Episode Details

Getting twenty five fundamental constants and physical laws just right to produce a universe full of electrons, neutrons, and protons … all the way up to planets and stars

Last week, we learned that “Fine Tuning” can mean three very different things.  Today, we’re going to explore the first of those three: the exquisite precision needed to produce a universe made up of “usable stuff” … electrons, protons, and neutrons, all the way up to planets and stars. Our guests today — Elie Feder (PhD in mathematics) and Aaron Zimmer (physics, mathematics and philosophy) — are the hosts of a podcast which focuses exclusively on that question.

Scientists have long been looking for a Grand Unifying Theory: something that would explain everything.  What they’ve found are a variety of physical laws and a collection of 25 different fundamental constants.  And there’s something odd about those constants: they’re not straightforward numbers that derive cleanly from any equation … they can only be measured. And when measured, they’re not simple numbers: they’re unpredictable and often involve long strings of digits.  They look strange, contrived, and … “ugly.”  In our metaphor from last week, it’s like trying to explain why there are 1760 yards in a mile: … why 1760? … why not 2000, or 1500, or even possibly 1750?  Why?  Who came up with this number?  This was puzzling to astrophysicists.  A big mystery.

But as those astrophysicists continued to put a microscope on those constants, they learned something new; something very provocative.  As they developed methods to better measure the constants, they found the constants were tuned to an exceptionally high degree of precision. And if the constants were changed by a little bit, the equations wouldn’t work.  The analogy that’s often used is balancing a pencil on its sharpened tip.  It was as if we learned that it’s not 1760 yards to a mile, but rather 1759.4691269378 yards.  And adjusting that by even a few per cent was enough to make it so that global distribution networks like Purolator and Fedex would no longer be able to function.  Getting back to cosmology, changing these 25 constants by even a few percent means the universe can no long