>> existed for something like four billion years, it supports the general >>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at "hiding") >>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >>> interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    But why can we not detect them, by radio or something? Surely we would
    have seen them already.

    It is not about visiting.

    Radio is just a brief phase that a civilization goes through. We're
    about over it now.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to All on Sat Jun 29 17:41:14 2024
    On Sat, 29 Jun 2024 11:26:56 -0700, john larkin
    <jlarkin_highland_tech> wrote:

    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>> existed for something like four billion years, it supports the general >>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for
    me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>*detect* our presence (given that we seem to make no attempt at "hiding") >>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >>>interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to
    visit us.

    The claim being made was that because we were not seeing any
    intelligent aliens, they must not exist, or are very rare. Which does
    not follow.


    A very advanced robot might.

    Even if they do have warp drives, they may still send a robot.

    But given the technological gulf between Earthlings and any
    civilization possessing any warp drive, we won't detect them unless
    they want us to.


    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Jeroen Belleman on Sat Jun 29 14:20:11 2024
    On 6/29/2024 11:25 AM, Jeroen Belleman wrote:
    On 6/29/24 19:11, Don Y wrote:
    On 6/29/2024 8:35 AM, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>>> existed for something like four billion years, it supports the general >>>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole >>>>>> notion behind an "empty" universe.  It's a tedious read (mainly for >>>>>> me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>>
    My guess: The Universe is mammoth, the technological and energy
    requirements of
    even short-distance interstellar travel are immense, the lifespan of >>>>> technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it. >>>>
    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>> *detect* our presence (given that we seem to make no attempt at "hiding") >>>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?

    I think we aren't nearly as conspicuous as you think we are. The
    deep space probes are tiny. There is not the slightest chance of
    finding them without knowing exactly where to look. The very
    presence of earth itself is barely noticeable beyond a few
    lightyears.

    Yet *we* look. Do we imagine other life forms will be MORE conspicuous?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From john larkin @21:1/5 to All on Sat Jun 29 14:45:26 2024
    On Sat, 29 Jun 2024 17:41:14 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 11:26:56 -0700, john larkin
    <jlarkin_highland_tech> wrote:

    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>>> existed for something like four billion years, it supports the general >>>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole >>>>>> notion behind an "empty" universe.  It's a tedious read (mainly for >>>>>> me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>>
    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of >>>>> technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it. >>>>
    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>>*detect* our presence (given that we seem to make no attempt at "hiding") >>>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >>>>interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that >>>which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to >>visit us.

    The claim being made was that because we were not seeing any
    intelligent aliens, they must not exist, or are very rare. Which does
    not follow.


    A very advanced robot might.

    Even if they do have warp drives, they may still send a robot.

    But given the technological gulf between Earthlings and any
    civilization possessing any warp drive, we won't detect them unless
    they want us to.


    Joe Gwinn

    I think that life on Earth is someone's high school science project.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Joe Gwinn on Sat Jun 29 14:50:33 2024
    On 6/29/2024 2:41 PM, Joe Gwinn wrote:
    The claim being made was that because we were not seeing any
    intelligent aliens, they must not exist, or are very rare. Which does
    not follow.

    .. or, we don't know how to recognize them (see _... WHERE IS EVERYBODY?_)

    Even if they do have warp drives, they may still send a robot.

    But given the technological gulf between Earthlings and any
    civilization possessing any warp drive, we won't detect them unless
    they want us to.

    The issue presented in _Remembrances ..._

    Note many "scholars" have warned that we probably shouldn't WANT
    to be "discovered"

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Joe Gwinn@21:1/5 to All on Sat Jun 29 18:22:27 2024
    On Sat, 29 Jun 2024 14:45:26 -0700, john larkin
    <jlarkin_highland_tech> wrote:

    On Sat, 29 Jun 2024 17:41:14 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 11:26:56 -0700, john larkin
    <jlarkin_highland_tech> wrote:

    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net> >>>wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>>>> existed for something like four billion years, it supports the general >>>>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole >>>>>>> notion behind an "empty" universe.  It's a tedious read (mainly for >>>>>>> me coming from a non-chinese culture... just keeping track of the >>>>>>> characters is difficult) but has some good ideas to chew on at its core.

    My guess: The Universe is mammoth, the technological and energy requirements of
    even short-distance interstellar travel are immense, the lifespan of >>>>>> technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it. >>>>>
    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes >>>>>but I'm sure anyone with technology comparable to ours would be able to >>>>>*detect* our presence (given that we seem to make no attempt at "hiding") >>>>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable >>>>of interstellar travel are exceedingly rare, there would be little >>>>reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that >>>>which they study.

    Joe Gwinn

    An intelligent alien lifeform is probably thousands of light-years
    away. Unless they have a Warp Drive, there's no way they would want to >>>visit us.

