Inflation and curvature
- Thread starter prometheus
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Arf, I have to ask what the answers are to your two questions. If an object is in free fall it is being accelerated by gravity. So an observer at rest relative to the accelerated clock (not in a gravitational field on the surface) would see the clock as running slower due to its relative acceleration I would think. But the observer on the surface is in a stronger gravitational field ... I'm going to guess that he would see the falling clock running faster than the clock in his reference frame. I don't understand the reference to "maximum" rate?
Ok, you've got me - I'm not actually Spartacus. Damn, you're good!
Vapid ad hominems? You've left out the minor little detail that Guest's assessments of people tend to be quite accurate. You've managed to build up a seriously warped impression of the guy. It seems obvious to me you're still sore over the gravitation threads. You have no other reason to react the way you do toward him.
Or maybe he's just not as insecure as you think he is...? So far you've shown yourself to be a pretty poor judge of people's character and motivations.
What I can't believe, is that Farsight was not all over this, using his physics reasoning abilitites to defend his "speed of light" varies in a gravitational field concept??:shrug:
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quantum wave said:
1) If the clock is in free fall (not experiencing a force of gravity) what's the potential?
In free fall the clock, as a rigid body, is in equilibrium--its acceleration towards the centre is the same as the local gravitational constant g--so the force of gravity is 'canceled' by the acceleration of the clock.
The potential will change if the distance to the centre, R, changes. If the clock is in a stable orbit which is nearly circular the potential won't change--this is more true for a clock orbiting a black hole, and gets more true as a black hole gets larger.
2) Does an observer on the surface see a clock in free fall as running at "maximum" rate?
Again, for a clock in a circular orbit the potential is constant so it will run more slowly than if it was in empty space, but faster than if it was on the surface. It will run 'freely' at the rate determined by the gravitational field at that distance, and its internal dynamics.
More questions:
Will the clock in "empty" space slow down if it accelerates? Will it speed up if its velocity decreases, and what if the velocity approaches zero in a free vacuum?
You're entitled to your opinion, even if it surprises (or disappoints) me. And the notion that I "don't like" Guest because he's critical of me is absurd. I intellectually wrestle with many members on this forum, you included, and I believe I continue to show most people respect.przyk said:
FYI, I've received a couple of PMs from lurkers (none of who have been mentioned in this thread) that agree with me 100% that Guest contributes very little to the demeanor of the culture of the site.
Whatever...I'm dropping the subject. Caustic personalities like Guest would probably love all of this attention so I'll just go back to ignoring him.
I've been tied up on the house, Magneto. Decorating, gardening, that kind of thing. I'll take a look.
RJ: Guest is an abusive troll who contributes zip.
Yeah, like that time he just proclaimed himself a world leading expert in things like electromagnetism, that his work was worth several Nobel Prizes, that all his detractors would one day be teaching his work, that he had the one true understanding of Einstein's work (despite not knowing the details or understanding the mathematics and being contradicted explicitly by what Einstein said), that he had a model of nature which couldn't model anything and he replied to a challenge about his claims by commenting he could beat anyone in an arm wrestle.
Oh sorry, that's you I'm describing! How silly of me to get you confused with a troll. All those behaviours of yours clearly make you beyond reproach!
Guest might be abrasive but he's said more valid physics and maths here than you ever have. You and Magneto suffer from similar problems, you think that providing BS counts as providing something better than nothing. Someone who says 1+1=2 contributes more valid and worthwhile physics/maths than someone providing 100 pages of nonsense they made up which failed (or would fail if submitted) peer review.
If you want your claims evaluated without all the commentary stick to submitting to journals and stop making said claims on forums. But you've already done that and you got rejected from all of them. If you had done work which was worth publishing maybe you'd not be stuck on forums whining about the injustice of it all.
Managed to come up with a single phenomenon in physics you can model yet? Must be a bit cheesing, having work which is less applicable than string theory
Sorry, I'm playing catch-up here. I can see that RJB has responded, but I feel I owe you a reply too. Just remember this: where gravitational potential is lower, clocks go slower. Gravitatational potential is lower nearer the surface of a planet, and as RJB said, there a bit of confusion in the way gravitational potential is said to be zero an infinite distance from a planet.
It isn't like that. The strength of the gravitational field is a measure of the local gradient in gravitational potential. Have a look at wiki to get a handle on it. Gravitational potential is lowest in the middle of the "upturned hat" on the right. The degree of slope at any one point indicates the strength of the force of gravity at that location.
Yes and no, this is the principle of equivalence, but it's important to remember that the clock on the surface of the planet is undergoing acceleration, not the clock in free fall. It can get a bit confusing, so IMHO it's best to focus on gravitational potential rather than accelerating clocks.
Discouraged? Not at all, Magneto, I like to engage. Thanks for the compliment by the way. See above re potential, I do recall having this back to front before now, c'est le vie, that sort of thing happens quite a lot in physics. Re the speed of light varies in a gravitational field:
Fair enough.
Agreed.
Yes, gravitational fields are everywhere, but I don't think that's a real problem. I'd say the interpretation is the real problem, and that Robert Close's The Other Meaning of Special Relativity solves the problem.
OK.
I might quibble about historical detail, but fair enough.
Thanks for that. I'll look into it properly.
I'm not sure about the 1917, but I'd say that's what's generally accepted today. And it's wrong. Frequency doesn't change.
Make that proper-time clock a parallel-mirror light held to disregared radial length contraction flat clock to see my POV. The light goes slower so the clock ticks slower, so the frequency appears to have increased and wavelength appears to have decreased. Conservation of energy applies.
