# The Naked Scientists Forum

### Author Topic: the constant velocity of baseballs  (Read 7508 times)

#### thebrain13

• Sr. Member
• Posts: 442
##### the constant velocity of baseballs
« on: 03/07/2006 00:05:56 »
lets say in the future, the baseball players given the advancement of steroids of course, were able to hit the balls with incredible force. They were able to strike the ball so hard that according to newton the balls should accelerate to an incredible speed of 1000 times the speed of light. However, people in the stadium notice that the balls do not leave the stadium at 1000c but in fact very close to c. Anyways, mark gwiremac is about to break willie ayms alltime season record for home runs at 10,000hr, a home run is to hit a ball out of earths atmosphere in the future.

Somebody in the stands, adam, realizes that record breaking balls are worth a lot of money, but he has a dilema because you cant just catch a ball traveling at c, you might break your hand. So he decides to build a spaceship, he figures if he can travel to 99.999 percent the speed of light, the ball might be traveling just slow enough to catch it without breaking his hand. so he figures a spaceship with enough power to accelerate him to 10c according to newton should be sufficient, so he builds the ship and waits for mark to hit the ball. He waits a few innings and finally mark hits the ball, adam eagerly awaits in his very quick moving spaceship, but to adams bewilderment he finds out that although he is traveling at almost c from earth, the ball seems to be traveling at 2c from earth, or approaching him at the speed of light. wtf he says, that didn't work at all. Confused and defeated he heads back to earth, and after a lot of thinking he finally figures it out. The speed of baseballs is constant!

Isn't this an inevitable consequence of s.r? and if so what is so unique about the constancy of the speed of light, given baseballs do the same thing?

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #1 on: 03/07/2006 01:53:49 »
quote:
Originally posted by thebrain13

lets say in the future, the baseball players given the advancement of steroids of course, were able to hit the balls with incredible force. They were able to strike the ball so hard that according to newton the balls should accelerate to an incredible speed of 1000 times the speed of light. However, people in the stadium notice that the balls do not leave the stadium at 1000c but in fact very close to c. Anyways, mark gwiremac is about to break willie ayms alltime season record for home runs at 10,000hr, a home run is to hit a ball out of earths atmosphere in the future.

Somebody in the stands, adam, realizes that record breaking balls are worth a lot of money, but he has a dilema because you cant just catch a ball traveling at c, you might break your hand. So he decides to build a spaceship, he figures if he can travel to 99.999 percent the speed of light, the ball might be traveling just slow enough to catch it without breaking his hand. so he figures a spaceship with enough power to accelerate him to 10c according to newton should be sufficient, so he builds the ship and waits for mark to hit the ball. He waits a few innings and finally mark hits the ball, adam eagerly awaits in his very quick moving spaceship, but to adams bewilderment he finds out that although he is traveling at almost c from earth, the ball seems to be traveling at 2c from earth, or approaching him at the speed of light. wtf he says, that didn't work at all. Confused and defeated he heads back to earth, and after a lot of thinking he finally figures it out. The speed of baseballs is constant!

Isn't this an inevitable consequence of s.r? and if so what is so unique about the constancy of the speed of light, given baseballs do the same thing?

I wont go into the bloody mess that will be left in the stadium by a baseball bat travailing at close to the speed of light, hitting a baseball coming the other way, with probably enough force to create a small nuclear explosion; to say nothing of a sonic shock wave coming off the bat travelling at almost a million times the speed of sound, and blasting the spectators out of their seats, and probably off the Earth.

