[rdtsc]

Didn't plenty of new ideas start with analogies? I can think of Feynman and Einstein who described imagining or noticing things in real life which gave rise new ideas in physics.

[paulddraper]

They started by observations (e.g. light is constant speed), and using those in thought experiments (e.g. light on a train going 0.5c).

They didn't start by noticing everyday phenomenon and extrapolating those observations.

Similar, but different.

[paulddraper]

...unless you're talking about string theory. That's a close comparison to the waterbed theory.

[mannykannot]

You would have to explain to some extent what the analogy is, and what it means for the real world, before we could begin to discuss whether it is in any way correct, let alone useful.

[dhimes]

Probably just a semantic difference in what they mean by "start." In this instance, the waterbed analogy would suggest some sort of negative mass-energy and a mass-energy conservation law.