# The Naked Scientists Forum

### Author Topic: What controls time dilation?  (Read 17746 times)

Post by peppercorn click to view.

#### peppercorn

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##### What controls time dilation?
« Reply #50 on: 23/11/2010 16:38:36 »
Shrunk
You are just complaining all the time "don't post this stuff", "post diagrams"
This is how really fast moving black body radiates...
Er, Thanks!
Why have you drawn the majority of the radiation's vectors heading in the same direction of the objects movement?  That's definitely not right.

Post by jartza click to view.

#### jartza

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##### What controls time dilation?
« Reply #51 on: 24/11/2010 04:14:45 »
Shrunk
Why have you drawn the majority of the radiation's vectors heading in the same direction of the objects movement?  That's definitely not right.

It is right!!

So when a moving black object radiates, the radiation's center of mass moves at the same speed as the object moves.

Post by peppercorn click to view.

#### peppercorn

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##### What controls time dilation?
« Reply #52 on: 24/11/2010 11:31:18 »
Shrunk
So when a moving black object radiates, the radiation's center of mass moves at the same speed as the object moves.

How can radiation (a photon) have a centre of mass? First it has no mass and second it follows a linear track (in 4D spacetime, before you say anything!) - so 'centre' means what?
The photon has a vector, but I think you need to learn vector addition (in this case the object's vector and the photon's) before re-sketching. There is the added complication of observer-relativity for luminal(?) particles, that will require further explanation.

Post by jartza click to view.

#### jartza

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##### What controls time dilation?
« Reply #53 on: 24/11/2010 14:13:15 »
Shrunk
How can radiation (a photon) have a centre of mass? First it has no mass and second it follows a linear track (in 4D spacetime, before you say anything!) - so 'centre' means what?
The photon has a vector, but I think you need to learn vector addition (in this case the object's vector and the photon's) before re-sketching. There is the added complication of observer-relativity for luminal(?) particles, that will require further explanation.

Would you draw me a diagram, pretty please?

« Last Edit: 24/11/2010 14:46:03 by jartza »

Post by peppercorn click to view.

#### peppercorn

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##### What controls time dilation?
« Reply #54 on: 24/11/2010 15:02:04 »
Shrunk
Would you draw me a diagram, pretty please?
No, but I can say it easily in words: 'The radiation's vector will be, on average, perpendicular to the surface from which it leaves the object.'  For your box (we'll assume it's perfectly flat sided) that's (averagely) at a right angle from each side.  It doesn;t matter how fast it's going, this holds true.

How can radiation (a photon) have a centre of mass? First it has no mass and second it follows a linear track (in 4D spacetime, before you say anything!) - so 'centre' means what?
The photon has a vector, but I think you need to learn vector addition (in this case the object's vector and the photon's) before re-sketching. There is the added complication of observer-relativity for luminal(?) particles, that will require further explanation.
Are you going to explain any of this? Or learn any of the science you need to?

Or shall I just lock the thread?

Post by jartza click to view.

#### jartza

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• Posts: 230
##### What controls time dilation?
« Reply #55 on: 24/11/2010 16:01:36 »
Shrunk
[:0]peppercorn is a moderator [:0]

See this video peppercorn:
Laser gun points one way, laser ray goes completely different direction, because of the fast motion. Surely all types of radiation do the same.

#### peppercorn

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##### What controls time dilation?
« Reply #56 on: 24/11/2010 16:39:02 »
See this video peppercorn:
Time Dilation - Albert Einstein and the Theory of Relativity
Laser gun points one way, laser ray goes completely different direction, because of the fast motion. Surely all types of radiation do the same.

So this:

Was meant to represent the idea in the video ...No wonder I had no idea what you were talking about!
So the the last half-dozen messages have basically been about something that every scientist already accepts, Oy Vey!
« Last Edit: 05/12/2010 11:28:55 by peppercorn »

Post by jartza click to view.

#### jartza

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• Posts: 230
##### What controls time dilation?
« Reply #57 on: 26/11/2010 03:04:10 »
Shrunk

If the mass of the radiation is 1% of the mass of the disk, then the spinning energy of the radiation is 1% of the spinning energy of the disk, and the angular momentum of the radiation is 1% of the angular momentum of the disk.

#### peppercorn

• Neilep Level Member
• Posts: 1466
##### What controls time dilation?
« Reply #58 on: 26/11/2010 11:04:29 »
Here is a spinning black disk radiating some radiation. Etcetera, etcetera, etcetera.

It's interesting that you've drawn two (well made a second copy).
Maybe you could enlighten us with a diagram at time T and another at time T+1.  Do you understand this sort of concept?

#### yor_on

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##### What controls time dilation?
« Reply #59 on: 09/12/2010 09:49:16 »
What controls time dilation?

'Room time geometry'

To you the time always 'tick the same', but as you 'propagate' :) or 'move' your 'room time geometry' will 'contract' for you, making all distances shorter and also 'speeding up' the universe, relative your wristwatch. The only 'real' effect that you will see though is the 'Lorentz length contraction'. That is due to that your 'time', always, will seem 'as usual', making it very hard for you to decide whether the universe 'really' have 'speeded up' or not. Or expressed another way. If your 'times arrow' doesn't change for you, then you can't speak of a 'time dilation' from your perspective, (aka 'frame of reference'). Simple as that.

And it's mass, momentum, relative mass and motion that warps your 'room time geometry'. Either of them will do, as long as we are discussing 'matter'. Light though, light is weird.
=

ah, thinking of it, you will see some 'relative' light effects too as you look out the window. and just to emphasize :) Time is always 'as usual', from all frames of reference. And there is no way you, ever, will notice your time 'change'. The 'time dilation' exist in a conceptual mind-space where we, from assuming a 'universal equally large amount of time ticking', find it to differ when 'comparing' frames of reference. Thinking that way may help to understand that the strangeness we perceive doesn't lie in the way the universe 'works' but in our perception of 'reality'.
« Last Edit: 09/12/2010 10:01:18 by yor_on »

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##### What controls time dilation?
« Reply #59 on: 09/12/2010 09:49:16 »