The ball will never appear to be travelling at 2c, and as he speeds up, he will gradually catch up with the ball.  Since neither he nor the ball can travel faster than light, or even travel as fast as light, so no matter how fast the ball is travelling, it is always going to be slower than c, and he will always be able to travel just a little closer to the speed of light than the ball is travelling, and will ultimately catch up with the ball  he will simply have to budget a considerably larger amount of energy than he had anticipated  rather like trying to run through treacle.  Ofcourse, this is further confused by time distortions, so although the spectators (assuming they are still alive, after all they have been subjected to) may see that it takes our intrepid ball chaser a very long time to catch up with the ball, the ball chaser himself still thinks it is quite quick, because time is moving slower for him.  It is only when our ball chaser returns to Earth, to survey the ruins of the stadium, does he realise that several generations of spectators have been born and died in the time it took him to bring the ball home (which, the ball chaser may have thought only took a few hours).

George

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #2 on: 03/07/2006 03:46:40 »
the ball would appear to travel at just under 2c relative to the earth, from the moving spaceships point of view, that does not violate s.r. for example, if you flash two flashlights in the opposite direction from one another you view the two light signals moving from 2c from one another. When you move close to c, from the earth and then view a baseball moving in the same direction you are traveling, you view the baseball moving away from earth at 2c, thats what I was saying.

Anyways, the point of my post was to imply that any object with a very high amount of energy applied to it in comparison to its mass, will have a speed just under c, which is independant of the motion of the observer(unless the observer has extremely high amounts of energy applied to it). I was getting at the fact that the motion of light is the same as the motion of any object, granted an object has a very high amount of energy applied to it.
« Last Edit: 05/07/2006 16:24:24 by thebrain13 »

#### ukmicky

• Moderator
• Neilep Level Member
• Posts: 3011
##### Re: the constant velocity of baseballs
« Reply #3 on: 03/07/2006 04:01:11 »
« Last Edit: 03/07/2006 04:10:00 by ukmicky »

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #4 on: 03/07/2006 01:53:49 »
quote:
Originally posted by thebrain13

lets say in the future, the baseball players given the advancement of steroids of course, were able to hit the balls with incredible force. They were able to strike the ball so hard that according to newton the balls should accelerate to an incredible speed of 1000 times the speed of light. However, people in the stadium notice that the balls do not leave the stadium at 1000c but in fact very close to c. Anyways, mark gwiremac is about to break willie ayms alltime season record for home runs at 10,000hr, a home run is to hit a ball out of earths atmosphere in the future.

Somebody in the stands, adam, realizes that record breaking balls are worth a lot of money, but he has a dilema because you cant just catch a ball traveling at c, you might break your hand. So he decides to build a spaceship, he figures if he can travel to 99.999 percent the speed of light, the ball might be traveling just slow enough to catch it without breaking his hand. so he figures a spaceship with enough power to accelerate him to 10c according to newton should be sufficient, so he builds the ship and waits for mark to hit the ball. He waits a few innings and finally mark hits the ball, adam eagerly awaits in his very quick moving spaceship, but to adams bewilderment he finds out that although he is traveling at almost c from earth, the ball seems to be traveling at 2c from earth, or approaching him at the speed of light. wtf he says, that didn't work at all. Confused and defeated he heads back to earth, and after a lot of thinking he finally figures it out. The speed of baseballs is constant!

Isn't this an inevitable consequence of s.r? and if so what is so unique about the constancy of the speed of light, given baseballs do the same thing?

I wont go into the bloody mess that will be left in the stadium by a baseball bat travailing at close to the speed of light, hitting a baseball coming the other way, with probably enough force to create a small nuclear explosion; to say nothing of a sonic shock wave coming off the bat travelling at almost a million times the speed of sound, and blasting the spectators out of their seats, and probably off the Earth.

The ball will never appear to be travelling at 2c, and as he speeds up, he will gradually catch up with the ball.  Since neither he nor the ball can travel faster than light, or even travel as fast as light, so no matter how fast the ball is travelling, it is always going to be slower than c, and he will always be able to travel just a little closer to the speed of light than the ball is travelling, and will ultimately catch up with the ball  he will simply have to budget a considerably larger amount of energy than he had anticipated  rather like trying to run through treacle.  Ofcourse, this is further confused by time distortions, so although the spectators (assuming they are still alive, after all they have been subjected to) may see that it takes our intrepid ball chaser a very long time to catch up with the ball, the ball chaser himself still thinks it is quite quick, because time is moving slower for him.  It is only when our ball chaser returns to Earth, to survey the ruins of the stadium, does he realise that several generations of spectators have been born and died in the time it took him to bring the ball home (which, the ball chaser may have thought only took a few hours).

