Solar system is chaotic
Murray and Holman ran numerical simulations of the planets positions over a 200 million year period using their new technique. They discovered that although the outer planets appear in stable orbits, ...
Taking a closer look at “big G”
The gravitational constant was first measured by Lord Cavendish in 1798, who used a torsion-balance to measure the force between a pair of lead spheres. Cavendish measured G to be 6.754 x 10-11 metres...
Science chooses accelerating universe as “Breakthrough of the Year”
Astronomers have known for decades that the universe is expanding, based on measurements of the “red shift” of light emitted by galaxies. According to the standard cosmological model, ther...
Evidence mounts that the expansion of the Universe is accelerating
Astronomers have been puzzling over the expansion rate of the Universe and its mass for decades. If the mass of the Universe is large enough, the expansion will eventually decrease and the Universe wi...
Making light work of gravity gradients
The interferometer was built by Mark Kasevich and colleagues at Yale University in the US and used individual atoms, rather than macroscopic man-made objects, to measure the gradient. By observing the...
Gamma-ray bursts could test quantum gravity
Gamma-ray bursts appear to be related to the deaths of massive stars. Amelino-Camelia and colleagues claim that if the difference in the arrival times of photons with different energies can be measure...