    The claim being made was that because we were not seeing any
    intelligent aliens, they must not exist, or are very rare. Which does
    not follow.


    A very advanced robot might.

    Even if they do have warp drives, they may still send a robot.

    But given the technological gulf between Earthlings and any
    civilization possessing any warp drive, we won't detect them unless
    they want us to.


    Joe Gwinn

    I think that life on Earth is someone's high school science project.

    We would have no way to tell for sure.

    I recall a Star Trek (?) episode what that was almost exactly what was happening - I recall that this powerful being was about to turn half
    the matter in the Sun into antimatter, which explosion would be a
    sight to behold - from a very great distance. This was averted when
    the powerful being's parents appeared and scolded their Child for
    playing with predators or the like.

    Joe Gwinn

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bill Sloman@21:1/5 to john larkin on Sun Jun 30 13:45:17 2024
    On 30/06/2024 7:45 am, john larkin wrote:
    On Sat, 29 Jun 2024 17:41:14 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 11:26:56 -0700, john larkin
    <jlarkin_highland_tech> wrote:

    On Sat, 29 Jun 2024 11:35:47 -0400, Joe Gwinn <joegwinn@comcast.net>
    wrote:

    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    I think that life on Earth is someone's high school science project.

    The experiment has been running for at least half a billion years, and
    probably some 3.5 billion years.

    https://www.bbc.com/travel/article/20210117-stromatolites-the-earths-oldest-living-lifeforms

    The big bang was about 13.8 billion years ago. The "high school" would
    seem to need to be in some higher universe.

    High school projects do seem to have short time scales.

    --
    Bill Sloman, Sydney




    --
    This email has been checked for viruses by Norton antivirus software. www.norton.com

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Don Y on Mon Jul 1 16:43:21 2024
    On 29/06/2024 18:11, Don Y wrote:
    On 6/29/2024 8:35 AM, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>> existed for something like four billion years, it supports the
    general
    idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole
    notion behind an "empty" universe.  It's a tedious read (mainly for >>>>> me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its
    core.

    My guess: The Universe is mammoth, the technological and energy
    requirements of
    even short-distance interstellar travel are immense, the lifespan of
    technological civilizations is highly time-limited before such a
    civilization
    destroys itself, technological civilizations are very rare to begin
    with, and
    no technological civilization ever survives long enough to attempt it.

    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at
    "hiding")

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_
    gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?

    Being small insignificant and with feeble radio transmitters. The only
    reason we are still in contact with the most remote ones is that ground
    based low noise amplifiers have improved enormously since their launch.

    When it was operating and doing radar range imaging the EPR of the
    Arecibo dish was phenomenal along the direction it was pointing. Anyone
    in the beam would see a very distinctive flash potentially with
    obviously digital patterns in it if they were lucky.

    There have been the odd WOW signal detected on Earth but nothing that
    stood up to detailed analysis or was reproducible. The pulsar trace was originally marked LGM in the margins since it's very precise repetitive
    signal looked artificial at first glance.

    --
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Martin Brown on Mon Jul 1 14:02:15 2024
    On 7/1/2024 8:43 AM, Martin Brown wrote:
    On 29/06/2024 18:11, Don Y wrote:
    On 6/29/2024 8:35 AM, Joe Gwinn wrote:
    On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
    <blockedofcourse@foo.invalid> wrote:

    On 6/28/2024 10:08 PM, bitrex wrote:
    On 6/27/2024 5:17 PM, Don Y wrote:

    Most big librarys carry AW.

    .<https://europa.nasa.gov/mission/about/>

    If it turns out that there is life in the ocean of Europa, which has >>>>>>> existed for something like four billion years, it supports the general >>>>>>> idea of "random but inevitable" theories of Abiogenesis.

    _Remembrance of Earth's Past_ has an interesting take on the whole >>>>>> notion behind an "empty" universe.  It's a tedious read (mainly for >>>>>> me coming from a non-chinese culture... just keeping track of the
    characters is difficult) but has some good ideas to chew on at its core. >>>>>
    My guess: The Universe is mammoth, the technological and energy
    requirements of
    even short-distance interstellar travel are immense, the lifespan of >>>>> technological civilizations is highly time-limited before such a civilization
    destroys itself, technological civilizations are very rare to begin with, and
    no technological civilization ever survives long enough to attempt it. >>>>
    That wouldn't explain why there are no *signs* of intelligent life.

    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>> *detect* our presence (given that we seem to make no attempt at "hiding") >>>>
    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
    interesting takes on the Fermi paradox.

    That's a bit self-important.

    If the universe is teaming with life, but alien civilizations capable
    of interstellar travel are exceedingly rare, there would be little
    reason for those spacefaring aliens to visit any but the other
    advanced alien civilizations.

