Naked Science Forum

On the Lighter Side => New Theories => Topic started by: jimithy on 01/02/2021 17:43:30

Title: Does gravity pull or push?
Post by: jimithy on 01/02/2021 17:43:30
 Does the gravity that keeps us on the surface a force that pushes us down rather than pulls us down?
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 19:49:18
Does the gravity that keeps us on the surface a force that pushes us down rather than pulls us down?

This is a good question.  The Earth is surrounded by the entire mass of the external Universe.  Which contains billions of galaxies. Each of which contains billions of stars.

The combined mass of all this matter, within the Universe,  might well exert a "pushing" effect. 

Like how the combined mass of the matter within a steam-engine, exerts a "pushing" effect on the piston?



Title: Re: Does gravity pull or push?
Post by: evan_au on 01/02/2021 20:06:04
Quote from: charles1948
The Earth is surrounded by the entire mass of the external Universe.
That is true.

But that mass is distributed in all directions, so pretty much cancels itself out.
- If there were a slight imbalance of mass in our part of the universe (slightly more mass to the left compared to the right, for example), then it will pull slightly more on you and the Earth (and the Sun, and the Milky Way galaxy), and they will all accelerate slightly in that direction. So this will exert no force between you and the Earth that you could feel.

The gravity that we feel is the effect of the atoms of our bodies being attracted towards the center of the Earth, and the atoms of the Earth resisting the tendency of our feet (or our seat) to get closer to the center of the Earth.
- With sensitive instruments (or a big ocean) you can also detect the tidal effects of the Moon (because it is relatively close) and the Sun (because it is relatively big)
- With our most sensitive instrument LIGO (and similar devices), you can (just) detect the gravitational influence of merging black holes and neutron stars at large distances
- The gravitational effects of everything else is too small to measure, even with our most sensitive instruments

Einstein recast all this in terms of distortion of spacetime, but Newton's understanding of gravity is enough to describe anything humans can sense directly.
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 20:57:18
The combined mass of all this matter, within the Universe,  might well exert a "pushing" effect. 

If that was the case, then the force of gravity we experience wouldn't be dependent upon the mass of the Earth.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 21:39:33
The combined mass of all this matter, within the Universe,  might well exert a "pushing" effect.

If that was the case, then the force of gravity we experience wouldn't be dependent upon the mass of the Earth.

A good point.  But the mass of the Earth might "push back" a bit against the Universal inward push.  Which would account for why the Earth remains stable.  Instead of being instantly crushed into a Black Hole.
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 21:46:59
But the mass of the Earth might "push back" a bit against the Universal inward push. 

If that was the case, then objects with more mass would push back more, thus resulting in the opposite of what we actually observe.

Which would account for why the Earth remains stable.  Instead of being instantly crushed into a Black Hole.

Quantum physics is why objects are stable against gravitational collapse.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 21:54:48
But the mass of the Earth might "push back" a bit against the Universal inward push.

If that was the case, then objects with more mass would push back more, thus resulting in the opposite of what we actually observe.

Which would account for why the Earth remains stable.  Instead of being instantly crushed into a Black Hole.

Quantum physics is why objects are stable against gravitational collapse.

See - I knew somebody would appeal to "Quantum Physics" to explain the inexplicable!
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 22:04:11
See - I knew somebody would appeal to "Quantum Physics" to explain the inexplicable!

It isn't inexplicable. It's well understood. Subatomic particles exhibit a degeneracy pressure that pushes back against external pressure. It's a decidedly quantum phenomenon.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 22:17:18
See - I knew somebody would appeal to "Quantum Physics" to explain the inexplicable!

It isn't inexplicable. It's well understood. Subatomic particles exhibit a degeneracy pressure that pushes back against external pressure. It's a decidedly quantum phenomenon.

As you say, it's a decidedly quantum phenomenon.  Which means,  it doesn't make sense.  But just believe in it!
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 22:19:42
Which means,  it doesn't make sense.

Argument from incredulity. Just because it doesn't make sense to you doesn't mean it doesn't make sense to actual scientists.

But just believe in it!

We don't need to. We have tons and tons of physical evidence for it.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 22:39:26
You mean, you have statistical "meter readings".  Which prove the existence of the "Higg's Boson".

Really?
Title: Re: Does gravity pull or push?
Post by: Bored chemist on 01/02/2021 22:44:13
Which means,  it doesn't make sense.
It may not make sense to you.
There may be a reason for that.
Is it your field of study?
Title: Re: Does gravity pull or push?
Post by: Bored chemist on 01/02/2021 22:45:43

See - I knew somebody would appeal to "Quantum Physics" to explain the inexplicable!

