- #1
James Demers
- 62
- 35
For many, many years (don't ask), I've been running into the classic example of the local reference frame: the man in the box who can't tell if he's floating free in space, or falling into a gravity well.
It occurs to me that if one is in a falling box, a mass released at the top of the box will be subject to a wee bit less gravity than a mass released at the bottom of the box. A sensitive enough instrument would be able to detect a force pulling them apart. (This is nothing exotic: it's the tidal force.) Thus, the experiment would tell you that your box is not floating free, but is accelerating toward another mass. (A worrisome discovery, I would think.)
Is this just a matter of a poor choice of example, one that's persisted for about a century? Or is there something actually different between the two boxes?
It occurs to me that if one is in a falling box, a mass released at the top of the box will be subject to a wee bit less gravity than a mass released at the bottom of the box. A sensitive enough instrument would be able to detect a force pulling them apart. (This is nothing exotic: it's the tidal force.) Thus, the experiment would tell you that your box is not floating free, but is accelerating toward another mass. (A worrisome discovery, I would think.)
Is this just a matter of a poor choice of example, one that's persisted for about a century? Or is there something actually different between the two boxes?