Black Holes

Black Holes

From What The If? by Philip Shane

February 20, 2026 · 1h 1m

About this episode

MIT physicist David Kaiser discusses the intriguing possibility of primordial black holes and their implications for our understanding of the universe.

MIT physicist David Kaiser is one of those rare scientists who can make mind-bending physics feel like a great conversation over coffee — funny, generous, and genuinely thrilled by what we still don't know. And what he's working on is wild. What the if the universe is packed with invisible black holes smaller than an atom? Dave thinks the mysterious "missing stuff" that holds galaxies together might not be some exotic undiscovered particle — it could be tiny black holes that formed a split second after the Big Bang. If he's right, a handful of them could be cruising through our solar system right now, and we might be able to catch one in the act just by watching Mars wobble. We also dig into whether a rogue black hole might have flattened a Siberian forest in 1908, and rest assured, the residents of Brooklyn have nothing to worry about. Learn more about David Kaiser's primordial black hole research: MIT PBH Research Group: https://sites.mit.edu/mitpbh/ David Kaiser's essay in the London Review of Books — a great accessible overview with historical context: https://www.lrb.co.uk/the-paper/v46/n11/david-kaiser/black-hole-flyby The ultrahigh-energy neutrino paper (open access)…

People in this episode

Host: Philip Shane

Guest: David Kaiser

Topics covered

  • black holes
  • physics
  • cosmology
  • Big Bang
  • neutrinos
  • Mars

Keywords

  • black holes
  • primordial black holes
  • Big Bang
  • neutrinos
  • Mars wobble
  • cosmology

Mentioned in this episode

Organizations: MIT, London Review of Books, MIT PBH Research Group, APS, arXiv

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