On 21 Jun 2005 18:35:54 -0700, "Steven"
wrote:

I got it!

The distance changes based on the frame of reference.

If from the perspective of the stationary object, the two objects have
just separated by distance d, then from the perspective of either of
the moving objects, the distance has only increased by a fraction of d.
Length constriction makes the distance seem to be much smaller. It's
like saying 10 miles in one frame of reference is only 5 miles in
another.

Does that sound right?

Kinda. But the clocks used to measure speed change also!


the softrat
Sometimes I get so tired of the taste of my own toes.

--
When everything is coming your way, you're in the wrong lane. --
Steven Wright

On Wed, 22 Jun 2005 18:48:05 GMT, Aristotle
wrote:

On 21 Jun 2005 16:20:18 -0700, "cirejcon" wrote:



Steven wrote:
I'm sure this question has been asked many times before, but here
goes...

If two objects are moving in opposite directions, and both are moving
at .9c relative to a stationary object, how is it that their speeds
relative to each other do not surpass the speed of light?

In cases like this, you have to be very precise about the term
"relative velocity". You might mean how fast the distance
between the two objects is changing in your frame of reference.
This is referred to as the "closing velocity", and in this case
it would be 1.8c, as you would expect. The other definition is
1.8c?

Have you taken any physics courses?

Who gives a ****, 'Aristotle'???

He is welcome to our knowledge!


the softrat
Sometimes I get so tired of the taste of my own toes.

--
When everything is coming your way, you're in the wrong lane. --
Steven Wright

"the softrat" wrote in message
...
| On Tue, 21 Jun 2005 21:49:18 +0000 (UTC), "Martin Hogbin"
| wrote:
|
|
| "Steven" wrote in message
ups.com...
| I'm sure this question has been asked many times before, but here
| goes...
|
| If two objects are moving in opposite directions, and both are moving
| at .9c relative to a stationary object, how is it that their speeds
| relative to each other do not surpass the speed of light?
|
|
| Because space and time are not like you think they are.
|
| Martin Hogbin
|
| That is a non-responsive answer!
|
| As measured by this Third Observer, their relative speed is 1.8c. As
| measured by each other, their relative speed is 1.8c/1.81 which is
| approximately 0.9945c.

That's because their Speedo's are at the stop. I had this with my old motor
bike 40 years ago I was doing about 120 (that near c ain't it ? anyway it
felt like it ) and my Speedo was only showing 90. That was nearly before
Einstein had brought in speed limits and it hadn't gone through parliament
so I was not breaking the law. Modern rubbish... young tykes... mumble..
mumble.... snore. Hu! clocks you had no time to read clocks at 120 do you
think I'm daft.... snore

| However notice that there is this Third
| Observer. Relative to Him, neither object moves faster than c, nor
| does any object relative to another object move faster than c. As far
| as the Theory of Relativity is concerned, the Third Observer is
| irrelevant. The theory is concerned with what two observers measure
| with respect to each other.
|
| Note well that the three different observers get two different
| answers.
|
| HTH,
|
| the softrat
| Sometimes I get so tired of the taste of my own toes.
|
| --
| It's like pushing a car uphill with a rope.