The brightest star in the evening sky now is the planet Jupiter. If you look at it with binoculars you can follow Galileo, the first to spot its moons.
MARK COLLET
Rotorua
My friend and former colleague David Preest's letter "A young Earth" (Letters, June 20) led me to think
that he has to argue with many geologists/astrophyscists/molecular biologists...even a first year college physics textbook.
In Halliday & Resnick 9th Ed. Fundamentals of Physics, chapter 42, there is a section on "Radioactive Dating": In a moon rock sample, the ratio of the number of stable 40Ar atoms present to the number of (radioactive) 40 K atoms is 10.3. Assuming that all the argon atoms were produced by the decay of potassium atoms with a half life of 1.25 billion years. How old is the rock? See details for the calculation in the textbook, the answer is 4.37 billion years!
STEVE CHOU
Rotorua
