Subscribe to our daily newsletter
Why the 4th Gravitational Wave Is a “New Window on the Universe”
LIGO and Virgo reveal a gravitational wave was detected on two different continents. Here's what that means and why it matters.
The twin Laser Interferometer Gravitational-Wave Observatory (LIGO) is a collaborative effort. It’s basically a group of scientists who use specialized equipment to study gravitational waves. There are currently two such observatories in the US, one in Hanford, Washington and the other in Livingston, Louisiana. They use an interferometer, or a laser-based instrument, to detect even the minutest ripples in space-time as it relates to gravitational waves. The instrument is so delicate, it can pick up distortions one proton in width.
LIGO observatories are owned by the National Science Foundation (NSF) and are run by scientists at NASA, MIT, and Caltech. The Europeans now have their own gravitational observatory, known as Virgo, based in Italy. The two collaboratives recently started working together, and they’ve just made an announcement unveiling new results, a noteworthy milestone in gravitational astronomy.
Researchers announced what they called a “new window on the universe,” at the G7 Ministerial Meeting on Science, taking place Sept. 27-28. Back on August 14, Virgo for the first time detected a gravitational wave, made by a binary black hole system. The two LIGO locations picked it up just after. The wave was created when two black holes collided and merged. All three locations registered the resulting gravitational wave.
This was the first time in history such a wave was detected on two different continents. This is more than just a scientific second opinion, it gets us closer to a 3D picture of what Einstein's gravitational waves actually look like. The twin LIGO detectors in the United States mean scientists can detect gravitational waves, but only on one plane. The Virgo detection literally adds a new dimension to the breakthrough discovery of gravitational waves in 2015 (which is a hot favorite to win the Physics Nobel Prize this year). Professor Andreas Freise, a LIGO project scientist at the University of Birmingham, puts it like this: “It’s like if I give you just one slice of apple, you can’t guess what the fruit looks like.” The third detector also means scientists can triangulate the source of the wave to identify exactly where in the universe the signal originated.
National Science Foundation director France Córdova spoke at the press conference. She said, "This is an exciting milestone in the growing international scientific effort to unlock the extraordinary mysteries of our universe."
See a video depicting the recorded black hole merger here:
Gravitational waves were first predicted by Einstein’s general theory of relativity. LIGO’s recording of a black hole collision several months ago confirmed this famous physicists suppositions, first hypothesized in 1916. You can hear a recording of that collision. The most recently detected gravitational waves came from a location 1.8 billion light years away. These were two enormous black holes, the first 31 and the second 25 times the mass of our sun. The resulting black hole was 53 times our sun’s mass.
With three detection locations, scientists can better gauge the distance of the origin of these ripples in space-time. University of Texas astrophysicist J. Craig Wheeler perked the ears of some space heads back in August when he tweeted, “New LIGO. Source with optical counterpart. Blow your sox off!” The optical counterpart he mentioned wasn’t elaborated on until now. Scientists believe they may be able to detect other particles emanating from black hole collisions. But some space geeks took it to mean that LIGO and Virgo had detected the merger of a neutron star.
Aerial view of the Virgo detector. The Virgo collaboration/CCO 1.0
Still, what was announced is no less groundbreaking, according to Georgia Tech professor Laura Cadonati. She’s the deputy spokesperson for LIGO. “This increased precision will allow the entire astrophysical community to eventually make even more exciting discoveries," she said, "including multi-messenger observations." With these detectors, astronomers may also be able to find and study light, x-rays, neutrinos, and other subatomic particles emanating from cosmic events.
LIGO spokesman David Shoemaker, who is also of MIT, said, “This is just the beginning of observations with the network enabled by Virgo and LIGO working together.” He added, “With the next observing run planned for fall 2018, we can expect such detections weekly or even more often.”
More gravitational observatories are in the works in other locations, including one for New Delhi. With an international network, researchers believe they can gain better information, further test Einstein’s theory, and get more accurate location information for black hole and neutron star mergers, among other significant cosmic phenomenon.
Caltech’s David H. Reitze is the executive director of the LIGO Laboratory. He said, “We have taken one step further into the gravitational-wave cosmos. Virgo brings a powerful new capability to detect and better locate gravitational-wave sources, one that will undoubtedly lead to exciting and unanticipated results in the future.”
