A new material – Stanene – could be the world’s first to conduct electricity with 100% efficiency at the everyday temperatures enjoyed by us and our computer chips rather than the unearthly deep-freeze of nearly absolute zero.
Named partly from the Latin for tin – stannum – it consists of just a single layer of tin atoms and has the potential to take energy efficiency to a whole new level.
Scientists have spent the last ten years studying an amazing class of materials known as topological insulators which only conduct electricity on their surfaces and edges, rather than through their middles. Reducing a topological insulator to the point where it is only one atom thick gives it the extraordinary property of being able to conduct electricity with absolute efficiency, unlike every other material we know of which loses a chunk of the initial energy in the process of transfer.
There are a number of topological insulators around, but only Stanene is a perfect conductor at room temperature, giving it the most commercial potential.
Rare Earth Elements (the clue is in the name) are in short supply and we need more and more of them to build all sorts of things, from hybrid car batteries to flat-screen TVs.
Global demand for Rare Earth Elements (REEs for short) is expected to top 185,000 tons by 2015 and although some are actually quite plentiful, others live up to their name and are in short supply.
Scientists have been trying to recycle REEs from industrial waste water but up until now haven’t been able to find a way to do it that wasn’t hopelessly expensive and impractical.
Now though, it seems help is at hand…..a nanomaterial known as nano-magnesium hydroxide which has already proved its usefulness by removing some metals and dyes from waste-water, captured over 85% of REEs experimentally diluted in water.
This handy material, that looks like a flower under a high-powered microscope, offers us the triple whammy of saving REEs, protecting the environment and, since it will reduce our need to import REEs from abroad, it will also bring economic benefits.
Never mind planets that manage very nicely thank you without a star (see last post), scientists have now found others that are happily orbiting their personal sun so closely that according to all the physics we currently know, they shouldn’t exist either……
One in particular is Earth-sized and has an Earth-like density so is likely to be made of pretty similar material but it is just a bubbling ball of molten lava, circling its star in less than 9 hours in one of the tightest planetary orbits yet seen.
The problem, as far as scientists are concerned, is that current theories of planet formation can’t explain how it could either have formed so close to its star, or how it could have formed elsewhere and moved inwards. Not only that, but when this planetary system was forming, the star would have been bigger, so actually the planet’s present orbit would have been inside the star itself…..
Curiouser and curiouser……..So, it couldn’t have formed where it is as you can’t (as far as we understand things) create a planet inside a star, but neither could it have developed further out and moved inwards as there is no mechanism (that we know of) that would have stopped it going all the way in and being destroyed.
However it seems that the trick, whatever it is, is quite common as there is a whole new class of planets being discovered, all of whom are Earth-sized and all orbit their particular stars in less than 12 hours. Not that any of them can look forward to a long life, in astronomical terms, as gravitational tides will eventually move them so close to their star that its gravity will rip them apart.
Perhaps all Sol-type stars have such planets? Perhaps there used to be something similar running around inside Mercury’s orbit long ago?
We all know what planets are – whether they are small and rocky like the Earth or large and gaseous like Neptune, the one thing they have in common is that they orbit a star.
They formed, we believe, from accumulations of matter that slowly coalesced into planetary bodies of varying size and density and they are held by gravity in an endless orbit around their particular star.
Eventually the star dies and either consumes its planets in a massive supernova or, if it isn’t big enough to go out with such a bang, it collapses into a small dead star that carries on travelling through space surrounded by small dead planets.
However all these assumptions are going to have to be re-thought as some astronomers have now discovered a free-floating planet, unattached to any star whatsoever.
The things they know about it include the fact that It is only 80 light years from the Earth, has a mass six times that of Jupiter and apparently was formed very recently – just 12 million years ago. The things they don’t know include how and where it was formed and why it has ended up all on its lonely ownsome….
NASA’s Voyager 1 spacecraft, which has been travelling for 36 years, is now about 12 billion miles or 19 billion kilometres from the sun and has finally hit (not literally) interstellar space.
To be accurate, it is still – just – in a transition region immediately outside the solar bubble, where some effects of the sun are still apparent. The heliosphere, or solar bubble, is the area covered by the charged particles that surround the sun and it extends way beyond the outer planets.
Voyager 1 is actually crossing the boundary between the heliosphere and interstellar space itself – an area known, logically enough, as the heliopause.
Mission controllers still receive data every day from Voyager 1 and its sister craft Voyager 2, which is not far behind, having detoured past Uranus and Neptune. The signals from both craft are very dim – about 23 watts, or the power of the light bulb in your fridge. Which sounds bad enough, but by the time the signal has travelled for 17 hours all the way back to earth, it is only a fraction of a billion-billionth of a watt.
No-one knows when exactly Voyagers 1 and 2 will cross into true interstellar space, but barring disasters, they seem set to power out into the interstellar void, eventually snapping the tenuous thread of signal that still attaches them to their home planet.
Once upon a time (between 130,000 and 100,000 years ago) there were three major river systems flowing north across the Saharan sands and emptying into the Mediterranean.
Researchers have come up with this scenario after simulating paleoclimates in the region and, of course, evidence for these rivers is now buried by dunes. However, they may well have provided the migration routes for people who are known to have travelled (somehow) across the Saharan mountains to the more fertile lands that bordered the Mediterranean.
