captcass

How is energy conserved when length contracts?

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38 minutes ago, captcass said:

OK, I do understand that modern differentiation. So to avoid confusion, let's then just change it to "relativistic mass". Would they also see each other's relativistic mass increase?

In the past you might have said that, but the term "relativistic mass" is no longer used.  The energy increases asymptotically and energy has properties that used to be only associated with mass.

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Though I am not conceding that mass is anything other than a relativistic phenomenon, which is why I am studying particle physics and the why I got to the book..... :)

Sorry, I did not see the immediately preceding post by Janus.

1 hour ago, Janus said:

energy has properties

Energy has no "properties". It cannot be defined. I am looking at the evolution of time being the primary universal energy, which has me in particle physics and on to the book, yadda, yadda, yadda...

You seem to want to disassociate mass and energy......that the energy increases or decreases asymptotically makes no difference to me as I am looking at causative "events" (within what I am considering)  that do the same thing.

I cannot talk about that here, as it is speculation at this point and just something I am playing with (do I get to go to a -8 for that? :) ). 

So, I will not debate the properties of mass and energy here, I merely posited a question.

To me the term "invariant mass" has no real meaning, it is n accommodation to avoid confusion.

I read somewhere once that Einstein said he was sorry he put his equation into the E = Mc^2 form because the mass aspect was so often misunderstood....

"Invariant" mass changes with relativistic speeds, meaning it is not truly invariant......

59 minutes ago, captcass said:

So, I will not debate the properties of mass and energy here

Ooops......

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Sorry, it's late, but it seems to me that no one has really answered my original question. It seems to me it is being avoided through semantics......the responses also seem to be what is to me "tainted" with the prospect that invariant mass is somehow a separate reality from GR.

I empathize with this as we consider c to be invariant in a vacuum, too, and mass is related to c. But none of this answers my original question. How is the energy conserved?

 I am considering if it could be through release, for instance? Assuming Einstien's fundamental metric as a base, if the rate of time was universally slowed, would that fill the spacetime continuum with released, free, energy - a Big Bang? The cooling of space through the slowing of time (and frequency) that creates a relativistic energy field?

Like I say, I am just thinking about this and this is why I posited the original question. I don't want the moderator to slam me again, so I cannot pursue this here yet.

If the quantum particles are virtual, then mass is also virtual.

2 hours ago, captcass said:

asymptotically makes no difference to me

I am considering that time dilation creates densities in space (masses) that accelerate the dilation; an asymptotic relationship.....I know this is backwards, as everyone who has tried to set me straight in other threads knows. :)

That is why I am now trying to keep things to simple questions so I can resolve issues in my mind with the mainstream view here.

I would like to do that without getting shut down, so, I cannot even speculate on that here....

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Beautiful moon tonight! Round. Spherical. Curved. Can you see that space is curved in the "forward direction of time"? How the passage of time is evolving space (and the densities within it) "forward" with it into the dilation focus at the center of the spherical moon? How things seem to be "falling" towards the center of the sphere? Not just falling, but accelerating? I am calling that "evolving", because that is the evolution of events as in QM as I see them in my world.

A high velocity = a high rate of evolution of events.....hence relative velocity relates to relative rate of time that relates to relative motion, ((Cartesian direction and momentum (which relates to the rate of evolution/time)), which is altered into our "reality" of GR due to the "invariant truisms" of the equivalence principle and the subsequent constant value  of c.

This is why I spoke of relative and true motion in a previous thread.

First, the constant value of c in all frames, and the equivalence principle, itself, stipulates that there is a universal, invariant, rate of time shared by all observers regardless of their apparent position in a time dilation gradient. Space, throughout the continuum, evolves forward at this rate of time. GR confirming the precession of Mercury's orbit is one of the great proofs of GR, showing that SPACE evolves forward due to the passage of time.

When we do a relative motion plot, I used a radar screen plot earlier in another thread, we consider our own motion relative to the X axis (north/south) as "true". This is the inertial frame of the observer. A target's trajectory relative to this is its relative motion. The relationship between our "true" motion and the target's relative motion gives the resultant of the target's "true" motion relative to the shared reference of the X axis (north/south) 

As we stipulate the equivalence principle is true in SR, then even though the relativistic effects constitute "our reality", they do not represent  the "true motion" or properties of events outside our inertial frame. We are stuck in Einsteins's illusion until we figure out how to plot the "true motion" of external events.

This is, of course, maddeningly relativistic. I am therefore considering if we can use the relative motion of the Earth to the CMB as motion relative to "true north" and our velocity relative to a stationary CMB, as determined by Doppler effects, as our "true" velocity, to construct a vector basis to determine the "true motion" of other objects.