    We might get the equivalent of an anthropologist ever few million
    year, and they would do whatever needed to prevent detection by that
    which they study.

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?

    Being small insignificant and with feeble radio transmitters. The only reason we are still in contact with the most remote ones is that ground based low noise amplifiers have improved enormously since their launch.

    Wouldn't you expect other civilizations to also understand the issues
    involved, if they were interested in searching? We spot bits of
    space debris, comets, etc. and they aren't trying to signal their
    presence...

    When it was operating and doing radar range imaging the EPR of the Arecibo dish
    was phenomenal along the direction it was pointing. Anyone in the beam would see a very distinctive flash potentially with obviously digital patterns in it
    if they were lucky.

    But they don't have to see a pattern; just an unexpected "event" that
    attracts their attention. There's a wide field to examine so it seems
    they would focus their attentions on anything "unexpected" rather than systematically trying to canvas the entire space.

    Assuming "others" have the same technological limits (or abilities!)
    as we do is naive.

    And, assuming they abandon older technologies to concentrate on
    newer ones also seems specious; if lost while hiking, I can signal
    with a whistle or a mirror -- I don't have to rely on a cell phone to
    get help!

    There have been the odd WOW signal detected on Earth but nothing that stood up
    to detailed analysis or was reproducible. The pulsar trace was originally marked LGM in the margins since it's very precise repetitive signal looked artificial at first glance.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Martin Brown on Mon Jul 1 17:03:32 2024
    On 7/1/2024 7:54 AM, Martin Brown wrote:
    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at "hiding")

    The Fermi paradox of why aren't they here yet is somewhat tricky to explain. Our star is nothing like the oldest it could be so there are potentially technological societies that are billions of years ahead of us - plenty of time
    for robotic probes to visit anywhere in the galaxy.

    And, probes don't ave to "pass through"; there's no reason they can't
    sit and watch (if you have advanced technology, what limits might that
    overcome on designing durable products?)

    I suspect that unless there is some clever shortcut using physics we don't yet
    know about human inter stellar travel is just a pipe dream.

    But you don't need to *go* somewhere to know that it exists *or* what
    it is like. We've visited Mars without ever having set foot, there.
    Ditto the depths of the oceans.

    We can make educated assessments as to the suitability for "life"
    in places that we could never expect to actually visit. Or,
    discover some form of life and then set upon trying to sort out how
    to communicate with same.

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some >> interesting takes on the Fermi paradox.

    One potentially very interesting way a technological civilisation may be detectable from Earth by spectroscopy is the presence of CFCs and HCFCs in their atmosphere. Once they master fluorine chemistry their discovery and utility is inevitable until they realise the damage to the ozone layer. Then they get phased out. Planets in transit across their suns are now being checked
    and so far nothing unusual has been seen.

    Key point here is that fluorine is so reactive and calcium so abundant that you
    can't really get any fluoro-organic chemistry going without a technological civilisation. A handful of desert plants have mastered it to make monofluoracetic acid on Earth (extremely effective rodenticide).

    It takes industrial scale manufacture before CFCs would be visible from afar. SF6 is another common one but it's scale height works against seeing it high in
    the atmosphere (its molecule is rather heavy).

    But you (we) are still constrained by your knowledge of physical sciences
    (and "interstellar civilizations"). Who's to say that "they" haven't identified some other observable (by THEM) characteristic of civilization?

    There are a whole slew of questions that you have to consider before you
    even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)? - how much do YOU want to be found?
    - what might the consequences of such a detection be? (e.g., _Remembrance..._ posits an extinction level consequence)

    Adams's claim that "Space is big" can also be accompanied by "Time is LONG".
    Do these conspire for or against discovery (or being discovered)?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to blockedofcourse@foo.invalid on Tue Jul 2 05:25:09 2024
    On a sunny day (Mon, 1 Jul 2024 17:03:32 -0700) it happened Don Y <blockedofcourse@foo.invalid> wrote in <v5vg4n$1a4s7$1@dont-email.me>:

    But you (we) are still constrained by your knowledge of physical sciences >(and "interstellar civilizations"). Who's to say that "they" haven't >identified some other observable (by THEM) characteristic of civilization?

    There are a whole slew of questions that you have to consider before you
    even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)?
    - how much do YOU want to be found?
    - what might the consequences of such a detection be? (e.g., _Remembrance..._ >posits an extinction level consequence)


    And will our religious fanatic polly-tick-sians and leaders let us know IF life has been detected?
    The Mars Viking lander experiment was positive for life.
    http://www.gillevin.com/
    I remeber the annoucement,
    hours later it was plainly denied, experiment never to me mentioned again..

    So not to upset the poepe and earth center of the universe and adam and linda eeeh eva whatever

    Adams's claim that "Space is big" can also be accompanied by "Time is LONG". >Do these conspire for or against discovery (or being discovered)?

