• [Article] Realistic science in sci-fi

    From Jerry Brown@21:1/5 to All on Sun Jan 24 09:28:05 2016
    XPost: rec.arts.sf.tv, rec.arts.sf.movies

    On Sun, 24 Jan 2016 15:26:47 +1300, Your Name <YourName@YourISP.com>
    wrote:

    Under pressure
    The 1979 movie Alien (with Sigourney Weaver) was
    famously advertised with the tagline "in space no one
    can hear you scream.

    Audible sound waves cannot travel through a vacuum, and
    yet many science fiction movies feature sound effects in
    the vacuum of space. This is particularly true for the
    more fantastical movies, such as Star Wars and Star
    Trek, whereas the more realistic ones tend to avoid this.

    Rarely bothers me as I consider it to exist in the same plane as the
    score.

    One thing that science fiction gets partially right is
    explosive decompression. Atmosperic pressure is
    101 kiloPascals or 14.7 pounds per square inch. Blow
    open the hatch to your spacecraft and you'll briefly
    have a big force pushing you out the door. But the power
    of such forces is often grossly exaggerated.

    In The Martian movie (spoiler alert), astronaut Mark
    Watney is propelled with vast force from air leaking out
    of a small hole in his space suit. If this was the way
    air pressure worked, slicing your bike tyre open would
    launch you metres into the air.

    Fortunately, that doesn't happen.

    If a kilogram of air was expelled from an astronaut's
    space suit at 200km/h, an astronaut with a mass of 200kg
    (that's including the space suit) would be accelerated
    to just 1km/h.

    Mark Watney wouldn't "get to fly around like Iron Man",
    as he said in the movie, but would move closer to a
    snail's pace.

    Perhaps it is understandable that this is one of the
    relatively few areas where The Martian sacrifices
    scientific accuracy for drama.

    Not in the book; presumably added so that Watney play a less passive
    part at that point in the film (IIRC in the book he was barely
    conscious when recovered from the ascent vehicle).

    --
    Jerry Brown

    A cat may look at a king
    (but probably won't bother)

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)
  • From Your Name@21:1/5 to All on Sun Jan 24 15:26:47 2016
    XPost: rec.arts.sf.tv, rec.arts.sf.movies

    In one topic recently the idea of realistic space sequences in sci-fi
    shows / movies came up (e.g. Babblealong 5 vs Star Wars). By
    coincidence this article was in yesterday's New Zealand herald
    newspaper (23 January, 2016) ...

    Be prepared to suspend scientific belief
    when you go to the movies
    ----------------------------------------
    It's a month since the release of Star Wars: The Force
    Awakens, and for pedants there's much to find wrong with
    the Star Wars movies. Laser beams moving slower than
    300,000km a second, and that sort of thing.

    To be honest, I can live with those inaccuracies. Star
    Wars is a fantasy with spaceships instead of dragons,
    and isn't supposed to be as scientifically accurate as,
    say, The Martian or 2001: A Space Odyssey.

    But could more science be slipped into science fiction,
    including the Star Wars movies, without spoiling the
    fun? Let's go off-world and see if it could happen.


    Dogfights in outer space
    A staple of science fiction is combat between spacecraft
    flying through outer space. Unsurprisingly, these fights
    of fancy are often reminiscent of combat on Earth.

    In Star Wars, the spacecraft fly around like fighter
    planes, with engines pushing them along the direction of
    travel and with speeds that appear to be hundreds of
    kilometres an hour.

    But spacecraft orbiting just above our atmosphere travel
    at almost 8km every single second (about 28,800km/h).
    And because of the vacuum of space, they can orient
    themselves arbitrarily.

    If you want to slow your spaceship, just turn around,
    "fly backwards" and fire your engines.

    What would combat between two orbiting spacecraft be
    like? Well, head-on two spaceships would approach each
    other at almost 16km a second! Fast, but not exactly
    cinematic.

    If the combatants wanted to execute turns (and had
    unlimited fuel), they would fire rockets at 90 degrees
    to the direction of travel. It would be circle work in
    outer space.

