Science Forums

# Is Space Zero Gravity (0 G)

## Recommended Posts

Why does this sound exactly like what I said on the first or second page about gravitational neutralization.

Wait, who brought up Lagrange points?

No. It doesn’t sound anything like what you said.

You said:

Additionally, there are parts of space, many gravitational fields can interrupt one another and create langrange points where, if a mass was sitting there, it wouldn't experience even infinitesimal amounts of gravitational tug. I tried to explain that earlier when I said "gravitational neutralization". Notice how all langrange points are sort of a zero g space - welcome to the inspiration for anti-gravity propulsion - the gravitational fields of the sun, moon, and earth do not effect these langrange points but seem to distort around them, as the waves interfere with one another.

And that is wrong. At a Lagrange point, the gravitational forces from two bodies effectively cancel. What about the gravitational forces from all of the other bodies? Those forces are still present, so your statement that “If a mass was sitting there, it wouldn't experience even infinitesimal amounts of gravitational tug” is wrong.

And you continue to confuse gravity fields with gravity waves, among other things.

• Replies 178
• Created

#### Popular Days

Very true and an important point. The static gravitational field of a single mass does not have any energy and therefore cannot do any work. The static field does not drain any energy from the mass that produced it.

This is apparent from dimensional analysis. Energy = force x distance and has the dimensions of ML2T-2 while a gravitational field only has the dimensions of L2T-2. Obviously, a gravitational field contains no energy until another mass is introduced.

If the second mass is stationary, there will be gravitational potential energy. If the second mass is moving, then some of the gravitational potential energy is transformed into kinetic energy. When the second mass is orbiting the first, it is constantly falling inward so gravitational potential energy is exchanged for the orbital kinetic energy exactly; energy is conserved and the mass can orbit indefinitely.

As long as the orbital distance remains constant, there is no energy released from the system and thus no gravitational waves propagate outwards.

Yes. For example, when neutron stars orbit one another the gravity is so great that they are pulled together and as they get closer they accelerate toward each other at great speed, releasing a great deal of gravitational energy in the form of gravitational waves, travelling at the speed of light. This has already been detected.

On Lagrange Points: While Lagrange points do exist, they have been calculated only as a solution to a two-body problem, such as earth-moon or earth-sun. Calculating a three-body solution, such as earth-moon-sun gets very difficult (I think impossible in closed form). When you add in even more bodies, it is certainly impossible. The presence of Lagrange points does not establish that there are points in space with zero gravity; only that there are points where the gravitational forces from two bodies effectively cancel out.

Yes they don't actually cancel out because if they did an object at that point would travel in a straight line. But from the perspective of a rotating frame of reference, in which there is centrifugal force rather than centripetal acceleration, there is zero net force at these points, i.e. the gravitation cancels the centrifugal force.

There is a very nice contour diagram of the resulting potential energy surface, in the Wiki article I was referencing. Here: https://en.wikipedia.org/wiki/Lagrangian_point#/media/File:Lagrange_points2.svg

This shows that at at L4 and 5 there is a potential energy minimum, so objects at these points tend to stay there, while at L1,2, and 3, there are maxima so objects at these points are unstable and any tiny deviation will send them away from that point.

Neat, huh?

Edited by exchemist
##### Share on other sites

No. It doesn’t sound anything like what you said.

You said:

And that is wrong. At a Lagrange point, the gravitational forces from two bodies effectively cancel. What about the gravitational forces from all of the other bodies?

Still applies. Just not at that exact point. There is a point of total equilibrium between the gravitational forces because the number of gravitational influences are finite. You're not going back into my posts far enough. Edited by Super Polymath
##### Share on other sites

And you continue to confuse gravity fields with gravity waves, among other things.

How so?
##### Share on other sites

Okay, the CMBR is from when the universe was, what, 137,000 years old?

The universe was tiny, everything was causally connected, however, unless you're with the cold bang theory, space has expanded so much since then that light and gravity no longer had the time to make it here from beyond the particle horizon. Back then, there was no particle horizon, everything was closer together.

EXACTLY.  Everything was causally connected.  Then it expanded and that causal connection was lost.  But the fields propagating across the universe were not lost; they are still propagating.  That's why we can see the CMBR from something causally disconnected from us.  That's why we can still be affected by gravity from something causally disconnected from us.

Are you getting this yet?

Edited by billvon
##### Share on other sites

And you continue to confuse gravity fields with gravity waves, among other things.

How so?

You do not seem to understand the difference between statics (i.e. fields) and dynamics (i.e. waves.)  It suggests you have never had any training in EM fields.

##### Share on other sites

Still applies. Just not at that exact point. There is a point of total equilibrium between the gravitational forces because the number of gravitational influences are finite. You're not going back into my posts far enough.

