Physics Help Forum Question about Time

 Special and General Relativity Special and General Relativity Physics Help Forum

 Dec 20th 2016, 10:31 AM #1 Junior Member   Join Date: Dec 2016 Posts: 2 Question about Time I’m writing a philosophy paper and need a little help with some maths on Time. To use the example within the documentary “The Illusion of Time” (Example Link: https://www.youtube.com/watch?v=YRwZ55zjzxc - Example illustrated From: 24:15min – 26:50min in the vid). The presenter explains how if we are standing at Point “A” (lets say us on earth), and an Alien is standing at Point “B” 10 billion light years away from us, that if the alien gets on a bike and starts riding away or towards us at a speed then the Aliens perception of “NOW” time would change possibly as drastic as being 200 years in the future or past, depending on the direction the Alien was to ride. My question is, while I’m sure there isn’t a simple equation… is there possibly a simple equation that can help explain this effect? Possibly an equation that shows, if the distance between point A and point B is “X” distance, and the Alien at point B moves directly further away (being a positive speed), or closer towards (being a negative speed), over a total distance of “Y” then when the Alien stops moving how much would it’s “now” time have change (in terms of seconds) compared to the person who stayed still at Point A. I'm no physicist but I'd really like to find a simple way of explaining this phenomenon and showing it's working through numbers to use within my paper about Time and our perceptions of it. If anyone out there can help that would be amazing!!!! Many thanks, - Anthony
 Dec 20th 2016, 10:42 AM #2 Senior Member   Join Date: Aug 2010 Posts: 331 Accidental double post. Last edited by HallsofIvy; Dec 22nd 2016 at 06:09 AM.
 Dec 20th 2016, 10:46 AM #3 Senior Member   Join Date: Aug 2010 Posts: 331 I think you are referring to the "Lorentz transformation": If A is moving at speed v relative to B then A measures time elapsing at a rate equal to $\displaystyle \frac{1}{\sqrt{1- \frac{v^2}{c^2}}}$$\displaystyle \left(t- \frac{vx}{c^2}\right)$ where t is the rate at which B measures time elapsing.
 Dec 20th 2016, 12:12 PM #4 Junior Member   Join Date: Dec 2016 Posts: 2 Thanks for that - I think we're on the right track ... with the Lorentz transformation, for my limited understanding in its basic formula it more so shows what B's perception of time would be when in a similar space or when visualizing a similar space as A, but while B is traveling at a different speed to A. Any ideas how i might account for a different distance between them? In the documentary they show how over a large distance a very small speed can change the perception of time quite greatly. I guess I'm still having trouble figuring out how to calculate that side of things. Thanks for the help so far
 Dec 21st 2016, 09:04 AM #5 Senior Member   Join Date: Jun 2010 Location: NC Posts: 393 Non-relativistic Time Hi, There are some other aspects of time. 1.21 Events and Time | THERMO Spoken Here! Perhaps this will be of value. JP
 Mar 30th 2018, 01:08 AM #6 Member   Join Date: Mar 2018 Location: Xinhui Guangdong Province China Posts: 60 the real fourth dimesion of cosmos The Real Fourth Dimension of Cosmos I suppose that a straight line in the real cosmos is a so-called extension line and we use homogeneous coordinate(X1,X2) to represent a point on it in my second article The Appropriate Mathematics to Explain Cosmos(Physics). Next, let’s calculate the differential quotient against X2. Pay attention please, not against time t. Here X2 is a variable quantity. X=X1/X2 So, dX/dX2=(X2dX1/dX2-X1dX2 /dX2)/X2²= -X1/X2² = -X/X2 So, X = - X2dX/dX2 Also, X = ∫Vdt We arrive at ∫Vdt = -X2Vdt/dX2 So t = -X2dt/dX2 So ( 1/(t+C)) dt = - (1/X2)/dX2 = (i²/iX2)diX2 Here c is an integration constant, and i is the imaginary unit. We can see X2 is the real fourth dimension of cosmos, and time t is abstraction by people, just as Einstein said. When representing a point in the three dimension space, the homogenous coordinate is (X1,X2,X3,X4) , the symbol of the real fourth dimension change from X2 to X4. Where is the so-called fifth dimension? Chen Li Qiang March 12, 2018 From Xinhui Guangdong Province, C

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