|The following is reprinted
John's Bathroom Reader Plunges Into the Universe.
Most of the time we're willing to shovel down the popcorn and watch Yoda
lift X-Wings out of the swamp using nothing but the Force and a smattering
of questionably parsed English, or let Jean-Luc Picard get the Enterprise
out of a scrape by the convenient discovery of yet another type
of particle beam. But every once in a while we just have to vent about
some of the truly egregious "fiction" in science fiction.
1. Sounds in Space
The tag line from Alien got it right: "In Space, no one
can hear you scream". The reason no one can hear you scream is that
sound needs air to travel in, and there's none in space.
Most of space is a hard vacuum, with a molecule or two of hydrogen floating
around in every cubic meter - not nearly enough to transmit sound. Every
sound in the movies, from photon torpedoes and laser beams to exploding
starships and hyperspace booms, would never happen in real life.
For that matter, you'd never see laser beams in space either, since in
a vacuum there's no medium to reveal them. So a real-life laser dog fight
in space would be really boring to watch.
2. Faster-Than-Light Travel
Warp drives and hyperspace are very useful in science fiction, but there's
one catch. According to Einstein, the speed of light isn't just a good
idea, it's the law. Nothing can go faster than the speed of light in a
vacuum (that's about 186,000 miles per second).
Even inching toward the speed of light is difficult - immense energy
is required to get to even a fraction of the speed of light, and the closer
you get to the speed of light, the more energy is required. The amount
of energy you'd need to achieve the speed of light is infinite (i.e.,
more than you've got, even with those supercool long-lasting batteries).
So just tossing in a few more dilithium crystals into the warp drives
isn't going to make it happen.
There are loopholes in our understanding of the physics that
make faster-than-light travel theoretically possible. For example,
it's theoretically possible to create a "bubble" of space that
breaks itself off from other space and moves faster than light relative
to that space (all the while everything inside both "spaces"
moves no faster than the speed of light). This is known as an Alcubierre
Warp Bubble. The catch (there had to be one) is that these bubbles
require the existence of exotic matter that has negative energy, and wouldn't
you know, there isn't really any lying around, and it's not clear that
any actually exists.
3. Laser Bolts You Can Dodge
from the issue of Imperial Stormtroopers being bad shots, let's review
a fundamental fact of light (which is what lasers are): It travels at
186,000 miles per second. So the idea of ducking before the laser hits
you is just plain silly.
Not to mention (of course) the idea of a laser bolt being visible as
a streak that has a beginning, a middle, and an end. If you were zapped
by a laser from a laser gun, it would look like a single stream of light,
with one end attached to the barrel of said gun, and the end attached
to whatever portion of your head had not melted yet (assuming you're having
a laser battle somewhere where there is enough air around to illuminate
the entire beam).
Most "laser" beams in science fiction movies travel slower
than bullets do today. Let's see Obi Wan whip his light saber around fast
enough to stop the spray of a Mac-10 (and let's not even begin
to talk about all the things wrong with a sword made of light).
4. Human-Looking Aliens
is endemic on the various Star Trek series, where creatures from
entirely different sectors of the universe look just like humans except
for the occasional bulging ridge on their foreheads. Yes, this is the
result of having only humans at casting calls, but in a large sense, all
these "humanoid" variations ain't gonna happen.
Look, humans evolved on earth and shared a basic body format (four limbs,
one head, side-to-side symmetry) with just about every other vertebrate
on the planet. It's a form that works fine for this planet, but not even
every vertebrate sticks with it (see: snakes, whales, seals, etc).
Given that any planet with life on it will have that life evolve in it's
own way, the chances of the universe being stocked with chesty alien princesses
who crave human starship captains is slim at best.
Related to this is the following.
5. Half-Breed Aliens
don't even interbreed with other species here on earth. Our DNA is simply
too different from other species to allow such a mating to produce offspring.
Given this, what are the chances of successful mating with an alien species
that may not even have DNA as its genetic encoding medium?
