As someone with a brain, and it hurts, can we close this thread?

Nope!

When no, then no :-)
Sorry for reopening the brain hurting themes it again, but In the mean time I've read some related threads anf finally Solomon wrote (in "Lightspeed revisited-all egg heads in on this one!") exact what I was looking for (Es99 would probably too, if I'd ask for?).

Peter

Can I throw Bose-Eintein Condensates into the mix? These have been used to slow light down to 36MPH.

EEEK

If the ideas of relativity don't disturb you then you haven't understood them.

Lasers have also been used to speed light up past the 'speed of light', though it is a trick of where in the wave front the light 'particle' is. or wavicle??

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I love deadlines. I love the whooshing sound they make as they pass.

Can I throw Bose-Eintein Condensates into the mix? These have been used to slow light down to 36MPH.

EEEK

If the ideas of relativity don't disturb you then you haven't understood them.

Lasers have also been used to speed light up past the 'speed of light', though it is a trick of where in the wave front the light 'particle' is. or wavicle??

Yup My brain Hurts!

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I may just have to stop reading this thread, my head is KILLING me now....lol

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Air Cold, the blade stops;
from silent stone,
Death is preordained

Calm Chaos Forums : Everyone Welcome

I may just have to stop reading this thread, my head is KILLING me now....lol

Aspirin could be a good choice. LOL

Well if this re-opening doesn't get ES back nuffin will!

I'll 'ave a little cogitate and get back......I think....

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Shouldn't this really go the science boards, its a bit heavy for the cafe, I think its doing all our brains in.......

Why should they have all the fun?

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Why should they have all the fun?

Indeed.

Looks like someone else could do with a bit of cheering up????



;-)

Cute arn't they!

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If someone leaves their part of the Galaxy travelling towards us at 50% speed of light relative to their starting point, and we leave our part of the Galaxy and travel toward them at 50% speed of light relative to our starting point,are we travelling towards each other at lightspeed assuming both starting points are static in space relative to each other?

Sounds pretty logical so far.

No. We would be travelling towards each other at 80% of light speed. In special relativity velocities don't just add together. It would take too much work to justify the formula here; but, if you have some grasp of algebra, you can find plenty of books that derive what I will simply state. If you are sitting around and see one object moving towards you with speed u and a second moving towards you in the opposite direction with speed v, someone on one of those objects would see the second approaching with speed:

v' = (u + v)/(1 + uv/c^2)

So................. Those travelling at 50% the speed of light observe others travelling at only 40%. Is this where time dilation comes in, or where time passes more slowly for those at near light speed?

Shouldn't this really go the science boards, its a bit heavy for the cafe, I think its doing all our brains in.......

Surely you mean
"Those travelling at 50% the speed of light observe others travelling at only 30%" (50 + 30 = 80) This is simple arithmetic no wonder you don't get the algebra. hehehe

I'm assuming c in the equation is light speed and the equation looks about right to me. I will let you know when I plug some numbers in.

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I love deadlines. I love the whooshing sound they make as they pass.

I've plugged the numbers in and it don't work. I come up with 1,200,000 km/s which is 3 times the speed of light. Which is 300,000 km/s

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I love deadlines. I love the whooshing sound they make as they pass.

Revision ... it does work, the algebra is wrong. Algebra isn't wrong ... you do * and / before + ... I'm being an ass

It shouldn't be v' = (u + v)/(1 + uv/c^2)
It should be v' = (u + v)/(1 + (uv/c^2))

Which comes out at 240,000 km/s, or 80% light speed

Further breakdown v' = (150 + 150)/(1 + (150 * 150/ 300^2)) in 1000s of km/s
v' = 240 in 1000s of km/s

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I love deadlines. I love the whooshing sound they make as they pass.

It appears I'm running off at the mouth (fingers?) I've just never seen the equation for working out time dialation before. Just trying to learn something new.

I've had a think and this is how I see the universe...

What you maybe asking is 'why?' does time dialate. Other than saying it just does, we've measured it; it is a consequence of light speed NOT changing and being a fundamental constant. If light doesn't change speed (in a vacuum, of course) then space and time must. There are lots of fundamental constants and, as yet, humans are not clever enough to find the 'why these values?'. But we have found some 'definitely not these values'.

Space and time are not absolute but light speed, in a vacuum, is.