    Executing a 180-degree turn would take some time at
    these speeds. Even if you executed a crushing 10G turn,
    it would take four minutes to turn around. Time enough
    for a snack and some social media updates. Perhaps that
    explains why movie directors prefer speeds and
    manoeuvres barking back to the Battle of Britain.


    Under pressure
    The 1979 movie Alien (with Sigourney Weaver) was
    famously advertised with the tagline "in space no one
    can hear you scream.

    Audible sound waves cannot travel through a vacuum, and
    yet many science fiction movies feature sound effects in
    the vacuum of space. This is particularly true for the
    more fantastical movies, such as Star Wars and Star
    Trek, whereas the more realistic ones tend to avoid this.

    One thing that science fiction gets partially right is
    explosive decompression. Atmosperic pressure is
    101 kiloPascals or 14.7 pounds per square inch. Blow
    open the hatch to your spacecraft and you'll briefly
    have a big force pushing you out the door. But the power
    of such forces is often grossly exaggerated.

    In The Martian movie (spoiler alert), astronaut Mark
    Watney is propelled with vast force from air leaking out
    of a small hole in his space suit. If this was the way
    air pressure worked, slicing your bike tyre open would
    launch you metres into the air.

    Fortunately, that doesn't happen.

    If a kilogram of air was expelled from an astronaut's
    space suit at 200km/h, an astronaut with a mass of 200kg
    (that's including the space suit) would be accelerated
    to just 1km/h.

    Mark Watney wouldn't "get to fly around like Iron Man",
    as he said in the movie, but would move closer to a
    snail's pace.

    Perhaps it is understandable that this is one of the
    relatively few areas where The Martian sacrifices
    scientific accuracy for drama.


    Technobabble
    It isn't hard to find errors in the technical dialogue
    of science fiction movies. After the release of Star
    Wars: The Force Awakens, American astrophysicist Neil
    deGrasse Tyson took to Twitter to complain that the
    latest Star Wars was using parsecs as units of time
    instead of distance.

    This Star Wars error is decades old - it was Han Solo's
    gaffe in the original Star Wars - and I suspect J J
    Abrams was deliberately trolling nerds by repeating it.

    Technical dialogue in movies is often a series of
    scientific words thrown together to quickly convey
    something that feels technical. We need to invert the
    neutrino quantum metric scanner, or some such nonsense.
    That said, it's served its purpose. When Han Solo says
    of the Millennium Falcon "It's the ship that made the
    Kessell Run in less that 12 parsecs", the audience
    knows he's bragging about his ship's speed.

    Real technical discussion often takes far longer and
    is far less accessible than movie dialogue. In the
    minute following the real-life Apollo 13 explosion in
    1970, the astronauts exchanged these words with
    mission control:

    Swigert: "Okay, Houston, we've had a problem
    here."

    Lousma: "This is Houston. Say again please."

    Lovell: "Houston, we've had a problem. We've
    had a main B bus undervolt."

    Lousma: "Roger. Main B undervolt."

    This surprisingly calm exchange doesn't convey the
    lethal gravity of the situation.

    The 1995 movie of Apollo 13 portrays these events
    with a little more drama; the astronauts are not as
    calm and time is compressed.

    Actor Bill Paxton's line "We have a wicked shimmy up
    here" was added to the movie dialogue, which is not
    technical and further conveys to the audience that
    something is really amiss.

    A more common compromise in science fiction movies is
    exposition. Mark Watney (played by Matt Damon) in The
    Martian does a lot of thinking out loud that falls into
    this category: "If I want water, I'll have to make it
    from scratch. Fortunately, I know the recipe: Take
    hydrogen. Add oxygen. Burn."

    Would a real astronaut say this out loud? Perhaps not.
    But is it scientifically accurate? Well, yes it is.
    Are we willing to accept such compromises when
    watching science fiction? I guess it depends on how
    captivating the movie is and how pedantic we are.
    I can suspend my scientific disbelief when watching
    movies such as Star Wars: A New Hope. But don't get me
    started on the midichlorians dialogue from the first
    of the Star Wars prequels The Phantom Menace.

    - Michael J Brown
    Associate Professor at Monash University


    * End of article *

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