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Hypothethical question: When facts become Wrong Answered


I had this weird thought awhile ago. IT seems that alot of people's ideas that were considered OK and accepted are later found out wrong and disproven. Do you think that in a few hundred years alot of what we are thinking are not true?

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Possibly.... Our current scientific knowledge may have a completely different version in the next million years or so. Think about it, there are different sides to a story. Our knowledge may might as well be only one side. Things fit together in different ways, but as long as it makes sense/fits, then yeah it's a fact. Well, string theory might be wrong, but it's only a theory just now. Anyway, 18th century science to us is considered wrong, but to them, it's right. I wonder how the 15th century was to them.... The point is, facts are facts until proven wrong, or they find a better fact that fits better...

Facts and inferences are different. Some of the inferences made by 18th and 19th Century scientists, for example, their theory of heat being a material, or their theory of the ether, are now recognized as wrong. But those theories were inferred from facts which are as true today as they were back then (heat flows from warm regions to cold regions, and light is a wave phenomenon).

What's so wrong about light being a wave? I've read both books that said that the wave theory is wrong because we can see photons (QED)and that said that particle theory is wrong because things about little clocks and arrows are too much thought up, while everything can be nicely explained with simple waves...

Light exhibits the characteristics of both waves and particles.

Who said there was anything wrong with light being a wave?

If one reads Kelsey's paragraph TOO fast, it could be misinterpreted that way. But a careful reading corrects that problem :-)

Nobody said (or should have said) that the wave theory of light is "wrong."

The existence of diffraction and interference are sufficient to demonstrate that light is a wave. You can't get wave interference without a wave.

The existence of the black-body radiation spectrum and the photoelectric effect are sufficient to demonstrate that light is also a particle (with energy proportional to frequency).

What I wrote above was that the theory of the ether was wrong. Light waves are not some sort of oscillating medium (analogous to sound waves in air or metal). The waves are oscillations of the electromagnetic field, which is not a material medium.

I though that you used 'heat flows from warm regions to cold regions, and light is a wave phenomenon' as examples of what used to be the working theory but now is proved wrong...

Oh! Sorry about that, my writing was not very clear. What I meant was, that the old 19th century theories (phlogiston and ether) are now seen as wrong. But the original facts upon which they based their theories -- how heat flows, and the wave nature of light -- were true back then, and are still true today. It's the explanations which have changed.

Well, that's what they thought! Their thermal model was that heat was an actual material substance (phlogiston) which flowed through matter; objects which contained a lot of phlogiston were hot, and those without it were cold. It was a very physically-oriented theory. A lot of our terminology, even today, is derived from that (very influential) theory -- think about heat "flowing," or "heat capacity," for example.

Only today, when our Biology teacher said something like 'Actually water is rather a weird thing... Who knows what's so special about it?' and I told him that the unusual thing about it is that the molecule is strongly polarized, he went ballistic about water being polarized is our IDEA of how to explain why it's so strange, and that we should've said that it expands when being cooled down when near to zero, and has a very high boiling point compared to H2S.

Well, in a way he is right, and your answer was incomplete. The facts which make water unusual compared to similar materials are its anomalous density, and its high boiling point (which is coupled to its very high heat capacity and heat of vaporizaton). Molecular polarization and atomic-scale clustering are our best model for explaining those unusual facts.

That's not a problem with science, that's a problem with a hide-bound teacher.

Don't you think that the majority of people back then interpreted these as facts?

No, I think the majority of people back then didn't have any idea that these concepts even existed, let alone whether they were true or false. I think the scientists of the day understood that they were interpretations, just as we understand the difference between our interpretations and observed facts.

Oh, right, the deficiency of widespread information available through books weren't really all that developed... How about the mid-19th century? They already have newspapers developed don't they? Then telegraph and a host of other info transmission techniques.

"Ideas" are not "facts" (unless you watch Fox News). Ideas, hypotheses, even proper scientific theories, can all turn out to be incorrect, disproven, or falsified. Actual facts -- objective data about the world or the universe, or mathematical theorems -- exist outside of our opinions of their truth, and remain true even as our ideas change.

The mass of the proton, 938 GeV, is a fact. It was true 13.6 billion years ago, it's true today, and it will remain true forever. That the proton is made up of three valence quarks embedded in a "sea" of virtual quarks, antiquarks, and gluons, is a prediction of a scientific theory (quantum chromodynamics) which may turn out to be wrong, either next week or in a hundred years.

