Where is most of the universe? And why don't we know yet? Yes—we’re talking about dark matter and dark energy, the mysterious stuff that’s predicted by physical theory, but which still remains elusive in experiments.

After speaking to an actual physicist, Tom and Stuart attempt to explain what dark matter and dark energy are supposed to be, and what physicists would have to see in their experiments to know that they exist. They also come down with a serious case of physics envy.

The Studies Show is sponsored by Works in Progress magazine, which has just published this excellent new article on the history of French nuclear power. Why has France been so successful at building nuclear plants while other countries have dropped the (radioactive, probably flourescent green) ball? “Liberté, Egalité, Radioactivité” tells you everything you need to know. Find it and much more, all for free, at worksinprogress.co.

Show notes

* August 2025 Science article about a “big blob” of dark matter in the Milky Way

* LIGHTS ALL ASKEW IN THE HEAVENS

* Cosmic microwave background? Or pigeon droppings?

* 1984 Nature paper about “cold dark matter” and the formation of galaxies

* WMAP probe map of the cosmic microwave background

* Two papers from 1998 on the accelerating expansion of the universe

Credits

We’re very grateful to Prof. Andrew Pontzen of Durham University for talking to us for this episode (all mistakes are our own). The Studies Show is produced by Julian Mayers at Yada Yada Productions.

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