Carbon dating reference
While these values do not compute an age for the Earth, they do establish a lower limit (the Earth must be at least as old as any formation on it).
This lower limit is at least concordant with the independently derived figure of 4.55 billion years for the Earth's actual age.
The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites.
This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204).
Unfortunately, the age cannot be computed directly from material that is solely from the Earth.
There is evidence that energy from the Earth's accumulation caused the surface to be molten.
Over time, the amounts of Pb-206 and Pb-207 will change in some samples, as these isotopes are decay end-products of uranium decay (U-238 decays to Pb-206, and U-235 decays to Pb-207).
Is it still relevant now with advances in carbon and carbon repair? By Kurt Gensheimer So you’re about to mosey on over to your local bike shop and drop more coin for your first genuine racing bike than most people pay for an entire motorcycle.
The checkbook is in hand cocked and ready to besmirch every last dollar in your savings account, and all that’s left to do is negotiate with the shop so you at least have a little bit of cash left to buy some inner tubes.
But before your visions of grandeur run rampant and your checkbook becomes more hollow than Landis’ Maillot Jaune, are you sure carbon is the right frame material for your needs?
Kurt Gensheimer thinks the bicycle is man’s most perfect invention.
He firmly believes ‘singlespeed’ is a compound word.