# Simple proof that SR is self contradictory (1 Viewer)

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#### Redfern

##### Guest
Shortest Proof That SR Self Contradicts In The World

Suppose SR is correct, it would then follow that the Lorentz contraction formula is correct. That formula is:

L = L0 (1-v^2/c^2)1/2

Suppose that formula is true. As you can see, if v=c, then L = (L0) times zero, hence L=0.

Now, by the fundamental postulate of relativity, all photons in a single inertial reference frame have the same speed, which is 299792458 meters per second. So let us discuss photons, so that we know v=c in the above formula.

The question now is, how are we to interpret Length contraction. IN the case of bodies, we conclude that the bodies themselves shrink. In the case of motion through space, we have to say that the distance traveled has shrunk.

So consider a photon moving though space. Suppose that in its frame, it has traveled 299792458 meters, and suppose that this value is L, according to another observer in an inertial reference frame.

Thus, an observer in an inertial reference frame has to have the following relativistic calculation:

299792458 = L0 (1-1)^1/2 = 0, which is clearly contradictory.

This is the shortest proof that relativity is self contradictory in the world.

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#### chroot

Staff Emeritus
Gold Member
This has been talked about at length already here in the last couple of days. Are you TheAthiestKing/Tempest?

The shortest rebuttal of the shortest proof that relativity is self contradictory is this:

A photon cannot be in an inertial frame, by definition. The reason? It doesn't experience distance or time; it's a singular coordinate system.

The argument you're making is similar to saying that the fact that 1/0 is undefined means math is "self-contradictory."

- Warren

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#### Redfern

##### Guest
Let me try this again.

A photon travels 2997923458 meters in its own frame, be it inertial or non-inertial. What is the distance this photon has traveled according to an observer in an inertial frame.

This photon has speed c in an inertial frame for sure, so that the distance traveled by the photon in the inertial frame is length contracted according to the following formula:

L = L0 (1-v^2/c^2)^1/2 = L0 (1-1)^1/2 = L0 (zero) = 0

Thus, regardless of the L0, L must equal zero. But L is the distance that the photon has traveled in the inertial frame, which is clearly nonzero. Thus, the photon is stationary in the inertial frame, contrary to the fact that its speed is c.

So the conclusion is, that in a single inertial frame, a photon has speed v=0, and a photon has speed 299792458 meters per second, which is impossible.

#### chroot

Staff Emeritus
Gold Member
Ahem. Let me try this again, too.

Originally posted by chroot
This has been talked about at length already here in the last couple of days. Are you TheAthiestKing/Tempest?

The shortest rebuttal of the shortest proof that relativity is self contradictory is this:

A photon cannot be in an inertial frame, by definition. The reason? It doesn't experience distance or time; it's a singular coordinate system.

The argument you're making is similar to saying that the fact that 1/0 is undefined means math is "self-contradictory."

- Warren

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#### Redfern

##### Guest
It is not being asserted that the photon is or isnt in an inertial frame, that simply doesn't matter. And no I'm not atheistking/tempest.

#### chroot

Staff Emeritus
Gold Member
Originally posted by Redfern
It is not being asserted that the photon is or isnt in an inertial frame
Coulda fooled me:
So the conclusion is, that in a single inertial frame, a photon has speed v=0
And yeah, the distinction matters quite a lot.

- Warren

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#### Redfern

##### Guest
You aren't following the argument as the argument was intended, perhaps that's my fault.

There is a photon which moves a distance L0 in its own frame. Now, some observer who is in an inertial frame measures that distance as L. If the fundamental postulate of relativity is correct, then L=0, hence the photon's speed in the inertial reference frame is zero. But the fundamental postulate of SR is that the speed of a photon in any inertial frame is c=299792458 meters per second. Hence, the fundamental postulate of special relativity is self contradictory.

#### NateTG

Homework Helper
Your post assumes that we have a valid reference frame where something with length is moving at c, which is not possible in special relativity. Thus there is no paradox.

#### Njorl

##### Guy in a red jumpsuit
Originally posted by Redfern
You aren't following the argument as the argument was intended, perhaps that's my fault.

There is a photon which moves a distance L0 in its own frame.

There are effectively no distances or time in this frame. It makes no sense to say that a photon has moved in such a frame. Moved where? There is no place to move, and no time to move during.

Maybe this will help.

How big is the universe. Assume it is x lightyears across for you and me. How big is the universe in the photon's frame? The length contraction multiplier is zero, so the universe is zero lightyears across.

How old is the universe? For us it is y years old. For the photonic frame, the time dialation multiplier is zero. For the photon, the universe is zero years old. How long will the universe exist? For us it will last z years, for the photon, it will again be zero years.

Comparissons with a lightspeed frame are not inconsistant, they are just not interesting.

Njorl

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