Category Archives: Quantum Theory

Q: If God were all-seeing and all-knowing, the double-slit experiment wouldn’t work, would it? Wouldn’t God’s observation of the location of the photon collapse its probability wave function?

Physicist: Deep… It depends on how entangled God is with the rest of us. If He can make the observation, and then keep a completely straight face forever (never leak any information about the result in any way), then His … Continue reading

Posted in -- By the Physicist, Philosophical, Quantum Theory | 23 Comments

Particle physics, neutrinos, and chirality too!

Physicist: This was an email correspondence that was too interesting to abandon, but covered so much ground that it didn’t easily parse into just a couple of questions. Q: What force is the ‘kinetic’ force? If 2 particles bounce of … Continue reading

Posted in -- By the Physicist, Particle Physics, Philosophical, Quantum Theory | 3 Comments

Q: What does a measurement in quantum mechanics do?

Physicist: This is a follow up of this post, that would’ve been too long and meandering with this included.  To sum up that post, a “measurement” is an interaction that exchanges information. In the Copenhagen interpretation, what that measurement does … Continue reading

Posted in -- By the Physicist, Entropy/Information, Philosophical, Physics, Quantum Theory | 14 Comments

Q: What exactly is the vacuum catastrophe and what effects does this have upon our understanding of the universe?

Physicist: The vacuum catastrophe is sometimes cited as the biggest disagreement between theory and experiment ever.  They disagree by a factor of at least 10107. According to quantum field theory the energy of empty space can’t quite be zero.  In … Continue reading

Posted in -- By the Physicist, Astronomy, Particle Physics, Physics, Quantum Theory | 22 Comments

Q: What is a “measurement” in quantum mechanics?

Physicist: Any interaction of any kind that conveys information is a form of detection. This question crops up frequently in conjunction with the “Copenhagen interpretation”. The Copenhagen interpretation of quantum mechanics (which comes in a couple different flavors) is generally … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics, Quantum Theory | 28 Comments

Q: Are all atoms radioactive?

The original question was: Some elementary particles spontaneously break apart at a given rate. Can the same be said about normally stable atoms and molecules? That is, even though they are stable, does their natural internal activity lead to a … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics, Quantum Theory | 5 Comments