Light
When we talk about light we usually mean the light we can see with our eyes. This is also called visible or optical light.
- How does light travel?
For us to see, light must travel from a light source to our eye. The light we see on Earth travels in straight lines.
Anything in the path of light has an effect on what we see. For example, a window is transparent – this means that the light can pass straight through it.
Relativity
Gravity is the force we are most familiar with in everyday life. It has been studied for longer than the other forces of nature. However, it is also the least well understood.
- Law of Universal Gravitation
Newton had correctly explained that every object in the Universe has a force which can be felt by every other object as a ‘pull’. We call it an ‘attractive’ force because it attracts objects towards each other.
The strength of this force is linked to the mass of the object. The more massive the object, the stronger the force. Newton also found that the force is linked to the distance between the objects. The further the distance, the weaker the force.
Life on Earth
How are living things connected? What do they need to survive? Can we find clues in the Solar System that help us find out why there is life on Earth?
Hot, Cold or Just Right
Karl Schwarzschild
Occupation: Physicist & Astronomer
Year born: 1873
Research Areas: Relativity, Black Holes, Quantum Theory, Stars, Comets
"Mathematics, physics, chemistry, astronomy, march in one front."