Gravity keeps us grounded.
It keeps the planets in orbit around the sun.
It keeps the moon in orbit around us.
But what would the universe be like if there were no gravity at all?
That's exactly what we're going to talk about, right now on life's biggest questions.
Hello and welcome back to LBQ, I'm charlotte dobre.
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Firstly, lets define gravity so we're all on the same page here.
Gravity is a force between any two atoms that causes them to attract.
Gravity is everywhere.
If you put two marbles on a plate, the marbles will have a slight gravitational attraction
to each others.
The bigger the objects, the easier it is to physically measure the gravitational pull
between them.
You can measure the pull between two huge pieces of lead for example, using very precise
instruments.
And of course, when you have a collosal amount of atoms clumpted together, like, oh, lets
say, planet earth, the gravitational attraction is significant enough that entire celestial
bodies like a moon will get pulled in.
The universe, despite being very vast, is very delicate.
If you change just one thing that has to do with physics, the entire universe would be
affected.
Lets consider just for the next few minutes, what would the universe be like if there was
no force of gravity.
According to James Overduin, a Towson university physicist, a universe without gravity would
be completely flat and featureless.
Gravity is essentially the curvature of space time.
Here's an analogy.
Picture a bowling ball on a trampoline.
The bowling ball represents matter and energy, and the trampoline represents the fabric of
space time.
The bowling ball obviously causes the trampoline to curve.
If gravity didn't exist, that would mean there is no curvature of space time, which
would then mean that matter and energy doesn't exist to cause that curvature.
So basically the stars, planets, moons, comets, asteroids, and life, would not exist.
Alright so since that's out of the way, just for fun, lets imagine, what if gravity
was suddenly switched off?
What would happen to us, to our planet, and to the universe.
In places where there is no gravity, like in space, a lack of gravity has a profound
effect on our bodies.
Astronauts who spend time living in space experience a loss of bone and muscle mass.
Astronauts also experience a loss of balance.
But gravity also affects things like our blood cells.
Its not entirely certain why, but our red blood cell count falls in an absence of gravity.
This causes something called space anemia, which brings on a weakened immune system and
even wounds take longer to heal.
Its also incredibly hard to sleep with no gravity.
So that's what happens when you visit space.
How about if you were born in a place with no gravity?
Well, this has never been studied, no one has ever been born and grown up in space.
But experts believe that we would develop differenty without gravity.
Our vital organs like our heart, lungs, brain and muscles would form in different ways.
Truthfully though, if gravity was suddenly switched off, you would simply fly into space.
Anything that wasn't attached to the earth would begin to fly off into space.
If you were outside on the street, you would begin floating up into space until you were
in the upper atmosphere and likely die from a lack of oxygen or extreme cold.
But its not just people and animals that would float away, anything in the atmosphere, our
oceans, river and lakes would quickly be lost.
Our moon would start floating away too.
Lets not forget that earth is broken up into tectonic plates.
Without gravity, pieces of the earth would break off.
Oh and the sun!
Lets not forget about the sun.
Without gravity to hold the sun together, the sun would basically explode engulfing
everything.
Essentially, we would all die.
Everything made up of matter and energy would simply float around, nothing would clump together
anymore.
The universe would be like a gigantic soup of atoms.
I guess it's a good thing gravity exists then hey?
I'm charlotte dobre, and you've been watching life's biggest questions.
If you enjoyed this video, you'll love our playlist biggest science questions.
As always make sure you turn on notifications and we'll see you in the next video.
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