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[monkeytroll]

[Puzzle] #245 - Silver [Maze Set] - Relativity

[Langley Moor]

W00t, knew my masters degree in physics would come in useful eventually!!! Will get onto this shortly, it's just a matter of length contraction - should take me about 10 minutes, but won't be able to do it til later this afternoon

[European Chris]

[European Chris]

Langley, how are you doing with this. I've also been (spoonfed) the relative velocity formula w=(Va+Vb)/(1+((Va*Vb)/c^2)).

Am I right in thinking that I have to find 'w' such that:

(1-(Va^2/c^2)/(1-(Vb^2/c^2)=25

It doesn't seem to factorise easily later on though. What are your thoughts?

[solitair]

OK, I reckon I'm going wrong somewhere which, given I haven't done this for a few years wouldn't surprise me in the least.

Anyway, I stand at:-

[Atrophied]

well, it does say "as a fraction of c", so I assume it has to be in a b/c format.

Your reasoning is perfect, I just (as in 5 minutes ago) confirmed the exact same thing with a spec relativity prof here at uni.

[Langley Moor]

*Nods*

I have the same working as Atrophied, so it could just be the method of entry - I'd suggest keeping it as fractions, but that's [ SQRT(24/25) ]c, which is irrational, so can't be right as a way of entering it..... I can't see any mistakes, but I'll have another look at it tonight if I get a chance. Am currently scrabbling around on the floor with bits of paper doing the 14-15 puzzle!

EDIT: I don't have this card btw, so I'm relying on other people to try entering answers at the minute. Only suggestion is 0.98c, i.e. without the space - that's the normal method of writing it.

[tomkirkman]

I think you have to assume that both are moving and that neither are seeing the true diameter of the disc. If that's a correct assumption then the formula EuropeanChris is using above should be correct.

I've found at least one possible solution to this equation which is where

[European Chris]

Bah, can the people who have put up the answer-or at least their working above put a spoiler on it. I've got the itch to solve this myself. Sorry if you haven't but I screamed like a girl a scrolled past it with my eyes closed. If you could leave any info if I'm on the right track though it would be well appreciated.

Oh Von's clue is:

[pickwick the second]

Elegant--possibly a reference to Brian Greene's book, The Elegant Universe? I've only just begun reading it...

[Ashin]

Take it from a physicist, you guys are on the right path, BUT, you are misreading the card so far....

BOTH of the scientists are moving at relativistic speeds.

They are looking at lengths, which solely revolves around the Lorentz equation.

Hope that's a big enough hint.

[European Chris]

Cheers Ashin, and thanks for spoilerising it guys. I've an ejaculatory urge to solve this myself.

[Atrophied]

Hmm, it doesn't explicitly say that they are both moving at relativistic speeds. However, if you have the card, and the points then you'd obviously know best. (You do have this card and the points, yes Ashin?)

[Ashin]

"What is the relative speed of the two observers as a fraction of the speed of light?"

I do not actually have the card (yet), but I am definitely 100% on my answer.

Also, I believe this card is written incorrectly, because in order for any calculation to work, both scientists have to be traveling perpendicular to the disc's axis. I'm about to send off an email to Mind Candy about this.

[Kvasir]