Michelson-Morley experiment proves nothing

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In summary, the Michaelson-Morley experiment proved that it is impossible to calculate the speed of a car using only the time it takes for a light signal to travel from one mirror to the other.
  • #1
yeti1112007
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I believe the experiment proves nothing and the comeout means nothing

the experiment similars to this:

in dashing a car with a velocity V , then Michelson and Morley throw a ball and it rebinds

back(velocity U ). the two great scientists note the time and try to calcuate the

speed of the car V. that is impossible!
 
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  • #2
Yes, that's the whole point of the Michaelson-Morley experiment!

In Gallilean relativity, Gallileo, long before Einstein or Michaelson and Morley noted that if you were in a carriage moving in a straight line with constant speed, there would be no (mechanical) experiment, such as throwing or dropping a ball that would tell you the speed of the carriage or even if it were moving. In effect that is because "f= ma"- any change in the motion of the ball would be the result of acceleration, not speed.

But I specifically put "mechanical" in parentheses because Gallileo knew nothing about electricity or magnetism and so did not consider such experiments. But Maxwell's equations show that the electric field generated by a charged body depends on its speed not its acceleration. That means that, theoretically, we should be able to do some kind of electro-magnetic to determine "absolute" speed- that an electromagnetic experiment could determine the speed of a carriage from "inside". And, of course, light is an ideal electro-magnetic field.

That was what the Michaelson-Morley experiment was designed to test- and gave a null result. Of course, there were any number of ways of accounting for that. Lorentz came up with a very clever theory in which that very change in magnetic field would be precisely enough to "shrink" the distance between atoms to account for the null result- and developed the "Lorenz transformation". Einstein went even farther and suggested that not only the lengths of material objects but even the space itself between objects was "shrunk". A variation of the Michaelson-Morley experiment, called the "Kennedy experiment" gave results that Einstein's theory predicted and Lorenz's didn't. There was even one theory that accounted for the Michaelson-Morley results by postulating extra dimensions (unfortunately I don't recall the name of the person who came up with it) that Einstein thought was very clever. It wasn't until the famous "eclipse" experiment of the late twenties gave results that matched Einstein but not the other theory that that was settled.
 
  • #3
yeti1112007, make sure that you Physics Forums Rules,

https://www.physicsforums.com/showthread.php?t=5374.'

In particular,

Posting Guidelines said:
Overly Speculative Posts:
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  • #4
yeti1112007 said:
I believe the experiment proves nothing and the comeout means nothing

the experiment similars to this:

in dashing a car with a velocity V , then Michelson and Morley throw a ball and it rebinds

back(velocity U ). the two great scientists note the time and try to calcuate the

speed of the car V. that is impossible!

does the windspeed affect the speed of the ball? perhaps a better illustration would be measuring the apparent speed of sound bouncing off a "mirror" in front of the car vs. the speed of sound bouncing off an identical wall to the side of the car. because sound uses this medium we call "air" to propagate in, the two great scientists would measure a speed difference.

if light actually did propagate by use of this hypothetical medium sometimes called "aether", if you believe it is reasonable that, at least at sometime during the year, the Earth in it's orbit around the Sun moves through this aether at a speed that we would expect, around 2[itex]\cdot \pi \cdot[/itex](93000000miles)/(1 year), the difference in speeds of light using the mirrors in "front" vs. the mirrors on the "side" would be measurably different. but since no difference was ever measured, and this experiment was repeated many times and in many different manners, i think the safest thing to conclude is maybe light (and all other E&M radiation) doesn't propagate within any medium. the only other explanation is that this aether somehow sticks to the planet Earth as it revolves around the Sun (therefore we are never moving through the aether). is that reasonable?
 
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  • #5
rbj said:
does the windspeed affect the speed of the ball? perhaps a better illustration would be measuring the apparent speed of sound bouncing off a "mirror" in front of the car vs. the speed of sound bouncing off an identical wall to the side of the car. because sound uses this medium we call "air" to propagate in, the two great scientists would measure a speed difference.
No, not if they were in an enclosed car where the air moves at the same speed as the car.

if light actually did propagate by use of this hypothetical medium sometimes called "aether", if you believe it is reasonable that, at least at sometime during the year, the Earth in it's orbit around the Sun moves through this aether at a speed that we would expect, around 2[itex]\cdot \pi \cdot[/itex](93000000miles)/(1 year), the difference in speeds of light using the mirrors in "front" vs. the mirrors on the "side" would be measurably different. but since no difference was ever measured, and this experiment was repeated many times and in many different manners, i think the safest thing to conclude is maybe light (and all other E&M radiation) doesn't propagate within any medium. the only other explanation is that this aether somehow sticks to the planet Earth as it revolves around the Sun (therefore we are never moving through the aether). is that reasonable?
NO, that is not the "only" other explanation. Another possible explanation is that your measuring sticks "contract" in the direction of motion so that you will measure the same speed of light in any direction.
 
  • #6
rbj said:
does the windspeed affect the speed of the ball? perhaps a better illustration would be measuring the apparent speed of sound bouncing off a "mirror" in front of the car vs. the speed of sound bouncing off an identical wall to the side of the car. because sound uses this medium we call "air" to propagate in, the two great scientists would measure a speed difference.

