however convincing the evidence is in favor of a scientific theory, we can never prove it right?

Question

but one piece of valid evidence can prove it wrong. whys this?

Answer 1

Because that's the way science works. Theories are always vulnerable to new data that can cause them to be re-evaluated, re-worked, or discarded. This is why scientific study is a valid method of understanding the universe, because new discoveries force new ideas rather than blind dogmatism.

Answer 2

Here is my attempt at a simple answer. A longer answer would involve suggesting you read lots of book on the philosophy of science by Popper, Kuhn, Lakatos, Feuerabend and many others.

The first bit is correct if you take a strict definition of 'prove'. The whole point is that is a way of gathering and evaluating evidence rather than a method of proof. However, science is something that happens within a community of scientists and is a useful tool (albeit not infallible) for making practical decisions. When many scientists reach a consensus - especially if the consensus is overwhelming - it often gets accepted as 'proof' in a less strict sense of the term. (The problem here is between an everyday/legal sense of the term proof and an ideal/mathematical sense of the term 'proof'). A key point is that science recognizes it is fallible and has a correction mechanism to reavaluate the situation if there has been an error.

The second answer is, on my understanding of science, a massive, massive oversimplification. A simple reading of Popper would suggest that a single valid piece of evidence can prove a theory wrong. No theory should fall on a single piece of evidence: the evidence could be wrong even if 'valid' on most measures; the statement of the theory could be mistaken about some of its predictions; the theory may have been wrongly interpreted. In general a successful, productive, useful theory requires a body of evidence to disprove it - not a single piece. Furthermore a good theory can usually be modified to account for one or two anomalies. Most theories thus suffer a death from a thousand cuts rather than a sudden extinction.

In addition many theories fail because they are replaced not by theories which make better predictions but by theories with greater scope, parsimony or coherence.

Answer 3

If this was not the case we would be stuck with a flat earth at the centre of the universe!

Scientific progress is based on the possibility that any/every theory could be 'wrong'. In fact, many theories attract a lot of interest because of exotic and difficult to test things they predict.

For example, one of the most successful theories of the 20th century is Einsteins theory of General Relativity. It has made amazingly exact predictions of things like black holes, gravitational lensing and time delays in satellites.

But just recently NASA started testing some of the stranger predictions of the theory with a probe costing over $700 million - Gravity B.

Why spend $700 million on testing a theory that seems to be clearly correct?

Because if there is something wrong with the theory the chance for advances in science is amazing - it would be like finally blasting through a high mountain pass to open up vast gold mines just over the hills!

Of course - all the other predictions of General Relativity that have been tested and proved correct would still need to be predicted by whatever came along afterwards ... so it's not like the theory would be thrown away completely.
Just 'upgraded' :)

Answer 4

One piece of valid contradictory evidence can disprove many scientific principles whose science was very weak or improperly performed. We cannot say that you can never prove anything just because some incorrect or poorly performed science was disproved. That is why experiments need to be repeatable by other scientists. So the same conclusions can be reached. I really don't think we are going to find something for example that falls up, or has less mass and more gravity. Poorly performed science will always be disproved. I think that when we hear that a particular finding was incorrect it proves that the scientific method works.

Answer 5

It is a theory, someone has said "I think the world works like this, and here is something to show why I think it is so", and then all the other scientists try to disprove them - jealousy that someone else had an idea??

Think back years ago, they thought the world was flat, and it was believed by everyone - and then it was shown centuries later that is wasnt, examples like that show why theories stay as theories.

Curiously, there are some Laws which were theories once, and were proved to be right (though amended later), for example Ohms Law, Kirchov's Law, Pascals Law etc. but they have to be pretty good theories for that to happen

Answer 6

Scientific Theory is developed as a hypothesis, evidence can be obtained to say that your hypothesis is correct but is it real?! Altenatively, evidence can be obtained to "p[rove" your hypothesis incorrect, but does it mean that it is wrong?

The biggest scam of all - Carbon dating..... How can a sample of a few hundred years at most be extrapolated with any accuracy into 400 billion?!

For me the true science is in understanding the question and accepting that all scientific theories are right until proven otherwise. Black is black, reason being absorption of the entire light spectrum.... However, does is absorb all colours equally? Thus determining its shade of black....

True science is understanding what will answer most of the questions, and proceed to show that your answer is the least challengable.

Answer 7

Science and the techniques that are used to prove or disprove are always advancing. It was only back in 1974 that scienctists disproved the sea floor was a flat waste land by the invention of the submersible called ALVIN which discovered hydrothermal vents and the most interesting facts of the sea floor.
In science hypothysis's are stated about a point, it is very rare for it to be stated as a fact until nothing can disprove the hypothysis.

Answer 8

Interesting question. Try taking it literally. One a scientific theory has been proven beyond any doubt whatsoever it becomes a scientific fact or a 'law'. A theory is just that - something that on the balance of probability is correct. You then need only one contra-indication to let you know that the balance was inaccurate.

Answer 9

It comes from a history of believing that a theory is absolutely correct without exception only to inevitably have somebody come along with an exception.

There is no point in declaring a theory completely proven and it is never a goal of science to do so. As technology improves our methods of measurement and observation, we will invariably find chinks in any theoretical armor.

Answer 10

That's science for ya! But just because one part of a theory may be wrong, doesn't make the whole theory wrong...especially if it works (ie. Theory of Relativity...parts have since been proven wrong BUT the idea, as a whole, remains valid because we've proven that a nuclear chain reaction can be sustained and controlled).