@Olivier5,
The types of arguments made in support of SR can be truly fascinating. The following quotes are all from Einstein himself: This argument appears to be designed to prove that common sense is of little value, at least when it comes to SR:
Quote: Just how little merit there is in calling upon the so-called "common sense", is shown by the following counterexample.
OK, there's the thesis, next comes the "counterexample," but first:
Quote:Lenard himself says that so far no objections could be raised against the validity of the special principle of relativity (that is the principle of relativity of uniform translational motion of coordinate systems).
"Lenard" is a writer who questioned SR. But Al is saying that Lenard has found SR unobjectionable. So, from this point on, the argument is directed against one who
ACCEPTS SR,
not one who rejects it. Now for the counterexample:
Quote:The uniformly riding train can equally well be regarded as "at rest", the rails together with the entire surroundings can be regarded as "uniformly moving". Would the "common sense" of the train driver allow for that? He will point out that it is not the surroundings that he needs to continuously heat and lubricate, it is the locomotive, and consequently it must be in the latter that the result of his labour shows itself.
http://en.wikisource.org/wiki/Dialog_about_Objections_against_the_Theory_of_Relativity
This is absolutely flabbergasting. Basically, he's saying that the common sense of the fireman on the train will inform him that it is the train, not the surface of the earth, which is moving.
That's certainly true. And that would certainly undermine any claim that the train isn't moving. So, common sense would undermine SR. OK. True that.
Hasn't he just argued that "common sense" will reject SR? Sure, he has. But how could this possibly show "how little merit there is in calling upon the so-called "common sense," as he claimed he was going to show?
Basically his argument is simply that Lenard, who accepts relativity, must also reject common sense. That's true too. But how does it prove that common sense is worthless?
It doesn't, and can't. Suppose Lenard happened to reject SR. Then common sense would fully support his position, not counter it. Common sense only opposes those who assert the validity of SR to begin with. His basic response to Lenard is simply: "You MUST reject common sense, because you accept SR, so shut the hell up about common sense."
What's going on here? He saying common sense has "little merit" to those who accept SR. But in doing so he has shown that SR has little merit to those with common sense.
The common sense position unquestionably prevails here. It is easy to determine that energy is required to keep the train moving. "Common sense" (aka simple known laws of physics) MUST lead one must conclude that the train IS moving.
Al therefore says: So we can reject common sense (known physical laws)
But anyone with a lick of common sense (knowledge of physical laws) will simply say: So we can reject SR.
) .
