I guess I have a small problem with this use of the word "fact" which to me is something provably true. What this piece is actually saying is that half of scientific theory is probably wrong.
Only in mathematics are things provably true. In science, things are considered true based on the best theories and experimental evidence we have so far, and our observational abilities increase as technology gets better over time. For example, Newtonian mechanics was considered "true" for centuries, until it was replaced by relativistic mechanics. In the 18th century, we just didn't have the equipment to measure phenomena at quantum scales; now we do. As we observe the world in greater detail, we find that things that seemed to be true before are now false. That's the best that science can do.
Actually, I'd say that in mathematics, things are provably true given that the initial assumptions are true. However, mathematics does not so far as I know deal with the truth of those initial assumptions (axioms), it simply accepts them as true.
Where this gets interesting is that you can say, what if this axiom was not true? Let's assume it's not. And then possibly come up with a whole new system of mathematics (like non-euclidean geometry) which may turn out to have actual use in previously unsolvable problems.
I think it's better to conceive of mathematical axioms as being part of mathematical system X or not, rather than as true or false. That is, they're not self-evident or universal or true according to some external standard, they're merely postulated as properties of a given mathematical structure.
Adding to this, maybe "true" is a bit of a loaded word. Newtonian mechanics works just as well today as it ever did. I prefer to think of it in terms of usefulness. 18th century knowledge is like a Pentium 3 that we just don't want anymore.
I have a more than small problem with the use of the phrase scientific theory[1] which to me is something provable.
>A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not "guesses" but reliable accounts of the real world.[2]
I'm not sure how you'd prove the theory that dinosaurs were cold-blooded, short of taking the rectal temp of a Stegosaur.
But you could falsify the theory by finding characteristics incompatible with being exothermic. Finding the dinosaurs with feathers and other characteristics of the (warm-blooded) birds probably helped, too.
Some of the "incorrect facts" are really theories that were substantiated to the best degree possible at the time, and no falsifying evidence existed at the time.
I suspect some, like "non-functional junk DNA", is a case of scientific qualifiers being ignored in the mainstream media and forgotten.
Humans like "facts", but we inevitably drop the error bars that originally accompanied each new "fact".
Depending on meaning of "wrong". If it means that there will be facts that are not accounted for by current version of certain theory - then it's probably true for most of them. If it means that our current interpretation of certain facts is completely incorrect - such as we think X is caused by Y, but in fact X is caused by Z which has zero correlation and no causal links with Y - I would be very surprised if it turned out like this for half of the established theories. Though for those that are just being developed probably much more than half of them will be wrong in this sense. I guess it also depends on the field - I'd say it's unlikely we'd have some overwhelming change in classical mechanics, but if you talk about something like biology or neurophysiology - there are a lot of things that are not clear, so it is entirely possible that our understanding, for example, of how addiction works - would be radically different in 20 years.
