Ask HN: Am I misunderstanding quantum mechanics? | Hacker News Reader

Ask HN: Am I misunderstanding quantum mechanics?

3 pointsdojitza19 comments

What I've gathered from my limited reading and research is the following:

1. The universe is fundamentally infinite and continuous, both on a macro and micro scale (infinitely large, and infinitely divisible)

2. Observation on a scale currently available to humanity interprets the continuous and infinite as finite and quantifiable - some information is lost in the process. A piece of reality we call an electron is shot at an another one, and we have learned how to observe the displacement of those pieces.

3. Quantum superposition is nothing but a translation of the reality of continuous fields into our quantifiable domain.

4. Measuring collapses the probability fields in a sense that no other way of measuring is available for us other than interpreting the continuous as a quantifiable and losing information in the process.

5. By repeating measurements and mapping the distribution out, we can get a rough estimate of the field that is observable through the interaction that we are using for measuring.

How far off am I? What are some good resources to read up on to deepen my understanding of what we currently know?

Thanks.

(1) seems incorrect. Large scale cosmology wrestles with the observational or physical bounds of the universe and what that means. Small scale goes granular due to the uncertainty principle. (Planck length).

The others seem to run together. In general, classical modeling works with problems appearing at the very large (relativity) and very small (quantum mechanics). At the very small, the act of observing something influences it’s future behaviour (or, that behaviour becomes unpredictable). But the overall behaviour is statistical and thus predictable (quantum effects like diffraction or tunneling).

Check out Brian cox, Timothy ferris, hawking or other science popularizers.

1. The part of the universe that we can see is finite

https://en.wikipedia.org/wiki/Cosmological_horizon

2. Electrons are all identical to each other, it's not right to talk about the wavefunction of one electron rather there is a wavefunction for all electrons. To me the profound things about entanglement is that entanglement of fermions makes solid matter possible. Entanglement of bosons is what makes lases shine.

5. Collapsing the wavefunction is permanent, you don't get do do it all over again.

1. The universe is fundamentally infinite and continuous, both on a macro and micro scale (infinitely large, and infinitely divisible)

My understanding is that neither of these things is definitely known to be true, and that there is considerable debate around both points. But IANAP...

Quantum mechanics is a great way to predict outcomes..

But has nothing to do with describing reality

No, it describes parts of reality quite well. That’s part of its problem.

No, it doesn't describe reality, it is a model that predicts the results of some simple experiments. (Physicist here)

Well, it predicts infrared spectroscopy to train detectors accurately enough to chemical structures. It can calculate other spectroscopic information so as to identify unknown materials being investigated. I'm sure there are other microscopic properties that can be investigated, such as tunnelling or material/catalysis design, but I've only worked in spectroscopy.

Edit: forgot... Minimization to transition states has been used to understand chiral synthesis and has been proposed as a means of training antibodies to assist in such synthesis. It's also been used to humanize antibodies (in combination with the classical forcefield molecular dynamics).

Are these all "simple experiments". Yeah, I guess so. No extreme physical conditions are required to perform them. Can be done in high school labs, ... Still, they're specific calculations of physical properties that reproduce nature. Not sure your point re: "doesn't describe reality" - Can relativity predict ir spectroscopy (not the shift thereof due to acceleration)? Does string theory predict anything testable vs. simpler theories?

Why are you asking that here and not in a physicist forum?

Cuz the physical world and how pcs work and issues re die size influence the world of HN?

Reply on news.ycombinator.com