Category Archives: Entropy/Information

Q: After the heat death of the universe will anything ever happen again?

Physicist: If you wait forever, then you might see something happen.  But the more practical answer is: no. The universe does a lot of stuff (for example, whatever you did today), but literally everything that ever happens increases entropy.  In … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics | 22 Comments

Q: Are some number patterns more or less likely? Are some betting schemes better than others?

Physicist: First, don’t gamble unless you can be sure you won’t get caught cheating or you enjoy losing money. Games of chance come in two flavors: “completely random” and “not quite completely random”.  It’s not always obvious which is which, … Continue reading

Posted in -- By the Physicist, Combinatorics, Entropy/Information, Math, Probability | 9 Comments

Q: What are “delayed choice experiments”? Can “wave function collapse” be used to send information?

Physicist: There are a lot of big claims made about entanglement, but there are two carved-in-stone facts that help cut through some of the more grandiose claims.  First, (maximally) entangled states always act exactly like a perfectly random state, until … Continue reading

Posted in -- By the Physicist, Entropy/Information, Experiments, Philosophical, Physics, Probability, Quantum Theory, Skepticism | 6 Comments

Q: What does it mean for light to be stopped or stored?

Physicist: We’ve gotten a handful of questions since this was published and led to articles like this, this, and, this.  In a nutshell, some dudes in Germany (Georg Heinze, Christian Hubrich, and Thomas Halfmann) have found a method to shoot … Continue reading

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

Q: Why doesn’t life and evolution violate the second law of thermodynamics? Don’t living things reverse entropy?

Physicist: In very short: nope. The second law of thermodynamics is sometimes (too succinctly) stated as “disorder increases over time”.  That statement seems to hold true, what with mountains wearing down, machines breaking, and the inevitable, crushing march of time.  … Continue reading

Posted in -- By the Physicist, Biology, Entropy/Information, Evolution | 68 Comments

Q: What is quantum teleportation? Why can’t we use it to communicate faster than light?

Physicist: Contrary to its exciting name, quantum teleportation doesn’t involve any physical stuff suddenly disappearing and then reappearing somewhere else.  Instead it’s a cute, clever, technique for transferring an unknown quantum state of one system (usually a single particle) to … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics, Quantum Theory | 25 Comments