list of common misconceptions about relativity?

Dmitry67

BTW is it true that E=mc^2 was discovered first by Oliver Heaviside?

robphy

Yes, indeed... that's a misconception.
A more specific variation of that misconception is that "Einstein came up with the idea of space-time."

Another is that "Einstein was responsible for the atomic bomb."

Shyan

In the book "Feynman lectures on physics",it is said that the formula arised from the concept of electromagnetic mass before einstein proposed it
It can also be found at en.wikipedia.org/wiki/electromagnetic mass

ZikZak

That isn't a misconception, because you happen to know the solution. The misconception is that students of relativity frequently DON'T understand that travel at nearly c is relative to anything, but rather absolute in some sense.

FalseVaccum89

That's a good one!

FalseVaccum89

Quite. His former instructor (the one who called him a 'lazy dog'), Hermann Minkowski came up with the idea. At first, Einstein didn't even like it, but he was eventually convinced of space-time's utility.

grav-universe

How about

If the sun became a black hole, the Earth and planets would be torn apart and pulled in.

As mentioned in another thread, that M-M demonstrates SR, since M-M can be easily explained ballistically, with the source of the apparatus at rest with the receiver, but rather it was originally the aberration of stars that demonstrated that light travels isotropically in a non-ballistic, non-Galilean manner regardless of the motion of the source and receiver.

harrylin

In fact, it was Poincare who came up with the invariant space-time interval in 1905.

bahamagreen

You are going to use student group discussions leading to their presentation...

The concept problems will involve the most students (with their varying experience) if the issues are simple to grasp, foundational to relativity, and yet tough enough to challenge them...

Is there absolute motion?
If two objects are in relative motion with respect to each other, can't we conclude that at least one of them must be in some kind of absolute, true, or real motion?
Won't this hold true for any and all possible frames of reference?

Is relativity "real"?
Is relativity a theory of measurement, or a theory of existence?
Is it just a way to transform data from a distant/fast source into what makes sense to us locally, or does it actually describe the distant/fast situation?

How does gravity get out of a black hole?
How is there gravitational attraction outside of the black hole?
If it comes from inside the event horizon, how does it get out?
If from outside the event horizon, where is the source mass?
Does gravitational attraction pass through a black hole from one side to the other, or is it blocked?

Why aren't photons allowed to carry flashlights?
Why is there no inertial frame of reference for c?
Why don't velocities add up like ordinary numbers in simple addition?

zonde

Is aberration classical or relativistic effect?

PAllen

Both. It has a derivation according to:

(1) corpuscular theory
(2) moving aether theory
(3) relativistic derivation

They don't agree exactly, but (last I knew) the differences were actually too small to detect.

rjbeery

For a myth, how about "SR has proven the aether does not exist." I'm not advocating for aether, but there's a big difference between proving that something cannot exist in a theory versus merely acknowledging that it isn't necessary in that theory.

zonde

Right. It's just that aberration is usually explained classically but for me it was quite enlightening to find out how it can be worked out in relativity.

zonde

As I see this is rather complicated question. Obviously it's a myth. But at the time people where probably hung on the idea of finding preferred frame. So such a myth would ban useless discussions.
But nowadays I would say that such a myth promotes kind of magical thinking. That's because dimensional modelling is very powerful tool for consistency checking but that myth kind of prevents using it. But that's my viewpoint.

zonde

And another thing that I considered quite interesting (somewhat related to relativistic interpretation of aberration). This is actually a paradox kind of thing but it of course is related to some misconception (if you have it).

Let's say we have situation like this:

Observers "1" and "2" are observing box with an "A" printed on it's side. We view this situation in rest frame of the box and first observer. Second observer is in motion in that frame. Neither observer can see the "A" on the side of the box when both observers are side by side.

Now let's change to rest frame of second observer:

The box and first observer is in motion in that frame. Because the box is in motion and light doesn't get to observer instantly second observer see the box in it's past position. So should the "A" be visible for him?