Herschel discovers mature galaxies in the young universe

29 April, 2014

I have a new article published by ESA:

 

"New Herschel results have given us a remarkable insight into the internal dynamics of two young galaxies. Surprisingly, they have shown that just a few billion years after the Big Bang, some galaxies were rotating in a mature way, seemingly having completed the accumulation of their gas reservoirs.

 

When galaxies form, they accumulate mass by gravitationally attracting vast, external gas clouds. As the gas clouds enter the galaxy, they fall into haphazard orbits. These disordered paths cause turbulence in the host galaxies, which can drive star formation. ..."

 

Read the full story here.


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New Scientist: Big bang breakthrough: The dark side of inflation

24 April, 2014

I have the cover story on New Scientist this week. It sprang from a dynamite email I received from John Peacock, Royal Observatory in Edinburgh, late on the day of the big bang announcement. It pointed out that there could be tragedy as well as triumph in the announcement, and that perhaps we would never know how the Universe truly began.

 

"The end of the beginning

 

Cosmology's big breakthrough is a triumph. But the joy is not unalloyed.

 

SUITABLE clients at Milliways, Douglas Adams's Restaurant at the End of the Universe, would have experienced six impossible things before breakfast. In the past decade or so, cosmologists have looked like they were halfway there.

Strike one: dark matter. Galaxies are whirling round faster than normal gravity alone can explain, so 80 per cent plus of the universe's matter is in a form neither we nor, so far, our detectors can see.

Strike two: dark energy. Contrary to all expectations, the universe's expansion is apparently accelerating, so the inwards gravitational tug of both normal and dark matter is being trumped by the effect of another substance so exotic no one knows for certain what it might be.

Strike three: inflation. After all that, the universe still looks rather less crinkly than we would expect, so it must have been smoothed out by a spontaneous faster-than-light expansion in the earliest phase of its existence, which then just stopped.

Extraordinary claims, requiring extraordinary evidence. So you could almost feel the collective sigh of relief last month when the team running the BICEP2 telescope, situated at the South Pole, announced that they had seen a sign of one of this terrible trio. Distinctive patterns of light polarisation in the cosmic microwave background (CMB) radiation were in fact two for the price of one. They represented an apparently unmistakable signature of inflation, but also provided indirect evidence for the existence of gravitational waves from the same era – another theoretically predicted phenomenon that has so far shied away from the limelight.

If the result is confirmed, it is heady stuff. Cosmologists will be able to begin whittling down a forest of ideas about how inflation might have happened, and close in on an understanding of the first microscopic moments of the universe's history.

But there is sobriety amid the popping of champagne corks. Besides the question of that all-important confirmation, there are wider-ranging considerations. "Although this is a historic advance, it is also a limit," says John Peacock, a cosmologist at the Royal Observatory in Edinburgh, UK. "We have now seen as far back in time as it is possible to see, and it is not to the very beginning." We may now know more about the moments following the big bang than ever – at the price of never knowing any more about the event itself. ..."

 

You can read the full story here (a registration is required).


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Hidden Black Holes Discovered by XMM-Newton

22 April, 2014

I have a new story posted by ESA:

 

"A pair of supermassive black holes in orbit around one another have been spotted by XMM-Newton. This is the first time such a pair have been seen in an ordinary galaxy. They were discovered because they ripped apart a star when the space observatory happened to be looking in their direction.


Most massive galaxies in the Universe are thought to harbour at least one supermassive black hole at their centre. Two supermassive black holes are the smoking gun that the galaxy has merged with another. Thus, finding binary supermassive black holes can tell astronomers about how galaxies evolved into their present-day shapes and sizes. "

 

Read the full story here.


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Across the Universe: Distant new world may point to undiscovered planets in solar system

26 March, 2014

I have a new posting on my Guardian blog:

 

"Today’s discovery of dwarf planet 2012 VP113 suggests that many planet-sized worlds lurk undetected beyond the orbit of Pluto, maybe even a giant ‘Super Earth’

 

We learned today that our solar system is larger than we had previously known. A newly discovered, extremely distant dwarf planet with the tentative name of 2012 VP113 was announced. It appears as nothing more than a dot on images but we know a few things about it.

 

For a start, it is approximately 450km across, which is pretty small by planetary standards and means that it is almost certainly an irregular lump of rock and ice rather than a spherical "world".

 

We know also that it never comes closer than 80 times the distance of the Earth to the sun. And it’s pink. Honestly, it is. ..."

 

You can read the full story here.

 

The most amazing thing about this story is that almost a decade ago, I wrote about the theoretical possibility of these worlds for New Scientist. You can read that story here.


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Across the Universe: Searching for life on Mars: where should the ExoMars rover land?

26 March, 2014

I have a new post on my Guardian blog. This one is not written by me but was kindly offered by planetary scientist, Peter Grindrod, to whom I am very grateful.

 

"On Wednesday, the European Space Agency starts considering potential landing sites on Mars for its 2018 ExoMars mission. Dr Peter Grindrod at Birkbeck, University of London, is one of the experts tasked with this job. He kindly contributed this guest blog

 

If you had to pick just one place to find life on Mars, where would you go?

 

In the 1970s, John Guest worked on the Nasa Viking mission to Mars. Twin orbiters, twin landers – nobody builds missions like that these days. As a geologist, John helped to decide where one of the landers would touch down.

 

John told me how he and his friend Ron Greeley only had a couple of days’ worth of images from the orbiters, at a frighteningly low-resolution by today’s standards. They had to choose a landing site that wouldn’t leave the landers in pieces and would still be scientifically interesting. I thought that the pressure and responsibility of that decision must have been massive. John seemed nonplussed by my concern.

 

I remembered this story because the European Space Agency has recently asked the same question.

 

But this is no longer the Mars that John and Ron knew with Viking. We no longer have to rely on just a handful of low-resolution images and a rushed decision. Instead we have hundreds of terabytes of data at our fingertips to call upon in the search. ..."

 

You can read the full post here.


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New Scientist: Big bang breakthrough: Who is the father of inflation?

25 March, 2014

I have a new story published by New Scientist today. For me, it was a particular thrill to swap detailed emails with physicist Alexei Starobinsky, who predicted the gravitational waves way back in 1979. His extraordinary theoretical insight has been vindicated by this new discovery. I so wanted to call this article 'Who's the daddy?'

 

"The first clear glimpse of ripples in space-time, known as gravitational waves, is being widely hailed as validation for inflation, the notion that the baby universe ballooned in size mind-bendingly fast just after the big bang. Reported last week, the discovery may earn some scientists a Nobel prize if confirmed by further experiments. But who are the founders of inflation?

 

Like the Higgs boson, which was hypothesised in various forms by several groups around the same time, it turns out that inflation has many fathers. That's partly because it draws on many disparate ideas in physics and cosmology. ..."

 

You can read the full story here.


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