A dusty mistake? The 'groundbreaking' Bicep2 Big Bang signal was just interstellar debris in the galaxy, scientists reveal


comments

In March last year, scientists believed they had glimpsed - for the first time - the rapid expansion of the universe just after the Big Bang, a theory called cosmic inflation.

But since then, the Bicep2 findings have been repeatedly called in to question, with many saying they did not show what they appeared to.

And now it seems the final nail has been put in the coffin, as new data is set to reveal that the initial finding was due to the effects of dust in our galaxy - and not cosmic inflation.

Gravitational waves from cosmic inflation generate a faint but distinctive twisting pattern in the universe. Shown here is the pattern observed with the Bicep2 telescope, providing what was thought at the time to be evidence for cosmic inflation after the Big Bang. The results have now been called into question

Gravitational waves from cosmic inflation generate a faint but distinctive twisting pattern in the universe. Shown here is the pattern observed with the Bicep2 telescope, providing what was thought at the time to be evidence for cosmic inflation after the Big Bang. The results have now been called into question

The latest revelations, made using data from Esa's Planck satellite, are set to be unveiled in a paper early next week.

However, according to the BBC, a summary of the paper was briefly posted on the French Planck High Frequency Instrument (HFI) website, before being pulled.

'Once the "galactic emission" [dust] is correctly subtracted, there still remains an excess [signal] but it is at present too weak to be considered a detection and could be the result of [experimental error],' the summary has been quoted as saying.

HOW DID ASTRONOMERS TRY TO FIND THE GRAVITATIONAL WAVES?

A telescope at the south pole, called Bicep2 (Background Imaging of cosmic Extragalactic Polarisation) was used to search for evidence of gravitational waves.

The instrument examines what is called the cosmic microwave background, the extremely weak radiation that pervades the universe.

The background radiation is not precisely uniform. Like light, the relic radiation is polarised as the result of interacting with electrons and atoms in space.

Computer models predicted a curl pattern in the radiation that would match what would be expected with the universe's inflation.

It did this by detecting a subtle property of the cosmic microwave background radiation. This is radiation that was created in the Big Bang and originally discovered in 1964.

Bicep2 measured the large-scale polarisation of this microwave radiation. Only primordial gravitational waves can imprint such a pattern, and only if they have been amplified by inflation. 

The latest findings are not entirely a surprise - but will still be a disappointment for anyone holding out hope that Bicep2 was correct.

The initial results were made using an extremely sensitive detector on an Antarctic telescope.

The team thought they had found a polarisation of light that would have proved the theory of cosmic inflation.

To make sure the signal they were detecting was correct, the team subtracted the lensing effect of massive galaxies.

But at the time, some scientists said the team had not correctly accounted for interstellar dust in our galaxy.

And now, using data from the Planck satellite, which characterised dust in the galaxy, it seems this fear has been confirmed. 

For their initial research, the Bicep2 astronomers scanned about two per cent of the sky for three years with a telescope at the South Pole, chosen for its very dry air, to aid in the observations.

Their research centered on a theory by Albert Einstein when something very explosive happens it leaves ripples in space-time known as 'gravitational waves'.

The very first gravitational waves can tell us about the birth of the universe and scientists have discovered they leave imprints in cosmic microwave background radiation - the afterglow of the Big Bang - as they pass through space.

The latest findings are not entirely a surprise - but will still be a disappointment for anyone holding out hope that Bicep2 was correct. For their research, astronomers scanned about two per cent of the sky for three years with a telescope at the South Pole, shown, chosen for its very dry air, to aid in the observations

The latest findings are not entirely a surprise - but will still be a disappointment for anyone holding out hope that Bicep2 was correct. For their research, astronomers scanned about two per cent of the sky for three years with a telescope at the South Pole, shown, chosen for its very dry air, to aid in the observations

The incredible find was soon dismissed by other research groups who thought the Harvard Bicep team in may have underestimated the effects of dust in the galaxy. Now, that explanation has been given more credit following a recent study by Esa's Planck satellite (shown)

The incredible find was soon dismissed by other research groups who thought the Harvard Bicep team in may have underestimated the effects of dust in the galaxy. Now, that explanation has been given more credit following a recent study by Esa's Planck satellite (shown)

The theory suggests that this initial spurt would have taken the infant universe from something infinitely small to something close to the size of a marble.

Earlier this year experts believed they had seen these gravitational waves and hailed the experiment as a massive step forward - but admitted the theory needed more work.

'It's just unbelievable quite honestly,' Professor Peter Ade, who helped build the instrument that detected the waves, told MailOnline at the time. 'This is confirming what is, to me, a wacky idea.'

These observations have eluded scientists for decades because it's difficult to separate the characteristic swirl of light created by gravitational waves, and the dust generated today by the Milky Way.

The Bicep team hoped to overcome this by looking at cleanest part of the sky, over Antarctica.

But they didn't use dust data compiled by Europe's Planck satellite, which had mapped the sky at many more frequencies than other satellites.



IFTTT

Put the internet to work for you.

Delete or edit this Recipe

0 comments:

Post a Comment