See the press conference for yourself here:
The team caught a glimpse of a process that takes 18,000,000,000,000,000,000,000 years.
- In Italy, a team of scientists is using a highly sophisticated detector to hunt for dark matter.
- The team observed an ultra-rare particle interaction that reveals the half-life of a xenon-124 atom to be 18 sextillion years.
- The half-life of a process is how long it takes for half of the radioactive nuclei present in a sample to decay.
A study looks at the ingredients of a good scare.
Catching fear in a bottle<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDYyNzg1Ny9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyOTQwMTcyMn0.WtpJ1E_dhK2o09fBpKARynj4_p5NXeklgsXsbd7xr9w/img.jpg?width=980" id="8ff51" class="rm-shortcode" data-rm-shortcode-id="f10dd9188b173f4a36e85e9325507c6b" data-rm-shortcode-name="rebelmouse-image" />
Credit: Photo Boards/Unsplash<p>Previous studies have tracked physiological signs of fear arousal, but none have established a one-to-one correlation between that arousal and specific, actual fear events.</p><p>Andersen says that much of the research has been conducted in lab settings with weak fear stimuli, observing subjects as they experience things like scary videos. Scares in these situations tend to be weak and difficult to measure. Even harder to track in these situations is the link between enjoyment and fear. </p>
Eyes everywhere<iframe src="https://player.vimeo.com/video/109695164" width="100%" height="480" frameborder="0" scrolling="no" class="rm-shortcode" data-rm-shortcode-id="267ba87cfb8591ed5830499574d2272a"></iframe><p>Andersen and his colleagues conducted their experiments at <a href="https://dystopia.dk" target="_blank" rel="noopener noreferrer">Dystopia</a> Haunted House, a commercial attraction in Vejle, Denmark constructed in an old, run-down factory. The Recreational Fear Lab has a long-standing partnership with the spook shack.</p><p>They outfitted 100 volunteers with heart monitors and sent them on their terrifying way through the 50-room horror mansion. The facility incorporates a number of fright mechanisms including frequent jump scares in which a sudden threat takes a visitor by surprise.</p><p>Researchers surreptitiously observed their participants on closed-circuit video as they made their way through the attraction. They tracked each individual's scares, scoring them for intensity according to their visible reactions. After exiting the attraction, individuals self-reported their experiences in the haunted house.</p><p>Combining these self-reports with observer notes and each participant's heart-rate data gave the researchers subjective, behavioral, and physiological insights into the ways in which fear is experienced, and when it's a good thing or not.</p>
A pair of inverted U-shapes<p>In analyzing their data, the researchers saw two separate inverted u-shape curves. One depicted participants' enjoyment based on their self-reports and observed behavior. A similar u-curve was detected in their heart rates showing that just the right amount of heartbeat acceleration is associated with fun, but too much is too much. It's the terror Goldilocks zone.</p><p>Says Andersen, "If people are not very scared, they do not enjoy the attraction as much, and the same happens if they are too scared. Instead, it seems to be the case that a 'just-right' amount of fear is central for maximizing enjoyment."</p><p>The research suggests that being scared is enjoyable when it represents just a quick minor physiological deviation from one's normal state. When it goes on too long, however, or triggers too severe a physiological change, it becomes disturbing. Game over.</p><p>Andersen notes that this is not dissimilar to the factors known to make interpersonal play enjoyable: just the right amount of uncertainty and surprise. These are, maybe not coincidentally, also the ingredients of a successful joke.</p>
A meteorite that smashed into a frozen lake in Michigan may explain the origins of life on Earth, finds study.
- A new paper reveals a meteorite that crashed in Michigan in 2018 contained organic matter.
- The findings support the panspermia theory and could explain the origins of life on Earth.
- The organic compounds on the meteorite were well-preserved.
Meteor streaks through Michigan sky<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="80b7f30820153b35fc515592d7475f53"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/EPu2qnqMYBo?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
The meteorite that smashed into Strawberry Lake carried pristine extraterrestrial organic compounds.
Credit: Field Museum