I learned this today. The energy from the photons in a laser beam can be used to propel a very light sail into space. A laser powered solar sail could let us look at the planets around the closest star to us. Laser propulsion has been suggested as the best way we have of reaching […]
#258 How can a laser power a solar sail? Read More »
I learned this today. The first war correspondent is technically William Howard Russell. William Howard Russell was a war correspondent during the Crimean War. The Crimean War was a war between Russia on one side and the Ottoman Empire, France, and the United Kingdom on the other side. It lasted from October 1853 to February
#257 Who was the first war correspondent? Read More »
I learned this today. The Richter scale is a way of measuring the strength of an earthquake by looking at the height of its seismic wave. The Richter scale was developed in 1935 by Charles Francis Richter. He was an American physicist who was very interested in seismology. He came up with his system because
#256 What is the Richter scale? Read More »
I learned this today. The surface tension of water is higher than almost all other liquids because it contains so much hydrogen. Surface tension is what allows droplets to form on leaves, like the picture with this post, and for you to keep adding drops of water to a glass without it spilling over the
#255 Why is the surface tension of water so high? Read More »
I learned this today. Julius Caesar is supposed to have burned the library of Alexandria down in 48 BC, but it appears that it wasn’t destroyed and probably survived for another three hundred years before fading away. The city of Alexandria is about 150 km to the Northwest of Cairo, in Egypt, on the coast
#254 Who burned down the Library of Alexandria? Read More »
I learned this today. Sustained G-force of 6 G are generally considered to be fatal because they squash our organs and starve our brains of oxygen. Gs is the shortened form of G-force, which is in itself a shortened form of the gravitational force equivalent. G-force can be caused by rapid acceleration or rapid deacceleration.
#253 How does G-force kill people? Read More »
I learned this today. Some planets have rings because they have captured debris, but that debris is too close to the planet to form into a moon. In our solar system, Saturn is obviously the most well-known planet with rings, but it is not the only one. Jupiter, Neptune, and Uranus also have ring systems.
#252 Why do some planets have rings? Read More »
I learned this today. Insulin is a peptide hormone that regulates the metabolism of carbohydrates, fats, and proteins in the body. How is insulin made? Insulin is made in the pancreas. The pancreas is an organ that is found just behind the stomach. It is responsible for making enzymes that are known as pancreatic juices.
#251 What is insulin? Read More »
I learned this today. It is impossible to know if the emperor Nero was as bad as people say because all of the contemporary sources were destroyed. Nero became emperor of the Roman Empire in 54 AD. He was the adopted son of Emperor Claudius and came to the throne on the death of Claudius.
#250 Was Nero as bad as people say? Read More »
I learned this today. There is some evidence that paleolithic people were the first to use coal. Humans have been using fire since about 400,000 years ago. Evidence for this was found in Qesem Cave in Israel. Archeologists discovered large quantities of burned bone and moderately heated soil lumps. A 300,000-year-old hearth was also found.
#249 When did people start using coal? Read More »
