[Farsight]

I think yes. We're capturing energy from the sun and keeping it in the system. Mass is the measure of a system's energy content, so the mass of the system increases. Seems cut and dried.

[Geezer]

I think yes. We're capturing energy from the sun and keeping it in the system. Mass is the measure of a system's energy content, so the mass of the system increases. Seems cut and dried.

To you, perhaps.

So now what happens if we don't use a solar powered rocket, but use a conventional rocket that obtained its energy from the system? Does the mass of the Moon still increase (and, because they are part of the same system, presumably by the same logic the Earth's mass would also increase)?

[yor_on]

Difficult one, for me that is

I look at it this way. If you take Earth as an example and then consider the Earths surface to be the place of its 'strongest' gravitation (1G) With other directions downwards or upwards as becoming 'weaker' gravitationally seen.

And you then lift that 1 kg. plate 1 meter (around three Feet) you will, when you have finished, placed that same plate in a marginally weaker gravitational field.

As you lifted it you lost some energy, but did that energy go into the plate? You could argue that it did so as if you let it fall it would get a kinetic energy from its 1 meter fall to the ground.

But assume that you put it on a table, 1 meter of the ground. Would you then tell me that it now had an higher energy than before lifting it? Remember that the gravitation is 'weaker' up there too

It's here 'potential energy' comes in as i understand it. As gravity is like a well, or a hole, with Earths ground as the highest gravitational nominator. And as we know that all things want to move toward that highest gravity we can say that without that table the plate definitely would fall to the ground. So it contain a 'need' to move if you like.

But it does not contain more atoms due to the lift, neither does the atoms electrons, molecules, etc jiggle more due to that lift. In fact it should have the other effect as I see it, they should jiggle slightly less as the gravitation is less 1 meter above, and therefore also contain a slightly lesser vibrational energy than the plate had closer to the ground. (Think of a black hole and that plate near a such, to see what I mean)

That it want to move to the strongest gravitational impact is due to how space bends around mass. When you count on potential energy you take a different approach.

"Potential energy is energy stored in an object. This energy has the potential to do work. Gravity gives potential energy to an object. This potential energy is a result of gravity pulling downwards. The gravitational constant, g, is the acceleration of an object due to gravity. This acceleration is about 9.8 meters per second on earth. The formula for potential energy due to gravity is PE = mgh.

As the object gets closer to the ground, its potential energy decreases while its kinetic energy increases. The difference in potential energy is equal to the difference in kinetic energy. After one second, if the potential energy of an object fell ten units than its kinetic energy has risen ten units. Potential energy units are joules." potential energy

There you treat the 'need' to find that gravitational balance down the gravity well as a real 'force' where the object moved 1 meter up have gained a 'real' possible energy, even if not measurable in the object itself. That energy is equivalent to the work done to lift it and will express itself as the plate meet the ground in kinetic energy.

So if I look at Geezers rocket working against the moon, forcing it away from its orbit, it has to transfer an energy as we move the moon further out from Earths and the Suns combined gravity well, or at least Earths.

But Geezers example have more variables in it as the rocket seem to be constantly working? so its complicated

On the other hand, I find most things complicated.

==
Even shoe lashes is complicated nowadays

[Geezer]

Difficult one, for me that is

I look at it this way. If you take Earth as an example and then consider the Earths surface to be the place of its 'strongest' gravitation (1G) With other directions downwards or upwards as becoming 'weaker' gravitationally seen.

And you then lift that 1 kg. plate 1 meter (around three Feet) you will, when you have finished, placed that same plate in a marginally weaker gravitational field.

As you lifted it you lost some energy, but did that energy go into the plate? You could argue that it did so as if you let it fall it would get a kinetic energy from it 1 meter fall to the ground.