By definition you can't explain the inexplicable.
So nobody did and nobody would bother to try.
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 22:51:36
You mean, you have statistical "meter readings".

That's hardly the only evidence we have for quantum phenomena (not that there's anything wrong with inferring data from instrument recordings in the first place). Tunnel diodes wouldn't work if quantum tunneling didn't exist. Nuclear fusion and fission wouldn't work either.

Which prove the existence of the "Higg's Boson".

No, it doesn't. There is no proof in science. It does provide very good evidence for it, though.

Does this thread need to be moved to New Theories? It's starting to get into science denialism territory.

EDIT: Actually, it looks like this thread was posted in the "Question of the Week" forum, which is probably not where it belongs in the first place. So I'll be moving it for that reason if nothing else.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 23:00:04
I regret your use of the word "denialism".  Doesn't it sound ideological, not scientific
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 23:08:52
I regret your use of the word "denialism".  Doesn't it sound ideological, not scientific

Nope. Ideology is about opinions. Science is about facts. If you deny the facts, you deny science.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 23:12:44
"Denialism"  doesn't sound scientific.  It's not appropriate.
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 23:13:53
"Denialism"  doesn't sound scientific. 

Good, because it's the opposite of science.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 23:22:30
"Denialism"  doesn't sound scientific.

Good, because it's the opposite of science.

No, the opposite of Science is Belief.  Like believing in the Higg's Boson. 
Title: Re: Does gravity pull or push?
Post by: Kryptid on 01/02/2021 23:26:19
Like believing in the Higg's Boson. 

There is plenty of scientifically-based evidence for the existence of the Higgs boson. But given that this thread is about gravity, please start a new thread if you are going to continue discussing that.
Title: Re: Does gravity pull or push?
Post by: charles1948 on 01/02/2021 23:35:39
I'll leave it at that.  Nobody believes in the Higg's Boson. 
Title: Re: Does gravity pull or push?
Post by: evan_au on 02/02/2021 09:18:31
Quote from: charles1948
why the Earth remains stable.  Instead of being instantly crushed into a Black Hole...
I knew somebody would appeal to "Quantum Physics" to explain the inexplicable!
If you are just talking about the Earth, the ancient Greek philosopher Democritus had an answer as good as any at the time:
- Matter is made up of something called "atoms", which are indivisible.
- Therefore, the atoms of the Earth prevent the atoms of Charles1948 from crushing them

Of course, if you are talking about the LHC or the core of the Sun, the indivisible atom isn't quite so indivisible, so you have to rely on Quantum Physics
- But Democritus' atomic hypothesis works ok for the bulk of the Earth
See: https://en.wikipedia.org/wiki/Democritus#Atomic_hypothesis
Title: Re: Does gravity pull or push?
Post by: puppypower on 03/02/2021 13:30:51
Does the gravity that keeps us on the surface a force that pushes us down rather than pulls us down?

If you look at the action of gravity, it causes mass to lower gravitational potential energy. If gravity was a force, like the other three forces, this loss of gravitational potential energy, should result in an exothermic output, where the action of gravity causes an equal and opposite reaction. This reaction should look like anti-gravity. One such action and reaction is gravity induced spin and rotation where the induced centrifugal force creates an anti-gravity appearing force vector, that acts away from the center of gravity.

In the EM force, if an electron lowers energy, it gives off a photon. If this photon hits another electron in an atom; action and reaction, the new electron gains the same amount of energy. Gravity appears to show the same behavior if we take into account rotation and centrifugal force as a reaction to the original action. 

If we look at the universe, and assume all the mass in the stars and galaxies is outputting gravitational energy, as gravity lowers potential, this output should have an anti-gravity style impact, relative to the source of the gravitational energy output. Galaxies and stars will rotate as part of the energy output reaction. Highly wound spiral galaxies outputted a lot gravitational energy output.

In the case of distant stars and galaxies, excess gravitational energy output, that reaches the earth, will have a force vector that pushes toward the center of the earth; direction opposite the gravity of the source. The result on earth is an action and reaction push, that reinforces its own  gravitational potential. The universe is designed to evolve forward in spite of a local reversal vector. There is a type of push on the earth, from the exothermic output stemming from distant gravitational potential, being lowered. This speeds up evolution, and prevents steady state situations, where stars linger in expanded states and don't fuse due to its own balanced reaction vectors.