One of these river systems is estimated to have been around 100 kilometres wide and the simulations also predict massive lagoons and wetlands in North East Libya, some covering 70,000 square kilometres.
These green corridors acorss the inhospitable desert would have provided fertile habitats for animals and plants throughout the year and given our ancestors the chance to cross up to 1000 kilometres of desert.
Scientists have found a volcano on earth that is roughly the size of the United Kingdom. In fact, it is nearly as big as the ones on Mars, making it one of the largest volcanoes in the solar system.
Surprised you haven’t seen it or heard of it? Actually, it is lying under about 600 feet of water, 1000 miles east of Japan and is part of an underwater mountain range that is thought to have formed around 130 million years ago.
Underwater volcanoes, known as sea mounts, are scattered all over the sea-floor in their thousands, but this newly discovered volcano, Tamu Massif is completely different. Most volcanoes are small and steep-sided, rising up from the sea floor like a wizard’s hat and, if they reach the surface, forming a small oceanic island. Tamu Massif is an example of a shield volcano, which has a completely different profile, lying so low and broad that if you stood on its sides, you probably wouldn’t see any slope to the ground at all.
Shield volcanoes form when the lava is ‘runnier’ and so flows for long distances before solidifying and Tamu Massif covers a staggering 120,000 square miles. By comparison, Hawaii’s Mauna Loa which is the largest active volcano on earth, is about 2,000 square miles or just 2% of the size.
Sea-grass meadows are an essential ecosystem in our oceans – and not only because they filter sediments, protect coastlines against floods and storms and provide habitats for fish and other marine life. Uniquely in nature, they store carbon in their roots and even in the soil in which they grow and amazingly, they account for 10% of all the carbon that is buried at sea every year. In fact they can store up to twice as much carbon as the world’s temperate and tropical forests combined.
Sadly, sea-grass meadows are in decline all around the globe, often from the impact of dredging but also because of degradation in the quality of coastal waters. In particular, the excessive nutrients found in run-off from agricultural and urban areas encourages algae to grow on the sea-grass, stopping it from receiving the necessary levels of sunlight.
Estuary managers around the world recognise the importance of this sea-grass ecosystem and have tended to assume that all they need to do is replant the lost sea-grass and the whole complex habitat will regenerate itself from the bottom up.
However, researchers have found that, surprisingly, the health of sea-grass meadows is closely linked to the health of the local top predator, the otter.
These carnivores love eating crabs, which love eating sea slugs that in turn love eating algae, so fewer crabs means there are more and larger sea slugs and less algae suffocating the sea-grass.
This chain reaction is called ‘trophic cascade’ and shows that apex predators, despite being carnivores, often play a crucial role in the maintenance of healthy vegetation. Revitalising ecosystems isn’t as simple as just replacing the items at the bottom of the food chain and leaving nature to do the rest – sometimes it has to happen from the top down as well.
Every ecosystem is a complex mosaic of interconnected plants and animals, but there is always one creature (and not always the most obvious) within each system that is the biological equivalent of the canary in the mine.
This is the creature that is known as the ‘key indicator’ specie, and the size and health of its population accurately reflects the health of the whole ecosystem around it.
For the ecosystem within the dwindling primary forests of Russia’s Far East, the key indicator specie is the rare Blakison’s fish owl which, with its six foot wingspan, is one of the largest owls in the world. Naturally, being such huge birds they need huge trees for their nests, which they build in the massive cavities that occur in old-growth mature trees.
So far, so unsurprising, but the trees have another essential role for both the fish owl and the surrounding ecosystem. When the mature trees eventually die, enough of them topple over into adjacent streams to disrupt the flow and so create complexities within the water channel. Because of the semi-blockage by the trunk, the stream now has both slow-moving backwaters and fast-flowing currents and these are essential habitats in the life-cycle of salmon – the favourite prey of the fish-owl.
Management and conservation of old-growth forests will not only protect these rare owls but will also sustain an ecosystem that is vital for eight salmon and trout species, twelve other owl species as well as endangered mammals such as the Siberian tiger, Asiatic black bear and wild boar.
Biologists have argued both ways on this one with some saying that, given the same starting point, evolution would have to follow the same path and others believing that small environmental changes could have disproportionate effects, leaving evolution heading towards an unfamiliar future.
The debate has been long-standing but of course the problem is in trying to find a way of proving the argument one or another.
The answer may well lie in the Caribbean islands of Cuba, Hispaniola (Haiti and the Dominican Republic), Jamaica and Puerto Rico, all of which have similar climates and ecologies. Anole lizards began colonizing these islands about 40 million years ago and have evolved into a wide variety of species on each island.
Scientists have now studied 100 of the 119 types of Anole lizard and have found a remarkable degree of convergence across the four islands, with very similar-looking lizards occupying the same sorts of environmental niches.
Whether the niche is living on tree trunks or down in the grasses, each island has evolved its own version of Anole lizard to fill that piece of the ecosystem and each version looks very much like its cousins on the other islands.
So relax, it looks like humans would definitely have evolved (but only if our distant ancestor wasn’t one of the estimated 96% of creatures wiped out in the Permian Mass Extinction or in the wrong 50% of creatures that survived or died in the later K-T extinction event, not to mention all the other mass extinctions in between….)
If the history of life on earth was re-run, evolution may very well follow the same track, but there’s no guarantee that our particular ancestors would be so lucky a second time….