    The microwave background could well be the sum of all the extraterrestial radio and teefee shows ;-0

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Jan Panteltje on Tue Jul 2 14:41:43 2024
    On 02/07/2024 06:25, Jan Panteltje wrote:
    On a sunny day (Mon, 1 Jul 2024 17:03:32 -0700) it happened Don Y <blockedofcourse@foo.invalid> wrote in <v5vg4n$1a4s7$1@dont-email.me>:

    But you (we) are still constrained by your knowledge of physical sciences
    (and "interstellar civilizations"). Who's to say that "they" haven't
    identified some other observable (by THEM) characteristic of civilization? >>
    There are a whole slew of questions that you have to consider before you
    even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)?
    - how much do YOU want to be found?
    - what might the consequences of such a detection be? (e.g., _Remembrance..._
    posits an extinction level consequence)


    And will our religious fanatic polly-tick-sians and leaders let us know IF life has been detected?
    The Mars Viking lander experiment was positive for life.
    http://www.gillevin.com/
    I remeber the annoucement,
    hours later it was plainly denied, experiment never to me mentioned again..

    That was because they realised pretty quickly that what they were seeing
    was an inorganic reaction of peroxide and perchlorate ions in the soil
    with the nutrients provided. The next generation search for life on Mars
    will use stable isotopically labelled materials and stands a pretty good
    chance of detecting anything that is alive or nearly so.

    There are hints that just maybe something is alive on Venus (unlikely as
    this sounds) phosphine has been detected in its atmosphere.

    https://www.nytimes.com/2020/09/14/science/venus-life-clouds.html

    --
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to '''newspam'''@nonad.co.uk on Tue Jul 2 14:54:35 2024
    On a sunny day (Tue, 2 Jul 2024 14:41:43 +0100) it happened Martin Brown <'''newspam'''@nonad.co.uk> wrote in <v6102q$1lkv4$1@dont-email.me>:

    On 02/07/2024 06:25, Jan Panteltje wrote:
    On a sunny day (Mon, 1 Jul 2024 17:03:32 -0700) it happened Don Y
    <blockedofcourse@foo.invalid> wrote in <v5vg4n$1a4s7$1@dont-email.me>:

    But you (we) are still constrained by your knowledge of physical sciences >>> (and "interstellar civilizations"). Who's to say that "they" haven't
    identified some other observable (by THEM) characteristic of civilization? >>>
    There are a whole slew of questions that you have to consider before you >>> even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)?
    - how much do YOU want to be found?
    - what might the consequences of such a detection be? (e.g., _Remembrance..._
    posits an extinction level consequence)


    And will our religious fanatic polly-tick-sians and leaders let us know IF life has been detected?
    The Mars Viking lander experiment was positive for life.
    http://www.gillevin.com/
    I remeber the annoucement,
    hours later it was plainly denied, experiment never to me mentioned again..

    That was because they realised pretty quickly that what they were seeing
    was an inorganic reaction of peroxide and perchlorate ions in the soil

    In an hour?
    It took NASA years to make ad test the experiment.
    The denial came an hour after the 'We found signs of life on mars'.


    with the nutrients provided. The next generation search for life on Mars
    will use stable isotopically labelled materials and stands a pretty good >chance of detecting anything that is alive or nearly so.

    They have had all sorts of landers now, never tested, and they land specifically where there is likely no life.
    Last place I would look is in an [old] volcanic crater
    Try here:
    https://panteltje.nl/panteltje/space/mars/index.html


    There are hints that just maybe something is alive on Venus (unlikely as
    this sounds) phosphine has been detected in its atmosphere.

    https://www.nytimes.com/2020/09/14/science/venus-life-clouds.html

    That is from Sept 2020, updates next year for budget increase :-)

    Any time NASA wants more budget for driving around the block they babble about signs of life in meteoroids
    and where not...
    Then after the budget increase it is all quiet again.

    Life is just a natural thing, chemical reaction if you will, that will happen wherever the environment allows it.
    You need some temperature cycling too (day night for example), polymerase chain reaction.
    Tides may help too.

    China just did a back side of the moon sample return.
    Maybe they can grab some Mars stuff and analyze it in a Chinese lab,
    they are not hampered by adam and lisa fairy tales.

    US latest moon lander did not even make it to the front side of the moon.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jan Panteltje@21:1/5 to All on Tue Jul 2 18:14:01 2024
    PS:

    This desert moss has the potential to grow on Mars
    https://www.sciencedaily.com/releases/2024/06/240630153052.htm
    June 30, 2024
    Source:
    Cell Press
    Summary:
    The desert moss Syntrichia caninervis is a promising candidate for Mars colonization
    thanks to its extreme ability to tolerate harsh conditions lethal to most life forms.
    The moss is well known for its ability to tolerate drought conditions,
    but researchers now report that it can also survive freezing temperatures as low as 196 C,
    high levels of gamma radiation, and simulated Martian conditions involving
    these three stressors combined. In all cases, prior dehydration seemed to help the plants cope.