But assume that you put it on a table, 1 meter of the ground. Would you then tell me that it now had an higher energy than before lifting it? Remember that the gravitation is 'weaker' up there too

It's here 'potential energy' comes in as i understand it. As gravity is like a well, or a hole, with Earths ground as the highest gravitational nominator. And as we know that all things want to move toward that highest gravity we can say that without that table the plate definitely would fall to the ground. So it contain a 'need' to move if you like.

But it does not contain more atoms due to the lift, neither does the atoms electrons, molecules, etc jiggle more due to that lift. In fact it should have the other effect as I see it, they should jiggle slightly less as the gravitation is less 1 meter above, and therefore also contain a slightly lesser vibrational energy than the plate had closer to the ground. (Think of a black hole and that plate near a such, to see what I mean)

That it want to move to the strongest gravitational impact is due to how space bends around mass. When you count on potential energy you take a different approach.

"Potential energy is energy stored in an object. This energy has the potential to do work. Gravity gives potential energy to an object. This potential energy is a result of gravity pulling downwards. The gravitational constant, g, is the acceleration of an object due to gravity. This acceleration is about 9.8 meters per second on earth. The formula for potential energy due to gravity is PE = mgh.

As the object gets closer to the ground, its potential energy decreases while its kinetic energy increases. The difference in potential energy is equal to the difference in kinetic energy. After one second, if the potential energy of an object fell ten units than its kinetic energy has risen ten units. Potential energy units are joules." potential energy

There you treat the 'need' to find that gravitational balance down the gravity well as a real 'force' where the object moved 1 meter up have gained a 'real' possible energy, even if not measurable in the object itself. That energy is equivalent to the work done to lift it and will express itself as the plate meet the ground in kinetic energy.

So if I look at Geezers rocket working against the moon, forcing it away from its orbit, it has to transfer an energy as we move the moon further out from Earths and the Suns combined gravity well, or at least Earths.

But Geezers example have more variables in it as the rocket seem to be constantly working? so its complicated

On the other hand, I find most things complicated.

Yoron - The fundamental question is "Did the mass increase?". In this case, we are not changing the kinetic energy of the plate - it's stationary in both end states.

If the mass actually did increase it should not be too difficult to devise an experiment to prove that it did. For example, we could apply a certain amount of electrical energy to accelerated the mass. As the mass increases, the resultant kinetic energy will be reduced for the same amount of electrical energy.

[yor_on]

I agree Geezer, but it's perfectly correct to count on it as 'potential energy' as that fits in all kinds of mathematical models describing the universe.

But when testing 'matter' and see if that plate isolated, after being lifted one meter, have gotten an increased energy I would expect the oposite. And if the 'jiggling' is less one meter up, then the mass should decrease as that is kinetic energy.

So it depend on what you choose to define as a 'system' I guess?
Maybe I'm thinking wrong though?

[Farsight]

To you, perhaps. So now what happens if we don't use a solar powered rocket, but use a conventional rocket that obtained its energy from the system? Does the mass of the Moon still increase (and, because they are part of the same system, presumably by the same logic the Earth's mass would also increase)?

Again, it's cut and dried. If you use energy from the system to make one part of the system move faster, it somehow comes at the cost of making some other part of the system move slower. The moon is large compared to the earth, so it's more complicated than the cannonball. See http://en.wikipedia.org/wiki/Tidal_power and note where it says "This loss of energy has caused the rotation of the Earth to slow in the 4.5 billion years since formation. During the last 620 million years the period of rotation has increased from 21.9 hours to the 24 hours we see now; in this period the Earth has lost 17% of its rotational energy". The earth's rotation has slowed down, so you could say the earth has lost some mass. But you can't quite say "the moon" has gained some mass. Instead the subsystem that is the moon in its circular orbit has gained potential/kinetic energy, and hence mass.   

[Geezer]

I agree Geezer, but it's perfectly correct to count on it as 'potential energy' as that fits in all kinds of mathematical models describing the universe.

But when testing 'matter' and see if that plate isolated, after being lifted one meter, have gotten an increased energy I would expect the oposite. And if the 'jiggling' is less one meter up, then the mass should decrease as that is kinetic energy.

