Category Archives: Probability

Q: Is it likely that there are atoms in my body that have traveled from the other side of the planet, solar system, galaxy, or universe?

Physicist: Not just likely, but essentially guaranteed! Technically, every atom in your body has been swirling all around the galaxy for billions of years (although it’s mostly stayed in the same place for the last 5 billion or so).  So … Continue reading

Posted in -- By the Physicist, Astronomy, Physics, Probability | 14 Comments

Q: How is radiometric dating reliable? Why is it that one random thing is unpredictable, but many random things together are predictable?

The original question was: Suppose there is a set of variables whose individual values are probably different, and may be anything larger than zero. Can their sum be predicted? If so, is the margin for error less than infinity? This … Continue reading

Posted in -- By the Physicist, Combinatorics, Math, Particle Physics, Probability | 9 Comments

Q: Will the world end in 2012?

Physicist: Firstly, happy new year! So, there’s been a lot of hoopla around 2012 doomsday stuff for a while.  Maybe not as much fuss as there was over the techno-apocalypse of Y2K, but still.  Although there are a variety of … Continue reading

Posted in -- By the Physicist, Paranoia, Probability, Skepticism | 17 Comments

Q: What are chaos and chaos theory? How can you talk about chaos?

Physicist: Chaos theory, despite what Jurassic Park may lead you to believe, has almost nothing to do with making actual predictions, and is instead concerned with trying to figure out how much we can expect our predictions to suck. “Pure … Continue reading

Posted in -- By the Physicist, Math, Probability | 11 Comments

Q: What is Bayes’ rule and how do I use it to improve my life?

Mathematician: Bayes’ theorem in one of the most practically useful equations coming from the field of probability. If you take its implications to heart it will make you better at figuring out the truth in a variety of situations. What … Continue reading

Posted in -- By the Mathematician, Equations, Math, Probability | 8 Comments

Q: How do I estimate the probability that God exists?

Mathematician: Before jumping into this question, it is important to realize that probabilities are not objective, observer independent quantities. We can think of the claim that a particular outcome will happen with a probability of 0.30 as meaning (loosely speaking) … Continue reading

Posted in -- By the Mathematician, Philosophical, Probability, Skepticism | 36 Comments