    So no problem for plants and plant like lifeforms to grow on mars.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Jan Panteltje on Tue Jul 2 20:46:04 2024
    On 02/07/2024 19:14, Jan Panteltje wrote:
    PS:

    This desert moss has the potential to grow on Mars
    https://www.sciencedaily.com/releases/2024/06/240630153052.htm
    June 30, 2024
    Source:
    Cell Press
    Summary:
    The desert moss Syntrichia caninervis is a promising candidate for Mars colonization
    thanks to its extreme ability to tolerate harsh conditions lethal to most life forms.
    The moss is well known for its ability to tolerate drought conditions,
    but researchers now report that it can also survive freezing temperatures as low as 196 C,
    high levels of gamma radiation, and simulated Martian conditions involving
    these three stressors combined. In all cases, prior dehydration seemed to help the plants cope.


    So no problem for plants and plant like lifeforms to grow on mars.

    I certainly wouldn't rule out the possibility of life on Mars. I've been
    down the UK's deepest salt mine and NASA have an experiment down there
    looking for microbes that can literally live in rock (*very* slowly).

    Again they are trying to figure out how you would find and cultivate
    them on Mars if they were present. Nothing beats experiment.

    Tardigrades are also pretty good at surviving space flight as are
    several lichens. Hard UV levels might be a bit much for terrestrial ones
    but if life did arise on Mars then something already there might have
    adapted when it slowly lost it's oceans, atmosphere and most of its
    water. Losing your magnetic shield is not good for a young planet...

    --
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Don Y on Tue Jul 2 20:38:03 2024
    On 01/07/2024 22:02, Don Y wrote:
    On 7/1/2024 8:43 AM, Martin Brown wrote:
    On 29/06/2024 18:11, Don Y wrote:

    Why does an alien race have to VISIT in order to EXIST?

    *We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
    yet we expend considerable effort "looking".

    What techniques have our deep space probes used /to prevent detection/?

    Being small insignificant and with feeble radio transmitters. The only
    reason we are still in contact with the most remote ones is that
    ground based low noise amplifiers have improved enormously since their
    launch.

    Wouldn't you expect other civilizations to also understand the issues involved, if they were interested in searching?  We spot bits of
    space debris, comets, etc. and they aren't trying to signal their
    presence...

    But we only really spot them when they get near enough to the sun and
    warm up enough to outgas. Considerable effort now goes into trying to
    find any and all Earth crossing asteroids that are big enough to matter
    and/or might one day be a threat to our planet.

    When it was operating and doing radar range imaging the EPR of the
    Arecibo dish was phenomenal along the direction it was pointing.
    Anyone in the beam would see a very distinctive flash potentially with
    obviously digital patterns in it if they were lucky.

    But they don't have to see a pattern; just an unexpected "event" that attracts their attention.  There's a wide field to examine so it seems
    they would focus their attentions on anything "unexpected" rather than systematically trying to canvas the entire space.

    There have been more than one WOW event seen but nothing in the same
    place twice and most of them have plausible astrophysical signatures.

    Seeing a narrow band signal at a non-natural frequency or a modulated
    one would be indicative of a civilisation. Pulsars almost fitted the
    bill at the time they were discovered - tagged LGM in the margin.

    Assuming "others" have the same technological limits (or abilities!)
    as we do is naive.

    They are still limited by the laws of physics as they apply in this
    universe unless they have found some much deeper understanding. You can
    put pretty good bounds on how far away people can watch terrestrial TV
    from but our planet was only non-thermal radio bright for less than a
    century. That is a blink of the eye in cosmological timescales.

    Give or take an order of magnitude I expect most civilisations will go
    through similar phases of technology to us (unless they are aquatic).

    And, assuming they abandon older technologies to concentrate on
    newer ones also seems specious; if lost while hiking, I can signal
    with a whistle or a mirror -- I don't have to rely on a cell phone to
    get help!

    Technological civilisations will only be non-thermal radio bright in an
    easily detectable way from after they invent AM broadcasting and before
    they invent spread spectrum UHF services or coax cable or fibre optics.

    Interestingly the Austrian actress Hedy Lammar co-invented spread
    spectrum RF but is mostly remembered for her film roles.

    http://www.women-inventors.com/Hedy-Lammar.asp

    Somewhat more detail here - her invention helped make allied torpedoes effectively impossible for simple jamming methods to block.

    https://www.aps.org/archives/publications/apsnews/201106/physicshistory.cfm

    Today it is hard to find anything that isn't spread spectrum and noise
    like in appearance unless you have the cryptographic key to unlock it.

