significance of 'c' (1 Viewer)

[clever angel]

hi ppl,

cna someone plzzz tell me what to write 4 this dot pt.

describe the significance of Einstein's assumption of the constantcy of the speed of light?

 

[wanton-wonton]

Einstein’s second postulate states that the speed of light in empty space always has the same value, c (3 × 108 m s-1), independent of the motion of the observer. In the thought experiment, Einstein realised that if both observers were to see the same speed of light, and since speed = distance/time, then the distance and time witnessed by both observers must be different.

In other words, if c is constant, then space(length)-time is relative, so to fully define where something is, 3 coordinates of space and time is required.

 

[Slidey]

3? Even thought there exists 3 spatial dimensions and 1 temporal dimensional (So far, heh)?

3+1=4?

 

[wanton-wonton]

3? Even thought there exists 3 spatial dimensions and 1 temporal dimensional (So far, heh)?

3+1=4?

What's that??

Anyway, it's not required at all, this whole dimension thing.

 

[richz]

Einstein’s second postulate states that the speed of light in empty space always has the same value, c (3 × 108 m s-1), independent of the motion of the observer. In the thought experiment, Einstein realised that if both observers were to see the same speed of light, and since speed = distance/time, then the distance and time witnessed by both observers must be different.

In other words, if c is constant, then space(length)-time is relative, so to fully define where something is, 3 coordinates of space and time is required.

hmm, i dont understand, what you mean by 3 coords of space and time

 

[wanton-wonton]

XYZ co-ordinates and time.

 

[Slidey]

What's that??

Anyway, it's not required at all, this whole dimension thing.

Er, considering you made reference to it in your post, and considering this is HSC physics... I would think you'd need to know what a dimension is and that you've got 4 of them, not 3.

 

[richz]

do u mean that it needs more coordinates to be more specific to where a person is??

 

[Slidey]

Basically, yeah. People say we are 3D, right? 3-dimensional. We can be located in a co-ordiante system by a set of co-ordinates: (x,y,z).

But we know that we also move through time, so that any coordinates (x,y,z) will NOT tell you where a person is, merely where they might be. You need a fourth co-ordinate, time to say exactly where a person is, because we also move through time.

So if you had all the co-ordinates (x,y,z,t) you would know where an object is.

This is, of course, relative to a specific frame of reference.

 

[acmilan]

Haha but then it gets more complicated and there can exist much more dimensions

 

[wanton-wonton]

Haha but then it gets more complicated and there can exist much more dimensions

That's something to do with the string theory, right? Well....surely....we don't need to know that stuff, purely out of interest only.

 

[wanton-wonton]

Er, considering you made reference to it in your post, and considering this is HSC physics... I would think you'd need to know what a dimension is and that you've got 4 of them, not 3.

There is four, I did say four.

"Three co-ordinates of space and time"

I think I know what you mean now, did you think I meant TWO co-ordinates of space and ONE time? Well I meant THREE co-ordinates of space and ONE time.