Would it be really bad if gravity just stopped?
I mean, what’s the worst that could happen … C’mon.
Hello Everyone, Crystal here for DNews asking important questions like, do we really need
gravity? and what would happen if it just stopped?
Would we explode?
Spin off into space?
Or just float along looking graceful and fluid like the astronauts on the international space
station?
Well to a certain extent, the answer is … yes.
Gravity is just one of those things we all take for granted.
Breathing, death, taxes, and gravity all important, all inevitable.
I’m sure just the word gravity evokes some distant memories of apple trees, guys in grey
wigs, and names of sciency people you remember being important like Galileo, Newton, and
Einstein, but Pop Quiz: What Is Gravity?
If you ask a physicist (and I asked several) they’ll tell you that gravity is a geometric
property of space time, as described by Einstein's Field Equations … diffEqs anyone?, and that
whole Newtonian F equals G times m one m two over r squared thing, is a childish simplification.
But what does that mean for us?
Gravity is the weakest of the four fundamental forces of nature but gravity and electromagnetism
are the big ones acting at scales relevant to human experience.
We experience Gravity as a force that keeps us accelerating towards the most massive body
in our vicinity.
In our case, that’s the earth.
In the Earth’s case that’s the sun … So scale is really important when we answer this
question.
If gravity suddenly stopped, humans would be fairly inconvenienced.
Firstly, it would be hard for us to move around given that we would have nothing to push against,
Newton’s laws of motion and action/reaction would still totally be in control, so objects
in motion would stay that way and vice versa.
I feel compelled to bring up the unrealistic fate of George Clooney’s character in the
movie Gravity so if you haven’t seen it *spoiler alert*! … but honestly, where did
the filmmakers think the force that sent him floating away from Sandra Bullock came from
anyway?
-- epic physics fail.
We know humans can live through the absence of gravity because astronauts experience something
similar all the time, so that’s not a problem.
What we can’t live without is air., gravity is the attractive force keeping our atmosphere
intact.
Without gravity, our breathable air would spring into the vacuum of space, and that
would be pretty uncomfortable for us.
Honestly, we probably wouldn't really notice because the tidal effects from our moon would
be changing so drastically that it would trigger earthquakes, Earth would expand and become
less dense while pieces of it would be flung off … things wouldn't be looking good.
We’d be long dead, but an observer with a galactic viewpoint would see the dissociation
of our planetary system, the death of stars, and basically the ultimate death of the universe
as we know it.
So, how important is Gravity?
very, very important.
Life as we know it wouldn’t exist without it.
I’d like to thank Casey Handmer in the Astrophysics department at Caltech for input on this video.
So are there any other crazy physics questions you want us to answer?
Subscribe to DNews and let us know in the comments down below.
And come find me on Twitter!
I’m @PolycrystalhD