Category Archives: Entropy/Information

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 statements seems to hold true, what with all of the mountains wearing down, machines breaking, and the inevitable, crushing … Continue reading

Posted in -- By the Physicist, Biology, Entropy/Information, Evolution | 5 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 | 13 Comments

Q: How do lenses that concentrate light not violate the second law of thermodynamics? If you use a magnifying glass to burn ants, aren’t you making a point hotter than the ambient temperature without losing energy?

Physicist: This is a surprisingly subtle question. It certainly impossible to create new energy, but there’s nothing to stop you from piping energy from one place to another (say, by running hot water from a boiler to somewhere else).  The … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics | 11 Comments

Q: Does opening a refrigerator cool down the room?

Physicist: Briefly yes, or no, not at all.  If you think of the room as including the inside of the refrigerator, then opening the door does nothing.  Otherwise, it does almost nothing.  But ultimately, if you leave the door open … Continue reading

Posted in -- By the Physicist, Engineering, Entropy/Information, Physics | 6 Comments

Q: Since the real-world does all kinds of crazy calculations in no time, can we use physics to calculate stuff?

The original question was: I’ve heard somewhere that they’re also trying to build computers using molecules, like DNA. In general would it work to try and simulate a factoring algorithm using real world things, and then let the physics of … Continue reading

Posted in -- By the Physicist, Computer Science, Engineering, Entropy/Information, Physics | 6 Comments

Q: Does how you deal cards affect how random they are?

The original question was: [My wife and I] always shuffle the deck at least 4-5 times before dealing.  But I’m sure that’s not enough and need some guidance.  Does the game previously played influence the amount of shuffling required to … Continue reading

Posted in -- By the Physicist, Entropy/Information, Math | 8 Comments