LIGO physicists eyeball a new gravitational wave

The third time's the charm

Physicists working at the Laser Interferometer Gravitational-Wave Observatory (LIGO) have spotted gravitational waves rippling through the universe for the third time, according to results published in Physical Review Letters on Thursday.

The discovery of gravitational waves was announced for the first time in February 2016. It was heralded as further proof of Einstein's genius. His theory of general relativity explained that gravity was caused by mass warping of the fabric of spacetime.

As mass travels through spacetime, a trail of gravitational waves is emitted, like when a stone is thrown into a pond.

Researchers working at the LIGO detectors in Louisiana and Washington in the US confirmed that the third gravitational wave was measured on January 4 of this year. The signal came from the final moments as two black holes collided and merged approximately three billion years ago.

The third wave, known as GW170104, came from a merger event between black holes measuring more than 31 and 19 times the mass of the sun, producing a single more massive black hole about 50 times as hefty as the sun. The rest of the mass was radiated away as gravitational waves.

GW170104 is more distant than the first (GW150914) and second (GW151226) events and is the second-heaviest.

Image comparing the distance and mass of the three black hole merger events detected so far (Image credit: LSC/OzGrav)

"The observation and interpretation of yet another LIGO signal, GW170104, confirms the success of our theoretical program to model binary black holes," said Alessandra Buonanno, co-author of the paper and professor of physics at the University of Maryland (UMD).

"For the third LIGO signal we could gather some evidence that at least one black hole might be rotating in a direction misaligned with the overall orbital motion – a spin configuration favored by some astrophysical formation scenarios of binary black holes," Buonanno added.

Although the theory of general relativity has existed for over a century, it is still far from complete – there are several unanswered questions. Einstein predicted that dispersion – an effect observed as light waves travelling through a prism are at different speeds due to its wavelength producing a rainbow – is forbidden with gravitational waves.

"Even for this new event, which is about two times farther away than our first two detections, we could not find any evidence that gravitational waves disperse as they travel in the fabric of space-time," Buonanno said.

"Einstein still seems to have been right about the true nature of gravity," said Peter Shawhan, co-author of the paper and associate professor of physics at UMD.

LIGO's second observation run began on 30 November and will last through August 2017. The current sensitivity has a network signal-to-noise ratio of 13 and a false alarm rate less than 1 in 70,000 years.

The detectors will be upgraded in late 2018, helping scientists to discover more about what goes on in the distant reaches of our cosmos. ®

Other stories you might like

  • Deepfake attacks can easily trick live facial recognition systems online
    Plus: Next PyTorch release will support Apple GPUs so devs can train neural networks on their own laptops

    In brief Miscreants can easily steal someone else's identity by tricking live facial recognition software using deepfakes, according to a new report.

    Sensity AI, a startup focused on tackling identity fraud, carried out a series of pretend attacks. Engineers scanned the image of someone from an ID card, and mapped their likeness onto another person's face. Sensity then tested whether they could breach live facial recognition systems by tricking them into believing the pretend attacker is a real user.

    So-called "liveness tests" try to authenticate identities in real-time, relying on images or video streams from cameras like face recognition used to unlock mobile phones, for example. Nine out of ten vendors failed Sensity's live deepfake attacks.

    Continue reading
  • Lonestar plans to put datacenters in the Moon's lava tubes
    How? Founder tells The Register 'Robots… lots of robots'

    Imagine a future where racks of computer servers hum quietly in darkness below the surface of the Moon.

    Here is where some of the most important data is stored, to be left untouched for as long as can be. The idea sounds like something from science-fiction, but one startup that recently emerged from stealth is trying to turn it into a reality. Lonestar Data Holdings has a unique mission unlike any other cloud provider: to build datacenters on the Moon backing up the world's data.

    "It's inconceivable to me that we are keeping our most precious assets, our knowledge and our data, on Earth, where we're setting off bombs and burning things," Christopher Stott, founder and CEO of Lonestar, told The Register. "We need to put our assets in place off our planet, where we can keep it safe."

    Continue reading
  • Conti: Russian-backed rulers of Costa Rican hacktocracy?
    Also, Chinese IT admin jailed for deleting database, and the NSA promises no more backdoors

    In brief The notorious Russian-aligned Conti ransomware gang has upped the ante in its attack against Costa Rica, threatening to overthrow the government if it doesn't pay a $20 million ransom. 

    Costa Rican president Rodrigo Chaves said that the country is effectively at war with the gang, who in April infiltrated the government's computer systems, gaining a foothold in 27 agencies at various government levels. The US State Department has offered a $15 million reward leading to the capture of Conti's leaders, who it said have made more than $150 million from 1,000+ victims.

    Conti claimed this week that it has insiders in the Costa Rican government, the AP reported, warning that "We are determined to overthrow the government by means of a cyber attack, we have already shown you all the strength and power, you have introduced an emergency." 

    Continue reading

Biting the hand that feeds IT © 1998–2022