Light and gravity

When Sir Isaac Newton devised his Law of universal Gravitation, he also suggested that light was subjected to the pull of gravity. On Earth, light always travels in a straight line, unless it hits an object. But light does bend as it passes close to bodies with very strong gravitational fields, such as very massive stars. This shows that the things we take for granted on Earth do not necessarily apply when super strong gravity is at work.

Black Hole

A black hole is a place in space where gravity is so super strong that nothing can escape it not even light. When scientists call a black hole a giant cosmic vacuum, they do not mean it sucks up anything that comes near it. However, anything passing close to a black hole will be affected by its strong gravitational pull. Astronomers think that events become very strange both near and inside black holes. The known world ceases to exist, time slows down, space is warped, and the accepted laws of physics no longer apply. No one should go into a mysterious black hole to investigate, because they would never return.
In most great mysteries, such as UFOs, science tries to explain the strange things that people claim to have seen. In the case of black holes, however things are the other way around. Scientists predicted the existence of black holes long before there was any real evidence that they existed. In fact, the very nature of black holes means they cannot be seen to be believed!

Varying Heights

Astronauts become 1-2 inches taller while they are in space. Without Earth’s gravity tugging on their bodies, the vertebrae in their spines stretch out. The extra height is only temporary, though. Astronauts shrink back to their normal size after returning to Earth.

Life in the slow lane

Time slows down when traveling at great speed in space, so space travelers age more slowly than they do on Earth. Albert Einstein figured this out
In 1905, long before we started flying in space. Einstein knew the speed of light never changes as it is constant. Time however, is relative said Einstein. It can change. It changes according to the speed of what is measuring it. The faster the speed, the slower time passes. In fact, a very accurate clock aboard a space shuttle was measured after its return to Earth it lost 2.95 x 10^-10 seconds for each second of the trip. If the shuttle had been traveling near the speed of light and had been gone for several years, the time loss would have been bigger. So if you went on a very long space trip and our space craft could travel close to speed of light we would be younger than our current same-age friends when we returned to Earth.

Escape Velocity

Imagine throwing any object straight up. The Earth’s gravity would gradually slow it down and make it fall back to Earth. But if the object was thrown upward fast enough, gravity would not be able to stop it escaping into space. The minimum speed needed for this to happen is called Escape Velocity is 25,000 miles per hour. Space Rockets must accelerate to a minimum of 17,000 miles per hour to stay in orbit around Earth. They must travel faster to escape from Earth.

Gravity

Gravity is a force that attracts every object that has mass towards every other object that has mass towards every other object. Mass is the amount of matter an object, or body contains. The amount of gravitational pull between two bodies depends on the mass of the two bodies and the distance between them. The greater the masses the greater the force. The further the distance between them, the smaller the force. The amount of gravitational pull between bodies is very massive, such as a planet.
This is called the Law of Universal Gravitation. It was first written by the English scientist Sir Isaac Newton (1642-1727). This law of gravity explains how the gravitational pull between bodies causes the planets to orbit the sun. A body has a gravitational field around it. Any other object in the field experiences a pull from the body, which pulls the object towards it.

Unsolved Mysteries

For centuries, people have been puzzled and fascinated by mysterious places, creatures, and events. Why have ships and planes vanished without a trace when crossing Bermuda Triangle? Are some houses really haunted by ghosts? Does the Abominable Snowmen actually exist? What secrets are held by a black hole? Read on my future posts to know about some of these facts.

Meteor Master

Hero who could spot and stop Doomsday Meteor would be Carolyn Shoemaker. Since 1983, she has discovered more than 800 asteroids and 32 comets, some of which cross Earth’s orbit. Mrs. Shoemaker is already a hero in the eyes of world astronomers. Working with her husband, Gene, and David Levy, she discovered Comet Shoemaker-Levy 9.
Jupiter’s gravity had grabbed the comet and forced it to orbit the gas giant instead of the Sun. The powerful gravity ripped the comet into 21 pieces, all of which slammed into Jupiter in 1994. The spectacular crash gave astronomers an exciting glimpse at the chemistry of Jupiter’s mysterious atmosphere.

Andromeda

The closest major galaxy to Earth, the spiral-shaped AndromedaGalaxy is the most distant object visible to the naked eye. It lies about 2.5 million light-years from Earth and contains over 200 billion stars.