- #1
Quinzio
- 558
- 1
Hi everyone,
I'm new and this is my first post here.
I'm 37 yo, I'm italian so forgive my english.
My question is about the law of relativity that says that an object moving is shorter, when I observe it.
The shortening is the famous sqrt(1-square(v/c)).
Ok, but now imagine this:
I have 2 big circles made of metal, like 2 hula-hops. They are big so big I can put them around the Earth. Lets' say they are 100 000 km in circumference.
On each circles there are 100 000 000 signs made with a pen, one sign every meter.
(1km =1000m)
The two circles are very close one to the other they are almost superimposed.
As far as they are still, no problem.
Now I start to spin one of the circles, and it spins at 3/5 speed light, so the signs travels at the same speed.
According to relativity, on the spinning circle the signs are now not at 1 meter, but at 0.8 meters. So the circumference of the spinning circle should be not 100 000 but only 80 000 km.
But wait. How is it possible ? Did I say something wrong ?
Do the diameter of the spinning circle get shorter ?
Is the circle broken somewhere ?
How to explain this situation ?
Here is a simple draw of the two circle.
The drawing is bad quality, just to give a clearer idea.
Thanks.
http://img267.imageshack.us/img267/3161/immagine1p.jpg
I'm new and this is my first post here.
I'm 37 yo, I'm italian so forgive my english.
My question is about the law of relativity that says that an object moving is shorter, when I observe it.
The shortening is the famous sqrt(1-square(v/c)).
Ok, but now imagine this:
I have 2 big circles made of metal, like 2 hula-hops. They are big so big I can put them around the Earth. Lets' say they are 100 000 km in circumference.
On each circles there are 100 000 000 signs made with a pen, one sign every meter.
(1km =1000m)
The two circles are very close one to the other they are almost superimposed.
As far as they are still, no problem.
Now I start to spin one of the circles, and it spins at 3/5 speed light, so the signs travels at the same speed.
According to relativity, on the spinning circle the signs are now not at 1 meter, but at 0.8 meters. So the circumference of the spinning circle should be not 100 000 but only 80 000 km.
But wait. How is it possible ? Did I say something wrong ?
Do the diameter of the spinning circle get shorter ?
Is the circle broken somewhere ?
How to explain this situation ?
Here is a simple draw of the two circle.
The drawing is bad quality, just to give a clearer idea.
Thanks.
http://img267.imageshack.us/img267/3161/immagine1p.jpg
Last edited by a moderator: