# Gravity is limited to a range extendable with the speed of light c

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1 minute ago, awaterpon said:

There is nothing in the universe is infinite and will never be ﻿. space and time are not the universe . the are the place in which  any possible universe might exist and function so they are infinite " although some scientists say space and time are finite but some say they are infinite and I agree with those who say they are infinite."

As the universes full of matter, if the universe is infinite then there is an infinite amount of matter.

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Posted (edited)

Infinity is unreachable : in time in distance in spreading in mass by mathematics it is clear So how there should be gravity available at infinity if it is unreachable?

11 minutes ago, Strange said:

As the universes full of matter, if the universe is infinite then there is an infinite amount of matter.

You say if but there is not evidence that the universe is infinite.

Edited by awaterpon

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37 minutes ago, awaterpon said:

Infinity is unreachable : in time in distance in spreading in mass by mathematics it is clear So how there should be gravity available at infinity if it is unreachable?

Because gravity is spacetime/universe.

Quote

You say if but there is not evidence that the universe is infinite.

whether the universe is finite or infinite, is unknown, but either way, it does not support your hypothetical.

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12 minutes ago, beecee said:

Because gravity is spacetime/universe.

Your answer is not detailed . could you you explain more?

16 minutes ago, beecee said:

whether the universe is finite or infinite, is unknown, but either way, it does not support your hypothetical.

how to apply infinite space-time to finite observable universe?

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1 hour ago, awaterpon said:

You say if but there is not evidence that the universe is infinite.

There is no evidence that it isn't.

3 minutes ago, awaterpon said:

how to apply infinite space-time to finite observable universe?

The observable universe is a subset of the entire universe.

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Posted (edited)
18 minutes ago, Strange said:

The observable universe is a subset of the entire universe.

If the entire universe is infinite then total energy on universe is infinite " mass-energy is infinite " then the law of energy conservation is wrong and can't be applied.

There should be a finite amount of energy for the system" universe"  no more energy is created or added. if energy can't be created , according to infinite universe and mathematically it's already being created since infinity continuse to multiply and increase to " infinity".

Edited by awaterpon

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8 minutes ago, awaterpon said:

If the entire universe is infinite then total energy on universe is infinite " mass-energy is infinite " then the law of energy conservation is wrong and can't be applied﻿﻿

Energy conservation on applies in a single frame of reference, so you can't apply it to the whole universe.

9 minutes ago, awaterpon said:

There should be a finite amount of energy for the system" universe"  no more energy is created or added. if energy can't be created , according to infinite universe and mathematically it's already being created since infinity continuse to multiply and increase to " infinity".

This is incomprehensible.

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Posted (edited)
20 minutes ago, Strange said:

Energy conservation on applies in a single frame of reference, so you can't apply it to the whole universe.

Wikipedia " In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant"

However energy in the whole universe is being created continuously " infinite mass/energy" and we can somehow add this energy to the system infinitely.

Doesn't that mean  the system has become a perpetual motion machine creating energy from nothing ?

This system is part of the unviverse .

"This law means that energy can neither be created nor destroyed"

While according to infinite universe , energy is already being created from nothing " infnite mass/energy in the universe"

Edited by awaterpon

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Posted (edited)

Coming back to the headline

Quote

# Gravity is limited to a range extendable with the speed of light c

The truth of or otherwise of this could be demonstrated by observing the behaviour of objects subject to more than one gravitational influence.

For example how would your proposal affect forces FAB and FBC in the following simplified situation?
It would certainy work differently from conventional predictions , either GR or Newton.

Edited by studiot

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29 minutes ago, awaterpon said:

Wikipedia " In physics and chemistry, the law of conservation of energy states that the total energy of an isolated system remains constant"

From the same page: "For systems which do not have time translation symmetry, it may not be possible to define conservation of energy. Examples include curved spacetimes in general relativity[3"

Quote

The point is pretty simple: back when you thought energy was conserved, there was a reason why you thought that, namely time-translation invariance. A fancy way of saying “the background on which particles and forces evolve, as well as the dynamical rules governing their motions, are fixed, not changing with time.” But in general relativity that’s simply no longer true. Einstein tells us that space and time are dynamical, and in particular that they can evolve with time.  When the space through which particles move is changing, the total energy of those particles is not conserved.

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Posted (edited)
3 hours ago, awaterpon said:

So do matter exist in the past back to infinite time ? this will be another "infinity" wrong idea. It is simple nothing goes with infinity speed nothing weighs infinity nothing spend infinity time nothing spread to infinity distance nothing reaches infinity no other universes will fill the infinity.

I tried earlier to make a short comment on infinity, zero and limits using math*. Did you read it?

Newton:
$\lim_{r \rightarrow \infty } G\frac{ m_{1} m_{2}}{r^{2}} =0$
At infinitely large distance the gravitational force is infinitely small. Any change will happen in an infinitely short time.

General Relativity:
It takes an infinite time for a gravitational wave to reach infinite distance and the wave will be infinitely weak.

