The equation of a circle [math](x-h)^2+(y-k)^2=r^2[/math] where (h,k) is the center and r is the radius. The equation of the circumference has no bearing on if it is or isn't a circle.

When a circle spins, the circumference shortens and the radius stays the same. Is a circle, spinning near c, still a circle?

Why does the circumfrence shorten when it is spinning?

Why does this deserve a poll?

relativity.

 

i want to see what the masses think about this. do you have a problem with that?

i want to see what the masses think about this. do you have a problem with that?

I don't see what the point of the poll is, seeing as it's not a matter of opinion, and the discussion itself is already underway.

 

I'm not interested in whether or not you think I have a problem.

so, what is the answer. you said it isn't a matter of opinion.

Yes I did, didn't I.

you didn't answer my question. what is the answer?

How should I know? If I knew that, I wouldn't have been querying it in the other thread, would I?

well, i figured you knew because of your stating it wasn't a matter of opinion.

well, i figured you knew because of your stating it wasn't a matter of opinion.

Are you retarded or just retarded?

a little bit of both.

To your credit, that's a better answer than I expected.

Can't we lock this stupid thread as it is already being discussed elsewhere?

It no longer is being discussed elsewhere.

Thank you. It hurt my eyes.

Now, I don't really believe what yourdadonapogos is saying. If the circle was spinning rapidly, the radius/diameter would too, so relativity would affect it too.

Just another reason...

I think we should have a poll about whether or not we should have a poll about the circle.

This thread needs lots of big diagrams.

Yeah, I really don't see how reletivity could only effect the circumference, and not the rest of the circle.

I'm not sure if yourdad meant to say that the circumference was actually affected, or if it just appears that way to someone in a different relatavistic frame.

Oh, OK. But if the circumference only apears to be effected I don't see what the problem is. Then the circumference divided by the radius would still equal pi.

Damn it - I spent a good few minutes hunting out this ancient thread, but its relevance is diminished somewhat by the question not ever being answered.

ok, if a meterstick is flying at a substantial fraction of the speed of light then it isn't a meter long to the outside observers. the circle works the same way the LENGTH gets shorter in the direction of acceleration. that means even if the radius wasn't a line, it wouldn't shrink in a way that affects its length. does that answer your question? i would put some BIG diagrams on here, but i don't know how.

 

maybe dave could reply when he gets back from his holiday.

 

edit: the circumference is shorter, circumference divided by radius doesn't equal pie. saying they are equal would be like saying [math]3/2=1/2[/math].

Oops...I meant to click yes...I don't know what I was thinking. I wouldn't think anything would change about a spinning circle, but I know a spinning disk changes...

i have come to the conclusion that since, it would still have the same equation, it is still a circle.

 

the definition of pi is the circumference over diameter, so i say that pi is not a constant.