George

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #5 on: 03/07/2006 03:46:40 »
the ball would appear to travel at just under 2c relative to the earth, from the moving spaceships point of view, that does not violate s.r. for example, if you flash two flashlights in the opposite direction from one another you view the two light signals moving from 2c from one another. When you move close to c, from the earth and then view a baseball moving in the same direction you are traveling, you view the baseball moving away from earth at 2c, thats what I was saying.

Anyways, the point of my post was to imply that any object with a very high amount of energy applied to it in comparison to its mass, will have a speed just under c, which is independant of the motion of the observer(unless the observer has extremely high amounts of energy applied to it). I was getting at the fact that the motion of light is the same as the motion of any object, granted an object has a very high amount of energy applied to it.
« Last Edit: 05/07/2006 16:24:24 by thebrain13 »

#### ukmicky

• Moderator
• Neilep Level Member
• Posts: 3011
##### Re: the constant velocity of baseballs
« Reply #6 on: 03/07/2006 04:01:11 »
« Last Edit: 03/07/2006 04:10:00 by ukmicky »

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #7 on: 03/07/2006 22:38:15 »
I just explained it, Yes it does. The fastest you can view an object moving away from YOU is c, the fastest you can view two objects moving away from EACH OTHER is 2c. Just think about it. how fast would two individual light beams move away from one another if you were in the middle of them, not if you were one of them, in the middle of the two beams. And that does not violate s.r.

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #8 on: 03/07/2006 23:56:28 »
quote:
Originally posted by thebrain13
Anyways, the point of my post was to imply that any object with a very high amount of energy applied to it in comparison to its mass, will have a speed just under c, which is independant of the motion of the observer. I was getting at the fact that the motion of light is the same as the motion of any object, granted an object has a very high amount of energy applied to it.

Light itself is rather peculiar, which is why light is the only thing that can travel at the speed of light (and, in fact, why light in a vacuum can never travel at a speed slower than the speed of light).  The thing about light (or, more accurately, about a photon) is that it has no rest mass.  Anything that accelerates up to the speed of light will have its rest mass effectively multiplied by infinity, and since infinity is impossible, it therefore cannot reach the speed of light.  Since a photon has no rest mass, so it is in a situation where one has zero multiplied by infinity, and so it alone can achieve that which cannot be achieved by anything that actually has a rest mass.

George

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #9 on: 04/07/2006 02:25:40 »
Im glad you didn't continue arguing that you can't view two objects moving away from each other at faster than c, that would of pissed me off.

Anyways, everything you say is true, however I think you are still missing my point. Im saying that when enough energy is applied to an object, its velocity will become so close to the same as light that the difference becomes negligible. So if you applied enough energy to an object that it should travel 1000c according to newton, its velocity would be so close to c that scientists today could not tell the difference between the speed of the object, and the speed of light.

Whats unique about light is c=c+v, or light always moves at c regardless of your velocity. I'm saying that this quality is not specific to light, but holds true with anything, granted that it has enough energy in comparison to its mass. I think Einsteins principle, that all Inertial frames of reference are equally valid, and mass dilation, should cause any object with alot of energy applied to it to do the same thing. And maybe, light acts the way it does because it, in fact has a very small rest mass,  So in otherwords you could say, light has enough energy in comparison to its mass to travel at 100,000c according to newton. With these assumptions you could essentially unify the motion of light and everything else under Two theories. And that is all inertial frames of reference are equally valid, and the mass conversion equation, which causes an object to just move closer and closer to the speed of light, and doesn't allow it to pass.

