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Thursday 5 November 2015

Evidence for a Multiverse? Where big meteors come from, and a new kind of telescope in the making....

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Evidence for a Multiverse

The 'multiverse' theory of reality - that ours is only one of a great many universes - has been around for a good long while. But now there are  - very tentative - claims that evidence supporting the existence of a multiverse has been found. The evidence comes from a mysterious glow, seen by ESA's Planck space observatory: Researcher  Ranga-Ram Chary removed the effects of stars, gas and dust from the cosmic microwave background. He should have found nothing except noise. But this was not the case. Instead, in a specific frequency, patches of the sky looked brighter than they should have. The signal, if it is real, could be evidence of our universe butting up against another when it was young - the glow is on the edge of the observable universe, so it's light  began the journey to Earth only a few hundred thousand years after the big bang.

Whatever the explanation, a lot more investigation will be needed. David Spergel, an astrophysicist from Princeton University, says he thinks it is worth looking into explanations that do not involve other universes. "The dust properties are more complicated than we have been assuming, and I think that this is a more plausible explanation."

Ranga-Ram Chary's paper is here.
Above: Planck's view of the sky. Courtesy of ESA.

A new kind of telescope: Terahertz telescope

It's not every day that a totally new kind of telescope gets proposed, but this is one of them: Terahertz radiation lies in the gap between infra red and microwaves. Until fairly recently there wasn't any practical way to even detect radiation in that frequency range, but now technology has caught up with the problem and a telescope that sees the sky in this newly available 'colour' of the electromagnetic spectrum may not be too far off (see title link). 

Above: The position of terahertz radiation on the electromagnetic spectrum.Courtesy of

Where do the super-fireball meteors come from? 

Fireballs are meteors that are especially bright - which almost always means unusually big. Rather than being pea sized lumps of rock these are up to the size of a van and can go off with the force of a small nuclear bomb. Usually they explode so high up - and so far away from population centers - that their effects are not felt. This was the case with the bright green Halloween fireballs of the last week... 

...but sometimes an especially big or tough rock can get closer to the ground before exploding, as the people of Chelyabinsk discovered in 2013...

But where such unusually big space rocks are hailing from is kind of a mystery. As part of a citizen science project reports of fireballs and super fireballs have been collected across two centuries of records. The pattern that emerges shows that the bigger space rocks aren't usually related to the normal meteor showers - instead they seem to be a law unto themselves, popping out of the sky as they please.

NASA's Orbiting Carbon Observatory begins to see patterns in greenhouse gasses

Of all the jobs that satellites do for us, monitoring our planet and how its climate is changing is one of the most important - and NASA's Orbiting Carbon Observatory 2 (OCO-2) is the daddy of climate change monitoring satellites. It's now more than a year into its mission, and patterns are beginning to emerge in the data it's returning - some expected and some not so much. "We can already clearly see patterns of seasonal change and variations in carbon dioxide around the globe," said Annmarie Eldering, OCO-2 deputy project scientist. "Far more subtle features are expected to emerge over time." 
Some the emerging trends in the data are:
  • Between mid-May and mid-July 2015 OCO-2 saw the concentration of atmospheric carbon dioxide over much of the northern hemisphere decreased by two to three percent.
  • Higher carbon dioxide levels of several parts per million are seen in regions where fossil fuels are being consumed by large power plants or megacities
  • Enhanced levels are seen in the Amazon, Central Africa and Indonesia, where forests are being cleared and burned to create fields for agricultural use.
  • There's a strong correlation observed between atmospheric carbon dioxide over the Pacific Ocean and the current El Nino. 
  • Fluctuations in carbon dioxide appear to be strongly linked with warmer sea surface temperatures.

Above: A visulaisation of the data returned by OCO-2 to date. Courtesy of NASA.

SOFIA observatory-in-a-plane studies exoplanets

A great video on how the SOFIA infra red telescope - which is mounted in a jet airliner to get it above most of our atmosphere - has begun hunting planets around other stars:

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