• from Quora - one problem with time travel, or predictions of the future

    From a425couple@21:1/5 to All on Thu Aug 31 12:48:27 2023
    XPost: alt.astronomy, alt.fan.heinlein

    Joseph Newcomer
    Follow
    Former Chief Software Architect (1987–2010)Updated Mon

    If an alien spacecraft landed on Earth (and its crew died later for some reason), how quickly could we learn from its spaceship how to build our
    own spaceship that could match its travelling ability?

    John W. Campbell got his engineering degree in 1930. In 1970, he wrote
    about what would happen if an SR-71 Blackbird was magically
    time-traveled to 1930.

    It was clearly from the future. But how far in the future?

    Electronics: not a single vacuum tube. Just little plastic cases with
    pins sticking out. They decide to sacrifice one to understand it. It
    appears as if the circuit diagrams are drawn on the chip. They can’t be
    sure, because much of the drawing is below the resolution the optical microscopes of the day allow. They do a spectroscopic analysis of the
    material. It is 100% pure silicon. Turns out the spectroscopes of 1930
    cannot detect the parts-per-billion of the dopants that create the semiconductors.

    Power: they’ve never seen a jet engine. There does not seem to be any
    way for the engine to operate. They try to run it. The fuel does not
    burn. Turns out the special fuel (if I recall, something called J6) can
    only be ignited by throwing some hypergolic igniter in on the ground. If
    it flamed out while running, it could not be restarted.

    Radio: the circuitry is more magic drawings on silicon. They can’t
    figure out how any of it works. Turns out it runs at a higher frequency
    than anything they know how to detect.

    Radar: They have no idea what that horn in the nose does. It seems to
    emit some kind of energy, because a tech got his hand in front of it an experienced some heating. So they tried using infrared detectors but saw nothing. Centimeter radar was beyond anything they knew about, and they
    had no way to detect frequencies that high, beyond anything they could
    even imagine.

    Construction: it is made of pure titanium. More titanium than exists in
    the entire world! Extruded into thin sheets. And welded! Everyone they
    checked with said that it was impossible to weld titanium because it
    would essentially “catch fire” and it would start oxidizing and would
    all burn away.

    So how far in the future did it come from? They got all kinds of people together, scientists , engineers, scientifiction authors. Where did this
    come from? Or, when did this come from? Consensus: maybe 400 years in
    the future.

    No, it was 40 years.

    So if we can’t reverse engineer something of human technology from 40
    years in the future, do you think we have any chance whatsoever of reverse-engineering something from an alien planet?

    When I became a programmer in 1963, if you added up all of the bits of
    memory in all the computers in the world, you would have at most a few
    megabits of memory. I am typing this on my iPhone, which has 128
    gigabytes of memory, that is, one terabit of information. Plus a GPS,
    Internet access, three cameras, and a telephone that can allow me to
    talk to anyone who has a telephone anywhere in the world in seconds.
    That’s a bit longer than 40 years, but not that much longer. This thing
    I’m holding in my hand is at a minimum 100,000 times more powerful than
    the supercomputer of 1963, and could be construed as a million times
    more powerful along some measures. It has more RAM than our mainframe of
    1983 had disk space to support 30 programmers. If I walk a block in any direction I will probably pass 20 phones equally powerful. And I live in
    a neighborhood of single-family homes

    So we probably won’t be able to do anything with that alien spaceship.
    It might use quantum computers that compare to our quantum computers
    like my iPhone compares to an IBM 704 vacuum tube computer.

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    87 comments from
    Kurt Guntheroth
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    Rich Pitaluga
    · Aug 25
    Excellent analysis: However, I submit that knowing something is possible
    - 𝙖𝙣𝙙 𝙝𝙤𝙬 𝙞𝙩 𝙃𝘼𝙎 𝙗𝙚𝙚𝙣 𝙙𝙤𝙣𝙚, 𝙚𝙫𝙚𝙣 𝙞𝙛 𝙮𝙤𝙪
    𝙘𝙖𝙣'𝙩 𝙖𝙨 𝙮𝙚𝙩 𝙚𝙣𝙩𝙞𝙧𝙚𝙡𝙮 𝙛𝙞𝙜𝙪𝙧𝙚 𝙤𝙪𝙩 𝙩𝙝𝙚
    𝙚𝙭𝙖𝙘𝙩 𝙙𝙚𝙩𝙖𝙞𝙡𝙨- is a great starting point.