If you don't understand why, consider this scenario. You have two spaceships, lets call them spaceship A and spaceship B. So lets say both spaceships are accelerated to 87 percent the speed of light relative to earth, which in order to accelerate them to that speed requires enough energy to accelerate an object to c, according to Newton. Both ships would be at rest relative to one another, so no relativistic effects are seen from both ships point of view and they both agree that they are moving away from earth at .87c. Right, no problems there. But what if now spaceship B accelerates to .97c or roughly 2c according to newton. How fast is he moving according to Spaceship A? Physics today, I believe would say, well spaceship A is moving at .87c, B at .97c, so .97c-.87c=.10c or a tenth the speed of light. But doesn't that imply absolute motion, and violate Einstein's theory that all inertial frames of reference are equally valid?
In other words, both consider .87c as being at rest, so when spaceship B is accelerated an additional 1c according to newton, space ship A would view it as accelerating to .87c from him. Or the same if both were at rest relative to earth, and spaceship B accelerated to .87c for the first time.
Thats an inevitable consequence given the equality of frames of reference. So if an object were accelerated to 1000c according to newton, an object accelerated to 1c according to newton or .87c to einstein, would view it as traveling 999c newton, or .99999999999999999999c according to einstein. If he accelerated to 3c newton, he views 997c newton and still .99999999999999c according to einstein. I know those .999999999999c are rough approximations, but my point is that at high enough energy levels any objects velocity remains constant, so why is c=c+v necessarry, and how is the constant velocity of light unique?

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #10 on: 04/07/2006 04:18:00 »
quote:
Originally posted by thebrain13
But what if now spaceship B accelerates to .97c or roughly 2c according to newton. How fast is he moving according to Spaceship A? Physics today, I believe would say, well spaceship A is moving at .87c, B at .97c, so .97c-.87c=.10c or a tenth the speed of light.

I think you are missing a key issue here  who is observing these ships.

If someone sees ship A travelling at .87c, and ship B at .97c, then he will see a difference in speed of .1c.

On the other hand, when this outside observer sees a difference of only .1c, the guys in the ships themselves will see a much greater difference in speed.  The apparent speed of the two ships, just as the apparent speed of light, depends upon the observer.

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/einvel.html
quote:

The relative velocity of any two objects never exceeds the velocity of light. Applying the Lorentz transformation to the velocities, expressions are obtained for the relative velocities as seen by the different observers. They are called the Einstein velocity addition relationships.

Thus, the pilot of ship A will actually see ship B pulling away from him at about 0.64c, not the 0.1c that an outside observer may see.

This is also in my view where some of this confusion about things travelling at 2c arises.

If an observer sees an a spaceship travelling left at 0.9c, and an one travelling right at 0.9c, then me may calculate that the difference in speed between those spaceships is 1.8cc (although he makes this calculation, he does not actually see either ship travel faster than c, it is only a calculation he makes); but the pilots sitting within each of those spaceships will only see the other spaceship travelling at 0.994c.  So no-one actually sees anything moving faster than c, even though they may make calculations that how the combined speed of separation ought to be greater than c.

George
« Last Edit: 04/07/2006 04:41:48 by another_someone »

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #11 on: 04/07/2006 05:49:14 »
God damnit, I started this post out by saying, thank you for not arguing that you can't view two objects moving away from each other at faster than c, that would piss me off. Well you did it, THINK ABOUT IT. This is the last time I'm going to explain this. There are three objects, Earth, and two spaceships traveling at c in the opposite direction from one another(save your link saying objects can't travel at c, I f***ing know that) the frame of reference is earth, earth views the TWO OBJECTS moving at 2c from EACHOTHER. Which is the fastest velocity you can see any two objects moving away from each other. The fastest you can see an object traveling away from YOU is c. You dont need to calculate ****. AND THAT DOES NOT VIOLATE SPECIAL RELATIVITY IN ANY WAY!!!

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #12 on: 04/07/2006 05:51:06 »
Oh yeah, and you completely missed the point of my post.

