why does a theory in physics always remain a theory?

Answer 1

Well, a long time ago a fellow named Plato pointed out that we can never really be absolutely sure about anything in the physical world because the senses we depend on for that can always be fooled. We could be sick, for example, and have hallucinations. A bit later, a guy named Descartes agreed, pointing out that a mischievous demon could be making us see stuff and all we could really be sure of was that we existed. Later still, an updated version posed that maybe aliens 10^100 time smarter than us could micromanage our every thought at their whim, making us believe we've proved things conclusively regardless of reality. They were called Googles (the answer to what you're asking yourself right now is yes). We could then never really be sure about anything, then, because we can't prove there aren't Googles because you'd have to assume there aren't Googles making you believe you've proved there aren't Googles, so your argument's circular. Got a headache yet?

Well, anyway, scientists got fed up with all that and said, look, we'd like to get some work done here, so will you philosophers agree to leave us alone if we forsake any pretense whatsoever of absolute knowledge? We promise never to even utter the word "truth", and everything will remain a theory. The philosophers then gave them their heady approval and went back to arguing over angels dancing on pins. Well, most of them, anyway.

Answer 2

It is a basic principle in science, that nothing can ever be proven beyond any doubt to be so; although it can be disproven. A theory is useful if it is consistent with all the physical phenomena it attempts to describe. But however well it describes events, one can never say for certain that at some point in the future an event will occur in defiance of the theory. If and when this happens, the theory can no longer be considered a true representation.
For example, take Newtonian Mechanics. It describes the motion of bodies very well under everyday circumstances, and thus was accepted physical theory for a long time. However, with more accurate measurements, and particularly with regard to objects moving at very high speeds, it becomes apparent that Newtonian mechanics is not an accurate description of the world. Hence, it has been replaced by Einsteinian relativity. But this too has limitations- it doesn't work on a very small scale for example, and even if it did, you could not discount the possibility that at some point we would discover physical phenomena with which it is not consistent. Thus, it must always remain just a theory. Anyone who claims to know absolute truths is a fool.

Answer 3

It's just a word.
A theory explains everything that is observed.
The word theory suggests it is both workable, but you are willing to throw it away when you are presented with a better theory.

It got that way when lots of scientific progress was made very quickly in the 18 and 19 hundreds.
For example: Ether theory explained a lot of things but had to be abandoned when it was shown that 'ether' didn't really exist.
The atom model where electrons are like little planets circling a core works to explain a lot of things - but it is not the way atoms are actually made up.

Interestingly enough, the laws of physics would also be called theories, had they been discovered today.
For example, the Newton's law of Gravity is good enough for everyday use. But refinement is needed for extreme situations (when relativity comes into play), so it is workable, not perfect. Had it been discovered this century, it would have been called the Theory of Gravity.

Answer 4

There is a theory about light that maintains that a photon can interact with an electron of an atom kicking it up into a more energetic state. When the electron returns to its rest state in one or more steps it releases the excess energy in one or more new photons. And yet no one has ever observed this to happen, only the results of many experiments. Theories explain phenomena that it may never be possible to observe close at hand because there are no tiny flashlights at that scale and the reactions may occur at incredible speeds, like photons flying off at the speed of light. There is always the possibility that with better technology, better 'observations' and explanations may be made.

Answer 5

Theoretical Physics though is a highly challenging field, it mostly deals with far-fetched propositions. Most of it depends on calculations and if there is something wrong with the formulae then the total theory goes wrong. Also most of the theories can't b practically proved.

Answer 6

Because the theory hasn't been fully proven to be true to be considered a law. If you prove a theory to be a law, then you'll probrably win the nobel prize.

Answer 7

There is no way to actually "prove" an assumption; observation and experimentation are pretty much the only way to get close to proving something.

Answer 8

you mean it doesn't get 'practical'?