3 hours ago, captcass said:

I cannot talk about that here, as it is speculation at this point and just something I am playing with (do I get to go to a -8 for that? :) ). 

Ooops.......

-7? or am I now back to -10? :)

 

 

 

On 3/1/2018 at 11:08 PM, Strange said:

I can’t see any connection with the twin paradox

The twin paradox enters the conversation because it assumes 1 observer is stationary while the other is traveling at high velocity. This is not possible. Relative velocity is relative, not just to each other, but a third, forth, etc. observer. Between any 2 observers, however, the effect is reciprocal. Both twins experience a universal rate of time and both see the the other having equal Lorentz contractions and increases in (mass, energy, relativistic mass), whatever each of you sticklers prefer, and time dilation. :) Turning to reverse direction of motion does not alter this reciprocal aspect as the turn is also relativistically reciprocal, though in opposite directions in Minkowski (and Cartesian) space. 

This means one does not age faster or slower than the other, to each other, but third, fourth, fifth, etc., outside observers will each perceive it differently, not just between the twins, but between themselves and the twins.

 

I think. :)

 

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1 hour ago, captcass said:

The twin paradox enters the conversation because it assumes 1 observer is stationary while the other is traveling at high velocity

It assumes that one undergoes acceleration while the other doesn’t. 

Still don’t see how this relates to your question about energy (although I assume the less aged twin will have used energy to accelerate)

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1 minute ago, Strange said:

It assumes that one undergoes acceleration while the other doesn’t.

I don't know what time zone you are in, but I am in a late one, so I suggest you get some sleep. :) like I am going to do....

The acceleration is still a reciprocal effect. I accelerate away from you, you accelerate away from me.....

4 minutes ago, Strange said:

till don’t see how this relates to your question about energy (although I assume the less aged twin will have used energy to accelerate)

I am just noting that relativistic effects are reciprocal between any 2 observers. Only a third observer can determine who he determines to be moving, accelerating, etc, in which directions relative to his own inertial frame.

'night, Strange.

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6 minutes ago, captcass said:

The acceleration is still a reciprocal effect. I accelerate away from you, you accelerate away from me.

No

If you are sitting in your car with the engine off and watch someone accelerate away, are you pressed back in your seat? (No)

if you start your engine and accelerate sea, are you pressed back in your seat? (Yes)

So, no it is not relative/reciprocal. 

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7 hours ago, Strange said:

So, no it is not relative/reciprocal. 

Is the visual effect reciprocal?

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Posted (edited)
4 minutes ago, captcass said:

Is the visual effect reciprocal?

What does that mean?

Does someone accelerating away look the same as you accelerating away from them? Yes. But so what.

Edited by Strange

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1 minute ago, Strange said:

Yes. But so what.

I agree completely about knowing who is accelerating due to the application of an external force and the resultant drag, but the drag would not be there if the two observers were being accelerated away from each other in two different gravitational fields. They would both be experiencing free fall. Would you gree with that?

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18 minutes ago, captcass said:

I agree completely about knowing who is accelerating due to the application of an external force and the resultant drag, but the drag would not be there if the two observers were being accelerated away from each other in two different gravitational fields. They would both be experiencing free fall. Would you gree with that?

If they are in free fall, then they are not accelerating. And you are no longer talking about the twins paradox. What is the point of leaping around from one random scenario to another?

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7 minutes ago, Strange said:

If they are in free fall, then they are not accelerating

I don't understand this. Are not bodies in free fall in a gravitational field accelerating? Is there not acceleration due to gravity?

 

9 minutes ago, Strange said:

What is the point of leaping around from one random scenario

You folk are the pro's.  Something occurs to me and I want to know your perspective. This helps me learn.....

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7 minutes ago, captcass said:

I don't understand this. Are not bodies in free fall in a gravitational field accelerating? Is there not acceleration due to gravity?

The "old-fashioned" (Newtonian) definition of acceleration is just a change in speed caused by a force. And Newtonian gravity is a force.

In GR, acceleration and gravity are the same thing. So if you are in a sealed box with no view of the outside. you cannot tell if you are sitting on the ground or accelerating through space at 1g. If you feel a force pushing you then you are accelerating. So someone in free-fall, e.g. in the space station, feels no force pulling them on them therefore they are not accelerating. If you can feel your chair pushing up on you then, in GR terms, you are  accelerating.

12 minutes ago, captcass said:

Something occurs to me and I want to know your perspective. This helps me learn.....

Sounds like a very inefficient way to learn. But whatever

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3 minutes ago, Strange said:

Sounds like a very inefficient way to learn

lol. It is just one avenue. But you folks do help me a lot.

 

4 minutes ago, Strange said:

So someone in free-fall, e.g. in the space station, feels no force pulling them on them therefore they are not accelerating.

