Does velocity really dilate time?

Uclock · Post by **Uclock** » Mon Mar 19, 2007 11:17 am

Hi all

Is there any proof that velocity causes time to dilate? In other words has there ever been an experiment on time dilation where no acceleration is involved?

Tony

ckam · Post by **ckam** » Thu Mar 29, 2007 11:51 am

yep, unstable particles running in circles at near-light speed tend to live longer than their friends at rest. Nereid once claimed that you yourself can make this experiment at home using cosmic rays. edit: I have just noticed "acceleration" in your post. well, circles have to go, but cosmic rays should work for you.

harry · Post by **harry** » Thu Mar 29, 2007 12:53 pm

Hello cham

That is not time dilation, but a physical change.

Uclock · Post by **Uclock** » Thu Mar 29, 2007 1:09 pm

ckam

yep, unstable particles running in circles at near-light speed tend to live longer than their friends at rest. Nereid once claimed that you yourself can make this experiment at home using cosmic rays. edit: I have just noticed "acceleration" in your post. well, circles have to go, but cosmic rays should work for you.

Ah, but unstable particles running in circles at near-light speed are experiencing acceleration, firstly they are accelerated to near-light speed then they experience centripetal acceleration as they are kept in position. Cosmic rays striking the upper atmosphere cause acceleration to the pions they produce which quickly decay into muons that deccelerate through the atmosphere so they also involve acceleration.

Tony

harry · Post by **harry** » Fri Mar 30, 2007 4:44 am

Hello Uclock

You said

Ah, but unstable particles running in circles at near-light speed are experiencing acceleration, firstly they are accelerated to near-light speed then they experience centripetal acceleration as they are kept in position. Cosmic rays striking the upper atmosphere cause acceleration to the pions they produce which quickly decay into muons that deccelerate through the atmosphere so they also involve acceleration.

So!!!!! What are you trying to say?

Uclock · Post by **Uclock** » Fri Mar 30, 2007 11:00 am

Hi Harry

All I am saying is that there is no 100% proof that velocity causes time dilation because all time dilation experiments involve an element of acceleration and it may be that it is purely the acceleration that causes the time dilation and not the relativistic velocity.

Tony

harry · Post by **harry** » Fri Mar 30, 2007 11:14 am

Hello uclock

Sorry mate. Now I understand and agree with you 100%

makc · Post by **makc** » Fri Mar 30, 2007 12:51 pm

it's like saying we can't prove that cyanide kills because there is always some % of admixture in it.

harry · Post by **harry** » Sat Mar 31, 2007 9:02 am

Hello All

Some links on time dilation

http://www.phys.unsw.edu.au/einsteinlig ... n.htm#true

http://www.phys.unsw.edu.au/einsteinlig ... aradox.htm

I had few more cannot find them.

Uclock · Post by **Uclock** » Wed Apr 04, 2007 12:25 pm

Hi makc

it's like saying we can't prove that cyanide kills because there is always some % of admixture in it.

A good analogy, but there is a difference here. It can be proven that acceleration dilates time if two atomic clocks and a centrifuge are used because the velocity would be negligible but as I understand it, no such experiment has ever been undertaken.

Tony

kovil · Post by **kovil** » Fri Apr 06, 2007 10:58 am

Uclock,

You may have proved your case already, as orbiting satellites have a time differentiation to the ground base station in the GPS system, and something had to be done to make the system work and give accurate answers, and there was a time differential problem of some sort. As the satellites are subject to acceleration by being in orbit, or are you seeing that at their velocity differential?

It may be subtle to separate acceleration from velocity, like trying to separate inertia from gravity. One may have to do the calculation from both directions and compare results, and see if there is any difference, and then decide which direction to look from to do the analysis in future.

harry · Post by **harry** » Mon Apr 09, 2007 3:09 am

Hello Kovil

Thats about right.