Popular Boards

Niels Bohr | Medical Entomology and Zoology | (2011)

Abstract

Introductory survey 1. Atomic theory and mechanics 2. The quantum postulate and the recent development of atomic theory 3. The quantum of action and the description of nature 4. The atomic theory and the fundamental principles underlying the description of nature.

Tags

Sample Definition And Size

This work is a collection of four essays by Niels Bohr, accompanied by an introductory survey. It is not an empirical study and does not involve a sample size or subjects.

Study Type

This is a theoretical/philosophical essay collection, not an empirical research study; it does not follow a study design such as RCT, observational study, or meta-analysis.

Conflicts Of Interest

No conflicts of interest are declared; as a philosophical/theoretical work published in 2011 (first paperback edition), it does not include conflict of interest disclosures.

Results Summary

The work presents conceptual discussions on atomic theory, the quantum postulate, the quantum of action, and the foundational principles underlying the description of nature. No quantitative results, statistics, p-values, effect sizes, or confidence intervals are provided.

Referenced In

Season 17, Episode 4: The Copenhagen Interpretation Explained

Hey StarTalkers! Season 17, Episode 4 saw Neil, Chuck and special guest Professor Sean Carroll answering a selection of questions about cosmology and quantum mechanics. As part of this, Sean answered a question from a listener – and Neil – about the “Copenhagen Interpretation” of quantum mechanics:

url pasted

Its development saw physicists like Bohr and Heisenberg waxing philosophical about scientific language and the nature of measurement. It’s a mind-bending topic, but luckily, the famous Schrodinger’s cat thought experiment is here to help.

The Basics of Superpositions

We normally think about atoms like a mini solar system: the nucleus sits in the middle like the sun and the electrons orbit around it like planets. The electrons are in a specific place, moving a specific speed, at all times.

But in quantum mechanics, the electrons aren’t really in a definitive location. They’re represented by a wavefunction, which includes all possible locations. It basically says “there’s a 60% probability it’s over here and a 40% probability it’s over there.”

So if you ask, “where is the electron?” This isn’t so easy to answer. The electron is in a superposition of multiple places at once.

Schrodinger’s Cat and Everything Wrong with Quantum Mechanics

The Copenhagen interpretation was the accepted answer to this question for a long time. The electron is considered in both places, until it’s measured. At that point, the wavefunction collapses into one possibility, and that is what we detect in experiments.

As Sean Carroll explains, the most extreme version states that only the outcomes of the measurements are actually real. The wavefunction is just math.

But Erwin Schrodinger had problems with this.

He set up a scenario where a cat was in a box with a cruel device that smashes a bottle of poison if a radioactive atom decays. This atom is also in a superposition prior to measurement, just like the electron’s position: if we don’t measure it, the atom has both decayed and not decayed.

But what would that mean for the cat? Well, according to the Copenhagen interpretation, it would mean the cat was both alive and dead. We would only collapse the wavefunction and find out when we opened the box.

This made a lot of people, including Schrodinger and Einstein, very uneasy.

2