# Is it the speed of light the max speed

• August 11th, 2011, 12:34 PM
Is it the speed of light the max speed
Is the speed of light the max speed?

What happens if we build something like this:
A big wheel with the diameter of 2m with a small wheel in the midle with 1m diameter and multiplied with 29.
Lets say 1 revolution per secon for the first wheel (2m/sec) the next wheel will have doble (4m/s) like at a bike.
2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x2x 2x2x2x2 = 536870.912 km/s - speed of light 300000km/s
I`m not science man, i just what to know what happens if this test was posible (maybe in a place with 0 gravity and no friction like space).

txs and sry for my bad english.
Attachment 42
• August 11th, 2011, 12:50 PM
PhysBang
You would find that you cannot apply enough force to get the wheel up to that speed.
• August 11th, 2011, 12:59 PM
Lets ignore the amount of foce needed to start the wheel and the centrifugal force generated or that the material from which the wheel is made of will not sustaine.
• August 11th, 2011, 01:19 PM
x(x-y)
Quote:

Lets ignore the amount of foce needed to start the wheel and the centrifugal force generated or that the material from which the wheel is made of will not sustaine.

So, let's ignore pretty much every physical aspect required for the wheel to spin in the first place? Therefore, you basically don't have spinning wheel. If you do not apply a force to the wheel in the first place, then it will not move- Newton's First Law of Motion basically.
• August 11th, 2011, 02:13 PM
So the force needed to start the wheel is imposibel to generate? Eaven if its vacum and 0 gravity?
• August 11th, 2011, 02:36 PM
x(x-y)
Quote:

So the force needed to start the wheel is imposibel to generate? Eaven if its vacum and 0 gravity?

If the wheel is not in motion, then you will need to provide a force in order for it to move- F = ma, a = F/m.
• August 11th, 2011, 03:31 PM
MagiMaster
PhysBang's answer is correct, and the point is that to get a wheel to spin at light speed requires infinite energy (which obviously doesn't exist). Basically, the faster it goes, the more energy it takes to make it go even faster. Since it already takes infinite energy to get to light speed, you can't go faster.
• August 13th, 2011, 04:22 PM
Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?
• August 13th, 2011, 06:05 PM
chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

• August 13th, 2011, 06:05 PM
x(x-y)
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

By this do you mean the recessional velocity of galaxies which are further away from Earth, in which case (as Hubble showed)

where v is the velocity of the galaxy (measured by the observer) and d is the distance (usually expressed in light years or parsecs) the galaxy is from us. In this case, recessional velocity can be larger than the speed of light as this is allowed by special relativity- the "expansion of space" is allowed by the laws of physics as we know them to exceed c.

If this is not what you are talking about, then clarify what you mean please.
• August 13th, 2011, 06:33 PM
brane wave
There are views on certain phenomenem like superluminal motion exceeding light speed.But i wouldn't agree that the idea of flt is impossible

http://en.wikipedia.org/wiki/Faster-than-light]Error[/URL]
• August 13th, 2011, 07:43 PM
Epidemos
Quote:

Originally Posted by x(x-y)
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

By this do you mean the recessional velocity of galaxies which are further away from Earth, in which case (as Hubble showed)

where v is the velocity of the galaxy (measured by the observer) and d is the distance (usually expressed in light years or parsecs) the galaxy is from us. In this case, recessional velocity can be larger than the speed of light as this is allowed by special relativity- the "expansion of space" is allowed by the laws of physics as we know them to exceed c.

If this is not what you are talking about, then clarify what you mean please.

As I mentioned, I'm only a groupie and, therefore, I have no idea really what I mean or am talking about... I tip toe very lightly on this board and really, really really like the response by chinglu and the link with the visuals.....
I do remember reading that recessional velocity is faster than the speed of light upon which I asked my Genius Geek RockStar if this was true and he said yes
• August 13th, 2011, 07:45 PM
Epidemos
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

REALLY COOL ANSWER with the link..... have been trying to wrap my lay-person brain on how time slows down as approaching speed of light - any simple link as one above? Thank you as well for being nice.
• August 13th, 2011, 08:21 PM
brane wave
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

The solution lies in knowing the question.I dont see a question here that breaks any known theory.
Einstein covered all this in detail.
• August 14th, 2011, 12:22 AM
Epidemos
Quote:

Originally Posted by brane wave
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

The solution lies in knowing the question.I dont see a question here that breaks any known theory.
Einstein covered all this in detail.

Thank you again ChingLu for your very kind post and thrilling link.....

And there is a benefit to not being very bright - I can't tell for sure if the above comment is an insult, backhanded or not....and if it is, I'm too dumb to care !
• August 14th, 2011, 06:54 PM
chinglu
Quote:

Originally Posted by Epidemos
Quote:

Originally Posted by brane wave
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

The solution lies in knowing the question.I dont see a question here that breaks any known theory.
Einstein covered all this in detail.

Thank you again ChingLu for your very kind post and thrilling link.....

And there is a benefit to not being very bright - I can't tell for sure if the above comment is an insult, backhanded or not....and if it is, I'm too dumb to care !

0-0-0-zero insult
• August 14th, 2011, 06:55 PM
chinglu
Quote:

Originally Posted by brane wave
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.

The solution lies in knowing the question.I dont see a question here that breaks any known theory.
Einstein covered all this in detail.

I was not trying to break SR with these statements.
The statements I made are true under SR. That implies you do not understand SR.
• August 14th, 2011, 07:00 PM
chinglu
Quote:

Originally Posted by Epidemos
Quote:

Originally Posted by chinglu
Quote:

Originally Posted by Epidemos
I'm just a groupie and everytime I have posted on this forum I get chewed up and spit out.......so if ya'all will bear with me.....

Would recessional velocity count as being faster than the speed of light?

Here is the way SR works.

Recessional and closing velocity apply from a rest frame's conclusions about a moving frame and light.

The light moves in all directions at c i the rest frame.

Now, in the view of the rest frame, a moving frame moves relative to the light causing recessional and closing velocity adjustments to the speed of light as applied to the moving frame from the rest frame calculations.

OK, now in the moving frame view, that view of the rest frame does not apply. In its view, the light moves in all directions at c just like the rest frame.

Here is an explanation of this.