    Joseph Newcomer
    · Mon
    There was a story in which some bad movie footage of a working
    antigravity machine was shown to top scientists. It smoothly floating up
    about six feet from the floor Unfortunately, it included footage of the
    machine then blowing up and killing its inventor. They were charged with re-creating the machine from the few notes and machine parts that were
    left after the fire.

    They succeed. It was ten times larger, needed the output of an entire
    fission reactor to work at all, and levitated only about an inch from
    the ground.

    They are called in for one last meeting. At the head of the table is the “inventor” of the antigravity machine, very much alive. What? Well, it
    was all fake. But the fact that they had seen a working machine
    convinced them that one could be built.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Bob Campbell@21:1/5 to a425couple@hotmail.com on Thu Aug 31 22:45:21 2023
    XPost: alt.astronomy, alt.fan.heinlein

    a425couple <a425couple@hotmail.com> wrote:

    So if we can’t reverse engineer something of human technology from 40
    years in the future, do you think we have any chance whatsoever of reverse-engineering something from an alien planet?

    Nonsense. Around 30 years ago I saw Jeff Goldblum write a computer virus
    to sabotage an alien space ship. He did it in a few minutes. On a Mac
    laptop. He then networked the Mac to the alien computer system and
    uploaded the virus. Because everyone knows alien computers don’t keep
    their AV software up to date.

    We can do anything. Alien technology is a piece of cake.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to All on Thu Aug 31 20:22:24 2023
    XPost: alt.astronomy, alt.fan.heinlein

    "a425couple" wrote in message news:g86IM.563207$U3w1.116117@fx09.iad...

    Joseph Newcomer
    Follow
    Former Chief Software Architect (1987–2010)Updated Mon

    If an alien spacecraft landed on Earth (and its crew died later for some reason), how quickly could we learn from its spaceship how to build our
    own spaceship that could match its travelling ability?

    John W. Campbell got his engineering degree in 1930. In 1970, he wrote
    about what would happen if an SR-71 Blackbird was magically
    time-traveled to 1930.

    It was clearly from the future. But how far in the future?

    Electronics: not a single vacuum tube. Just little plastic cases with
    pins sticking out. They decide to sacrifice one to understand it. It
    appears as if the circuit diagrams are drawn on the chip. They can’t be
    sure, because much of the drawing is below the resolution the optical microscopes of the day allow. They do a spectroscopic analysis of the
    material. It is 100% pure silicon. Turns out the spectroscopes of 1930
    cannot detect the parts-per-billion of the dopants that create the semiconductors.

    [[ The chemical test for Arsenic is very old and very sensitive. https://en.wikipedia.org/wiki/Marsh_test
    ]]

    [[My training to be an advanced electronic technician included disassembling
    a packaged IC and drawing its schematic. An optical microscope had plenty of magnification. The transistors (FETs) work very much like a vacuum tube and
    can be analyzed with variable voltage sources and an Ohm meter. Voltage on
    the gate, the yellow polysilicon top layer, increases or decreases the resistance between the end contacts, as a tube's grid voltage controls
    cathode to anode resistance. https://www.autodesk.com/products/fusion-360/blog/what-is-field-effect-transistor-fet/

    I did need a little help with the complex layout of the bipolar transistors, but once identified as a 3 terminal device similar to a triode they are
    pretty simple to analyze by measuring and graphing the voltage vs current characteristic. At first glance they appear to be two back to back diodes, a small forward current through one enables a much larger reverse current
    through the other. I've done it myself, to sort them into pairs with matched gain. An SCR is similar to the old Ignitron vacuum tube. The principle of a rectifying junction was well known from older Selenium, Copper oxide and
    "cat's whisker", Lead Sulfide crystal radio rectifiers and detectors. ]]

    Power: they’ve never seen a jet engine. There does not seem to be any
    way for the engine to operate. They try to run it. The fuel does not
    burn. Turns out the special fuel (if I recall, something called J6) can
    only be ignited by throwing some hypergolic igniter in on the ground. If
    it flamed out while running, it could not be restarted.

    [[ Diesel fuel doesn't ignite that easily either. Steam turbines are 1800's technology and gas turbines were attempted soon after but were not efficient enough to pursue, until the mid 30's. https://en.wikipedia.org/wiki/Nathan_C._Price
    ]]

    Radio: the circuitry is more magic drawings on silicon. They can’t
    figure out how any of it works. Turns out it runs at a higher frequency
    than anything they know how to detect.

    [[The military radio communications band is 225 to 399 MHz.]]

    Radar: They have no idea what that horn in the nose does. It seems to
    emit some kind of energy, because a tech got his hand in front of it an experienced some heating. So they tried using infrared detectors but saw nothing. Centimeter radar was beyond anything they knew about, and they
    had no way to detect frequencies that high, beyond anything they could
    even imagine.

    [[ A primitive form of radar existed in 1903: https://en.wikipedia.org/wiki/Christian_H%C3%BClsmeyer

    Professor Yagi in Japan was experimenting at close to 1 GigaHertz in 1928. Inductors and capacitors are the giveaway and indicate the operating frequencies, as does antenna dipole length and waveguide dimensions. James Maxwell, Oliver Heaviside or Charles Steinmetz could probably have figured radar out well before 1930.
    https://en.wikipedia.org/wiki/Oliver_Heaviside]]

    Construction: it is made of pure titanium. More titanium than exists in
    the entire world! Extruded into thin sheets. And welded! Everyone they
    checked with said that it was impossible to weld titanium because it
    would essentially “catch fire” and it would start oxidizing and would
    all burn away.

    [[ Titanium was discovered in 1791, Argon in 1894. The welding techniques
    are from scientific apparatus, 1800's again. ]]

    So how far in the future did it come from? They got all kinds of people together, scientists , engineers, scientifiction authors. Where did this
    come from? Or, when did this come from? Consensus: maybe 400 years in
    the future.

    No, it was 40 years.

    So if we can’t reverse engineer something of human technology from 40
    years in the future, do you think we have any chance whatsoever of reverse-engineering something from an alien planet?

    [[ Who is "we"? Apparently writers, not practicing scientists. Military electronic tech used to be at least 20 years ahead of what civilians knew about, now I can't say. There were guided cruise missiles, spread spectrum radio, automatic gunnery computers, sonobuoys and acoustic homing torpedos
    in WW2. The USA had a guided cruise missile toward the end of WW1 but the retreating Germans left it no targets. ]]

    When I became a programmer in 1963, if you added up all of the bits of
    memory in all the computers in the world, you would have at most a few
    megabits of memory. I am typing this on my iPhone, which has 128
    gigabytes of memory, that is, one terabit of information. Plus a GPS,
    Internet access, three cameras, and a telephone that can allow me to
    talk to anyone who has a telephone anywhere in the world in seconds.
    That’s a bit longer than 40 years, but not that much longer. This thing
    I’m holding in my hand is at a minimum 100,000 times more powerful than
    the supercomputer of 1963, and could be construed as a million times
    more powerful along some measures. It has more RAM than our mainframe of
    1983 had disk space to support 30 programmers. If I walk a block in any direction I will probably pass 20 phones equally powerful. And I live in
    a neighborhood of single-family homes

    [[The progress of computing is incremental and evolutionary. George Boole published the original theory, Claude Shannon refined it, later innovators figured out how to implement their work in rapidly improving hardware. The first computer I built had 256 Bytes of memory, soon increased to 32k with pre-production samples from memory chip makers. The company I worked for
    then supplied the test equipment that let them measure and improve their processes. ]]

    [[ In Army electronic school in 1970 we were estimating what could or
    couldn't be done with a 1 GHz computer. I became a repairman for a variant
    of an Internet-like system introduced in 1962. https://www.computerculture.org/2012/02/recalling-the-autodin-part-i/
    It was capable of secure global digital wireless communication, using HF,
    VHF and troposcatter radio links. The encrypted voice equivalent was AUTOSEVOCOM. https://en.wikipedia.org/wiki/Automatic_Secure_Voice_Communications_Network
    ]]

    So we probably won’t be able to do anything with that alien spaceship.
    It might use quantum computers that compare to our quantum computers
    like my iPhone compares to an IBM 704 vacuum tube computer.

