Despite what is often maintained, the speed of light isn't a constant. It only reaches its maximum 300,000 kilometres a second in a vacuum. When light passes through different media its speed slows. The slowest speed recorded is through sodium at -272 C during which the speed of light fell to 60kph – about the speed of a bicycle. Travelling through a diamond its speed is halved to 130,000 kilometres a second
Astonishingly a team of scientist at Harvard managed to bring light to a complete halt by shining it through a Bose Einstein condensate of the element rubidium.
Light is invisible to the naked eye. It is only when it hits something that it be comes visible. If light were visible it would appear as a mist between you and whatever you were viewing.
Rubidium was discovered by Robert Bunsen , 1811-99. Bunsen didn't invent the Bunsen burner. It was named after him.
Astonishingly a team of scientist at Harvard managed to bring light to a complete halt by shining it through a Bose Einstein condensate of the element rubidium.
Light is invisible to the naked eye. It is only when it hits something that it be comes visible. If light were visible it would appear as a mist between you and whatever you were viewing.
Rubidium was discovered by Robert Bunsen , 1811-99. Bunsen didn't invent the Bunsen burner. It was named after him.