Physics

Because light takes a certain amount of time to reach the Earth, by looking at the most distant stars, it is possible to gauge the size and age of the universe However, scientists can only see as well as the most advanced telescopes named ‘observable universe’. The universe is estimated to be around 28 billion light-years in diameter.

It was first believed that atoms were the smallest thing in the world, but atoms are split into subatomic particles of protons, neutrons, and electrons. In the 1970s, scientists discovered that protons and neutrons are made of smaller particles known as quarks. It is theorised that quarks could made up of even smaller particles called ‘preons’.

When light from the sun is low in the earth’s atmosphere, it has to travel through lots more air than when it is directly overhead. This affects how the light is scattered. As red light has a longer wavelength than all the other colours, this is the one colour that does not get scattered away. Therefore, sunsets appear to be orangey-red.

This all depends on whether a blind person has been blind from birth, or if they were once sighted and have lost their sight. A person that has been blind from birth will not have the same visual experiences or knowledge as a sighted person. Therefore, it is sensible to accept that they will not have the same visual dreams as a sighted person.

Something as big as the Earth could stay floating in space. It is all to do with gravity. In other words, gravity is caused by mass, so objects with mass attract one another. The object with the biggest mass will have the greatest pull. The Earth does not fall from the sky because it is held within the gravitational field of the Sun.