    [[ If an antigravity particle exists the Sun would repel it and we wouldn't know. If we acquired a sample we probably could soon integrate them into our physics, and then our hardware. ]]

    23.2K views
    View 1,422 upvotes
    View 8 shares
    1 of 78 answers
    87 comments from
    Kurt Guntheroth
    and more

    Rich Pitaluga
    · Aug 25
    Excellent analysis: However, I submit that knowing something is possible
    - 𝙖𝙣𝙙 𝙝𝙤𝙬 𝙞𝙩 𝙃𝘼𝙎 𝙗𝙚𝙚𝙣 𝙙𝙤𝙣𝙚, 𝙚𝙫𝙚𝙣 𝙞𝙛 𝙮𝙤𝙪
    𝙘𝙖𝙣'𝙩 𝙖𝙨 𝙮𝙚𝙩 𝙚𝙣𝙩𝙞𝙧𝙚𝙡𝙮 𝙛𝙞𝙜𝙪𝙧𝙚 𝙤𝙪𝙩 𝙩𝙝𝙚
    𝙚𝙭𝙖𝙘𝙩 𝙙𝙚𝙩𝙖𝙞𝙡𝙨- is a great starting point.

    [[ Santos-Dumont built the first airplane in Europe based on knowing only
    that the Wrights had succeeded, which meant that an engine could finally be built light and powerful enough. Like them he was already an experienced
    pilot, of his dirigibles. ]]

    Joseph Newcomer
    · Mon
    There was a story in which some bad movie footage of a working
    antigravity machine was shown to top scientists. It smoothly floating up
    about six feet from the floor Unfortunately, it included footage of the
    machine then blowing up and killing its inventor. They were charged with re-creating the machine from the few notes and machine parts that were
    left after the fire.

    They succeed. It was ten times larger, needed the output of an entire
    fission reactor to work at all, and levitated only about an inch from
    the ground.

    They are called in for one last meeting. At the head of the table is the “inventor” of the antigravity machine, very much alive. What? Well, it
    was all fake. But the fact that they had seen a working machine
    convinced them that one could be built.

    [[ A hovering UFO model powered by an electrostatic ion drive was a boy's
    hobby project of the 1930's. I made and released flying models that
    resembled shiny saucers from some angles in the 1950's, from Exeter NH. Some disappeared in the distance beyond the tree line. ]]

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to All on Thu Aug 31 22:42:34 2023
    XPost: alt.astronomy, alt.fan.heinlein

    "a425couple" wrote in message news:g86IM.563207$U3w1.116117@fx09.iad...

    ...
    So we probably won’t be able to do anything with that alien spaceship.
    It might use quantum computers that compare to our quantum computers
    like my iPhone compares to an IBM 704 vacuum tube computer.

    -------------------

    Or it might use vacuum channel transistors which we do understand: https://en.wikipedia.org/wiki/Nanoscale_vacuum-channel_transistor

    That tech has advantages in space and doesn't need the expensive and
    difficult processing of our semiconductors.

    "Theoretically, a vacuum-channel transistor is expected to operate faster
    than a traditional solid-state transistor, and have higher power output and lower operation voltage. Moreover, vacuum-channel transistors are expected
    to operate at higher temperature and radiation level than a traditional transistor making them suitable for space application."

    There would be a considerable advantage for a long space voyage in a tech
    more easily repaired than ours. We can't fix either vacuum tubes or
    transistors and have to replace them, while I've restored eroded car starter electrical contacts by adding brass with a torch and filing it to shape.

    This describes how to make a part as complicated as a centrifugal pump
    housing from scratch, or by copying a broken original: https://maritime.org/doc/foundry/index.php

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to Jim Wilkins on Fri Sep 1 11:50:51 2023
    XPost: alt.astronomy, alt.fan.heinlein

    "Jim Wilkins" wrote in message news:ucrj3k$3kjbm$1@dont-email.me...

