Category Archives: — By the Physicist

Q: How does a Tesla coil work?

Physicist: Stripped down to it’s most essential parts, a Tesla coil is a wire sticking out of the ground. To get sparks to fly out of the top the rest of the machine “sloshes” electrons up and down the wire. … Continue reading

Posted in -- By the Physicist, Engineering, Physics | 53 Comments

Q: What are Feynman diagrams, how are they used (theoretically & practically), and are there alternative/competing diagrams to Feynman’s?

Physicist: Feynman diagrams are primarily a way to keep track of what you’re doing.  Physicists aren’t geniuses or anything, and they get distracted pretty easily. When you’re trying to calculate the probability of a particular particle interaction you’ll find yourself … Continue reading

Posted in -- By the Physicist, Combinatorics, Equations, Particle Physics, Physics, Quantum Theory | 11 Comments

Q: Does the 2nd law of thermodynamics imply that everything must eventually die, regardless of the ultimate fate of the universe?

Physicist: The 2nd law of thermodynamics states that in any closed system entropy will increase over time. The exact rate at which entropy increases is situation dependent (e.g., being on fire or not). As a quick aside, one of my … Continue reading

Posted in -- By the Physicist, Biology, Entropy/Information, Evolution, Paranoia, Philosophical | 9 Comments

Q: What is The Golden Ratio? How is it used in Mathematics?

Physicist: The golden ratio, g, is . The golden ratio is defined in many (equivalent) ways but the best known is: if A and B are two numbers such that the ratio of A+B to A is equal to the … Continue reading

Posted in -- By the Physicist, Equations, Geometry, Math, Philosophical | 8 Comments

Q: Why can’t you have an atom made entirely out of neutrons?

Physicist: The short answer is; you probably can, but not for long. If you’ve taken a little chemistry you probably know that the electrons in an atom “stack up” in energy levels.  The more electrons you add, the higher the … Continue reading

Posted in -- By the Physicist, Particle Physics, Physics | 17 Comments

Q: What is the physical meaning of “symmetries”? Why is there one-to-one correspondence between laws of conservation and symmetries? Why is it important that there is such correspondence?

Physicist: This is the shortest answer yet: “Noether“. When a physicist talks about symmetry, they don’t usually mean symmetry the way everyone else in the world does.  The backbone of mechanics (both classical and quantum) is the “Lagrangian”, .  Basically, … Continue reading

Posted in -- By the Physicist, Equations, Philosophical, Physics | 1 Comment