    Drake has a nice equation where some of the unknowns when he originally
    wrote it down have now become rather better hard numbers. It turns out
    that planets around stars are much more common than first thought.

    Ones in the Goldilocks zone with all three phases of water are rarer.

    --
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Martin Brown on Tue Jul 2 14:27:20 2024
    On 7/2/2024 12:38 PM, Martin Brown wrote:
    Being small insignificant and with feeble radio transmitters. The only
    reason we are still in contact with the most remote ones is that ground
    based low noise amplifiers have improved enormously since their launch.

    Wouldn't you expect other civilizations to also understand the issues
    involved, if they were interested in searching?  We spot bits of
    space debris, comets, etc. and they aren't trying to signal their
    presence...

    But we only really spot them when they get near enough to the sun and warm up enough to outgas. Considerable effort now goes into trying to find any and all
    Earth crossing asteroids that are big enough to matter and/or might one day be
    a threat to our planet.

    But that's assuming it isn't making a DELIBERATE effort to be found/noticed!

    When it was operating and doing radar range imaging the EPR of the Arecibo >>> dish was phenomenal along the direction it was pointing. Anyone in the beam >>> would see a very distinctive flash potentially with obviously digital
    patterns in it if they were lucky.

    But they don't have to see a pattern; just an unexpected "event" that
    attracts their attention.  There's a wide field to examine so it seems
    they would focus their attentions on anything "unexpected" rather than
    systematically trying to canvas the entire space.

    There have been more than one WOW event seen but nothing in the same place twice and most of them have plausible astrophysical signatures.

    Seeing a narrow band signal at a non-natural frequency or a modulated one would
    be indicative of a civilisation. Pulsars almost fitted the bill at the time they were discovered - tagged LGM in the margin.

    Assuming "others" have the same technological limits (or abilities!)
    as we do is naive.

    They are still limited by the laws of physics as they apply in this universe unless they have found some much deeper understanding. You can put pretty good
    bounds on how far away people can watch terrestrial TV from but our planet was
    only non-thermal radio bright for less than a century. That is a blink of the eye in cosmological timescales.

    Give or take an order of magnitude I expect most civilisations will go through
    similar phases of technology to us (unless they are aquatic).

    Again, you're assuming they aren't making an attempt to be found -- either because it hasn't (yet) occurred to them *or* because they are deliberately "hiding".

    [One of the issues indirectly addressed in _Remembrance..._]

    Flip the issue around: if tasked with drawing attention to your existence,
    how would some other civilization approach the task? Reread your above statements for clues.

    If you believe other civilizations are benevolent (or, non-MALevolent)
    and would like to interact with them, one might opt to be more
    noticeable, in stead of trying to discover them. I.e., HOPE that
    they are looking and find a way to make yourself more noticeable,
    especially given that you may exist in different times (real and
    relativistic).

    "Kilroy was here"

    Then, flip that around, again: the fact that we haven't noticed any
    such deliberate attempts -- assuming the folks who might make them have
    the same "sort" of technological evolution we do -- does this absence
    mean they don't exist? Or, don't want to be FOUND?! (_Remembrance..._)

    And, assuming they abandon older technologies to concentrate on
    newer ones also seems specious; if lost while hiking, I can signal
    with a whistle or a mirror -- I don't have to rely on a cell phone to
    get help!

    Technological civilisations will only be non-thermal radio bright in an easily
    detectable way from after they invent AM broadcasting and before they invent spread spectrum UHF services or coax cable or fibre optics.

    Assuming they are ONLY concerned with the technology for LOCAL communication. What would they use to be NOTICED on a glactic scale? Gravity wave transmission (and detection) would be a much higher bar for "others" to
    meet; if you WANT to find those others (by helping them find YOU), then
    you would adopt a technology that spans time/distance AND is relatively
    easy for those "others" to develop/maintain.

    E.g., when hiking, a whistle or a mirror is far more useful than a
    cell phone as cell phone coverage often doesn't address the regions
    in which you might find yourself. But, everyone has ears -- and a
    whistle is omnidirectional (and inexpensive, small, easy to operate, etc.)

    Interestingly the Austrian actress Hedy Lammar co-invented spread spectrum RF but is mostly remembered for her film roles.

    http://www.women-inventors.com/Hedy-Lammar.asp

    Somewhat more detail here - her invention helped make allied torpedoes effectively impossible for simple jamming methods to block.

    https://www.aps.org/archives/publications/apsnews/201106/physicshistory.cfm

    Today it is hard to find anything that isn't spread spectrum and noise like in
    appearance unless you have the cryptographic key to unlock it.

    Drake has a nice equation where some of the unknowns when he originally wrote it down have now become rather better hard numbers. It turns out that planets around stars are much more common than first thought.