    Or it might use vacuum channel transistors which we do understand: >https://en.wikipedia.org/wiki/Nanoscale_vacuum-channel_transistor

    ----------------------

    The rapid advance of European technology in the last 200 years isn't typical
    of Earth history and perhaps that of others. Until 1800 we were slowly catching up to where Rome left off. Rome had better roads, bridges and especially public water and sewer systems, better than London's until the 1850's. The Gothic cathedrals are fancier imitations of the standard large Roman building (Basilica). They limited their large apartment complexes (Insulae) to 6 stories because that's how high the fire pumps could reach.
    They had excellent concrete, hot air central heat and glass windows that
    swung open, clocks that sounded the hour, book-style Bibles written on
    vellum that lasts longer than modern paper, and a banking system that
    allowed foreign travellers to write checks instead of carrying cash. Other great civilizations in China and India had remained satisfies with their
    level of tech for a very long time.

    Advancement of ours slows when the product becomes good enough, airliners haven't changed much in appearance or performance since the 707 of the
    1950's, they aren't even as fast now. Cruise ships may be larger but they don't usually go much faster than RMS Titanic.

    If other civilizations exist and weren't driven by war to advance their tech they may be satisfied with lives similar to ours.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to All on Sun Sep 3 09:05:12 2023
    XPost: alt.astronomy, alt.fan.heinlein

    There are clever devices using bypassed tech from our own past that have
    been difficult to decipher, the Antikythera device being a prime example.
    The Pyramids and Inca stone walls have provoked alien tech explanations from writers who weren't practical problem-solving engineers. The inaccurate Egyptian value for Pi disproves such influence. They used 256/81, less
    accurate than 22/7.

    Before the rise of Rome their Etruscan neighbors created exquisite gold
    jewelry using methods still not fully understood. https://www.jckonline.com/magazine-article/granulation-reviving-an-ancient-technique/
    https://en.wikipedia.org/wiki/Etruscan_jewelry

    There are hints in this ancient manuscript of the craftsmanship techniques: https://www.britannica.com/topic/De-diversis-artibus
    His methods are similar to modern microelectronics assembly, and depend on familiarity with the surface tension of molten metal.

    The origin of this automaton was unknown until it was repaired and wrote out the name of its builder:
    https://www.fi.edu/en/history-resources/automaton

    There's a functioning automaton like it in the movie "Hugo" that looks mechanical but is actually operated by an X-Y plotter moving the hand with a magnet under the writing table.

    The Hybrid transformer in an old dial telephone and a 60's era Weco phase modulated modem seem to perform magic, as does a magnetic amplifier until
    you learn the non-linear magnetic properties of the core material.

    Although they are just wood, the reasons the old violins by Stradivarius and Guarnerius sound so good has been very difficult to determine.

    The power source of this 1840 perpetual motion device is unknown: https://en.wikipedia.org/wiki/Oxford_Electric_Bell

    I have a 1971 HP 8555A Spectrum Analyzer whose heart is this crystal with seemingly magical properties:
    https://en.wikipedia.org/wiki/YIG_sphere

    This crystal device has special electromechanical properties that are easily determined by using a vector network analyzer: https://www.spectrumcontrol.com/globalassets/documents/rf2m-us/white-paper---saw-filter-2018.pdf

    Some could be analyzed more thoroughly if there were enough examples that
    one could be sacrificed for dissection, like the IC that I reverse
    engineered for training. It was a good example that contained op amps, comparators, voltage references, current mirrors, CMOS logic gates, PNP and
    NPN bipolars, and a power MOSFET. Modern science has many powerful
    analytical tools that the general public and lightly educated science
    writers are unaware of, such as the vector network analyzer.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Dean Markley@21:1/5 to Jim Wilkins on Sun Sep 3 08:13:02 2023
    On Friday, September 1, 2023 at 11:51:20 AM UTC-4, Jim Wilkins wrote:
    "Jim Wilkins" wrote in message news:ucrj3k$3kjbm$1...@dont-email.me...
    Or it might use vacuum channel transistors which we do understand: >https://en.wikipedia.org/wiki/Nanoscale_vacuum-channel_transistor ----------------------

    The rapid advance of European technology in the last 200 years isn't typical of Earth history and perhaps that of others. Until 1800 we were slowly catching up to where Rome left off. Rome had better roads, bridges and especially public water and sewer systems, better than London's until the 1850's. The Gothic cathedrals are fancier imitations of the standard large Roman building (Basilica). They limited their large apartment complexes (Insulae) to 6 stories because that's how high the fire pumps could reach. They had excellent concrete, hot air central heat and glass windows that swung open, clocks that sounded the hour, book-style Bibles written on vellum that lasts longer than modern paper, and a banking system that allowed foreign travellers to write checks instead of carrying cash. Other great civilizations in China and India had remained satisfies with their level of tech for a very long time.

