Tuesday, January 07, 2020

Quantum overview

I quite liked this simplified list of quantum interpretations that appeared in a recent book review in TLS.  John Gribbins came up with this:
As it stands today, depending on how you want to interpret the results from a litany of physical and mathematical experiments all validating each other, you are left, basically speaking, with only so many possibilities of how you might understand the world. Gribbin chooses six of the more scientifically realized and commonly endorsed. As he summarizes them:
One. The world does not exist unless you look at it.
Two. Particles are pushed around by an invisible wave. But the particles have no influence on the wave.
Three. Everything that could possibly happen does, in an array of parallel realities.
Four. Everything that could possibly happen has already happened and we only noticed part of it.
Five. Everything influences everything else instantly, as if space does not exist.
Six. The future influences the past.
As explained further down, this list equates with the Copenhagen Interpretation (number one, roughly) and the rest are:
the Pilot Wave, Many Worlds, Decoherence, Ensemble and Transactional interpretations
I like this bit of quirky information, too (in my bold):
Bohr said that the world revealed by measurements is the only reality worthy of the name, that the act of measurement actively constructs the reality that is being measured. Put an electron in a box. According to the Copenhagen interpretation – as Jim Holt describes in When Einstein Walked with Gödel – it “does not have a definitive location until we look inside to see just where it is. Prior to that act of observation, the electron is in a mixture of potential locations spread throughout the box”. This mixture is “mathematically represented by a ‘wave function,’ which expresses the different probabilities of detecting the electron at the various locations inside the box”. In French the wave function is poetically called the densité de présence, which is a helpful way of thinking about it.



13 comments:

GMB said...

Yeah. Total idiocy. A rebellion against science and the scientific method. Going so far as to reverse cause and effect. Total fantasy and Voodoo

It all goes back to aether-denial.

John said...

It works. Forget about reality it is irrelevant. It is important to distinguish between the interpretations of QM and QM.

GMB said...

No we cannot have idiotic fantasy posing as science. The idea is just to sack a few people until the survivors decide they might like to do their job.

Steve said...

John, you're firmly in the Copenhagen Interpretation group, then.

John said...

John, you're firmly in the Copenhagen Interpretation group, then.

No I'm not. It's mysticism dressed up as science.

GMB said...

Empires, when they want to die, will often head to Afghanistan. Science workers, when they want to lock in some egregious bullshit, will often shoot straight to Copenhagen. Far from the prying eyes of the public.

Steve said...

"No I'm not. It's mysticism dressed up as science."

I think there are a range of possible views as to what Copenhagen means, and I don't think all would fit your description.

But I see now that you are presumably more an "instrumentalist", according this bit from Wikipedia:

Some physicists, including Paul Dirac[74], Richard Feynman, and David Mermin, subscribe to the instrumentalist interpretation of quantum mechanics, a position often equated with eschewing all interpretation. The position is summarized by the sentence "Shut up and calculate!". While this slogan is sometimes misattributed to Dirac or Feynman, it seems to have been coined by Mermin.[75]

John said...

That's correct Steve. Reality is for those who can't handle drugs and mathematics.

GMB said...

After the aether-denial pay op have been going a decade or two, as I remember things, Bohr got a scholarship to spend time with a couple of scientists. He spent a few months with each and one of them was Rutherford.

Rutherford was shooting helium nuclei (alpha particles) at thin sheets of very thin gold. As a result of these experiments Rutherford put together a model of the atom that no-one could be happy with.

But without the aether it was kind of all that could be done. Particularly as another tendency was to put electricity into its own little box.

It was Bohr that worked hard to get people to accept the model. He has all these politely worded arguments. My interpretation of his arguments goes something like this:

“Sure the model sucks. But fuckit. We have to move on.”

Bohr elaborated things with electrons in shells, photons created ex nihilo and any amount of other bullshit but it served the chemists well and at about this point there could be no turning back.

GMB said...

The deal is that you don’t have to be too bright in order to control people that are smarter than you are. You just invest about three decades forcing people to believe stuff that cannot possibly be true. So if you can apply enough political pressure the institutions will do the rest.

John said...

The deal is that you don’t have to be too bright in order to control people that are smarter than you are.

Ah I see you understand politics. Maybe it is just their public persona but I find politicians to be singularly narrow minded tedious thinkers and policy often mirrors that. Politicians are typically boring little tits who control the entire country.

GMB said...

Imagine a dynastic mind so devious that it would conceive of outlawing the aether.

GMB said...

John Gribbon's been at it a long time. I seem to remember I had one of his books when I was about 16.