So it depend on what you choose to define as a 'system' I guess?
Maybe I'm thinking wrong though?

I agree. There is an increase in potential energy, and the math seems to be sufficiently correct. The question was "does the mass increase?". If someone wants to conduct the experiment I suggested, or they already have done something similar, we could find out quite easily.

Regarding the system, once you define what is in your system, you can't arbitrarily remove components of it and say they are no longer part of the system, even although the effects they produce are minimal. If you take the plate from one meter above Earth to 10 billion meters above Earth then bring it back to one meter again, it will have exactly the same PE that it had before.

By "jiggling", are you referring to the kinetic energy of the molecules that make up the plate?

[Geezer]

To you, perhaps. So now what happens if we don't use a solar powered rocket, but use a conventional rocket that obtained its energy from the system? Does the mass of the Moon still increase (and, because they are part of the same system, presumably by the same logic the Earth's mass would also increase)?

Again, it's cut and dried. If you use energy from the system to make one part of the system move faster, it somehow comes at the cost of making some other part of the system move slower. 

Who said anything about any part of the system getting faster? Are you saying there was, or was not, an increase in the mass of the Moon, the Earth, or the system in either or any of the cases?

If it's as "cut and dried" as you say, I'm sure you will be able to predict the outcome of the experiments.

[yor_on]

yeah, by 'jiggling' I meant the 'motion' atoms create in matter, same as a gas 'jiggles' more as it gets hotter. and my thought was that the closer you move matter to a gravitational well the more 'jiggling' you will find.

And in this case, by removing matter from the well. I think the 'jiggling' should decrease. And as the 'jiggling' should transform into kinetic energy I would expect that piece of matter to become lighter, as the well recedes even though I'm not entirely sure on it.

It's a little like the photon transferring what we call mass due to being constricted inside that perfectly mirrored box. But a little more possible to test, maybe

It's like a drum skin. If you beat on it very fast will that increase its mass. I think it will.

===

Or make a really big hole

[Geezer]

yeah, by 'jiggling' I meant the 'motion' atoms create in matter, same as a gas 'jiggles' more as it gets hotter. and my thought was that the closer you move matter to a gravitational well the more 'jiggling' you will find.

And in this case, by removing matter from the well. I think the 'jiggling' should decrease. And as the 'jiggling' should transform into kinetic energy I would expect that piece of matter to become lighter, as the well recedes even though I'm not entirely sure on it.

It's a little like the photon transferring what we call mass due to being constricted inside that perfectly mirrored box. But a little more possible to test, maybe

It's like a drum skin. If you beat on it very fast will that increase its mass. I think it will.

===

Or make a really big hole

I think if there was any increase in the kinetic energy of the molecules in the plate, it would simply get warmer, just as it does when you heat it in an oven. As I understand it, sticking plates in ovens does not increase their mass  []

If it does, it would be quite easy to measure, or are we talking about a very minute increase in mass?

[yor_on]

Yeah, it's very small if it is so. I mean, it is the atoms higher 'bouncing' frequency that will create what mass there will be more.

Lightarrow could probably count on it and RD and Maddidus and JP and . . .
Thinking of it, probably most all of you here, except me of course :))
Awh

*Takes out his pocket calculator*

"One , two, three, four, and? Where was I?"

Hang on a minute Geezer, I think I'm getting close here

[Geezer]

Ah! Then you would be referring to non-rest mass associated with relativistic effects. But I don't think that applies in this situation. The plate is static relative to Earth before and after it was moved, so I think we'll find it has exactly the same mass in both states.

And even if there was a very small change in mass, I don't think we'd want people to get the idea that its potential energy was caused by a change in mass. I think that would be very misleading.

[Farsight]

Who said anything about any part of the system getting faster?

I thought you did. Check out the wiki “orbital mechanics” article for how you accelerate an object in the orbital direction to gain altitude.   