It ISN'T a fact that the mass of a proton is 938 GeV or 57 lillumjackies. It is a fact that the proton has a mass, and WE call it 938 GeV. Also, some people think (or used to think) that its mass depends on its speed, so it took some time to call it 938 GeV instead of 0,000000whatever kilograms. And that means that the word 'mass' is not what we used to think for the last many many many years, because if you weigh it, you can get a lot of different results.

Sorry, but I'm a terrible teenager :)

0) You sort of caught me in a stupid mistake, but then you just copied it :-) I should have written either "938 MeV" or "0.938 GeV."

1) Units are part of the physical quantity, and therefore part of the fact. Converting from one unit to another does not change the value. I could write 938 MeV, 1 amu, 1.673×10-24 g, or whatever; but I can't just write "57". All of those quantities (number plus unit) refers to the same physical mass.

2) It has been well known to physicists that mass does not depend on speed. That is a misconception which has been promulgated to schoolchildren (ahem) and the public.

3) Mass and weight are different things. If you want to specify the weight of an object as an objective fact, then you need to indicate the conditions under which it was weighed (what planet, where on that planet, in vacuum, air, water, or some other medium, and so on).

4) You're an intelligent, well-read teenager, who, like most intelligent teenagers, enjoys playing word games, and being contrary just because you can.

Why can you say that a mass (amu, g) is equal to an energy (eV) ?

(a) From the equivalence of mass and energy, E=mc2.
(b) I built in an assumption into my units which I should have stated explicitly.

Technically, the high-energy physics units of mass are eV/c2 (and MeV/c2 et seq.). However, we commonly (universally) work in "natural units" where c=1, h-bar=1, and so on. So, in many papers, and most informal discussions, we use eV for energy, mass and momentum, even though that is technically ambiguous.

i wasn't aware that it is used that way, thanks for the axplanation.

No problem! Since we do this kind of stuff all day, every day, carrying around all of the factors of "c" gets pretty tedious. In natural units, you can write E = m, or more correctly, E2 = m2 + p2, and by doing all the work in eV the units are guaranteed to balance.

Ack, algebra.....give me good ole geometry any day...*sigh*.  E2 = m2 + p2 looks WAY too familiar.

2) It's written in the very begining of the Feynman lectures (the bit about why experiments can be wrong and if we saw that a spinning top has the same mass as when it lies on the floor, it doesn't mean it's mass is always constant), and I've been taught to believe that very book. I've added "used to think" because I've read something about things being different.

3) I use the word 'weigh' as the verb to 'get to know the mass', because you can't 'mass' things...

4)Oh yes. This is exactly what all my class does all the time ;)

Yes, I know. Feynman was part of the same generation that continued that misinformation. Lev Okun has been the most vocal promoter of trying to change the popular presentations. Within the nuclear and particle physics community, we never use a velocity-dependent mass -- it makes all the calculations really ugly and needlessly complex. Treat "m" as a frame-independent constant, and all the boosting into different rest frames becomes much simpler.

Facts are facts until they are proven otherwise. Turns out Pluto was only a dingleberry.

Pluto is exactly what it always was, a big ball of rock and ice about 2,300 km in diameter; that's a fact. The label we use to describe it has changed, because we decided that the label was too general to be useful scientifically.

Ah, the Bill Clinton school of fuzzy scientific thought, eeerhm, it depends on how you would define what planets are...Johnny, how many planets are in our solar system...It fn depends on what you mean by planets...Teachers would now need to qualify everything they teach as facts or accepted theories.

No, not everything. Teachers need to stay current, or they aren't teaching properly. Science teachers need to know about science -- including current activities in science -- or they are teaching children ignornance and disdain for knowledge. I'm sure the Glenn Becks of the world (and their toadies) would love to have everyone taught ignorance and blind acceptance of authority.

It was the ONE thing I REALLY hated about highschool.

The more I read, the more I found out the school was still teaching from textbooks that had 1950's (or earlier) data in them (I was in highschool in the 1970's)

No - Really?! Man, and all along I thought Pluto literally shrunk when its official definition changed!

Golly.

;-P

Hey, if somebody's going to pull a snarky example, they'd better expect a snarky response.

And all this time I thought Pluto was a dog......it was a sad day when I discovered otherwise....

i just posted a random thought and i never expected this much comments! holy sheez!

You learned a valuable lesson, then. Think less randomly, or think more before thinking randomly :-)

You can not really tell, and you actually can not tell if what they thought is not actually fact and we just all think something different which is not true.


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