News Round-up 05/08/2011

Well it’s been a few months due to a lack of laptop and too much work but I will now at least try a weekly news round-up….I guess like Nature if I make it a Thursday!

‘That’s no Moon…’

…in fact its two. It has been proposed in nature this week that the Earth didn’t have just one Moon it did in fact have two. If you have seen a certain episode of QI will recall Stephen Fry incorrectly claiming Earth already had two moons, this is in fact a different one! The researchers propose that two moons formed around 4 billion years ago after a Mars sized protoplanet collided with the Earth. One of these moons was smaller than the other and it is this that was gravitationally attracted by the larger lunar object eventually leading to a lunar collision. This collision occurred at very slow velocity (less than the speed of sound) over the course of a few hours therefore not causing any large shockwaves or any surface melting. The scientists propose at the time that the bigger moon would have had a magma ocean with a thin film on top, as they collided material would have been distributed on the surface and the magma would have been redistributed on the near side of the moon. This agrees with observation that the near side of the moon is comprised of low lying flat plains and the far side is composed of highlands!

Photonic Diodes

A caltech group this week have proposed new ways to isolate light on photonic chips for future light based electronics. Photonic chips that utilise light for energy and information transfer are a desireable future technology for computer chip technology, with the potential to run much faster than current technology (as information can travel at the speed of light). A lot of the desire to use photonic chips comes from the success of using light in optical fibres to transfer information between continents with minimal data loss. Research into photonic chips has been going on for decades, however consistent problems have been that engineers haven’t been able to develop a viable optical equivalent to the electronic diode, allowing current to travel in one direction without back scatter. In the past optical equivalents have been created that either utilise magnetic fields or generally aren’t compatible with silicon. However Feng et al. at Caltech have managed to create a silicon waveguide, a slab of silicon with a 200 nanometre thick and 800 nanometre wide channel. Standard waveguides channel light in both directions, this differed by using layers of materials with differing refractive and reflective properties that prevented light traveling in two directions, therefore fulfilling the requirement of an optical diode. The team hope to incorporate this into a device in the future, where we may well see ultrafast technologies. 

  Life on Mars?

Reported by the journal Science yesterday and by most of the media, NASA have found the best evidence yet of flowing liquid water on Mars. It has been known for some time that Mars contains water in it’s ice form commonly found at the poles and that there are many channels suggesting that at some point in the past Mars had water flowing on its surface. This report (and associated images) however show a series of dark tendrils a few metres wide extending from a rocky outcrop. They appear in the martian summer months when the sun shines on the mountainous region and disappear again in the winter suggesting that thawing mud may be the source of the tendrils. The best explanation for water in this case it that it is a salty solution that has a lower melting point than standard water so that even in low temperatures the water thaws and can flow whereas ice may remain in other regions of the martian surface. This discovery has ignited theories regarding the search for extraterrestrial life on Mars with the potential that hardy microbes may survive in the melt water muds for a few months a year, although as said in Jeff Wayne’s War of the Worlds ‘The chances of anything coming from Mars are a million to one he said’…..or probably much more.

 

Now for a song related to a story here….has to be

 

…and I guess http://www.youtube.com/watch?v=W8JLqsbK5V0

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