Also going back to the idea that aliens probably won't look like Humans,
how would you do it anyway? It's not exactly the "Insert Tab A Into
Slot B" proposition it would be here at home.
6. Brain-Sucking Aliens
Good News of an Alien Facehugger Attack T-Shirt, art by Mike
Ditto aliens that control your body by using your brains, or gestate
in your chest, or whatnot. Let's posit that any creature that controls
the brain of any other creature (not that any exist here on Earth) does
so only after a few million years of what's called "speciation"
– i.e., one species eventually enters a symbiotic relationship with
another species. This relationship would have to be pretty specific, as
symbiotic relationships are here on Earth.
Which is to say just because you're in a symbiotic relationship with
one species doesn't mean it transfers over to another species, especially
an alien species, who's body chemistry, DNA, brain wiring, etc., isn't
even remotely close to your own. So don't worry about the "Puppet
Master" scenario too much, or that you'll be nothing more than a
glorified egg sac for some nasty breed of space monster.
7. Shape-Shifting Aliens
aliens are all very well, but there's a tiny problem in having a roughly
human sized lump of alien protoplasm turning itself into, say, a rat,
to scurry around in the ventilation shaft: Where does rest of the alien
go? You can't just make 99% of your mass disappear into thin air (or reappear,
as the case may be); it has to go somewhere.
Unless that "rat" is running around with a highly compressed
mass of a human-sized object (which presents its own problems), shape-shifting
in to different sized objects is not very likely (one of the smart things
about Terminator 2 was that the T-1000 only shape shifted into
things of roughly the same mass, like human beings or a floor).
8. Time Travel
an itch to spend time in the Arthurian England? Or perhaps Gettysburg
during the Civil War?
The same relativistic principles that keep us from going faster than
light also keep us rom traveling backward in time and messing with the
past. It's possible to slow down time - the closer you get to
the speed of light, the slower time moves for you relative to your original
frame of reference - but to get the clock spinning in the other direction
would require you to go faster than light, and you can't do that.
Again, there are theoretical loopholes that could allow it - worm holes,
actually, which are "tunnels" in the fabric of space-time that
could possibly allow travel back in time. but once again, keeping these
wormholes open would require exotic matter with negative energy. Got any?
Neither do we.
9. The Planetary Gravity Scam
Everywhere you go in science fiction, people are walking around like
they weigh just what they do on Earth. Chances of that happening in the
real universe? Slim. Consider our own solar system. On Mars, a 180-pound
man would weigh just 70 pounds; on Jupiter, 424 pounds (not that you can
walk on Jupiter, as it has no solid surface). That man on the moon? Just
30 pounds. The man's mass is the same, it's just that different planets
have different gravitational pulls.
The idea that all the planets that humans might visit would exactly match
Earth's own gravitational profile is a little much. As is, alternately,
the idea that all alien creatures would be as comfortable in our gravitational
field as we are.
10 The Planetary Sameness Principle
Tatooine looks just like the
Yuma Desert in Arizona. Actually, it is the
Yuma Desert of Arizona! I stand corrected, it's Tunisia ... y'know, on the continent of Africa, Earth. Photo via Wookieepedia
The desert planet of Tatooine. The ice planet of Hoth. The jungle planet
of Dagobah. What do these planets all have in common? One planetary-wide
ecosystem. Which isn't too likely.
Our own planet has varying zones and ecological areas: desert, tundra,
jungle, and so on; other planets in the system also show marked zones
of varying atmospheric and weather patterns. Mars has ice caps as well
as (relatively) temperate zones; Jupiter has distinct weather systems
based in different areas on its globe. The planets that show a sameness
are the ones we couldn't live on. Venus is all desert, but that's because
a runaway greenhouse effect makes it hot enough to melt lead. Pluto is
all ice, but it's so far away from the Sun that its atmosphere freezes
for most of its orbit.
There may well be purely desert or jungle planets, but most planets we'd
want to live on would probably be able to accommodate both.