There is no sense in even speculating about such a hypothetical Lagrangian point. Just consider the three-body problem:

"In 1887, mathematicians Heinrich Bruns[4] and Henri Poincaré showed that there is no general analytical solution for the three-body problem given by algebraic expressions and integrals. The motion of three bodies is generally non-repeating, except in special cases"

Indeed, the Lagrangian points we have been discussing here are special cases of the Circular restricted three-body problem in which two massive bodies move in circular orbits around their common center of mass, and the third mass (a satellite) is negligible with respect to the other two. That reduces to a two-body problem that can be solved.  With respect to a rotating reference frame, the two co-orbiting bodies are stationary, and the third body can be stationary as well at the Lagrangian points.

So, while you may suppose that there are Lagrangian points for all of the masses in the solar system, or even all of the masses in the universe, the complexity is such that these points, if they exist at all, can never be calculated and could not possibly be stable for more than an instant. More likely, they do not exist at all so not worth worrying about.

##### Share on other sites

How so?

Like so:

What I said was that these lagrangian fields/waves are generated by gravitational fields/waves, and they are, are they not?

There are no Lagrangian fields or waves, just points in space where the gravitational forces from two massive bodies will cancel out on a much smaller body, allowing it to be parked relative to the two large rotating bodies.

Given they're produced by the gravity of large bodies like those of the sun & earth, or the sun & the moon, as the link text says, which are all moving through space orbiting the sun or the sun circling the Milky Way & therefore are generating gravitational waves to form the gravity fields of Lagrange points-which themselves do not stay set, they orbit the sun and will release gravity waves just like everything else.

The sun and moon moving in nearly uniform circular motion in stable orbits do not produce gravity waves, only static gravitational fields. Gravity waves do not form gravity fields! Gravity fields do not transmit energy. Gravity waves are energy that was released when energy is lost from a gravitational system, usually when a large orbiting body falls into a gravity well, losing potential energy that is not all converted to kinetic energy. In order for energy to be conserved, the potential energy that is not converted to kinetic energy must be released from the system, and it is radiated away in the form of gravity waves. Since gravity is so weak, we can only detect these waves when the objects involved are very massive, like neutron stars and black holes.

##### Share on other sites

So, while you may suppose that there are Lagrangian points for all of the masses in the solar system, or even all of the masses in the universe, the complexity is such that these points, if they exist at all, can never be calculated and could not possibly be stable for more than an instant.

Given all of the mass objects in the universe (& the ever changing distances between each of them) are finite, a gravitational equilibrium point somewhere near the center of all of the objects in any causally connected region of the universe will always be there, though it will always be relocating. It's a point that is the sum of a nigh-infinitude of gravitational fields where the sum of all of their collective micro-gravity meets at perfectly equal strength from all directions. Perfect momentary neutralization.

It's conceptually impossible for these total lagrangrian points not to emerge, just mathematically haggard to predict them. We don't need math to prove their existence, only to pinpoint or locate them.

We can't even predict the weather with perfect accuracy, but Omega (as envisioned here) could predict these temporary total-lagrangian points.

Now, a point of zero g space could also theoretically be artificially produced using the Casimir effect.

Edited by Super Polymath
##### Share on other sites

EXACTLY. Everything was causally connected. Then it expanded and that causal connection was lost. But the fields propagating across the universe were not lost; they are still propagating. That's why we can see the CMBR from something causally disconnected from us. That's why we can still be affected by gravity from something causally disconnected from us.

Are you getting this yet?

Yes, but the remnant microgravity of the earth doesn't present like a particle, if the earth's gravity can no longer make it to the particle horizon how could anything on the other side be attracted to it? In the same sense that we would only see what is now presumably a galaxy cluster beyond the particle horizon as a primordial blob on the CMB, no gravitational force from beyond the particle horizon can get to us or be felt by us that emmenates from any mass beyond the particle horizon! Edited by Super Polymath
##### Share on other sites

Like so:

There are no Lagrangian fields or waves, just points in space where the gravitational forces from two massive bodies will cancel out on a much smaller body, allowing it to be parked relative to the two large rotating bodies.

The sun and moon moving in nearly uniform circular motion in stable orbits do not produce gravity waves, only static gravitational fields. Gravity waves do not form gravity fields! Gravity fields do not transmit energy. Gravity waves are energy that was released when energy is lost from a gravitational system, usually when a large orbiting body falls into a gravity well, losing potential energy that is not all converted to kinetic energy. In order for energy to be conserved, the potential energy that is not converted to kinetic energy must be released from the system, and it is radiated away in the form of gravity waves. Since gravity is so weak, we can only detect these waves when the objects involved are very massive, like neutron stars and black holes.

Okay, so the gravitational forces propagating from the earth & the sun & the moon to generate lagrange points are gravitational fields. Thank you.

According to Einstein all gravity propogates

"Because Jupiter is moving around the Sun, the precise amount of the bending depends slightly on the speed at which gravity propagates from Jupiter"

This was confirmed by the test spoken of in that article.

So the gravitational field has set range, the causal limit of the particle horizon or less.

Edited by Super Polymath
##### Share on other sites

Yes, but the remnant microgravity of the earth doesn't present like a particle

Correct.  It presents as a distortion in spacetime.

if the earth's gravity can no longer make it to the particle horizon how could anything on the other side be attracted to it?

