Category Archives: Math

Q: How/Why are Quantum Mechanics and Relativity incompatible?

Physicist: Quantum Mechanics (QM) and relativity are both 100% accurate, so far as we have been able to measure (and our measurements are really, really good).  The incompatibility shows up when both QM effects and relativistic effects are large enough … Continue reading

Posted in -- By the Physicist, Entropy/Information, Physics, Quantum Theory, Relativity | 33 Comments

Q: What the heck are imaginary numbers, how are they useful, and do they really exist?

Mathematician: Imaginary numbers arise quite naturally when you start asking certain basic mathematical questions. Probably the best example is the following: Once we know how to multiply and add, we might ask ourselves “are there any numbers x that satisfy … Continue reading

Posted in -- By the Mathematician, Math, Philosophical | 19 Comments

Q: Why do weird things happen so much?

Physicist: First, “normal” things don’t catch the eye.  There’s a natural bias toward noticing the out-of-the-ordinary. Also (mathematically speaking), although the chance of any one particular unlikely event is unlikely (because it’s unlikely), there are a very large number of … Continue reading

Posted in -- By the Physicist, Math, Philosophical | 3 Comments

Q: What’s the highest population growth rate that the Earth can support?

Physicist: Zero. Populations tend to grow exponentially, which is why the growth rate is defined as R in P = AeRt, where A is the population at time t=0, and P is the population at any other time t.  If … Continue reading

Posted in -- By the Physicist, Biology, Math | 5 Comments

Q: Why does math work so well at modeling the world around us?

Mathematician: One important thing to realize about mathematics is that it was primarily created for practical purposes. For example, numbers were likely used in the beginning to count possessions, multiplication for trade, and geometry to measure plots of land (or … Continue reading

Posted in -- By the Mathematician, Math, Philosophical | 12 Comments

Q: Why is it that when you multiply a positive number with a negative number you get a negative number?

Mathematician: Consider what would happen if when we multiplied a positive number by a negative number we got a positive number. For example, suppose that 3*-5 = 15 rather than the usual 3*5 = 15. Now, if all the other … Continue reading

Posted in -- By the Mathematician, Math, Philosophical | 6 Comments