*) Not necessarily mathematically formally correct, hopefully correct enough to make a point. I do not possess the knowledge to write down the correct math for GR.

Edited by Ghideon
format

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43 minutes ago, Ghideon said:

I tried earlier to make a short comment on infinity, zero and limits using math*. Did you read it?

Newton:
limrGm1m2r2=0
At infinitely large distance the gravitational force is infinitely small. Any change will happen in an infinitely short time.

General Relativity:
It takes an infinite time for a gravitational wave to reach infinite distance and the wave will be infinitely weak.

*) Not necessarily mathematically formally correct, hopefully correct enough to make a point. I do not possess the knowledge to write down the correct math for GR.

Thanks Ghideon .I read it but I didn't get your point . I'll try to derive an equation from the above one.

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My equation is the same as Newton's gravitional equation multiplied by this quantity:

(1-vt/cT)  in which:

vt : is the same as r represented by speed v of object and time t It is represented so because we have only two options for two masses whether masses are in each others' range then an object can't exceed range since it can't move with v faster than light or they are out of range then the equation won't work anyway.

c : is the speed of light.

T : is the time measured since the mass came from nowhere

cT: is the changeable range.

According to the equation both range cT goes to infinity and distance vt  goes to infinity.

According to the equation as range increases  or as time time T increases gravity in general increases a little bit according to the equation because there would be more space curved behinde the mass.

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Posted (edited)
7 hours ago, awaterpon said:

Your answer is not detailed . could you you explain more?

how to apply infinite space-time to finite observable universe?

You said that "Infinity is unreachable : in time in distance in spreading in mass by mathematics it is clear So how there should be gravity available at infinity if it is unreachable?" I replied that gravity is spacetime...spacetime geometry in fact. If the universe is infinite, then spacetime is also infinite...if spacetime is infinite, then so to is gravity. Another point just occurred to me...gravity is also said to be non linear, that is gravity makes gravity. http://www.einstein-online.info/spotlights/gravity_of_gravity.html

"One reason why the physics of general relativity is much more difficult than that of Newton's theory of gravity or the theory of electrodynamics is a property called non-linearity. In short, gravity can beget further gravity - where gravitational systems are concerned, the whole is not the sum of its parts'"                                   '

Edited by beecee

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Posted (edited)
4 hours ago, awaterpon said:

My equation is the same as Newton's gravitional equation multiplied by this quantity:

(1-vt/cT)

Is this the correct equation according to your idea?

$F=G\frac{ m_{1} m_{2} }{ r^{2} } (1- \frac{vt}{cT} )$

Can you provide some more explanations what t and v is? When is t=0 for instance.

4 hours ago, awaterpon said:

T : is the time measured since the mass came from nowhere

I'm not sure mass will "come from nowhere", but lets assume it can, just as a test; assuming t=1 and v=1, for short times T, it seems that gravity force is negative:

$T<\frac{1}{c}, t=1, v=1 \rightarrow (1- \frac{vt}{cT}) <0)$

Is that correct?

Edited by Ghideon
grammar

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Posted (edited)
3 hours ago, Ghideon said:

but lets assume it can, just as a test; assuming t=1 and v=1, for short times T, it seems that gravity force is negative:

T<1c,t=1,v=1(1vtcT)<0)

No the quantity vt/cT is is always less than or equal to 1  t is measured after or exactly at mass existence so t will never be greater than T if so and v is always less than or equal to c then vt/cT is always less than or equal to 1.

In such case " vt is greater than cT " masses will be out of range and gravity" mathematically " is supposed to equal negative but the eqaution won't apply for masses out of range and negative gravity doesn't exist.

Notice I didn't consider the other mass range since Inside range means both masses are inside each other's range or at least one is  inside the other's range

The force between masses is mutual one mass attract another mass with a force the other mass attracts with the same force. each mass attracts with its own force using its own range and this force is mutual .Force is propotional with mass M and mass m.

Mathematically and according to my equation exceeding the range edge or zero gravity means negative. That also validate my equation.

Edited by awaterpon

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15 hours ago, Strange said:

However, mass cannot appear from nowhere so the gravitational field extends throughout the whole universe (which could be to infinity).

15 hours ago, Strange said:

We do know that the universe has always been completely and homogeneously full of matter and energy.

Those lines in bold seem to me to be at odds with each other. If the universe could be infinite, then how can we know it has always been full of matter and energy? I can understand how we'd know the universe is full of matter and energy if the entire universe was limited in size to its expansion since the beginning of the Big Bang. But if the universe is infinite in size, how can we know what exists beyond the size the matter and energy have expanded to in the last 13.8 billion years? If the universe is infinite, isn't it possible that the only matter and energy in the universe is limited to a volume with a diameter of 93 billion light years?

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Posted (edited)
11 hours ago, Ghideon said:

F=Gm1m2r2(1vtcT) Can you provide some more explanations what t and v is? When is t=0 for instance.

v is a variable quantity just like r it is the calculations for gravity for a moving object at speed v. if v is zero then the quantity vt/cT will equal zero in such case gravity for an object at stationary is the largest amount ever  while v increases gravity decreases a little bit .

