Physics Puzzle: Magnetic Attraction

Here’s a physics puzzle even non-physicists can attempt: you are given two identical bar magnets, like the one shown in the picture below, except for one being a fake - just a piece of unmagnetized iron - and the other being a real bar magnet (remember, they have two “poles”, traditionally called North and South). […]

Math Puzzle: you’re Gonna Carry that Weight

We’re on a streak of math puzzles this month! This week I’ve brought together several classics on weighing.

Here’s the quintessential classic. You are given 24 coins, one of which is a fake and therefore weights more than the other 23 genuine coins. You are given a set of scales (of the old kind, i.e., the […]

Math Puzzle: a Numbers Game

Last week’s puzzle was solved a bit too easily, so it’s take 2 for me this week with yet another math puzzle - more of a logic puzzle really.
Imagine the following game played between myself and yourself:
1. The game is carried out in turns.
2. The first person to call out 50 wins.
3. Each turn, each […]

Math Puzzle: Prime Numbers

Take any prime number, square it and subtract 1. The result will be divisible by 24. Can you explain why?
(Examples: 5^2-1 = 24.    7^2-1 = 24*2.    11^2-1 =24*5, etc … )

I’ve Struck Gold! Gold, I Tell Ye!

By mistake, I’ve stumbled upon the following channel a couple of days ago on Youtube:
http://www.youtube.com/user/nptelhrd
What is it, you ask? Well, basically, it’s a group of Indian universities which have uploaded university-level lectures - entire courses, really - onto the web, free of charge. You’ve got lecture sets about artificial intelligence, signal processing, mechanics, physics and […]

Recommendation: Fantastic Contraption

I don’t normally give any recommendations here, but I’ll make an exception this time.
I got addicted the past couple of days to a cute online game called Fantastic Contraption, at www.fantasticcontraption.com. It’s a physics based engineering game (and this IS a physics blog, after all) in which you have to transport a block from one […]

Physics Puzzle: Ain’t no Mountain High Enough

Being a physicist isn’t all about solving complicated differential equations or doing complicated field theory. In fact, a good measure of a physicist’s quality is his or her ability to do “back-of-the-envelope” calculations: quick estimations of quantities of interest, done using nothing more than basic physics, a scrap of paper, some ingenuity and perfect command […]