Hugo Slabbert ⚠️Nov 26, 2023

K, I apparently am late to the "sharks have been around for a ridiculously long time" thing. I mean, I know they're ancient, but I really did not have a clue just how ancient, relative to other "things that have been around forever".

The one that blew my mind is the age of sharks relative to the existence of the universe.

By our best understanding, the Big Bang happened about 13.8 billion years ago. Sharks have existed on Earth for about 450 million years. That means sharks have existed for approximately 3% of the entirety of the existence of the Universe.

Standard "some things that sharks are older than" list:

  • Saturn's rings (~100 million years old)
  • The Pleiades cluster (75-150 myo)
  • One galactic orbit of the sun (200-225 my)
  • North Star, aka Polaris (estimated at ~70 myo)
  • The Atlantic Ocean (~150 myo)
  • Pangea (formed ~335 million years ago)
  • Trees (390 myo)
Show threadChrisNov 26, 2023
@hugo I don’t think there’s quite consensus on this one yet, but the current leading theory about the age of the inner solid iron core of the earth says it’s about 500 million years old. So just “a bit” older than sharks, apparently.
Show threadHugo Slabbert ⚠️Nov 27, 2023
@chrisvest is it? I thought the current scientific consensus was about 4.5 billion years.
Show threadChris
@hugo 4.5 bn is the age of the earth itself, I think. The debate on the solid inner core is between two different methods of measuring. Upper bound is 4.2 bn by thermal model. Paleomagnetic points to 0.5 bn: https://en.m.wikipedia.org/wiki/Earth's_inner_core#Paleomagnetic_evidence
Earth's inner core - Wikipedia

Nov 27, 2023 at 12:28amIvory for iOS
Show threadHugo Slabbert ⚠️Nov 27, 2023
@chrisvest neat, thanks!