#### rosy

• Neilep Level Member
• Posts: 1018
• Chemistry
##### Re: the constant velocity of baseballs
« Reply #13 on: 07/07/2006 23:51:48 »
OK, I think the point the brain is trying to make about baseballs may be that in the limit as the kinetic energy tends to infinity, the rest mass becomes negligible relative to the non-rest-mass (sorry, I don't know the correct term), so the baseball would behave "like a photon". The speed of everything is subject to the upward limit of c (in whatever frame) but real "objects" don't go that fast anyway, so we don't discuss much what they'd do if they did.

That's how I understand SR, anyway.

What's special about light, relative to matter, is just this property of having zero rest mass (any "mass" is due to the fact it's moving). I think people think gravitational waves should move at c too, but that's about where I lose interest.

#### rosy

• Neilep Level Member
• Posts: 1018
• Chemistry
##### Re: the constant velocity of baseballs
« Reply #14 on: 07/07/2006 23:56:23 »
The space ships... I don't think you can't "see" things moving away from each other. You can see one move, you can see the other move, you can calculate their velocity relative to each other.
Whether you do that on paper (as with spaceships and such) or implicitly in your head (as with, say, two tennis balls), is neither here nor there.

#### rosy

• Neilep Level Member
• Posts: 1018
• Chemistry
##### Re: the constant velocity of baseballs
« Reply #15 on: 07/07/2006 23:59:48 »
Oh... and there's no point in being rude to George, you won't get a rise... you'll just annoy other people.

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #16 on: 08/07/2006 00:38:41 »
I said, thank you for not arguing that you cant see two objects moving away from each other at faster than c, that would of pissed me off. Then he comes back and argues the same thing, for the third time, prolonging my post so nobody will read it, with arguments about nothing. Should I of explained for the fourth time, softly again? so he can post again, or should I follow up with my previous claim of guartanteed anger in an attempt to end this argument. So people can finally see what Im actually saying? I choose the latter, and as far as I know its worked, although it does appear we're side tracked again. And it doesn't even matter anymore this post is to long now, nobody is going to follow all that. My point is as good as DEAD now. Dismantled by mindless knitpicking. Like all my posts, with the exception of maybe, where have all the scientists gone, but that one is only so successfull because, people want to think all that they devote their mind to is just PERFECT.

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #17 on: 08/07/2006 00:59:31 »
OK, lets get a few things straight.

If you think getting angry will get people to accept your point of view, you may make a good politician, but you'll make a lousy scientist.  You certainly wont convince me of anything except that you are incapable of keeping your cool.

In fact, there is no point in thanking me for not arguing over something.  I will not argue something if I believe it is right, and that is all.  If I were to agree with something simply to receive your gratitude, then I would be insulting your intelligence, and doing you a disservice.

If you wanted me simply to ignore anything I disagree with, then why bother posting it in the first place?

As for whether I did or did not argue about you issue about 2c, what I did say was an attempt to bridge the difference between what you were saying and what Mike was saying (and Mike is not that much of an idiot that you can shout him down either  he knows what he's talking about  most of the time ).  All I suggested was not that you were wrong, but that Mike and you were viewing the same thing from two perspectives, and that both of you might be right.  If you would rather fly into a temper rather than think about what is written in reply to you, that is your problem.  As Rosy said, I'm not going to get upset, I'll just walk away  I don't need the hassle, so why bother.  If you view that as you're having convinced me of your point of view through an outburst of temper, then you are extremely naοve.

George
« Last Edit: 08/07/2006 01:05:47 by another_someone »

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #18 on: 08/07/2006 01:36:46 »
Maybe I misunderstood you, I thought you were disagreeing with me for the third time, but you do agree with what I am saying now right?

Somewhere along the line I got the point across, that was my only goal. Im not trying to get a raise out of you, I dont even know who you are. Im just trying to sharpen your responses.