Are you saying there was, or was not, an increase in the mass of the Moon, the Earth, or the system in either or any of the cases?

If you add energy to the system the system gains mass. If you don't, it doesn't. Mass is a measure of the energy content of a system, and overall the system isn’t moving with respect to you. However the earth and the moon are, so when you change their motion you wouldn’t say they've gained or lost mass. It’s akin to a gyroscope: if you spin it, you add energy, and when you consider it to be an overall system because you put it in a black box, you'd say it isn’t moving with respect to you, so you’d say it had more mass. But if you focussed on some moving portion of the gyroscope, you’d say it has more angular momentum rather than more mass.

If it's as "cut and dried" as you say, I'm sure you will be able to predict the outcome of the experiments.

Experiments are difficult to do. There's a lot of energy tied up in matter, for example only about 1 gram of matter was converted into energy by the Hiroshima bomb. So you can't realistically heat a container of gas and see that it weighs more. This is what Einstein said in his 1905 paper "Does the Inertia of a body depend upon its Energy content?". See http://www.fourmilab.ch/etexts/einstein/E_mc2/www/.

[Farsight]

But it does not contain more atoms due to the lift, neither does the atoms electrons, molecules, etc jiggle more due to that lift. In fact it should have the other effect as I see it, they should jiggle slightly less as the gravitation is less 1 meter above, and therefore also contain a slightly lesser vibrational energy than the plate had closer to the ground.

Imagine you used some aspect of this "jiggle" to operate a clock. Clock run slower nearer the ground, due to gravitational time dilation. That means the jiggle must be slower near the ground. 

[litespeed]

GPS Satellite clocks run FASTER then their counterparts on the earth's surface, when the observer is on the earth next to the ground clock. This is because the orbiting satellites are under the influence of two contradictory relativistic effects that are not equal.

Specifically, these satellites are subject relativity in TWO ways. The larger of the two  increases the speed of the satellite clocks by about 45 microseconds per day, as observed from the ground. This is because the satellites are significantly further from the earth's gravitational center.

However, the satellite clocks are also effected by speed. They are traveling quite fast relative to a ground observer, and time is accordingly slowed down by about 7 microseconds per day. Subtract 7 microsecond from 45 microseconds and the clocks need to be synchronized such that the overall effect is to decrease 37 microseconds per day.

http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html

PS: I know of one case in which potential energy can be hugely decreased in a given mass. Gunpowder. Remove all the charcoal from the mix and replace it with exactly the same mass of sand. And of course vice versa.

I do not know whether the mass of GPS satellites is increased or decreased when sent into orbit. This is because I do not have the math training to know whether the mass is decreased in proportion to the increased distance from the earth. I do know it is increased by the velocity transferred to them by accelerative forces.

However, the potential KINETIC energy of the speedy satellites is vastly greater then the one on the ground.

[VernonNemitz]

Vernon, I hold to that virtual particles 'exist' as you seem to do. Their interactions definitely prove it. That Feynman meant that we couldn't really say what they were, I take to mean that we can't really say what they are . And we can't, but we can count on them and observe their interactions, whatever they might be.

Then I saw you support the Higgs field, sounds okay to me too. When it comes to the Higgs boson? Don't know, maybe the LHC will clear that up?

But now I see that you expect gravitons too? Isn't that contradictorily?
Or do you see string theory as encompassing all those descriptions?

First, thank you for letting me know this Message Thread was active again.

I don't know a lot about the proposed Higgs particle, but I think I can say this relatively safely, "Any proposed particle, if it actually can exist, already exists among the random/temporary virtual particles in the vacuum.  The "Higgs field" would thus be, in crude terms, the percentage of all the vacuum-self-energy virtual particles that are Higgs particles.  Whatever percentage that is, it is apparently enough (for theory to match observation) that ordinary particles are always able to interact with Higgs particles, and as a result most of them appear to possess mass."