For instance, this is a whole new perspective for me. Up until this moment everything I've studied says all bodies are accelerating in gravitational fields. Can you suggest some further source for study for me so I can understand how they are not?

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10 hours ago, captcass said:

 

The twin paradox enters the conversation because it assumes 1 observer is stationary while the other is traveling at high velocity. This is not possible. Relative velocity is relative, not just to each other, but a third, forth, etc. observer. Between any 2 observers, however, the effect is reciprocal. Both twins experience a universal rate of time and both see the the other having equal Lorentz contractions and increases in (mass, energy, relativistic mass), whatever each of you sticklers prefer, and time dilation. :) Turning to reverse direction of motion does not alter this reciprocal aspect as the turn is also relativistically reciprocal, though in opposite directions in Minkowski (and Cartesian) space. 

 

I think. :)

 

Turning does break the reciprocal effect. This is because measurements made in an accelerated frame differ from those made in an non-accelerated (inertial) frame. 

If you are in an inertial frame all you need to know to determine the time dilation of another clock is its relative velocity to you.

If you are in an accelerated frame, you additionally have to take into account three new factors: The magnitude of the acceleration, the direction of the other clock relative to the acceleration, and the distance to the clock along the line of acceleration.   Both the acceleration magnitude and distance effect the degree of difference in tick rate you will measure.  The direction determines whether it is a faster tick rate or a slower one.   If the clock is in the direction of acceleration, you will measure it as ticking fast, if it is in the opposite direction, you will measure it as ticking slow.   This measurement holds for clocks whether they share your accelerated frame or not.  (This means that if you are in an accelerating rocket, a clock in the nose will run faster than one in the tail, even if they don't move relative to each other in the rocket frame.)

With the twin paradox this means that when the traveling twin turns around, he is both a great distance from the Earth twin and accelerating towards him.  This combination results in the Earth twin clock advancing very quickly during the turnaround period according to the traveling twin, which more than compensates for the fact that it ticks more slowly during the coasting periods of the both the outbound and return legs.  The Earth twin, which remains in an inertial frame throughout only measures the traveling twin's clock run slow due to relative velocity.

 

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Posted (edited)
2 hours ago, captcass said:

I agree completely about knowing who is accelerating due to the application of an external force and the resultant drag, but the drag would not be there if the two observers were being accelerated away from each other in two different gravitational fields. They would both be experiencing free fall. Would you gree with that?

But now you have to invoke GR and gravitational time dilation.  And this has nothing to do with what the clocks "experience" but with their relative positions in the gravitational fields. 

For example consider two satellites orbiting the same body at different altitudes.  Both are in free fall and experience 0 g.   If this is what determined the gravitational time dilation difference between them, then it should be zero, and the only time dilation would be from their orbital velocity difference, and if R is the radius of a clock's orbit then its time dilation factor should be  found by.

 T = t0 sqrt{1-GM/Rc2}

since orbital velocity is

v = sqrt{GM/R}

However the actual time dilation for an orbiting clock is

 T = t0 sqrt{1-3GM/Rc2}

 

The difference being due to the fact that one of the orbiting clocks is higher in the gravitational field than the other.

1 hour ago, captcass said:

I don't understand this. Are not bodies in free fall in a gravitational field accelerating? Is there not acceleration due to gravity?

 

You folk are the pro's.  Something occurs to me and I want to know your perspective. This helps me learn.....

They are accelerating in the sense that they are changing velocity with respect to some observer at rest with respect to the gravitational field.  They are not accelerating in the sense of being in an accelerated frame, as they would not measure clocks in the direction they are falling as running fast, but would instead measure their respective tick rate depending on their relative position in the gravitational field.

Put another way, if you had a rocket gaining velocity towards a clock due to its firing of its own engines and far removed from any gravity field, it would measure that clock as running fast due to the rocket's acceleration as an additional factor along with the time dilation due to the difference in velocities.

With a rocket falling towards the surface of a planet in free fall, the rocket would measure a clock on the ground as running slow due it's lower position in the gravity field in addition to the time dilation caused by the difference in velocities.

Edited by Janus

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Very clear, thank you.

1 hour ago, Janus said:

With a rocket falling towards the surface of a planet in free fall, the rocket would measure a clock on the ground as running slow due it's lower position in the gravity field

And as it descends, its clock ticks slower. So the outside observer at rest in relation to the gravity field sees the rocket's clock continue to tick slower at an accelerating rate as it also appears to accelerate in velocity, right? Does that relate to what we see in stellar systems where planets that are closer to the star and deeper in the gradient also have slower tick rates and higher velocities? This is exactly what I have been researching, trying to gather a perspective that makes the relationships clear. I was researching one of the constants when I got side tracked into particle physics and had the question I started this thread with.