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #19 on: 08/07/2006 02:27:15 »
Lets not get into a debate about whose responses need sharpening  we are not playing baseball here, we are trying to get to some truth (if that is your desire).  The truth takes patience, not knee jerk reactions.

It is not a case of your being right or wrong about the 2c issue, it was a matter of different perspectives on the matter.  What you say about an observer being able to see two spaceships travelling apart at almost 2c is valid, and is not a violation of special relativity  but that is only the view of the outside observer (which is what I said earlier  but then Michael was not wrong, he merely did not understand the perspective you were looking at it from).  In fact, there are ways in which an outside observer can see phenomena that apparently happen at several times the speed of light (what is known as the lighthouse effect, where a beam of light is reflected off a distant target, and the reflection can move at an apparent speed that is several times the speed of light, but the light light itself only moves at the speed of light, and it is only the appearance of the reflection that appears to move faster).

The issue about their being something special about light that its speed remains constant shows that you have not understood what has been said so far.  Any object that travels close to the speed of light (even 50% of the speed of light) will have its apparent speed distorted by the observer.  When you get to actually travelling at the speed of light (whether you are a massless photon, or if by some miraculous way, you manage it by some other means), then that distorted apparent speed will be such that everyone who looks at you will swear that your speed is the speed of light, and this will be true no matter what speed they may be travelling at.  If you were to travel at very close to almost the speed of light, then most other people who are travelling significantly slower than you will still think your speed is almost the speed of light.

This last point was what I tried to show with the two space ships.

Let me make the numbers a little clearer.

If an outside observer views two spaceships moving at 85% and 86% of the speed of light respectively, the pilot of the ship travelling at 85% of the speed of light will see the other ship moving at 3.7% of the speed of light.  Thus, even though the outside observer only sees a .01c difference in speed between the spaceships, the the pilots themselves see a .03c difference in speed (3 times what the outside observer sees).

Now, if the outside observer sees the ships passing at 98% and 99% of the speed of light respectively, you the pilot of the ship travelling at 98% the speed of light will see the other ship pulling away from him at 33.6% of the speed of light (i.e. this time he sees the speed difference as 33.6 times that which the outside observer sees).

Now lets move even closer to the speed of light.  Suppose the ships are moving at 98.5% and 99.5% of the speed of light respectively, the pilot of the slower ship will see the other ship pulling away from him at 50% of the speed of light.

Now lets get even closer to the speed of light.  Suppose the ships are moving at 98.9% and 99.9% of the speed of light respectively, the pilot of the slower ship will see the other ship pulling away from him at 83% of the speed of light.

Now lets get even closer to the speed of light.  Suppose the ships are moving at 98.99% and 99.99% of the speed of light respectively, the pilot of the slower ship will see the other ship pulling away from him at 98% of the speed of light.

Can you see where all of this is leading to.  If the faster of the two ships were to actually be travelling at 100% of the speed of light, then the slower ship, even though the slower ship is travelling at 99% of the speed of light, will see the faster ship pull away at 100% of the speed of light relative to itself.

The only unique thing about light itself is that because it is massless, it can actually travel at 100% of the speed of light, whereas anything with any real mass can only get ever closer to the speed of light (e.g. 99.999999...% of the speed of light), but can never actually reach it.

Ofcourse, the real question is what is the true difference in speed between the two space ships, is it .1% of the speed of light, or is it 98% of the speed of light, or some other value.  Relativity would say that all references would be equally as valid, although I suppose it would be more logical to argue that the real speed difference in the one the pilots of the ships themselves see, and it is the outside observer who sees a distorted image.

George
« Last Edit: 08/07/2006 03:16:37 by another_someone »

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #20 on: 09/07/2006 22:44:59 »
Okay so, if an object were moving at 99.9999999999 percent the speed of light( and I question how we know that light doesnt travel at 99.9999999999999 percent the ultimate speed limit) would be seen as still, traveling 99.9999999999 percent the speed of light, even relative to somebody who just accelerated to 99 percent c. In mathmatical terms, the speed of the accelerated object O, is relative to your velocity. So O=O+v (granted you dont want to knitpick some .00000000000001c difference in velocity) And lights constant velocity is what people are talking about when they refer to light as being unique.