HallsofIvy said:
No, not if they were in an enclosed car where the air moves at the same speed as the car.

well, that would be like the aether that sticks to and travels around with the planet Earth so that we are never moving through it with any appreciable velocity. i think that's a sort of specious exception. of course i meant that the car was moving through the air just as we would expect the Earth to be moving through the aether, if it existed, at least during sometime of the year.


if light actually did propagate by use of this hypothetical medium sometimes called "aether", if you believe it is reasonable that, at least at sometime during the year, the Earth in it's orbit around the Sun moves through this aether at a speed that we would expect, around 2[itex]\cdot \pi \cdot[/itex](93000000miles)/(1 year), the difference in speeds of light using the mirrors in "front" vs. the mirrors on the "side" would be measurably different. but since no difference was ever measured, and this experiment was repeated many times and in many different manners, i think the safest thing to conclude is maybe light (and all other E&M radiation) doesn't propagate within any medium. the only other explanation is that this aether somehow sticks to the planet Earth as it revolves around the Sun (therefore we are never moving through the aether). is that reasonable?

NO, that is not the "only" other explanation. Another possible explanation is that your measuring sticks "contract" in the direction of motion so that you will measure the same speed of light in any direction.

yeah, i guess. they would be sort of intelligent measuring sticks, but that's no farther fetched than an intelligent aether that somehow knows we're moving through it and moves with us.
 
  • #7
HallsofIvy said:
But I specifically put "mechanical" in parentheses because Gallileo knew nothing about electricity or magnetism and so did not consider such experiments. But Maxwell's equations show that the electric field generated by a charged body depends on its speed not its acceleration. That means that, theoretically, we should be able to do some kind of electro-magnetic to determine "absolute" speed- that an electromagnetic experiment could determine the speed of a carriage from "inside". And, of course, light is an ideal electro-magnetic field.

maybe you are right. I will review the Maxwell's equations and maybe I make some mistake about electromagnetism and light
 
  • #8
George Jones said:
yeti1112007, make sure that you Physics Forums Rules,

https://www.physicsforums.com/showthread.php?t=5374.'

In particular,

I am a Chinese of the mainland, and I am now in China. I am very interested in the theory of

the unchaging velocity of light. But information are poor here because books are copying

each other. So I put what I thought here hoping for more information. I am sorry for

breaking the rules
 
  • #9
i don't think asking questions or even challenging (as hypothesis) conventional wisdom is breaking the rules. but, yeti, be careful of what you write. you are neither the only nor first person to declare Einstein wrong. and everyone else before ended up eating their words (or stubbornly remained crackpots).
 
  • #10
Are you seeking more information? Your first post sounded like you were espousing a (wrong) personal belief.

The speed of light is seen as constant by all observers. Michelson-Morely *disproves* the aether hypothesis that said that light travels in a medium and that there would be a detectable "wake" of the Earth through the aether which would manifest itself by comparing beams of light when the Earth was at opposite ends of its orbit. Observing no such wake, the experiment shows there is no aether. It actually proves quite a bit, and while the experimental error may have been quite large at the time, it's since been confirmed to remarkable accuracy.

Moreover, things like nuclear power and nuclear weapons wouldn't work if relativity was wrong.
 
  • #11
A helium balloon inside a vehicle travels in the direction of acceleration when the vehicle accelerates.
 
  • #12
rbj said:
i don't think asking questions or even challenging (as hypothesis) conventional wisdom is breaking the rules. but, yeti, be careful of what you write. you are neither the only nor first person to declare Einstein wrong. and everyone else before ended up eating their words (or stubbornly remained crackpots).

It seems I have a lot to learn before I know the turth.
 

Related to Michelson-Morley experiment proves nothing

1. What is the Michelson-Morley experiment?

The Michelson-Morley experiment was a scientific experiment conducted in 1887 by Albert Michelson and Edward Morley to measure the speed of light and to test the existence of the luminiferous ether, a hypothetical substance thought to be the medium through which light travels.

2. How did the Michelson-Morley experiment work?

The experiment involved splitting a beam of light into two perpendicular beams and then recombining them to see if there were any changes in the speed of light. The experiment was repeated at different times of the year to account for the Earth's movement around the sun.

3. What were the results of the Michelson-Morley experiment?

The results of the experiment showed that there was no significant difference in the speed of light in different directions, indicating that the Earth is not moving through a stationary ether. This result was unexpected and contradicted the prevailing theories of the time.

4. Does the Michelson-Morley experiment prove anything?

The Michelson-Morley experiment did not prove anything definitively, but it did provide evidence that the concept of a stationary luminiferous ether was incorrect. This result led to the development of Albert Einstein's theory of relativity, which revolutionized our understanding of space and time.

5. Why is the Michelson-Morley experiment important?

The Michelson-Morley experiment is important because it challenged the prevailing beliefs of the time and ultimately led to the development of one of the most groundbreaking theories in physics. It also paved the way for future experiments and discoveries in the field of relativity and cosmology.

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