PBS Space Time

Dark Forest: Should We Not Contact Aliens?

In 1974 we sent the Arecibo radio message towards Messier 13. The message was mostly symbolic; we weren’t really expecting a reply. Yet surely other civilisations out there are doing the same thing. So, why haven’t we heard anything? What if the silence from the stars is a hint that we shouldn’t be so outgoing? What if aliens are deliberately keeping quiet for fear that they might be destroyed?

Dark Forest: Should We Not Contact Aliens?

14m 12s

  • The Final Barrier to (Nearly) Infinite Energy: asset-mezzanine-16x9

    The Final Barrier to (Nearly) Infinite Energy

    S10 E34 - 19m 39s

    One of the final challenges is deciding on the physical vessel to contain our mini artificial stars--and we have some pretty sci-fi options that are nearly ready to go.

  • The Crisis in Physics: Why the Higgs Boson Should Not Exist!: asset-mezzanine-16x9

    The Crisis in Physics: Why the Higgs Boson Should Not Exist!

    S10 E33 - 16m 36s

    Quantum physics predicts the universe should’ve collapsed right after the Big Bang, because all particles were immeasurably heavier. Yet it obviously didn’t. Observations confirm this puzzle, and experiments at the Large Hadron Collider still haven’t explained why. At its core is the lightness of the Higgs boson, part of the “hierarchy problem,” which many call physics’ biggest unsolved mystery.

  • Does Timescapes Disprove Dark Energy?: asset-mezzanine-16x9

    Does Timescapes Disprove Dark Energy?

    S10 E32 - 14m 30s

    The universe is expanding and that expansion is accelerating under the power of dark energy and eventually all matter and energy will be dispersed over such unthinkable distances that nothing can stop space from blowing up infinitely. Unless of course cosmologists blundered and dark energy doesn't even exist. Then it's back to the drawing board.

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