If Jack came past me at 50% light speed when I am 'stationary' at the same moment an explosion happened we would both agree thet the explosion did happen.
We would not agree on when it happened or where exactly it happened.

This is because my time is a function of Jack's space and time and likewise his time is a function of my space and time. Space and time cannot be seperated, they have to be looked at as functions of each other called, unimaginatively, spacetime.

If I could see a clock in Jack's spacecraft I would see the second hand moving slowly. It would look normal to him. If he could see a clock on my spacecraft he would see the second hand also moving slowly, although it would look perfectly normal to me.

Time does not exist for anything moving at the speed of light, although matter (anything with mass) cannot move at the speed of light. Light has no 'intrinsic mass' (I am not sure what non-intrinsic mass is other than E=mc^2 says matter = energy) and so travels at the speed of light. It has moments i.e. a photon leaves a star and enters my eye. I see the time interval (at least 8 light minutes, poss light years) because I am not travelling at light speed.

Light allways travels in straight lines but gravity can bend space so light follows the curves in space (poss. spacetime). A black hole bends space so much that light cannot escape. In the same way as throwing a ball into the air follows a straight line curved by gravity and the ball does not have enough velosity to escape so falls back to the ground. If you fell from the balls top point (ball moving from left to right), at the same moment, you would see the straight, horizontal line. Because we are 'stationary' we see a curve (parabola).

I keep using stationary in inverted commas because it is very hard to have a stationary object, poss. impossible. You are allways moving relative to something it's just hard to tell what. If I was falling at the same rate as the ball I would be stationary to the ball. It would still hurt when I landed. This is more important in day to day life. Balistics works 'cos everything we see/use is in the same gravity field.

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I love deadlines. I love the whooshing sound they make as they pass.

Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

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Can I throw Bose-Eintein Condensates into the mix? These have been used to slow light down to 36MPH.

EEEK

If the ideas of relativity don't disturb you then you haven't understood them.

Lasers have also been used to speed light up past the 'speed of light', though it is a trick of where in the wave front the light 'particle' is. or wavicle??

Laser is light right? so it don't matter if you can speed it up, it's still going the speed of light, just that light at the time :p

life is so easy when you're bottle blonde, not a care in the world.

and this "v' = (u + v)/(1 + uv/c^2)" looks like the value of my sun block. sheesh you cant pull the wool over my eye's

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I AM NOT FAT! I AM BIG-BONED!

Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

hmmm what was wrong with my post? it was saying the same, with the same type of squiggly lines, but my bit had more relevance, in that it proves people have heart attacks when the quarterly bills drop in the letter box. ;p
oh and you should go see what i ask Spit for advice on lol

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I AM NOT FAT! I AM BIG-BONED!

Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

hmmm what was wrong with my post? it was saying the same, with the same type of squiggly lines, but my bit had more relevance, in that it proves people have heart attacks when the quarterly bills drop in the letter box. ;p
oh and you should go see what i ask Spit for advice on lol

I have mud for Brain Cells, I try to keep my words down to 3rd grade english......

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Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

hmmm what was wrong with my post? it was saying the same, with the same type of squiggly lines, but my bit had more relevance, in that it proves people have heart attacks when the quarterly bills drop in the letter box. ;p
oh and you should go see what i ask Spit for advice on lol

I have mud for Brain Cells, I try to keep my words down to 3rd grade english......

did you read spits page on your team site?

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I AM NOT FAT! I AM BIG-BONED!

Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

hmmm what was wrong with my post? it was saying the same, with the same type of squiggly lines, but my bit had more relevance, in that it proves people have heart attacks when the quarterly bills drop in the letter box. ;p
oh and you should go see what i ask Spit for advice on lol

I have mud for Brain Cells, I try to keep my words down to 3rd grade english......

did you read spits page on your team site?

:-)

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Due to a recent post by Sammie, Fun with Gov't Meddling! I decided to bring this thread up again.......

hmmm what was wrong with my post? it was saying the same, with the same type of squiggly lines, but my bit had more relevance, in that it proves people have heart attacks when the quarterly bills drop in the letter box. ;p
oh and you should go see what i ask Spit for advice on lol

I have mud for Brain Cells, I try to keep my words down to 3rd grade english......

did you read spits page on your team [img] [/img] site?

:-)