    Advancement of ours slows when the product becomes good enough, airliners haven't changed much in appearance or performance since the 707 of the 1950's, they aren't even as fast now. Cruise ships may be larger but they don't usually go much faster than RMS Titanic.

    I would argue that airliners have changed greatly. They are much safer, more fuel efficient although I am not certain they are more comfortable. As far a cruise ships, again, they are much safer, more efficent as well. As far as speed, cruise ships
    don't need speed. People are on them for leisure, not transportation.


    If other civilizations exist and weren't driven by war to advance their tech they may be satisfied with lives similar to ours.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Michael F. Stemper@21:1/5 to Jim Wilkins on Sun Sep 3 10:50:01 2023
    XPost: alt.astronomy, alt.fan.heinlein

    On 03/09/2023 08.05, Jim Wilkins wrote:
    The inaccurate Egyptian value for Pi disproves such influence. They used 256/81, less accurate than 22/7.

    Cool! That's 2^8/3^4. There was probably some arcane numerological reason to use
    a fraction that was the ratio of powers of primes. And, while it might be less accurate than 22/7, it's only a 0.6% error. Their tools and measuring instruments
    were not likely to have been able to do anything closer than that anyway.

    --
    Michael F. Stemper
    What happens if you play John Cage's "4'33" at a slower tempo?

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to Jim Wilkins on Sun Sep 3 12:25:39 2023
    XPost: alt.astronomy, alt.fan.heinlein

    "Michael F. Stemper" wrote in message news:ud29va$vog6$1@dont-email.me...

    On 03/09/2023 08.05, Jim Wilkins wrote:
    The inaccurate Egyptian value for Pi disproves such influence. They used 256/81, less accurate than 22/7.

    Cool! That's 2^8/3^4. There was probably some arcane numerological reason to use
    a fraction that was the ratio of powers of primes. And, while it might be
    less
    accurate than 22/7, it's only a 0.6% error. Their tools and measuring instruments
    were not likely to have been able to do anything closer than that anyway. Michael F. Stemper
    ------------------------

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

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Jim Wilkins@21:1/5 to Jim Wilkins on Sun Sep 3 13:05:58 2023
    "Dean Markley" wrote in message news:60d9ebeb-3008-403f-b957-21a58dd820cen@googlegroups.com...

    On Friday, September 1, 2023 at 11:51:20 AM UTC-4, Jim Wilkins wrote:
    "Jim Wilkins" wrote in message news:ucrj3k$3kjbm$1...@dont-email.me...
    Or it might use vacuum channel transistors which we do understand: >https://en.wikipedia.org/wiki/Nanoscale_vacuum-channel_transistor ----------------------

    The rapid advance of European technology in the last 200 years isn't
    typical
    of Earth history and perhaps that of others. Until 1800 we were slowly catching up to where Rome left off. Rome had better roads, bridges and especially public water and sewer systems, better than London's until the 1850's. The Gothic cathedrals are fancier imitations of the standard large Roman building (Basilica). They limited their large apartment complexes (Insulae) to 6 stories because that's how high the fire pumps could reach. They had excellent concrete, hot air central heat and glass windows that swung open, clocks that sounded the hour, book-style Bibles written on
    vellum that lasts longer than modern paper, and a banking system that
    allowed foreign travellers to write checks instead of carrying cash. Other great civilizations in China and India had remained satisfies with their level of tech for a very long time.

    Advancement of ours slows when the product becomes good enough, airliners haven't changed much in appearance or performance since the 707 of the 1950's, they aren't even as fast now. Cruise ships may be larger but they don't usually go much faster than RMS Titanic.

    I would argue that airliners have changed greatly. They are much safer,
    more fuel efficient although I am not certain they are more comfortable. As far a cruise ships, again, they are much safer, more efficent as well. As
    far as speed, cruise ships don't need speed. People are on them for
    leisure, not transportation.

    If other civilizations exist and weren't driven by war to advance their
    tech
    they may be satisfied with lives similar to ours.

