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  1. Naked Science Forum
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  3. New Theories
  4. Does Gravity Have Energy?
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Does Gravity Have Energy?

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Offline JLindgaard (OP)

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Does Gravity Have Energy?
« on: 16/09/2022 20:34:27 »
 I am sending a link of this thread to Ben McAllister.
We know gravity does not have energy. This is why the Sun will grow and become more massive.
As it does, it's gravity will increase. If the field around the Sun is empty space except for the solar wind and planets,
how can the Sun's gravity increase its mass and kinetic energy?
 I read the Bible today, Genesis 1:1 In the beginning God created the heaven and the earth.

 So when the Sun one day will consume both Mercury and Venus, that is because? Since space is empty and gravity has no energy, what could allow the Sun to become more massive and have a greater gravity while entropy (solar wind, radiation) is causing the Sun to lose mass?
 And yet I'm not allowed to ask a question because 2 * (-2) = -4.
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Offline Kryptid

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Re: Does Gravity Have Energy?
« Reply #1 on: 16/09/2022 20:52:42 »
Quote from: JLindgaard on 16/09/2022 20:34:27
I am sending a link of this thread to Ben McAllister.

Feel free to do that.

Quote from: JLindgaard on 16/09/2022 20:34:27
We know gravity does not have energy. This is why the Sun will grow and become more massive.

That's a non-sequitur.

Quote from: JLindgaard on 16/09/2022 20:34:27
As it does, it's gravity will increase.

I know of no physicist who claims that the Sun's gravity will increase. Its size will increase, but not its mass.

Quote from: JLindgaard on 16/09/2022 20:34:27
If the field around the Sun is empty space except for the solar wind and planets,
how can the Sun's gravity increase its mass and kinetic energy?

The Sun's gravity won't increase its mass. Not sure what you mean about kinetic energy, though.

Quote from: JLindgaard on 16/09/2022 20:34:27
So when the Sun one day will consume both Mercury and Venus, that is because?

Because the Sun will expand outwards, engulfing the orbits of Mercury and Venus. Being in the Sun's atmosphere will boil them out of existence. It has nothing to do with an increase in the Sun's mass. There are other red giant stars out there that have masses similar to that of the Sun, so we know it's possible to have a red giant with Sun-like mass. Mira has only 18% more mass than the Sun, despite being a red giant with a radius over 300 times that of the Sun: https://en.wikipedia.org/wiki/Mira Arcturus is only 8% heavier than the Sun but has a radius 25 times larger: https://en.wikipedia.org/wiki/Arcturus

Quote from: JLindgaard on 16/09/2022 20:34:27
Since space is empty and gravity has no energy, what could allow the Sun to become more massive and have a greater gravity while entropy (solar wind, radiation) is causing the Sun to lose mass?

What I want to know is why you insist that the Sun will become more massive in the red giant phase when no source I know of claims such a thing. I've explained it to you before in other threads that such is not the case. If you are knowingly posting arguments that are false, that is known as straw-manning. That is a logical fallacy.

You were warned about circumventing locks twice in the past. You were warned that you would be suspended if you did it again. As such, I'm giving you that week of suspension.

And for Ben McCallister's and others information, these are the relevant quotes made in prior threads about these matters:

Quote from: Colin2B on 05/09/2022 23:37:06
I am tiring of this whinging. We appear to have a troll who also haunts other forums.
I’m hearing more moaning than I am scientific explanation, so time for it to stop.

Quote from: Colin2B on 16/09/2022 14:10:19
I do not confuse value and result. In math, value is a number signifying the result of a calculation or function.
If someone presents the calculation 2 * (-2) then the value & result are both -4

This thread is descending into absurdity and I am very tempted to lock it

Quote from: Colin2B on 16/09/2022 17:20:57
That is an incorrect use of the term “value”
As you have decided to invent your own definitions for standard terminology this thread is locked.
Do not attempt to resurrect it or any of the topics contained in it, in a separate thread otherwise your posting rights will be removed.

As this thread does indeed contain a topic discussed in a prior locked thread, it too shall be locked and will remain locked unless instruction is given to me from the required authorities to open it again.
« Last Edit: 16/09/2022 20:58:18 by Kryptid »
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Offline evan_au

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Re: Does Gravity Have Energy?
« Reply #2 on: 16/09/2022 23:36:24 »
Quote from: OP
the Sun will grow and ...will consume both Mercury and Venus
...and quite possibly the Earth, too.
In about 5 billion years, the Sun will have consumed all the hydrogen in its core, and will expand into a red giant phase lasting over a billion years.

But after that, it will shrink to a white dwarf, which is much smaller than its current size - in fact, similar in size to the Earth.
See: https://en.wikipedia.org/wiki/Sun#After_core_hydrogen_exhaustion

Quote
the Sun will ... become more massive.
Not so. As the Sun expands in its red giant phase, the outer atmosphere expands so much that it is no longer gravitationally bound to the Sun, and about half the mass of the Sun will puff off in a "planetary nebula" (like a giant smoke ring).

This leaves the Sun with about half of its current mass.
See: https://en.wikipedia.org/wiki/Sun#After_core_hydrogen_exhaustion

Quote
become more massive...As it does, it's gravity will increase.
No; as the Sun's mass decreases, the strength of its gravitational hold on Earth will decrease.
- This will move Earth's orbit further from the Sun - and might be the only thing that prevents the Earth from being totally destroyed (like Mercury & Venus).
See: https://en.wikipedia.org/wiki/Sun#After_core_hydrogen_exhaustion

Quote
planets...how can the Sun's gravity increase its mass and kinetic energy?
Because the Sun's mass has halved, all the remaining planets will orbit further from the Sun.
- "Normally" (in a human lifetime, where the Sun's mass hasn't changed), it would take a lot of energy to increase the radius of a planet's orbit.
- An immense amount of energy is involved in blowing off the Sun's outer atmosphere
- But the increased orbital radius of the planets comes "for free", with no change in the kinetic energy of the planets.

Quote
We know gravity does not have energy
In Newton's theory of gravity, the gravitational field shows itself to be a "conservative" force, so the planets can continue in their elliptical orbits for billions of years, continuously exchanging gravitational potential energy for kinetic energy (and back again) without losing energy.

In Einstein's theory of gravity, we discover a very subtle effect of Gravitational Waves, which means that a tiny amount of Earth's gravitational energy is carried away by Gravitational Waves. This amounts to a steady energy loss of about 200 Watts for the whole Earth, which is far less than my motor vehicle or my solar panels generate.

In a hypothetical theory of Quantum Gravity, the force of gravity is carried by a hypothetical particle called the "Graviton", which carries a tiny amount of energy and travels at the speed of light. Because (according to Einstein), all mass/energy creates a tiny gravitational field, that means the Graviton has a gravitational field all of its own. This circular argument means that all current candidates for a theory of quantum gravity have intractable infinities which crop up near black holes. This is still very much a work in progress!
See: https://en.wikipedia.org/wiki/Graviton
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