    Yes, _The Drake Equation: Estimating the Prevalence of Extraterrestrial Life Through the Ages_ has some interesting opinions on the various "factors".
    But, again, the emphasis is on the chances of such life EXISTING, not
    WANTING TO BE DETECTED (or not).

    Earth hasn't made up its mind on this, yet. We're not aggressively trying to be "seen". Yet, neither are we taking steps to remain hidden.

    Ones in the Goldilocks zone with all three phases of water are rarer.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Martin Brown@21:1/5 to Don Y on Wed Jul 3 11:38:07 2024
    On 02/07/2024 01:03, Don Y wrote:
    On 7/1/2024 7:54 AM, Martin Brown wrote:
    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to
    *detect* our presence (given that we seem to make no attempt at
    "hiding")

    The Fermi paradox of why aren't they here yet is somewhat tricky to
    explain. Our star is nothing like the oldest it could be so there are
    potentially technological societies that are billions of years ahead
    of us - plenty of time for robotic probes to visit anywhere in the
    galaxy.

    And, probes don't ave to "pass through"; there's no reason they can't
    sit and watch (if you have advanced technology, what limits might that overcome on designing durable products?)

    It still puts quite hard limits on how small a device can observe the
    Earth even with diffraction limited optics. Monitoring radio traffic is
    much easier if the frequency is such that it escapes.

    I suspect that unless there is some clever shortcut using physics we
    don't yet know about human inter stellar travel is just a pipe dream.

    But you don't need to *go* somewhere to know that it exists *or* what
    it is like.  We've visited Mars without ever having set foot, there.
    Ditto the depths of the oceans.

    Indeed and remote sensing is getting very good now. I expect that
    someone will find a planet with evidence of an industrial atmosphere
    within the next century or so (maybe sooner).

    We can make educated assessments as to the suitability for "life"
    in places that we could never expect to actually visit.  Or,
    discover some form of life and then set upon trying to sort out how
    to communicate with same.

    That can be fraught with difficulties. I expect life as reproducing photosynthetic slime is extremely common anywhere that is stable enough
    to allow a billion years of reactions. Aqueous environment might not be strictly necessary but most other things have solid phases that sink.

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_
    gives some
    interesting takes on the Fermi paradox.
    [snip]

    It takes industrial scale manufacture before CFCs would be visible
    from afar. SF6 is another common one but it's scale height works
    against seeing it high in the atmosphere (its molecule is rather heavy).

    But you (we) are still constrained by your knowledge of physical sciences (and "interstellar civilizations").  Who's to say that "they" haven't identified some other observable (by THEM) characteristic of civilization?

    They may have done but there are still hard limits on how big an antenna
    must be to obtain signal that is above the background noise floor.

    There are a whole slew of questions that you have to consider before you
    even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)?
    - how much do YOU want to be found?
    - what might the consequences of such a detection be?  (e.g., _Remembrance..._
    posits an extinction level consequence)

    Encounters between species with advanced technology don't usually end
    well for the ones still in the iron age when they come up against
    automatic weapons. If we ever meet alien space travellers we had better
    hope that they are friendly. Even so their advanced technology could
    wreak unintentional havoc.

    Adams's claim that "Space is big" can also be accompanied by "Time is
    LONG".
    Do these conspire for or against discovery (or being discovered)?

    Space is mind bogglingly *BIG* the gaps between stars are huge.

    The only place where stars are close together are in globular clusters
    and in environment so odd that it is probably one of the places where
    you can pretty much rule out life evolving. Close three body encounters
    happen often enough to lob whole stars out at very high speed and leave
    the remaining ones ever more tightly bound. They are extremely pretty.

    Arecibo's first ever deliberate message was sent to M13 it will take
    about 25k years to get there and another 25k for a reply if the intended recipients happen to notice it. Chances are there is no-one there.

    https://en.wikipedia.org/wiki/Arecibo_message

    I reckon in 50k years +/- 500 no one on Earth will even remember that
    the message was sent.

    https://en.wikipedia.org/wiki/Messier_13#/media/File:Messier_13.jpg

    Just naked eye as a faint fuzzy blob under Hercules right shoulder -
    more obvious in binoculars (visible in summer).

    Worth seeing first hand in a 15" scope or larger.

    --
    Martin Brown

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Don Y@21:1/5 to Martin Brown on Wed Jul 3 04:28:31 2024
    On 7/3/2024 3:38 AM, Martin Brown wrote:
    On 02/07/2024 01:03, Don Y wrote:
    On 7/1/2024 7:54 AM, Martin Brown wrote:
    *We* can't (yet) travel interstellar distances in single lifetimes
    but I'm sure anyone with technology comparable to ours would be able to >>>> *detect* our presence (given that we seem to make no attempt at "hiding") >>>
    The Fermi paradox of why aren't they here yet is somewhat tricky to explain.
    Our star is nothing like the oldest it could be so there are potentially >>> technological societies that are billions of years ahead of us - plenty of >>> time for robotic probes to visit anywhere in the galaxy.

