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"  What are these gravitational wave fingerprints, and why do we care? To understand these gravitational wave fingerprints, you first have to understand a somewhat tricky concept: Because it takes time for light to travel, looking far out in space is also looking far back in time. For example, when you look at the sun (which is 8 light minutes away) you&amp;#039;re seeing the light that was expelled from it 8 minutes ago. And when astronomers spy our galactic neighbor, the Andromeda galaxy, they see it as it was 2.5 million years ago. Right now, the time period that most interests astronomers and cosmologists is the birth of the universe\u2014 the first few seconds after the Big Bang. That&amp;#039;s because we have some huge arguments and questions we want to settle, like: Why didn&amp;#039;t everything just immediately crumple into black holes? And, why isn&amp;#039;t all the matter in the universe evenly spread out? But as much as we&amp;#039;d like to, we can&amp;#039;t look back that far. Even if you took the best telescope imaginable, the farthest light we can see in any direction is a low murmur of microwaves, called the cosmic background radiation. It shows the first time the universe separated from a broiling amalgam of matter into discrete atoms and other particles\u2014which are things that can actually be seen. It dates back to 380,000 years after the big bang, and while everything that came before that moment is unseeable, there&amp;#039;s a catch. Unlike light, gravitational waves\u2014ripples in space-time caused by the movement of matter\u2014can actually barrel through mass like it&amp;#039;s no big deal. And when, in 2002, astronomers discovered that the light coming from the cosmic background radiation was polarized, they realized that gravitational waves (from as far back as a trillionth of a trillionth of a trillionth of a second after the universe formed) could have left their fingerprint in that polarization. It&amp;#039;d be excruciatingly faint, but if you could somehow separate that fingerprint from the background, you&amp;#039;d reveal information and details about the unknown primordial universe. What did the BICEP team originally claim they could show? On March 17, the excited astronomers of the BICEP team (named after the advanced, South Pole telescopes they were using) announced that they&amp;#039;d found these fingerprint swirls of gravitational waves on the cosmic background radiation. This was huge news, and not just because it was the first experiment to claim to have tangible evidence of what was going on in the primordial universe. RELATED: Can We Protect Mars Explorers From Deadly Cosmic Radiation? Based on this fingerprint, the Bicep team claimed that they showed proof of &amp;#039;inflation&amp;#039;\u2014a cosmological theory that posits that in the first few seconds after the big bang, the universe started wildly and rapidly expanding. Opponents of the inflation theory were crushed. Champagne was uncorked, and the team reasonably expected that this finding would not only foretell a new age in cosmology, but (as came up in the press conference) a few Nobel prizes to boot. What went wrong? Soon after the results of the experiment were published, other scientists started picking them apart. Confirming the theory of inflation was big news, and certainly deserved a double- and triple-check. The outside experts almost immediately came upon something fishy. The problem hinges on the fact that between the Earth-based BICEP telescopes and the cosmic microwave background is not just empty space but actually a whole lot of grit\u2014chiefly, polarized interstellar dust in our own Milky Way Galaxy. And because the fingerprint polarization we&amp;#039;d expect to see on the cosmic microwave background is so faint, enough polarized dust could severely mess up the reading. We could be looking at swirls of light polarization actually caused by the dust, not the cosmic microwave background. RELATED: Milky Way Could Have 100 Million Planets Hospitable for Complex Life. The BICEP team was well aware of this issue, and so to cancel out any error induced by this dust, the experimenters used a dust map created by another research team to find a spot in the sky with hardly any dust in the way. The problem? Bicep&amp;#039;s critics discovered that the dust map was either dead wrong, or the experimenters misread the map. Why wasn&amp;#039;t the dust map error caught? While other dust maps exist, the Bicep team&amp;#039;s map was unfortunately based on unpublished data\u2014it was only a preliminary map, one which was shown at a conference the year before. This map arguably could have given the team the most advanced information. But because it hadn&amp;#039;t been published and thoroughly checked, the team&amp;#039;s reviewers were unable to ensure its accuracy and validity. This oversight shocked more than a few scientists.  Where do we stand now? The researchers behind the experiment have just issued a follow-up paper in the science journal Physical Review Letters. Contrary to expectations, they did not withdraw their claim. Instead, while they&amp;#039;ve stated that they acknowledge the interstellar dust map error, they nonetheless stand by their results. They say that based on some theoretical models, they don&amp;#039;t think there could have been enough dust to mess up their reading. RELATED: The $1 Unbreakable Origami Microscope Meanwhile, most other cosmologists are arguing that the dust map could have fudged most or even all of the results, and until they actually have the correct data, it&amp;#039;s just too early to confirm one way or the other. The good news is that in the upcoming months, new dust data from the Planck satellite (owned by the European Space Agency) should clear up this mess. The BICEP team could still very well be right. Or utterly wrong. We&amp;#039;ll just have to wait until the dust has settled. "^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.popularmechanics.com/space/a3101/grav-waves-or-no-grav-waves-16911781/>