It’s invisible, it’s everywhere but in a very universal sense it’s also nowhere to be found. We take it for granted like we take the air that we breathe and the sun on our faces becasue it’s always there – it always has been and it hopefully always will be.
For a long time it’s existence was so subtle that we didn’t know anything really needed to be discovered until an apple fell from a tree and started off Newton’s scientific thinking. Yet to this day we don’t really know what it is? Is it a force exerted on us by increasing mass or a particle that can be generated. It literally keeps out feet on the ground.
I am of course talking about gravity.
We don’t know it – but gravity is important to us. Really important, like our health relies on it in a big way. For starters there’s muscle and bone degradation, heart issues being a part of that. Astronauts try and offset this with a rigorous exercise regime they have to follow and the effects can be treated to some degree. A baby growing in its mother’s womb would also be adversely affected and even deformed in zero or low G. In 2005 Astronaut John Phillips vision went from 20/20 to 20/100 after spending six months in orbit. For some reason the back of the eyeball flattens and the condition can last even when back on Earth. The cause of this is still a bit unknown but it’s another effect of lack of gravity on the human body.
When we consider long range space exploration, the effects of gravity on the human body finding way to create or simulate the effect of gravity on a space mission is one of the biggest engineering problems we face as we look at venturing further and further into space.
With all this in mind, I’ve been thinking about this and about what the possibilities are, their drawbacks might be and what it may means for the future creators of spacecraft.
Simulated Gravity Using Inertia
Using interia to simulate a gravitational effect has already been thought about and commonly used in Science Fiction stories. Even back in the 1960’s when 2001 was made the famous wheel space station created the effect of gravity by spinning and the humans would use this to exist in a very normal way where this inertial pushed outwards.
A similar concept was used in Interstellar on the Endurance which span it’s entire frame to create an inertial gravitational effect. A slightly different approach was to create a centrifuge on the spacecraft, this was used on Discovery in 2001 and in Babylon 5 on on the Earth Alliance ships (which look like the Leonov depicted in the film 2010 Odyssey 2 but that’s another story for another time).
The big issue with this approach is of course there are still areas of the vessel where humans have to operate in zero gravity and the huge resource of spinning the centrifuge isn’t without cost or danger. If it was to seize for even a moment certain doom would likely result.
Gravity ‘Just is’
Because of the sheer complexity of trying to work it all out, many sci fi stories don’t bother with the realities of creative gravity and it’s ‘just there’. Alien, Star Trek, Star Wars all focus on stories and choose not to bog themselves down with the thought of how their people stick to the floor. What they do is they just assume it there anyway. Much simpler and no one really bothers to ask questions and just watch the film or read the story anyway. It seems that this particular technical quandary is left for hard scifi and those that want to make it part of the story.
But what’s the point of all this? Why am I even going through the potential issue of it all when right now it doesn’t even matter?
Well – I’m glad you asked that as I’ve been thinking and I think there’s places where some more thought is needed on this because – well there’s no real reason really it’s just for the sake of exercising the grey matter. So let’s exercise the grey matter some more and see where thing in the minds of imaginary work creators might be going wrong.
Have a look at this excellent professional sketch:
Here are depicted three possible methods of how artificial gravity could work. The first we’ve already discussed. Using a rotation action to create an outward pushing force.
The second occurs on Earth and if we humans could find a way to mimic this effect on a smaller scale then the result would mean a spherical design to ensure the maximum benefit for those living on the spacecraft.
The third one is the more readily seen little thought about option where a floor has some kind of gravity generator built into it. But then surely on the other side of that floor – another floor equally useful could exist which is the other way round to the first or the first is the other way around to the second. That could make using a tubolift tricky. Imagine now Captain picard having to get the right way in and falling on his head.
Spacecraft Design for Gravity
This is the point I’m making here. How spacecraft are thought up and created in Science Fiction is very much based on the physics we find of Earth and built like the buildings or cities we live in. The reality is that it’s very likely that this will not be the case. Our comprehension of future space travel is limited by our understanding of the physics we live in – when that changes (and it will I expect) the whole way in which we live and work out there in the great void will the similar but also different to the way in which we live on Earth and will likely seem very strange and unusual.
Even though we have learned so much since mankind has started it’s exploration of space our journey of understanding has just begun and if there’s one thing we can cling onto for all that it’s worth – Things happen very differently in space than on Earth and certainly more different that we commonly think they do.
That’s why so many conspiracy theories exist.
I hope you’ve enjoyed this post, this little venture into the unknown of artificial gravity. If this interests you have a look at some of my other work. The main page should help you find something.
(Most images in this post are not mine and I claim no ownership – but the written bit was all me.)
© Simon Farnell 2020