If we look at the earth through the “glasses” of human reasoning—that only snail-paced present geological processes can explain the past—then the earth does indeed look old.
We are told that starlight from distant galaxies takes billions of years to arrive on earth.
Perhaps no concept in science is as misunderstood as "carbon dating." Almost everyone thinks carbon dating speaks of millions or billions of years.
This tutorial is designed to help secondary science teachers learn how to integrate literacy skills into their science curriculum.
This tutorial will demonstrate a number of strategies teachers can impart to students to help them use context clues to determine the meaning of unfamiliar words within science texts.
The method assumes, among other things, that the earth's age exceeds the time it would take for C-14 production to be in equilibrium with C-14 decay.
Since it would only take less than 50,000 years to reach equilibrium from a world with no C-14 at the start, this always seemed like a good assumption.In reality, its measured disequilibrium points to just such a world-altering event, not many years ago.Digging for Clues: Effective Vocabulary Strategies : Click "View Site" to open a full-screen version.Once the tree dies, it ceases to take in new carbon, and any C-14 present begins to decay.The changing ratio of C-12 to C-14 indicates the length of time since the tree stopped absorbing carbon, i.e., the time of its death.Obviously, if half the C-14 decays in 5,730 years, and half more decays in another 5,730 years, by ten half-lives (57,300 years) there would be essentially no C-14 left.