One thing I often see people confused about is artificial gravity in science fiction.
Ironically it seems that the more realistic the depiction of gravity is, the more it confuses
casual viewers.
I realise that perhaps most of you will be well aware of most of this stuff but I’m
gonna lay it out anyway for anyone who is a little unclear.
Ok so we basically have three methods of artificial or simulated gravity that we see in science
fiction, Centrifugal Artificial Gravity or “Spin Gravity”, Linear Artificial Gravity
or “Thrust Gravity” and Technological Artificial Gravity, which a lot of people
like to call “Magic Gravity”, let’s start with that one.
The grand majority of Sci-fi stories employ this kind of explanation for their artificial
gravity.
It basically relies on the idea that in the world in which the Sci-Fi story is set, a
piece of technology has been developed which allows for the manipulation of gravity.
This allows people to install grav-plating or something and set up a gravitational pull
of 1G or close to it, inside their spacecraft or station.
This way the art team and the writers can design all of their ships and stations based
off real life naval ships and aircraft where up is up and down is down, and if it’s a
show or movie then they can record all the scenes on sets that look just like the inside
of a submarine or something and it’s all very easy for the viewer to understand.
You’ll notice that in most of these Sci-Fi stories, very few details will ever be given
about the gravity systems, they’ll talk about the laser cannons and the hyperdrive
or whatever as much as they can but everyone just take the gravity for granted and never
talks about how it works, and it’s always the very last thing to break down, even when
the ship is a smouldering ruin the gravity is always still working.
This is because the existence of this kind of technology opens a whole new can of worms,
if we could manipulate gravity like this, we would not be using it just to create artificial
gravity inside our spacecraft, we’d be using it to PROPEL our spacecraft among a thousand
other crazy things that this tech would allow us to do.
If they go into too much detail and reveal that they can literally just set any kind
of gravity in any space or direction on a whim, then immediately you’d have people
like me and I’m sure most of you wondering why they don’t have gravity railguns launching
projectiles at ludicrous speeds, or gravity drives pushing their ships around when they
are not travelling at FTL.
Now obviously I understand the need for this kind of pseudoscience in a lot of SF Stories,
it simplifies everything and makes it easier to focus on the characters and the unfolding
stories and makes sure that nobody in the audience is confused.
But I think it would be nice to see a few more instances of realistic artificial gravity
in mainstream science fiction, for a good enough writer it doesn’t do too much to
detract from the storytelling and it would allow more casual audiences to perhaps learn
something about physics and space travel that they would otherwise have never learned.
Ok so next up is Centrifugal Gravity or Spin Gravity.
This is something I’ve had to explain to people a lot because, perhaps reasonably,
it does bend the mind a little bit.
So basically Spin Gravity works by installing an enormous spinning centrifuge hab on your
ship or station, inside the arms of the hab are all of the various interior rooms and
hallways of the craft, these rooms and hallways are built with their floors against what we
would call the outside of the ship, so everyone’s feet are constantly pointing outwards from
the ship.
The hab then spins at such a speed that the centrifugal force exerted on the people inside
it is equal to the pull we feel from earth’s gravity.
This way so long as the hab is spinning at a fixed speed, everything inside will seem
fairly earthlike, with a clear up and down and constant simulated gravity.
This has one particular advantage over thrust gravity, which we’ll cover in a moment,
and that is that a vessel using a centrifuge hab can remain completely stationary and still
have internal gravity so long as the hab spins, making this the best realistic option for
space stations and other fixed installations.
Ok so last up is Linear Artificial Gravity or Thrust Gravity, this is perhaps the simplest
means of simulating gravity with realistic technology.
A vessel employing thrust gravity would be built much like a high rise building, tall
and narrow with all of its engines mounted on the bottom facing down.
All the internal rooms and hallways would sit with their floors facing toward the engines
and their ceilings toward the nose.
When the ship accelerates to 1 G of acceleration, the floor of the rooms is now being propelled
upward toward the feet of the crew and passengers at exactly the right speed to simulate earth-like
gravity, while in actuality, the deck of the ship is being pushed up into your legs and
feet rather than the mass of the planet pulling you down.
Developing something like this that would work over extreme distances is not yet possible,
but is not a particularly outlandish thing to aim for.
This would prioritise engine efficiency over engine power, if an engine could be built
that could continue to burn at 1G non-stop toward its destination, flip at the half-way
point and decelerate for the rest of the journey, then the crew would experience constant earth-like
gravity as a happy side-effect, without any specific artificial gravity system even being
necessary.
There are some downsides to this method, as mentioned earlier, a ship operating on thrust
gravity would not be able to maintain the simulation of gravity if the ship was to stop
moving, and speeds higher or lower than 1G would lead to either near-weightlessness or
tremendous bodily stress for the crew.
And if the vessel ever needed to employ any kind of sharp or sudden manoeuvres, even as
simple as flipping the ship to begin a breaking burn, everyone on board would need to be securely
fastened into their seats for the duration of the manoeuvre.
So, in conclusion, I wouldn’t hold out hope for Star Wars style Gravity Plating at any
point in our future, though we have no idea what kind of crazy elements and materials
we might one day encounter so anything is possible.
But I think Works like the Expanse, 2001 and Babylon 5 are proof that realistic means of
Artificial Gravity can be constantly present in a Science Fiction series without detracting
from the experience, and perhaps give us a better impression of how the future of space
travel might actually look.