Thread: Gedanken experiment regarding acceleration.

I propose this experiment because there are fundamental components of Quantum theory that point to the answer "no" to the following questions.

Space is basically defined by the energy and matter within it, right?

In attempting to unify gravity with the other forces, Quantum Mechanics requires that without external interaction, the properties of acceleration would not exist. Yes, this is the same branch of science that predicts the existence of the Higgs.

To make it clear, I realize that you, me, the bucket, the car, all mentioned in this experiment has "size". They take up the "space" that we are residing in and do not behave as point-like objects, so the behavior is different for point-like objects.

Bear with me, as this is a thought experiment to guide us in what is to be considered rational behavior. Some of Einstein's best work stemmed from gedanken experiments like this.

So let's say we're in a box, as in some of Einstein's SR experiments, we'll call it an elevator car. There are windows in the sides but when we look out of them we can't see anything because we are floating in a space that is reasonably removed from any energy or matter.

We have no way of judging our motion or location, as there are no external references or forces.

Now, without laughing please, imagine a giant external hand begins pulling on a cable attached to our elevator car.

The car begins to accelerate in an upward direction. (Up as defined by the design of the car only)

Initial thought is that we would expect to feel the acceleration. Due to the equivalence of Inertial and gravitational mass, we probably would not be able to tell the difference between this acceleration and a sudden exposure to a gravitational field.

Correct?

Are you sure?

The mathematics that predict the Higgs Boson say no.

Remember there is nothing external to the elevator to gauge motion by.

My mind says yes, we would feel it, since motion is relative and meaningless in this experiment but acceleration is unique.

I believe in fact, that we, in the elevator car, would not be able to differentiate whether it was gravity or inertia we were experiencing.

Take it a step further. Now imagine we have a bucket of water sitting on the floor of our elevator car, in it's mock gravitational field.

The elevator car begins to spin on the axis of the cable.

As this acceleration occurs we would begin to feel the effects of centrifugal forces. The surface of the water would take on a concave shape, we would begin to be pulled toward the walls of the car.

Again, is this correct?

Again, without a surrounding space full of matter and energy to interact with, QM says no.

Finally, some brilliant minds visit this forum, I want to hear from them!

I don't want a mathematical treatment of the subject. I want feedback on rationalization.

Anyone?

Sorry, but this thought experiment does not generalize to quantum mechanics. It deals with large-scale objects and phenomena. We have known for quite a while now that the two worlds of quantum mechanics and classical physics/relativity do not mesh well. We do not know how gravity works on the quantum scale. Don't believe anyone who says they do unless they have a newly-acquired Nobel prize. Also, you seem to imply that qm does not support your intuition with regards to this experiment. Please specify.

Originally Posted by Azure Infinity

So let's say we're in a box, as in some of Einstein's SR experiments, we'll call it an elevator car. There are windows in the sides but when we look out of them we can't see anything because we are floating in a space that is reasonably removed from any energy or matter.

By "reasonably removed," do you mean we're in a universe with nothing else? Everything is gone? That's hardly reasonable, right, but unless you do it that way, your experiment fails--the effect you're trying to remove probably scales as M/R. In other words, the Milky Way is possibly weaker than the aggregate galaxies far, far away.