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2 hours ago, captcass said:

Very clear, thank you.

And as it descends, its clock ticks slower. So the outside observer at rest in relation to the gravity field sees the rocket's clock continue to tick slower at an accelerating rate as it also appears to accelerate in velocity, right? Does that relate to what we see in stellar systems where planets that are closer to the star and deeper in the gradient also have slower tick rates and higher velocities? This is exactly what I have been researching, trying to gather a perspective that makes the relationships clear. I was researching one of the constants when I got side tracked into particle physics and had the question I started this thread with.

As far as planets orbiting stars goes, the equation for an orbiting clock would give the time dilation for any given planet as measured by a distant observer. (As long as you are dealing with circular or nearly circular orbits,  adjustments would have to be made to deal with highly elliptical ones.   Of course for most normal stellar systems this going to be a very small effect  (for the Earth it works out to be about a difference of 1/2 sec per year.) And since our detection of extra-solar planet are by indirect means (measuring it parent star's wobble or it's transit in front of the star) and not direct observation of light from the planet, this is not something we presently would measure.

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3 hours ago, Janus said:

As far as planets orbiting stars goes, the equation for an orbiting clock would give the time dilation for any given planet as measured by a distant observe

Thank you. I see that and the extremely small difference in apparent tick rate, especially since the velocity differences between the planets seem so large when viewed as being elliptical orbits around the sun.

So I stepped back and looked at the differences in the velocities when viewed as spirals as the solar system moves forward relative to the CMB. From that perspective the differences in the velocities are in the .01 - .001 range and as we move out from the sun the velocities slow and approach the base velocity of the sun itself.

What got me thinking along these lines is that Einstein translates the differences in the clock rates into angular deflection and velocity. He calls these his "energy" components. So even though GR is based on the EP and the constancy of c, the apparent effects in time should also appear to manifest as a flow in the forward direction of time. That forward direction in a gravitational field is in the direction of the slower frames. This would account for the fact that gravity only has one direction and that it overpowers the other forces so much.

I am not saying GR is wrong. I am saying there is also a virtual flow in the direction of time that fits with the results of GR.

So that is why I asked if you thought there could be a relationship there.

Thanks everyone for the feedback, clarifications and links. I Don't know what else to ask at the moment.

 

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2 hours ago, captcass said:

There is no such thing as a particle..... :) 

For instance, this is from a paper on ArXiv, a respectable source, "Event ontology in quantum mechanics and downward causation"

"Concrete reality accessible to our senses is constituted by events
localized in space-time.That is, by certain entities that occupy a small region of space-time"
It concerns perception and downward causation, but I don't think that can be discussed here as it is speculation unsupported by math. It is an attempt to determine a common terminology, but also perception.
.

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13 minutes ago, captcass said:

For instance, this is from a paper on ArXiv, a respectable source, "Event ontology in quantum mechanics and downward causation"

You could provide a link. But it doesn't, from the title and quoted extract, appear to have any relevance to energy conservation.

 

2 hours ago, captcass said:

There is no such thing as a particle.....

"There are no fields only particles": https://arxiv.org/abs/1204.4616

"Fields and their particles": https://profmattstrassler.com/articles-and-posts/particle-physics-basics/fields-and-their-particles-with-math/

"Virtual particles: what are they?": https://profmattstrassler.com/articles-and-posts/particle-physics-basics/virtual-particles-what-are-they/

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1 hour ago, Strange said:

appear to have any relevance to energy conservation.

not saying it does. Just making a point.

 

1 hour ago, Strange said:

There are no fields only particles":

That is why the mentioned paper is trying to establish an ontology. You say tomato......

Anyway, not a continuation of this thread......

For anyone interested, here is a link to the arXiv paper. I hven't finished it yet, and do not intend to discus it in this thread when I do, but I am enjoying it so some here might. too.

https://arxiv.org/abs/1605.07531

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On 3/1/2018 at 11:36 AM, captcass said:

using natural units where c = 1= ħ, we can deduce that   2*10-16 m = 1 / GeV.

This was in my original question. Without re-reading it all, I don't believe anyone noticed (as I didn't when I posted it, duh) that it is in "natural units". To find the answer in the correct units, the c and h-bar elements have to added back in.

I think this would have been the correct reply to my question.

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Posted (edited)
52 minutes ago, captcass said:

This was in my original question. Without re-reading it all, I don't believe anyone noticed (as I didn't when I posted it, duh) that it is in "natural units". To find the answer in the correct units, the c and h-bar elements have to added back in.

I think this would have been the correct reply to my question.

Natural units as in pink unicorn urine per cubic cm? 

Edited by koti

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