We use metals for so many different purposes that a list would go on page after page. The most common and most well known are iron and aluminum. It just happens that these are the two most abundant metals in Earth’s crust.
The recent surge in debate among supposedly educated people about the shape of planet Earth is surprising, considering Eratosthenes, an ancient Greek scientist, measured its circumference 22 centuries ago.
My wife and I recently returned from watching the total solar eclipse on Aug. 21. Having been aware of the event and seeking ideal viewing sites since summer of 2016, we made arrangements and reservations that would have been impossible at a later time.
By Richard Brill on August 4, 2017 • Updated on August 3, 2017 at 7:42 pm
By Richard Brill Posted on August 4, 2017 • Updated on August 3, 2017 at 7:42 pm
In Einstein’s theory of general relativity, gravity is not a force as it was in Newton’s description. In Newton’s view, gravity was due to the attraction of two masses according to the size of the masses and the distance between them.