[peppercorn]

One way to accelerate a flywheel is to put it in a rocket. In the rocket a clock slows down because of time dilation, and the flywheel slows down because of Coriolis force. If we eliminate the Coriolis force, a person with his brain slowing down observing a flywheel that is not slowing down, will say that "this flywheel is speeding up".

No he won't. if "his brain is slowing down" - you mean he is in the rocket too, yes? But the flywheels being exposed to the same time dilation as the astronaut so his observation of it would be as normal.

If the flywheel were back on Earth and slowing (although I'm not certain how this would be down to the Coriolis effect), he might observe no change in its speed if the acceleration of his ship was just acceleration of his right.

[jartza]

No he won't. if "his brain is slowing down" - you mean he is in the rocket too, yes? But the flywheels being exposed to the same time dilation as the astronaut so his observation of it would be as normal.

If the flywheel were back on Earth and slowing (although I'm not certain how this would be down to the Coriolis effect), he might observe no change in its speed if the acceleration of his ship was just acceleration of his right.

Here's a method to accelerate a spinning disk:
You place the disk horizontally. Under the disk there should be an "under disk"
The under disk must always spin like the upper disk, sensors and motors take care of that. Then there is a mechanism that gives every part of the upper disk regular kicks, this "kick unit" is attached to the under disk. Now we have managed to produce such kicks that don't affect the spinning of the upper disk.

...And this way time dilation effect is eliminated from the spinning of the disk.

[peppercorn]

Here's a method to accelerate a spinning disk:
You place the disk horizontally. Under the disk there should be an "under disk"
The under disk must always spin like the upper disk, sensors and motors take care of that. Then there is a mechanism that gives every part of the upper disk regular kicks, this "kick unit" is attached to the under disk. Now we have managed to produce such kicks that don't affect the spinning of the upper disk.

...And this way time dilation effect is eliminated from the spinning of the disk.

This may be too far beyond my intellect, but I've really no idea what this device is or what relevance it has to time or its modulation.

I may regret suggesting this, but how about a diagram?

[jartza]

This may be too far beyond my intellect, but I've really no idea what this device is or what relevance it has to time or its modulation.

I may regret suggesting this, but how about a diagram?

Here is very simple device:
A spinning hotplate. (we call it SH) (the hotplate is hot)
This device exerts radiation pressure and radiation torque on objects.
Let's say SH is exerting radiation torque on an object that is free to spin. The object starts to spin to the same direction as the SH, this spinning is slowly accelerating. When the SH and the object spin at the same rate the torque that SH exerts on the object is zero. Now SH is exerting on the object radiation pressure, but no radiation torque.

SH can be used to accelerate spinning objects without disturbing the spinning, by adjusting the SH so that torque is zero .

[Bill S]

And this way time dilation effect is eliminated from the spinning of the disk

In which F of R is the time dilation effect eliminated?

[peppercorn]

Let's say SH is exerting radiation torque on an object that is free to spin.

One of these?
http://en.wikipedia.org/wiki/Crookes_radiometer

All these 'devices' are lovely, but they seem to have little to do with time or effects on it.
Please stick to the thread (if you must at all).

[jartza]

In which F of R is the time dilation effect eliminated?

Any F of R. Not accelerating F of R though.

[jartza]

One of these?
http://en.wikipedia.org/wiki/Crookes_radiometer

All these 'devices' are lovely, but they seem to have little to do with time or effects on it.
Please stick to the thread (if you must at all).

Quit fretting []
'Device' 2 is the same device as 'device' 1.
By device 2 if was clarifying device 1 for you.
So here's device 2:
Spinning hotplate emits photons, that carry angular momentum to a black object, that experiences torque.

[peppercorn]

One of these?
Quit fretting []
'Device' 2 is the same device as 'device' 1.
By device 2 if was clarifying device 1 for you.
So here's device 2:
Spinning hotplate emits photons, that carry angular momentum to a black object, that experiences torque.

Again, perhaps diagrams have a chance to 'illuminate' me and any others not so able to make the, erm, intuitive jumps.

[jartza]

Again, perhaps diagrams have a chance to 'illuminate' me and any others not so able to make the, erm, intuitive jumps.

You are just complaining all the time [] "don't post this stuff", "post diagrams"
This is how really fast moving black body radiates:

[diagram=610_0]

So how does a really fast spinning black disk radiate?

[peppercorn]

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.

[jartza]

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.

[peppercorn]

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.

[jartza]

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?
 []

[peppercorn]

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?

[jartza]

 [:0]peppercorn is a moderator [:0]  []

See this video peppercorn:
http://video.google.com/videoplay?docid=-6173480890398763094#
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]

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:

[diagram=611_0]

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! []

[jartza]

[diagram=612_0][diagram=612_0]

Here is a spinning black disk radiating some radiation.
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]

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]

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'.