Is The Theory of Relativity Fatally Flawed?

[Persol]

On impact an object will approach the velocity of whatever it is impacting. Whatever that may be...
http://www.doane.edu/Dept_Pages/PHY/PhysicsVideoLibrary/movies/horiztruck.mov

You'll also note that only horizontal motion really matters here, and it is shown quite easily using air trucks that only the relative motion matters....
http://www.doane.edu/Dept_Pages/PHY/PhysicsVideoLibrary/movies/aircoll1.mov

This isn't even Einstein's physics... this is Newtons. A ball dropped from a train will approach the velocity of the ground... regardless of which one is moving relative to the Earth.

 

[Quantum Quack]

persol, there is no rocket science needed to know that the embankment can not be deemed as moving if we assume the train is stationary....as this is illusion and not reality.

in this particular scenario as simple as it seems relativity of frame fails to make sense at all simply becasue I have yet to see an embankment moving whilst a train is stationary.
Of course the earth is rotating but this is also an aspect of the trains velocity.

It's all very well to discuss frames that are at relative velocity without considering the rest of the equation and that being the frame that both objects are subject to.

If we deem the earth as stationary then what is happeniong universally?

If we deem an object as stationary what is happening universally?

Object A v=0.8c
Object B v= 0.5c
Object C v = ? [object C is our universe]

just exploring the limitations of SR...that's all...

 

[2inquisitive]

by Persol:
"This isn't even Einstein's physics... this is Newtons."
=============================================================

Don't insult Sir Isaac that way. He would never place the train in the rest frame and
the Earth in the moving frame.

 

[Persol]

Don't insult Sir Isaac that way. He would never place the train in the rest frame and the Earth in the moving frame.

Regardless of you wanting to believe it, Newton's Laws completely support Galilean Relativity.

persol, there is no rocket science needed to know that the embankment can not be deemed as moving if we assume the train is stationary....as this is illusion and not reality.

But the problem is that you can, and need to. There is a realtive velocity between the train and the ground. If you consider one stationary, then the other is moving. If it makes you happier you can keep the train completely still and drive a flatbed truck by which you drop the ball on. From the trains point of view the trajectory is identical regardless of how fast the train is moving relative to the ground. Only the relative velocity matters.

just exploring the limitations of SR...that's all...

This is not SR.... this is pre-Einstein physics.

 

[2inquisitive]

Well, I suppose the physics are the same at low velocities, Sir Isaac just wouldn't
do it that way. But where Isaac is correct and Albert is wrong is when relativistic
velocities are introduced, hehe.

 

[Persol]

Yeah, but the ball being thrown from the train and bouncing doesn't use very high velocities... and follows almost perfectly the physics of Newton's time. It is in no way a proof against relativity, because at these velocities Einstein's relativity gives you identical answers.

Well, I suppose the physics are the same at low velocities, Sir Isaac just wouldn't do it that way.

An intergral part of Newton's theories was that you could not determine absolute motion. You could not figure out what was 'really' at rest. His forumlas work regardless of the frame of reference you pick. so yes... Newton would do it this way if he was on the train.

 

[2inquisitive]

The mistake was made in my Earth-based laser/passing spaceship paradox by the
relativists (Einstein) in assuming light was still traveling 299,792,458 m/s in the
APPARENT longer path the beam took from the rest spaceship/moving Earth frame
of reference. The laser beam 'appears' to take a longer path in that frame, but actually
DOES NOT. It would still take two seconds to travel to the spaceship and back to the
Earth in either frame. Einstein is measuring an 'apparent' distance and applying a REAL
'constant' light velocity to the path. The speed of light should be 'apparently' faster
than 299,792,458 m/s in that frame, but in reality it is still traveling the same distance
in the same length of time, just as Newton would figure it.

 

[Persol]

The speed of light should be 'apparently' faster than 299,792,458 m/s in that frame, but in reality it is still traveling the same distance in the same length of time, just as Newton would figure it.

I'm not going to argue with you about this, because it is purely your opinion, and nothing I or anyone else says or shows you will change your mind. Even in Newtonian physics the path would be longer.

 

[Yuriy]

Persol,
I have to disagree with you: in Science there is no place for opinions. Either it is true or it is false. No etiquette should stop us to say "Sir, you are wrong" when we deal with scientific discussion. For instance, Landau use to say "What a doggy nonsense you are telling us, sir!" no matter who did it in scientific dispute... In our case I have to say to 2inquisitive: "Sorry, sir, but you are telling us some doggy nonsense all the time in this thread"...

 

[2inquisitive]

I'm not going to argue with you about this, because it is purely your opinion, and nothing I or anyone else says or shows you will change your mind. Even in Newtonian physics the path would be longer.

Only if you put the spaceship observer at rest and the Earth/laser moving.
Let the spaceship observer keep the moving frame and he sees the laser
beam comming up from Earth in front of his direction of travel to intercept
him and then bounce straight back to the Earth. The laser beam does not
come straight at him as in the moving Earth scenario. Duh.

 

[marv]

I suppose I've missed a very good deal of this thread, but I'll chime in anyway. I've posted this elsewhere, but...

"...a man riding aboard a train drops a stone from a window to the ground. A man standing on the embankment observes this. The man on the train sees the stone fall in a straight line. The man on the embankment sees the stone fall in a parabolic path. In this "thought experiment", Einstein assigned a "reality" to both observations disregarding the physical or real path taken by the stone. In fact, the path taken by the stone does describe a parabola.

