Do you "believe in Quantum Mechanics"?

[Miguel]

Dear forumers,

Last week I took part in the exhibitions in London's South Bank to commemorate the 350th anniversary of the Royal Society. In case you were there, I was part of UCL's "A water molecule's point of view of ice" stand.

Anyway, at one point last sunday, I was approached by a man who identified himself as an engineer, and immediately followed with the great sentence "... and I don't believe in quantum mechanics". According to him, all this nondeterministic stuff was all a pile of crap, and that he knew of no predictions of Quantum Mechanics. I took this perhaps a bit too personally, and taught him about Bose-Einstein Condensates and the Aharonov-Bohm effect, in full knowledge that these were by no means the easiest things to understand. I also went with the gyromagnetic ratio of the electron, where theory and experiment match to 11 significant figures last time I checked.

It really bothers me when someone who should have learned some physics and maths then goes on and disregards 100 years of science as bullshit. So, fellow forumers, what's your take on quantum mechanics?

[gridwalker]

It is a whole lot easier when you have an understanding of the different behaviours that manifest above and below the planck length, but even then it is a mind-job to wrap your head around.

It fascinates me on an intellectual level, but I am dubious regarding the practical everyday relevance of the principles (and the vast cost of researching physics at ever smaller scales).

[xpensive]

Schrödinger is way out of my league, have a vague idea what Heisenberg's arguments with Einstein was about that's it I'm afraid

[Saribro]

An odd situation in the scientific community with theories such as quantum mechanics, is that the maths of them are (generally) accepted and used, but their meaning for the workings of the world is blatantly ignored (or even refuted). I recently read a book I liked that deals with some of this: "The fabric of reality" by David Deutsch. It also has some interesting stuff on how different fields of science (physics/biology/information theory/...) and their prevailing theories only really make sense as explanations of the world if you view them together (the 4 strands in the 'Theory of Everything' as he puts it). Even if you don't agree with what's in the book, it's a good one to make you think.

[JohnsonsEvilTwin]

I think once Cerne(or its american equivalent) has discovered the higgs-bossoon or "god particle", Quantum Mechanics will be a major driver of experiments that could lead to discoveries beyond our imagination.

Thus far it has very little real world benefits, but once we have learned to apply what we know with the right technology, the engineer who stated he "didnt believe" in Quantum Mechanics will look very stupid indeed.

And books trying to deliver "the theory of everything" will fail because large particles behave totally differently to small particles. Should be a different book for each

[Miguel]

Do you guys (I suppose you're engineers) receive any QM classes during your degree? My engineer friends were taught the very very basics during their first year, together with some basic optics. On the other hand, I met an american guy who got a full QM course in his last year of the Engineering BSc, and that made him change subjects. Eventually, he got an MSci and PhD in physics. So I don't know how this works in the rest of the world.

Regarding gridwalker's answer, which seems to hint high energy physics and string theory, I wasn't really looking to go that path, but focusing on more "mundane" aspects of the theory. The physics of semiconductors is a good example. Or predicting the properties of solids.

I suppose many people have doubts because they don't see the point of introducing additional complexity, or why things would have to be non-deterministic. Could it be that I forged my point of view because all the textbooks I've had emphasised the experiments that classical physics failed to explain? If you've never heard of these controversies, of course, it certainly could make a difference.

Anyway, I don't think I fully understand quantum mechanics... and it's the tool I use daily! There's always room for surprise, but that's a good thing IMHO.

PS: As far as I know, what the theories of everything try to do is merging General Relativity and Quantum Field Theory (which is quantum mechanics adopted to special relativity). Gravity is a real b*tch.

[Ciro Pabón]

Believe in quantum mechanics? What is this, religious talking?

Real engineers believe nothing (about things, that is. We believe only in people).

Quantum mechanics is a theory, for the love of Pete. We think it works. Deterministic theory doesn't work. Heck, furthermore: we do not think it works, we can prove it works... That's the litmus test, do not worry about people that denies experimental results, they might have a degree but they don't deserve it.

It took me almost forty years of reading physics and doing experiments to finally have a huge moment: that very day I understood that an electron is not a small billiard ball. A billiard ball is a figment of my mind, made of a huge amount of matter, a human concept. I know, I know, that doesn't make any sense... keep reading physics, the day will come.

Finally, if you want to see quantum mechanics in action, simply put two fingers together and leave a narrow slit between them. Look through the slit. You'll see the diffraction pattern (small dark lines). There you have it.

Believe... hrumph.

Even my 9 years old little girl understands quanta (she doesn't believe in them, she has a good education). I was one day explaining to her something about matter and time and she answered: "oh, I see, dad. The universe is pixelated". Then she went to play dolls. Yeah, guys, the universe is pixelated.

Believe me...

[autogyro]

Earth Air Fire and Water

Should be able to build an F1 car on that.
After all it is all relative.

[Ciro Pabón]

Oh, no, no, no, no. I don't subscribe to that point of view. Relative is movement, relative is time, relative is speed. Humongous stupidity is not.

Try to build an unsound structure for a building and then say: "don't worry, everything is relative".

In my country you have to have a license to be an engineer (or a doctor, or a lawyer). Why?

Simple: other people's lives depend on you. That's not relative. After all, my little girl could be living in that building, you know, and I love her. I do not want an engineer that doesn't "believe" in experiments building it.

[autogyro]

Everything is relative, you just proved that.

[Ciro Pabón]

That's your point of view. I think your post just proved that stupidity is not relative.

I apologize if that seems too hard and opinion, no disrespect intended. After all, relativity is a theory of physics, not an argument you can use for anything, specially when you feel defeated in a discussion. I'm up to my ears of people that confounds truth with reason.

In the end, you don't have to believe in quantum theory, you have to understand it and be able to repeat the simple experiments that prove it works better than deterministic theory. It's a very simple concept, but apparently one that is not well taught in engineering schools, as Miguel conversation proves.

To paraphrase autogyro: "Yes, we ended in second place in this race, but, you know, everything is relative. I want to be declared the winner". Yeah, sure.

[autogyro]

Truth is pure belief and facts change, it is all relative.
Life is theory after all.
Unless your religion 'science' can prove otherwise.
You must have a theory on atheism Ciro, an ism that does not exist.
Ask Dawkins, he always trips up on that one.
Is 42 actualy the answer or is it that you do not realy know?

[Ciro Pabón]

Well, last post in this conversation (by me, of course).

Truth in engineering is not relative. Check your license and your ethics code.

Truth in engineering exists: it depends on experiments.

Simple. It's a thing called science, ask Galileo, he can explain that concept to you.

I believe your last post is full of postmodernism... but there is not such thing as postmodernistic engineering. You can use that argument in social sciences. Try to post in the F1Social forum, please.

[Saribro]

PS: As far as I know, what the theories of everything try to do is merging General Relativity and Quantum Field Theory (which is quantum mechanics adopted to special relativity). Gravity is a real b*tch.

Well, 'theories of everything in physics' is what you're describing, which is ... an insufficient attempt at 'everything', IMHO. But yes, gravity sucks. :)

[autogyro]

OK Ciro, I see its time for engineering mass, pass the wafer.
Not little billiard balls said it all.
Have a good weekend mate.

Truth does not depend on experiments, facts do.
Facts can be changed by newer experiments.
The truth cannot be changed, it is just very difficult to grasp by human beings.