    And, probes don't ave to "pass through"; there's no reason they can't
    sit and watch (if you have advanced technology, what limits might that
    overcome on designing durable products?)

    It still puts quite hard limits on how small a device can observe the Earth even with diffraction limited optics. Monitoring radio traffic is much easier if the frequency is such that it escapes.

    But, it can *land*! Again, it all harkens back to "do you want to be found" ("known to be looking")

    I suspect that unless there is some clever shortcut using physics we don't >>> yet know about human inter stellar travel is just a pipe dream.

    But you don't need to *go* somewhere to know that it exists *or* what
    it is like.  We've visited Mars without ever having set foot, there.
    Ditto the depths of the oceans.

    Indeed and remote sensing is getting very good now. I expect that someone will
    find a planet with evidence of an industrial atmosphere within the next century
    or so (maybe sooner).

    Or, a *dead* planet (atmosphere stripped away) that shows signs of having
    once been "alive". If the threshold is just "looking for life" (vs a real "civilization"). then I suspect the number of samples is considerably larger.

    You have to assume folks know at least as much as we do about finding
    likely candidates -- even if they are no longer habitable. (i.e., its
    unlikely a place like Mercury would ever be examined, in detail, unless
    there was evidence that its orbit may have shifted)

    We can make educated assessments as to the suitability for "life"
    in places that we could never expect to actually visit.  Or,
    discover some form of life and then set upon trying to sort out how
    to communicate with same.

    That can be fraught with difficulties. I expect life as reproducing photosynthetic slime is extremely common anywhere that is stable enough to allow a billion years of reactions. Aqueous environment might not be strictly necessary but most other things have solid phases that sink.

    A sea-borne creature could still develop intelligence and a notion of "civilization". We're unlikely to find anything LAND-based on Europa...

    _If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
    interesting takes on the Fermi paradox.
    [snip]

    It takes industrial scale manufacture before CFCs would be visible from
    afar. SF6 is another common one but it's scale height works against seeing >>> it high in the atmosphere (its molecule is rather heavy).

    But you (we) are still constrained by your knowledge of physical sciences
    (and "interstellar civilizations").  Who's to say that "they" haven't
    identified some other observable (by THEM) characteristic of civilization?

    They may have done but there are still hard limits on how big an antenna must be to obtain signal that is above the background noise floor.

    There are a whole slew of questions that you have to consider before you
    even worry about "how" to detect (or signal to) other civilizations.
    - how much (effort/cost) do you want to detect them?
    - how much do THEY want to be detected?
    - how can they evade detection (assuming they actively don't want to be found)?
    - how much do YOU want to be found?
    - what might the consequences of such a detection be?  (e.g., _Remembrance..._
    posits an extinction level consequence)

    Encounters between species with advanced technology don't usually end well for
    the ones still in the iron age when they come up against automatic weapons. If
    we ever meet alien space travellers we had better hope that they are friendly.
    Even so their advanced technology could wreak unintentional havoc.

    Exactly. This is one suggested reason why there aren't many DETECTABLE civilizations (fear that the folks who detect them may not be friendly
    yet their presence will let them know of a habitable planet!)

    Adams's claim that "Space is big" can also be accompanied by "Time is LONG". >> Do these conspire for or against discovery (or being discovered)?

    Space is mind bogglingly *BIG* the gaps between stars are huge.

    The only place where stars are close together are in globular clusters and in environment so odd that it is probably one of the places where you can pretty much rule out life evolving. Close three body encounters happen often enough to
    lob whole stars out at very high speed and leave the remaining ones ever more tightly bound. They are extremely pretty.

    Arecibo's first ever deliberate message was sent to M13 it will take about 25k
    years to get there and another 25k for a reply if the intended recipients happen to notice it. Chances are there is no-one there.

    https://en.wikipedia.org/wiki/Arecibo_message

    I reckon in 50k years +/- 500 no one on Earth will even remember that the message was sent.

    But, it will have an effect on both parties, regardless. Even if only a panic among the "faiths" as they suddenly have to account for (or deny) another creation.

    https://en.wikipedia.org/wiki/Messier_13#/media/File:Messier_13.jpg

    Just naked eye as a faint fuzzy blob under Hercules right shoulder - more obvious in binoculars (visible in summer).

    Worth seeing first hand in a 15" scope or larger.

    My "star gazing" is limited to periodic meteor showers. Our *black*, cloudless skies make such sights relatively easy to observe (and exciting in their unpredictability!) I pity folks who can't just "look up" and experience these sorts of things; they truly are "breathtaking"!

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)