What Einstein ignored in his "thought experiment" was the momentum provided by the moving train. The man on the train, possessing the identical forward momentum, simply didn't observe it. By insisting on two separate "realities", Einstein was led to the conclusion that space can in fact be different for two different observations. In actuality, only the observations and not the reality differ.

...and...

[Another] experiment purports to prove that a man standing in a closed elevator cannot tell the difference if he were motionless on the surface of the Earth or if he were accelerating in an "upward" motion in free space without the influence of gravity. If you were in such a situation and held two identical weights in outstretched hands, you could instantly tell the difference. When dropped while on the surface of the Earth, the weights will fall toward the center of mass and not in parallel paths. In space under the influence of inertia, the weights will fall in absolute parallel paths.

This led Einstein to the wrong conclusion that gravitational mass and inertial mass were equivalent. This led further to his conclusion that speed faster than light, or 299,792.458 km/sec, is impossible because inertial "mass" increases with speed and becomes theoretically infinite at that speed. I enclosed mass in quotation marks because inertia confers no mass to an object. What inertia does do, however, is to store energy. A bullet, weighing only a few grains in the hand, can strike its target with the energy of a ton because the inertia of the bullet, at the point of impact, releases that stored energy. The bullet, at impact, still weighs only a few ounces if measuring its actual mass.

Not to detract from Einstein's accomplishments, but much of it has gone to the benefit of science fiction.

 

[Persol]

What you are attributing to Einstein in the first quote was in existance way before his time.

 

[marv]

What you are attributing to Einstein in the first quote was in existance way before his time.

I guess that I could say in my best robotic voice, "Does not compute." So I'll ask you to please expand on your comment.

 

[Persol]

In this "thought experiment", Einstein assigned a "reality" to both observations disregarding the physical or real path taken by the stone.

This is not Einsteins idea... it was shared by Newton and Galileo.

Furthermore, this isn't describing a 'different space' for two different people, and Einstien wouldn't claim that it did.

The problem is that the 'real path' is unknown to everybody. Perhaps we are all moving at 10000 mph through space, in which case the parabola isn't the 'real' path. There is no way of determining absolute velocity, thus all frames of reference are just as real as the next.

experiment purports to prove that a man standing in a closed elevator cannot tell the difference if he were motionless on the surface of the Earth or if he were accelerating in an "upward" motion in free space without the influence of gravity.

The idea still stands. The two weights in your thought experiment are experiencing different vectores due to gravity... but both are behaving exactly as they would if just accelerating.

 

[marv]

Furthermore, this isn't describing a 'different space' for two different people, and Einstien wouldn't claim that it did.

Einstein did indeed do so in my fourteenth reprint of his Theory....

The two weights in your thought experiment are experiencing different vectores due to gravity... but both are behaving exactly as they would if just accelerating.

Wrong. In one experiment, the reaction of the two weights is due to gravity. In the other, the reaction is due to inertia.

 

[Quantum Quack]

from what I see, the relativity of frames of SR requires the use of light in the thought experiments. But as soon as we use objects of mass such as balls and stones the SR logic fails but the defenders of the faith simply claim that it is no longer SR we are discussing but something else. Even though the postulate about the laws of physics being true to all frames is supposedly held as being valid.

 

[Quantum Quack]

2inquisitive,
I think that if you construct your thought experiment mentioned earlier with the use of "bullets of mass" instead of a beam of light you may achieve something, I'd do it myself but I drank too much last night and can hardly type. [chuckle]

 

[Persol]

Einstein did indeed do so in my fourteenth reprint of his Theory....

I'd like to see exactly what it says please.

Wrong. In one experiment, the reaction of the two weights is due to gravity. In the other, the reaction is due to inertia.

You missed my point. The result of each is exactly the same.

But as soon as we use objects of mass such as balls and stones the SR logic fails but the defenders of the faith simply claim that it is no longer SR we are discussing but something else.

Very simply because you can't throw a ball from a train at close to the speed of light. This is what I claimed wasn't SR, because you were claiming that a ball thrown from the train would react differently depending on the train moving... which is experimentally false... and doesn't require SR to prove.

Now if you want to start talking about balls and stones approaching the speed of light, you'll have to say so. My assumption was that you were talking about normal everyday ball/stone speeds.

However the bigger problem here is that if you do assume the train is going .5c relative to the earth, the reaction when the ball hits the ground is not to bounce off, but to vaporize. It is pointless to try and mix everyday mechanics with things going that fast because the conclusion will bear no resemblance to what you'd see if you drop a ball from a normal-speed train.

 

[Quantum Quack]

Persol,
maybe it's approprate to ask you and any one else at what velocities does SR apply and what velocities SR doesn't apply to.
And does SR predict differring results due to differring velocities?

The thinking :
Compare both a beam of light and a ball of mass at speed where both objects have reality. Such as a train at v= < 100kph

 

[marv]

Your mind is made up, Persol, and it's no use presenting you with logical arguments alternative to your mind-set.

For example, I said:
Wrong. In one experiment, the reaction of the two weights is due to gravity. In the other, the reaction is due to inertia.
And you replyed:
You missed my point. The result of each is exactly the same.

That's fine, if you believe that the physical action and reaction of a mass accelerating on the surface of a body with significant gravitational effect is different from an accelerating body in space absent a significant gravitational effect.