Is there a clearly defined difference between a 'thought experiment' and a 'speculation'?

A thought experiment is bounded by the same rules as a physical experiment, it just happens in your head rather than in reality... To me, a speculation is more of a hypothesis or theory that does not have much support. You could use a thought experiment to disprove a speculation, or provide support for it. But then a thought experiment could also be used to disprove or provide support for a generally accepted theory that has gone far past the point of being considered a speculation.

In general or according to forum policy?

Is there a clearly defined difference between a 'thought experiment' and a 'speculation'?

 

A thought experiment would consist as a series of steps, each of which should be argued based on accepted physics. Most thought experiments are based on interpretations and so one can easily get confused. If these series of steps don't fit together then there is either something new in the physics hiding behind it or something is not right with interpretation, or probably a bit of both.

 

A speculation also could (and should) be well-founded on accepted physics or observations. For example speculating that the mass of the Higgs boson is maybe 200 Gev is not just plucking a number out of thin air. It is based on our understanding of the standard model. (Note the standard model does not predict this mass by itself).

 

Many speculations that get aired on this forum are not of this kind.

In general or according to forum policy?

 

The other replies give a clear understanding of the general view, but to avoid another warning you better give the forum view.

 

It might help if I add that this question arises because I cannot understand why Fig. 1 on:

 

http://www.scienceforums.net/forum/showthread.php?t=51884

 

is classified as 'speculation'. There has been other similar cases in the past, but this is the first one that I feel has the clarity needed to make my case.

 

My thanks to AlphaSheeppig and ajb for their replies.

Speculation, as treated by the forum, is "new" science. i.e. a challenge to existing science, rather than as an extension. Or it can be something that is not particularly part of science at all, e.g. something that fails to be testable or falsifiable.