#### rosy

• Neilep Level Member
• Posts: 1018
• Chemistry
##### Re: the constant velocity of baseballs
« Reply #21 on: 09/07/2006 23:50:35 »
quote:
And lights constant velocity is what people are talking about when they refer to light as being unique.

Is it? I'd always (well, since I had any clue at all) rather assumed it was the zero rest mass of the photon that was unique (and allowed it to reach c )... and that that was what people were talking about...

And I don't think you *can* not nitpick the odd 1 x 10-n c when you're talking about up-around c.

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #22 on: 10/07/2006 00:29:09 »
quote:
Originally posted by thebrain13
Okay so, if an object were moving at 99.9999999999 percent the speed of light( and I question how we know that light doesnt travel at 99.9999999999999 percent the ultimate speed limit) would be seen as still, traveling 99.9999999999 percent the speed of light, even relative to somebody who just accelerated to 99 percent c. In mathmatical terms, the speed of the accelerated object O, is relative to your velocity. So O=O+v (granted you dont want to knitpick some .00000000000001c difference in velocity) And lights constant velocity is what people are talking about when they refer to light as being unique.

Special relativity tells us that light, like gravity, ought to travel at c.

But the point is that the effects of constant speed refer to something, whatever it is, that travels at c.  If it were shown that light does not travel quite at c, then light would not be seen to have a constant speed, only an almost constant speed (this is unlikely, since it contradicts special relativity elsewhere,but the unlikely is not the same as the impossible).  But do note that this only refers to light travelling in a vacuum, it does not apply to light in any other situation.

If light were only to travel at 99.9999999999999 percent of c, then to someone travelling at 99 percent of c, light would appear to have slowed down very slightly (my calculator does not have enough digits to work it out, but as a possible example, it may possibly appear to now be travelling at 99.9999999999998 percent of c).

George

#### thebrain13

• Sr. Member
• Posts: 442
##### Re: the constant velocity of baseballs
« Reply #23 on: 10/07/2006 00:44:09 »
the number I gave you was one 3 millionths of a kilometer per second. You think that difference of velocity isn't nitpicking, especially when your comparing that to 300,000 kilometers per second? You think differentiating between 299,999.99999997 km/s and 300,000 km/s (granted c is a perfectly round number, better put that in or else it might get nitpicked) isn't nitpicking? Differences this small are negligible and beyond instumental measurement. c is given with a plus minus well bigger than these numbers. You've brought nitpicking to a new level, you are nitpicking, nitpicking!!!

#### another_someone

• Guest
##### Re: the constant velocity of baseballs
« Reply #24 on: 10/07/2006 01:10:51 »
quote:
Originally posted by thebrain13

the number I gave you was one 3 millionths of a kilometer per second. You think that difference of velocity isn't nitpicking, especially when your comparing that to 300,000 kilometers per second? You think differentiating between 299,999.99999997 km/s and 300,000 km/s (granted c is a perfectly round number, better put that in or else it might get nitpicked) isn't nitpicking? Differences this small are negligible and beyond instumental measurement. c is given with a plus minus well bigger than these numbers. You've brought nitpicking to a new level, you are nitpicking, nitpicking!!!

If you look at the equation I gave you about, and the sample calculations I showed you, you will see that as you approach c, even the very slightest fraction difference from c can make a disproportionately large difference in outcome.  At very low speeds, when your speed if very much less that c, then 3 millionths of a kilometre per second will have no noticeable effect, but if that 3 kilometre per second is the total by which you are away from c, then that makes a great deal of difference.

It is not me that is nitpicking, it is the equations that describe special relativity that are nitpicking.

George

#### The Naked Scientists Forum

##### Re: the constant velocity of baseballs
« Reply #24 on: 10/07/2006 01:10:51 »