We know how hard it can be to find satisfying holiday gifts for the special physicist in your life. Department stores don’t carry Grand Unification Theories. CERN’s gift shop doesn’t sell undiscovered particles. And the secrets of dark energy are out of stock everywhere.

But have hope: Your physicist friends and family can be wowed with more tangible treasures, too.

Take a gander at these seven showstopping gift ideas and science-themed knick-knacks.

1. Perpetual motion machine

OK, not really. Perpetual motion machines violate the first law of thermodynamics: the law of conservation of energy. In our universe, a machine can’t produce more energy than it consumes. But if that’s true, then how does this marvelous toy work? The secret is a hidden battery in the base that propels the marble upward. Still, it’s a clever trick that’s sure to be a conversation starter.

2. Shashibo cubes

Shashibo cubes (the name stands for shape-shifting-box) are beautiful, tactile magnetic puzzle toys. For those people in your life who love fidget spinners or pop-its, this is a great addition to their collection. It keeps the hands busy so the mind can ponder the mysteries of the universe.

3. JWST skirt (and t-shirts, and socks, and accessories – space clothes are cool!)

In 2021, skirts designed to look like the Perseverance Rover’s parachute were all the rage. But it’s a new year, and JWST is the new hotness. Stay fashionable with this awesome JWST mirror skirt.

4. Science crochet patterns

Prefer to make your gifts rather than buy them? Learn how to crochet your very own representation of hyperbolic space!

5. A good read

There are plenty of brilliant books out there waiting to be discovered. Try The Way Things Work Now by David Macaulay or What If?: Serious Scientific Answers to Absurd Hypothetical Questions by Randall Munroe (the creator of XKCD). What If? 2: Additional Serious Scientific Answers to Absurd Hypothetical Questions is also here to keep you pondering. Or, if you want a bit more existential dread in your life, pick up The End of Everything (Astrophysically Speaking) by Katie Mack.

6. Chalk

When inspiration strikes and you need to get an idea out of your brain and onto a blackboard, it’s handy to have a good supply of chalk available. If the physicist on your list has been extra nice this year, consider splurging on “the Rolls Royce of chalk.”

7. Klein bottle (or a Klein bottle toque!)

What is a Klein bottle, and what does it have to do with four-dimensional space? Watch this video to find out, and it’ll make you want one immediately. Cliff Stoll’s enthusiasm for math and science is contagious, and his mathematical objects make for fantastic gifts.

Happy holidays from everyone at Perimeter Institute!