    Airliners have benefited from military advances in engines, structure and electronics. Civil aviation which doesn't use military tech is pretty
    stagnant and resistant to change, favoring proven reliability. Many light planes have late WW1 performance and still closely resemble the Spirit of St Louis, except for the Wright J-5 radial and huge gas tank at the center of gravity.

    As for safer, the Costa Concordia suffered damage similar to Titanic's, but further back. Titanic was opened from the bow to between the forward
    funnels, into the forward coal bunker of boiler room 5 and possibly back
    into 4.

    The recommended fixes were applied to the third ship of the class, HMHS Britannic, which nevertheless was damaged nearly the same way by a WW1 mine
    and sank in half the time.

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Daniel65@21:1/5 to Jim Wilkins on Mon Sep 4 20:18:53 2023
    XPost: alt.astronomy, alt.fan.heinlein

    Jim Wilkins wrote on 4/9/23 2:25 am:
    "Michael F. Stemper" wrote in message
    news:ud29va$vog6$1@dont-email.me...
    On 03/09/2023 08.05, Jim Wilkins wrote:
    The inaccurate Egyptian value for Pi disproves such influence. They
    used 256/81, less accurate than 22/7.

    Cool! That's 2^8/3^4. There was probably some arcane numerological
    reason to use a fraction that was the ratio of powers of primes. And,
    while it might be less accurate than 22/7, it's only a 0.6% error.
    Their tools and measuring instruments were not likely to have been
    able to do anything closer than that anyway.

    And the Egyptians were doing it, what, 5,000 years before the Europeans
    (or whomever) came up with the 22/7 approximation.

    --
    Daniel

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  • From Jim Wilkins@21:1/5 to All on Mon Sep 4 07:45:21 2023
    XPost: alt.astronomy, alt.fan.heinlein

    "Daniel65" wrote in message news:ud4au9$1d7b1$1@dont-email.me...

    And the Egyptians were doing it, what, 5,000 years before the Europeans
    (or whomever) came up with the 22/7 approximation.
    Daniel

    ---------------------

    https://www.exploratorium.edu/pi/history-of-pi
    "The first calculation of π was done by Archimedes of Syracuse (287–212 BC), one of the greatest mathematicians of the ancient world....Archimedes showed that π is between 3 1/7 and 3 10/71."

    "A similar approach was used by Zu Chongzhi (429–501), a brilliant Chinese mathematician and astronomer....He calculated the value of the ratio of the circumference of a circle to its diameter to be 355/113."

    The number was of only theoretical interest until the British Navy began searching for and more importantly investing in measurement accuracy after a fleet was wrecked on rocks due to a navigational error.

    https://en.wikipedia.org/wiki/Jesse_Ramsden
    The key to his improvement was finding more accurate ways to generate
    precision screw threads. Before him screw threads were usually cut freehand
    or by winding a brass and black iron wire around a brass rod and then
    dipping it in solder, which joined only the brass. Removing the iron wire
    left a spiral between the brass wires that served as a guide. The actual cutting tool looked like a comb, with hand-filed cutting teeth. https://www.jamesriser.com/Machinery/chasers/making_chasers.html
    That was good enough for the short screws in clocks but not for accurate measurement. A metal lathe that guided the cutting tool with a precision leadscrew was introduced in 1797, and enabled the Industrial Revolution. https://www.lindahall.org/about/news/scientist-of-the-day/henry-maudslay

    Government support such as Maudslay received from the Admiralty was critical
    to many early advances since it could provide startup money to create better tooling for faster production. At first private investors were reluctant to take that risk with their own money, the government had both tax funds and means of enforcement to assure delivery. The only manufactured product the government need to buy in large quantity was improved firearms, so they led
    the way to mass production, more in America than Europe. https://www.nps.gov/spar/learn/historyculture/thomas-blanchard-and-his-lathe.htm
    By the 1850's other industries like watchmaking had seen the advantage and followed.

    The US government still heavily supports technological advancement by
    creating demand for aerospace products that civilian society wouldn't. Consumers including me tend to stop buying new once the current products are good enough. I'm still happily using an iPhone 6S and driving a carefully maintained 23 year old car. Yesterday I readjusted the valves.

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