[Geezer]

Farsight:

We reposition the Moon relative to the Earth using a conventional rocket (using energy from within the system).

I don't think anyone would argue that we have not altered the potential energy of the system (although I would not be totally surprised if someone did  [])

There had to be a redistribution of mass within the system to accomplish this but;

Did the mass of the system change, and if it did, why did it change?

(BTW, no matter was converted into energy or vice versa during this process.)

[yor_on]

Not bad Vernon
Gotta think on that one.

As always it seems to fall down to how defining that Higg's field.
You can define it as 'particles' but if you do you seem to need to have a 'soup' of them as inertia is expected to be existent everywhere (deep space too). Then again, if distance and time is 'elastics' then that seems to question the very grounds we stand on when discussing 'virtual particles'. Down there 'distance' as we see it might become something different which then would leave space for this 'soup' too.

I like to see it as a 'field', which doesn't define anything really? The reason why I do so is because I find 'forces' questionable, well not macroscopically then, but I differ between that and QM, and what might exist beyond that. And if we have 'isolated' Higgs bosons 'traveling' I suppose I will be wrong, or possibly that the 'transformations' between what's 'under QM', as I see 'virtual particles' to be, and our macroscopic world is more magical than I ever thought.

==

What I was thinking of Geezer when discussing that 'jiggling'?
Awh, did you have to ask me that one?

We have what we call 'invariant mass'. The definition for that is the mass that will be intrinsic to a object no matter  what frame of reference you place it in, space or a black hole.

So it can't be that one. As it is a result of the objects interaction in a gravitational field you might call it relativistic mass as you did, or maybe even momentum.

But if I would be right there, then you might have another problem
As gravity is everywhere, as far as I know, how do we get to the right 'invariant mass'?

[yor_on]

Farsight "Imagine you used some aspect of this "jiggle" to operate a clock. Clock run slower nearer the ground, due to gravitational time dilation. That means the jiggle must be slower near the ground."

You make a very good point there. Time slows down relative an 'outside' observer when closer to a gravitational object. The way I was thinking of it was in the terms of potential energy, and that energy becomes more the further away you move your object from that 'impact zone' where gravity is at its highest.

==
Within limits of course as at some point it will no longer feel that gravitation (like deep space, Lagrangian points) enough to have the 'urge to move'.
==

Then i took that definition and compared it to the object (matter) it 'operated' on, and suggested that as we moved matter away from gravity its 'jiggling' would become less. As that 'jiggling' is transformed into kinetic energy the objects mass also would become less.
==

So if I choose your interpretation. Am I right in understanding it as that you associate 'slowing time' relative the observer as having less energy?

Which I then understand to lead to that a black holes energy level is less the closer you come to it as 'time' slows down relative our observer?
===
Or am I misunderstanding your suggestion?

Never the less, any which way the plate will differ in mass which then would lead to the question. Where exactly do we define the 'proper mass' for an object?


---
So, now at last it almost makes sense
   

[VernonNemitz]

So now what happens if we don't use a solar powered rocket, but use a conventional rocket that obtained its energy from the system? Does the mass of the Moon still increase (and, because they are part of the same system, presumably by the same logic the Earth's mass would also increase)?

Details matter.  What sort of rocket is that?  If for purposes of thought-experiment you have magically introduced it from outside the Earth-Moon System, then you have introduced/added a great deal of potential energy (in the form of the rocket's potential ability to accelerate something like the Moon) to that System.  It should then be obvious that after the rocket has done its work, some potential energy has become real energy that has been added to the System, and thus the mass (that is, total mass-energy) of the Earth-Moon System would be greater than before.

On another hand, if the entirety of the rocket is constructed from Moon-matter, then its process of operation will cause a large amount of Moon-matter in the form of rocket exhaust to leave the Earth-Moon System at high velocity, and very likely the total mass-energy of that System, after the rocket does its work, will have become less than it was originally.

So, what would you prefer?  A proper answer DOES depend on the details!