[lutusp]

> Questions like "is X a science" looks often like the "True Scotsman" fallacy

True about Scotsmen, false about science. Science is easy to define, therefore easy to detect.

Either a field has testable, falsifiable ideas -- ideas that can be compared to reality in practical tests, indeed are compared to reality, and are promptly discarded if they fail the test -- or they do not. End of story, fini, full stop.

> Biology? No.

Biology, yes. Either DNA is the source of heredity or it isn't. It's testable and falsifiable. Either natural selection produces new species or it doesn't. Again, testable and falsifiable. Biology can make and test empirical claims, and it does, and it discards those ideas that fail the test. That's science.

Look at prions. At first no one knew what was going on, so they did some research. They took body fluid from one victim and passed it through a filter that would have stopped a virus, but the prions got through. This forced the explanation that something smaller than a virus was reproducing and causing fatal illnesses. This led to a much better assessment of what prions are. A falsifiable test was performed, the test succeeded, prions are real. Mad cow disease, Creutzfeldt–Jakob disease and a handful of other diseases would have remained unexplained, except for the science.

> An electron suffers a force inside an electrical field, 100% (exactly) of the time.

It's easy to describe physics as a science, for the reason that it is very much a science. What's hard is comparing physics to other endeavors that might or might not be sciences. But there's no reason to use physics as a science yardstick -- all one needs to do is ask, "what theories have you tested, falsified, and discarded?"

http://xkcd.com/435/

[raverbashing]

> Biology, yes. Either DNA is the source of heredity or it isn't.

As always, it's more complicated than that. But you can definitely test (and confirm) for DNA being a part of it.

But that's one part of biology, confined to planet Earth, and we're not sure it's the whole story.

Yes, it is proven, according to science rules that, (for all biological entities known) DNA (and RNA) conveys hereditary information.

But biological proofs are weaker than physics proofs. "Oh, you proved humans have this thing called blood cells and they're round?" Until you find people with congenital Anemia, and look, their blood cells are not round, because this makes them immune to Malaria. So it's not possible to generalize as much.

In Physics I am confident that the electrons (and chemical elements) in my computer are 100% indistinguishable from the ones in the Sun (albeit in different quantities and temperature of course)

And speaking about physics, light was a wave and this had been tested and verified multiple times. Until it wasn't.

[lutusp]

>> Either DNA is the source of heredity or it isn't.

> As always, it's more complicated than that.

No, it isn't. All one need do is demonstrate that DNA is not the source of heredity, i.e. falsify the claim. That's how science works. Epigenetics doesn't disprove the role of DNA, it augments it, in the same way that conduction and convection stand alongside radiation as mechanisms for the transport of heat energy.

> But biological proofs are weaker than physics proofs.

Not the scientific ones.

> And speaking about physics, light was a wave and this had been tested and verified multiple times. Until it wasn't.

That's misleading. There was a debate about whether light was a wave or a particle -- evidence supported both views. Eventually a new theory combined and fully validated all the prior observations by showing that light is both a wave and a particle. That theory is the best-supported and most powerful theory devised to date, and is the crowning achievement of 20th century physics. And it will eventually be replaced by an even better theory, one that explains more, with fewer preconceptions and arbitrary axioms.

That is science at its best, science driven by evidence, evidence that shapes theories, theories that must survive testing or be discarded.

[notahacker]

Epigenetics might augment theories of heredity, but the causal role of incompletely penetrant alleles in expressing a particular phenotype is falsified in the absence of any auxiliary hypotheses to explain their level of penetrance (especially if that phenotype may also be expressed without that allele). If naive falsificationism is the distinguishing characteristic of science, then an awful lot of biology, including some very useful statistical associations between allele X and phenotype Y (supported by statistical hypothesis testing that looks remarkably like that in social sciences...) gets discarded. If you had to throw away every theory whose counterexamples couldn't be adequately explained there wouldn't be much biology left. The AIDs denialists would have the right idea. Koch's postulates would, if anything, be too low a standard. Popper even had his doubts about the scientific validity of natural selection...

[raverbashing]

> All one need do is demonstrate that DNA is not the source of heredity

Oh, I'm not saying DNA isn't the source of heredity. I'm saying that there are other smaller factors. (you can google them). Heredity in the strict sense, yes, it's DNA, in the broader sense, well, you can have two different fenotypes with the same genotype.

> There was a debate about whether light was a wave or a particle -- evidence supported both views.

Not before the 20th century, diffraction of light (amongst others) firmly put it as a wave. http://en.wikipedia.org/wiki/Light#Wave_theory

And the wave theory of light is still widely used (when it's applicable of course).

[lutusp]

>> There was a debate about whether light was a wave or a particle -- evidence supported both views.

> Not before the 20th century,

Yes before the 20th century. I refer you to the debate between Newton and Huygens as well as Hooke, his contemporaries with respect to these ideas.

http://www.studyphysics.ca/newnotes/20/unit04_light/chp1719_...

Such debates persisted from then until the shaping of quantum theory.