# Inertial frames and related predictions

1. Jan 23, 2012

### spaghetti3451

As a result of observations made over many, many years, physicists have inferred that:

"No experimental test provides any way to distinguish an inertial frame from another."

This negative form of the statement is important, as it is a prediction which can be tested experimentally and thus falsiﬁed. It has never been.

I have been unable to undestand why the negative form of the statement is important. So, I have attempted to write down the positive form of the statement. This is it: "There is an experimental test that can distinguish between inertial frames."

This is not a prediction (as it does not follow from the experimental evidence of the last four hundred years), but the statement can be put to test through experiments. However, it will be very difficult to prove as all the experiments conducted so far have been unable to distinguish between inertial frames. So, the matter would remain inconclusive.

In spite of what I have written, I still don't understand the importance of writing down the prediction in a form in which it can be falsified. Any ideas?

Last edited: Jan 23, 2012
2. Jan 23, 2012

### ghwellsjr

Einstein's first postulate, the principle of relativity (not to be confused with Special Relativity which also requires his second postulate, which cannot be experimentally verified).

3. Jan 23, 2012

### spaghetti3451

I know that this is the first postulate, but I still don't see how the negative form of the postulate is important in that it can be experimentally tested and thus falsified.

4. Jan 23, 2012

### ghwellsjr

I have never seen the principle of relativity stated in a negative way. Einstein stated it in his 1905 paper as:
which appears to me to be a positive statement but of course it can never be proven, although it could be falsified by a single counter example. But this is why Einstein raised it "to the status of a postulate" so that it is assumed to be true without any proof.