If the CMB radiation can no longer make it to the particle horizon how can anything on the other side see it?  <- similar question.  Answer - because those fields began propagating while the universe was still causally connected.

##### Share on other sites

Correct. It presents as a distortion in spacetime.

If the CMB radiation can no longer make it to the particle horizon how can anything on the other side see it? <- similar question. Answer - because those fields began propagating while the universe was still causally connected.

In the same sense that we would only see what is now presumably a galaxy cluster beyond the particle horizon as a primordial blob on the CMB, no gravitational force from beyond the particle horizon can get to us or be felt by us that emmenates from any mass beyond the particle horizon!

You're basically arguing about fluctuations in space time that are removed from their source and thus do not pull an object towards whatever is actually there across particle horizon now.

Edited by Super Polymath
##### Share on other sites

In the same sense that we would only see what is now presumably a galaxy cluster beyond the particle horizon as a primordial blob on the CMB, no gravitational force from beyond the particle horizon can get to us or be felt by us that emmenates from any mass beyond the particle horizon!

We do indeed feel the gravitational force from mass beyond the particle horizon.  It is "old" - it takes billions of years to propagate to us, just as the CMBR has taken billions of years to propagate to us.  And, of course, it is infinitesimal.

You're basically arguing about fluctuations in space time that are removed from their source and thus do not pull an object towards whatever is actually there across particle horizon now.

"fluctuations in space time that are removed from their source" = gravity.  We make the simplification that gravity is intimately linked to a source with no delay because in the cases we observe (i.e. Earth to Sun) the delay is small.  But all sources of gravity have that delay, whether it's 8 minutes or 90 billion years.

Edited by billvon
##### Share on other sites

We do indeed feel the gravitational force that we get from mass beyond the particle horizon. It is "old" - it takes billions of years to propagate to us, just as the CMBR has taken billions of years to propagate to us.

Actually, you'd watched the video,it would take infinite time to pass the particle horizon moving at c, because space will be expanding faster than the speed of light. The CMBR is lingering radiation emitted when the universe was 380,000 or so years old, the universe was a lot smaller, back then the pre-galactic era's particles and gravity was close enough to reach our part of the universe. This is no longer the case.

"fluctuations in space time that are removed from their source" = gravity. We make the simplification that gravity is intimately linked to a source with no delay because in the cases we observe (i.e. Earth to Sun) the delay is small. But all sources of gravity have that delay, whether it's 8 minutes or 90 billion years.

Let's say what was once a bunch of quarks over here is now an asteroid over there, and that gravity of the quarks is all that made it to our side of the particle horizon. The gravitational influence is felt but it doesn't pull to its original source because its original source isn't there anymore.

If gravity were thought of as gravitons, which we haven't proven yet. There's a lot we don't know about what gravity actually is, but it's safe to say given the test that confirmed gravity is not superluminal, that objects outside our observable universe are also beyond our gravity's influence.

Funny thing is, we don't know if the CMB is a representation of all that was there at that time, as there was still a particle horizon even 380,000 or so years after the supposed big bang. It may be that all of the matter & energy (& "dark matter & energy") before & during recombination (or during the quark epoch) could have been infinite and might stretch out forever. That all depends on whether or not the universe is flat. Our best way to go about it is to keep looking for dark matter, dark energy (casimir effect), gravitons, whether wavelengths effect the gravity of photons, or defining the very substance of space, etc using particle accelerators & to keep advancing technologically.

Edited by Super Polymath
##### Share on other sites

None of this relevant, Billvon couldn't even comprehend causal limits, and I was originally correct about how the gravitational waves of the sun & earth and moon & earth literally neutralize each other out when acting on a third body, like a satellite. The rest of it, your whole argument, is a hack at unnecessary addendums.

"But satellites or space dust in Lagrange points don't produce gravity waves! They produce fields! Shapes!"

Is basically what your argument has been reduced to. An argument on purely discrediting the person who demonstrated that microgravity has a limited reach & can be neutralized. That ticked everyone off for whatever reason.

Not at all. You persist in a wholly wrong idea that gravitational fields are the result of gravitational waves. THEY ARE NOT. Everything I have said to you on this thread is trying to correct this error in your thinking.

This is not an irrelevance, as you seem now to be suggesting: it is such a fundamental misconception of yours that it makes almost everything you say on this thread into nonsense. That is why you are getting into an argument with billvon about causal connection and all the rest of it.

Edited by exchemist
##### Share on other sites

This is not an irrelevance

I was describing a field, you obviously couldnt tell me what a field was as a field even is propagated at around c, you said "fields don't propagate". Obviously my citation shows otherwise. So I stuck with a field as a ripple in a pond, which is why I went on with "wave". It was actually my most recent article cited that made me change my terminology, "before hand it was thought to be impossible to measure the speed of gravity without gravity waves". Your definition was a bit misinformative, you should have taken a more Einstein approach, less Newtonian. That would have fit better with modern results.

causal connection and all the rest of it.

I think you're being pretentious.

But that's just me.

Edited by Super Polymath

## Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

×   Pasted as rich text.   Paste as plain text instead

Only 75 emoji are allowed.

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.