Experiments in weighlessness on the ISS

One of NASA's astronauts has been doing some instructive and interesting experiments on the International Space Station described here.

"NASA and the American Physical Society (APS) have partnered to share unique videos from the International Space Station with students, educators and science fans from around the world. NASA astronaut Don Pettit will use everyday objects from Earth to demonstrate physics..."

The Earth - getting bigger or smaller?

This article from the BBC compares the ways in which the Earth is gaining and losing mass. It makes excellent discussion material for sixth form Physics students since it involves gravity, astronomy, mass-energy conversion and climate change all in one discussion!

"Using some back-of-the-envelope-style calculations, Dr Smith, with help from physicist and Cambridge University colleague Dave Ansell, drew up a balance sheet of what's coming in, and what's going out. All figures are estimated.

By far the biggest contributor to the world's mass is the 40,000 tonnes of dust that is falling from space to Earth, says Dr Smith."