I'm not quite happy with weak and strong gravitational fields here and would prefer to stick with low and high potential, or maybe light going towards or away from a black hole. But I catch the drift.
It does, but IMHO it doesn't address the issue of why, or why we observe the frequency to be red or blue shifted.
Sheesh, look at the time. Bedtime.
I think that's only true if the clock in free fall is in an inertial frame.Farsight said:
If it's orbiting a planet (it's a GPS satellite, say), then it's accelerating continuously towards a COG.
The principle of equivalence is really only valid in free space--whatever that is. It seems that "free" space has to include at least one material object that can accelerate for the principle to be testable--massless objects don't work.
Thanks to Farsight who addressed my questions and corrected me on the difference between gravitational potential and the strength of a gravitational field, and to Arf for helping keep us straight on free fall in orbit being accelerated toward the COG.
This may be off topic but is the concept of free space similar to an object in deep space like Newton's bucket?
This may be off topic but is the concept of free space similar to an object in deep space like Newton's bucket?
Oh come now - don't drop the whole conspiracy thing, you were so keen earlier!
Haters gonna hate... (I didn't see myself ever using that phrase!)
First, "Wrong" is a very strong term. You don't have to be "AlphaNumeric." I am not an abusive person like he is. The challenge that he has invited me into, and the language that I use in those post, is not a good representation of my character. AlphaNumeric's words push my buttons so hard, that self control goes right out the window, and I can't help myself, but to "Retort in Kind!"
Secondly, It seems a little strange to me that you call me wrong, by stating that "Frequency doesn't change" then you admit later that "frequency appears to have increased and wavelength appears to have decreased."
So, which is it, does the frequency of light in a gravity field change? Yes or no?:shrug:
I believe that you have theory, that you don't fully grasp yourself!!
What???:shrug:
Good catch, I wanted to put in potential, but thought that field strength would help to clarify. I will add a fourth bullet:
Ok, so what happens to light in a gravitational field:
1) In a "Strong" gravitational field near the event horizon black hole:
a) The Frequency increases or blue shifts
b) The Wavelength decreases or gets smaller
c) The Proper Time Clock ticks at a slower rate. Meaning that if the normal clock is not in a Gravity field it takes an event ten (10) seconds, then drop that same clock in the strong gravity field that same event could take fifteen (15) seconds.
d) A "Strong" gravitational field whose strength is defined by ($$\frac{1}{r^2}$$) is represented conceptually in a gravity field by the term "Lower Potential"
2) In a "Weak" gravitational field far away from the event horizon black hole:
a) The Frequency decreases or red shifts
b) The Wavelength increases or gets longer
c) The Proper Time Clock ticks at either a faster or normal rate. Meaning that if the normal clock is not in a Gravity field it takes an event ten (10) seconds, then drop that same clock in the weak gravity field that same event could take eleven (11) seconds or event ten (10) seconds as if there were no gravity field present.
d) A "Weak" gravitational field whose strength is defined by ($$\frac{1}{r^2}$$) is represented conceptually in a gravity field by the term "Higher Potential"
The problem with using this term gravitational potential is that some consider the gravitational potential to be a measure of intensity or strength of the field. While others consider the gravitational potential to be determined by the (Plus (+) or Minus (-)) sign of the gravitational potential energy. Some use the Minus (-) religiously while others not so much!
What is your concept, theory, or understanding for why we observe the frequency to be red or blue shifted?
Edit: Removed this form of the equation because it was found to be controversial by AlphaNumeric
($$\frac{1}{r^2} = \frac{1}{\mathbb{R}^{3}} = \frac{1}{S^2_{Sph}$$)
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You haven't retorted in kind. If you were to retort in kind you'd provide viable mathematics and physics, backed up with references to reputable journals and books and show understanding of the material of which you speak. Instead you've responded only part 'in kind', ie insults (or attempts at insults in your case).
Yes, I liberally sprinkle my replies with insults when I feel the other person is deserving of them. But my replies actually involve correct maths and physics, maths and physics I understand. You and Farsight choose to only see the insults so you can insulate yourself from the corrections I make of your claims, else you'd have to face up to your short comings.
I've already corrected you on this twice in another thread. I now see what your misunderstanding is, you don't know what $$\mathbb{R}^{3}$$ means.
I'll go into it over in the thread, since it's relevant there.
Suffice to say that the fact you continue to use notation you've been told is incorrect and that you haven't bothered to check shows your dishonesty. A bit like Farsight constantly wheeling out "String theory doesn't model anything in the real world".
Sorry Magneto, I didn't mean to sound rude.
No. Conservation of energy applies. Think about it - you've got a photon in a region of space, with no other particles or waves present. If it really did increase its frequency, where did the extra energy come from? Newton knew it wasn't action-at-a-distance. There are no actual gravitons rattling around. So the answer is nowhere. Now think gravitational time dilation, which is demonstrable, and reason that you and your clocks are moving slower in a region of low gravitational potential. Hence at that location, it looks to you as if the photon frequency is higher.
The parallel-mirror light clock is a clock that moves slower in a region of low gravitational potential. You hold it flat to avoid worrying about radial length contraction so the metre is unchanged.
Noted, Magneto.
Yes, we see a lot of confusion about this.
We are subject to an immersive scale-change. In a region where gravitational potential is low, everything goes slower, be it a clock or a brain. Because light goes slower. Hence the parallel-mirror light-clock goes slower too. Think of a train of light waves moving at c in this direction → like this /\/\/\/\/\/\, something like a concertina. Now reduce c, and it's like squashing the concertina. See post 105 where I gave Einstein quotes regarding c and GR.