The Layperson's Physics Party Survival Guide

Should you be a nonphysicist and find yourself at a physics party (maybe as a friend or spouse) here are 15 pieces of essential physics knowledge that might be helpful in making sense of conversations or even impressing the audience:

1. The universe is 15 billion years old. No one knows what happened before that (yes, that was the Big Bang). Also, 'before' may not be a meaningful term.

2. The Earth (and the solar system) are about 5 billion years old. The Sun will die in about 5 billion years. Your party, even if it is a very good one, will probably end before that.

3. The visible universe - including us - is made of atoms and radiation. Atoms are made of smaller particles such as quarks and leptons. This latter piece of information is only to be used in a pinch.

4. The existence of the multiverse (any other universe than our own) is not yet confirmed, no matter what Hollywood says.

5. Dark energy (68%) and dark matter (27%) dominate the universe. This is stuff that has observable gravitational effects but otherwise we don't know what it's made of. The remaining 5% is what we see with our eyes and telescopes.

6. Physics can describe pretty much everything at the level of our daily lives using a few equations that can be printed on a T-shirt.

7. Quantum physics says life is uncertain, and things are (cor)related.

8. Special relativity says time is relative, and length depends on how fast you are moving.

9. General relativity says there is no such thing as force: mass tells space how to curve; space tells mass how to move.

10. String theory: an exciting idea that the fundamental entities in the universe are not particles but strings. No experimental evidence for this theory is available yet.

11. It's not clear if philosophy has any clear connections to physics, but the idea is usually entertaining to explore. Please be warned that asking this question at a physics party could lead to a fight, not necessarily involving you.

12. Light connects mass to energy (E=mc^2), electricity to magnetism (B=E/c), and space to time (x=ct).

13. Three of the great unsolved problems in physics: the unification of quantum mechanics with gravity, the appearance of turbulence in liquids, an explanation of why time has a direction.

14. Experiment plays the role (mostly) in physics that proof does in mathematics.

15. You can take a physics toy (some of them, like the rattleback, can easily be slipped into your pocket) to the party and ask the physicists to explain how it works.

    Have fun!