Science You’ll Feel the Earth Move
posted by October 23 at 11:00 AMon
The problem: The Earth is going to die.
The Sun is slowly getting warmer as it burns the hydrogen in its core. In about 5 billion years, the Sun will begin evolving into a bloated red giant. Its outer gas shell will swell up, engulfing the Earth by the time it reaches its peak size and brightness 7 billion years from now.
But long before that,, raising average terrestrial temperatures to around 50 °C (120 °F). That will warm the oceans so much that they evaporate without boiling, like a pan of water left on a sunny kitchen counter.
The solution: Move the Earth, with a humongous, solar-powered kite.
That danger could be avoided by using a giant solar sail, says Colin McInnes, a mechanical engineer at the University of Strathclyde.
Solar sails are thin, mirror-like films that are propelled by the weak pressure of the sunlight that falls on them. McInnes’s idea is to put a free-floating solar sail at a point near the Earth where the pressure of solar radiation essentially balances the Earth’s gravitational pull.
His analysis shows that the reflection of sunlight from the sail will pull the Earth outwards along with the sail – in physical terms, increasing the Earth’s orbital energy and accelerating the centre of mass of the system outwards, away from the Sun.
A sailor’s life for us.