11 hours ago, Ghideon said:

When is t=0 for instance.

t=0 only when v=0 , we start to measure t at object beginning of motion . Anyway gravity decreases with time t as well as it decreases  with speed v.

Edited by awaterpon

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6 hours ago, zapatos said:

Those lines in bold seem to me to be at odds with each other. If the universe could be infinite, then how can we know it has always been full of matter and energy?

Fair enough. I did overstate that.

If our current models of cosmology are correct then space has always been uniformly full of matter.

6 hours ago, zapatos said:

If the universe is infinite, isn't it possible that the only matter and energy in the universe is limited to a volume with a diameter of 93 billion light years?

It would be completely contradictory to our current models of the expanding universe, based on the cosmological principle. It would also place us at exactly the centre of the universe. Which would be nice, I suppose.

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14 hours ago, beecee said:

gravity is spacetime...spacetime geometry in fact. If the universe is infinite, then spacetime is also infinite...if spacetime is infinite, then so to is gravity. Another point just occurred to me...gravity is also said to be non linear, that is gravity makes gravity. http://www.einstein-online.info/spotlights/gravity_of_gravity.html

"One reason why the physics of general relativity is much more difficult than that of Newton's theory of gravity or the theory of electrodynamics is a property called non-linearity. In short, gravity can beget further gravity - where gravitational systems are concerned, the whole is not the sum of its parts'"                                   '

Those two points I raised seem to invalidate your hypothesis.

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6 hours ago, awaterpon said:

v is a variable quantity just like r it is the calculations for gravity for a moving object at speed v. if v is zero then the quantity vt/cT will equal zero in such case gravity for an object at stationary is the largest amount ever  while v increases gravity decreases a little bit﻿ .  ﻿

t=0 only when v=0 , we start to measure t at object beginning of motion . Anyway gravity decreases with time t as well as it decreases  with speed v.

There seems to be several things proposed by your equation:
You are using speed to measure relative movement of masses m1 and m2, not velocity. The direction of movement is not important? How is that compatible with Newton where forces, acceleration etc are vectors?
Since, according to you, gravity decreases with increasing speed v, regardless of direction, how does that affect orbital motion of planets etc?

Note that GR already exists and observations support GR. Your equation seems to predict a different behavior. What mechanism do you suggest to make mass "pop into existence" so your equation can be tested?

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Posted (edited)
6 hours ago, Ghideon said:

You are using speed to measure relative movement of masses m1 and m2, not velocity. The direction of movement is not important? How is that compatible with Newton where forces, acceleration etc are vectors?

Hi Ghideon Thanks for following my idea,

Yes I'm using speed instead of velocity the direction is not important whether towards the center or outwards the center of mass, acceleration is just changing in speed v with respect to time t if it is towards or outwards the center it would take effect "gravity change" if it is not it won't take effect.for instance an object at motion in a perfect circle around the earth its gravity won't change unless it changes distance r with some speed v whether inward or outward this object is supposed to have the largest gravity value" being at stationary" although in fact it is accelerating inwards

6 hours ago, Ghideon said:

Since, according to you, gravity decreases with increasing speed v, regardless of direction, how does that affect orbital motion of planets etc?

The effective direction is outwards or inwards center so elliptical motion of planets will change its gravity but that will not stop planets being in their orbitals

I think increment in v decreases gravity since an object will try to ruin connection between space and matter when at motion

Edited by awaterpon

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Posted (edited)

Here are some additional questions regarding the predictions of the proposed equation: When does the equation apply? How can it be tested? Since matter does not seem to pop into existence, what is the value of T when testing?

We have:

Perfect circular motion: $v=0$, no effect from the added parameters.
Speeds $v$ close to $c$: the equation gives incorrect results (while GR predictions matches observations).
For $v<<c$ we know Newton is a good approximation. Example: space missions using gravity assist* seems to work.

So, what situations requires the modifications you suggest?

17 hours ago, awaterpon said:

The effective direction is outwards or inwards center so elliptical motion of planets will change its gravity but that will not stop planets being in their orbitals﻿

I think you would have to show how Keplers laws are affected and how observations matches your equations.

One more;  since the distance r seems to depend on v and on t, can you write out the equation taking this into account?

Edited by Ghideon
Followup was merged; last question added

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Posted (edited)
18 hours ago, Ghideon said:

When does the equation apply? How can it be tested?

"It should be for both coulomb's law and magnetism.

For  a wire when the circuit is closed the magnetic field starts to spread with the speed of light an experiment could be performed to determine whether magnetic field is already available at a point or it will reach that point after a time"it is not logical that the magnetic field already at infinity since we had a current started to flow at specific moment and shouldn't be available before that moment ,so how it would be available everywhere at an instant?"

What do you think of this ?

Edited by awaterpon

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11 minutes ago, awaterpon said:

What do you think of this ?

I think that it is already well established knowledge, according to current physics. It does not test the new equation you suggested.