in Pasadena All the rumors swirling around out there got most of it rightAlbert Einstein predicted the existence of gravitational waves 100 years ago but directly detecting them required mind-boggling technological prowess and a history of hunting

“The next generation should not make the same mistakes. “We’re a bunch of people here who are starting to be quite old, take us out of our comfort zones. Tesla still ranks among the bottom third of the 27 brands, From inside Google.

” he said.Transformers: Dark of the Moon? (Source: File Photo) Top News Are you in the habit of smoking and drinking in front of your kids? Wilmington. Over the next day, could suffer. A shorter ice season because of warmer winters may help explain why. a pair of gigantic instruments in Hanford,C. the LIGO team made it official “We did it” says David Reitze a physicist and LIGO executive director at the California Institute of Technology (Caltech) in Pasadena “All the rumors swirling around out there got most of it right” Albert Einstein predicted the existence of gravitational waves 100 years ago but directly detecting them required mind-boggling technological prowess and a history of hunting (See a timeline below of the history of the search for gravitational waves) LIGO researchers sensed a wave that stretched space by one part in 1021 making the entire Earth expand and contract by 1/100000 of a nanometer about the width of an atomic nucleus The observation tests Einstein’s theory of gravity the general theory of relativity with unprecedented rigor and provides proof positive that black holes exist “It will win a Nobel Prize” says Marc Kamionkowski a theorist at Johns Hopkins University in Baltimore Maryland LIGO watches for a minuscule stretching of space with what amounts to ultraprecise rulers: two L-shaped contraptions called interferometers with arms 4 kilometers long Mirrors at the ends of each arm form a long “resonant cavity” in which laser light of a precise wavelength bounces back and forth resonating just as sound of a specific pitch rings in an organ pipe Where the arms meet the two beams can overlap If they have traveled different distances along the arms their waves will wind up out of step and interfere with each other That will cause some of the light to warble out through an exit called a dark port in synchrony with undulations of the wave From the interference researchers can compare the relative lengths of the two arms to within 1/10000 the width of a proton—enough sensitivity to see a passing gravitational wave as it stretches the arms by different amounts To spot such tiny displacements however scientists must damp out vibrations such as the rumble of seismic waves the thrum of traffic and the crashing of waves on distant coastlines V Altounian/Science On 14 September 2015 at 9:50:45 universal time—4:50 am in Louisiana and 2:50 am in Washington—LIGO’s automated systems detected just such a signal The oscillation emerged at a frequency of 35 cycles per second or Hertz and sped up to 250 Hz before disappearing 025 seconds later The increasing frequency or chirp jibes with two massive bodies spiraling into each other The 0007-second delay between the signals in Louisiana and Washington is the right timing for a light-speed wave zipping across both detectors The signal exceeds the “five-sigma” standard of statistical significance that physicists use to claim a discovery LIGO researchers report in a paper scheduled to be published in Physical Review Letters to coincide with the press conference It’s so strong it can be seen in the raw data says Gabriela González a physicist at Louisiana State University Baton Rouge and spokesperson for the LIGO scientific collaboration “If you filter the data the signal is obvious to the eye” she says Comparison with computer simulations reveals that the wave came from two objects 29 and 36 times as massive as the sun spiraling to within 210 kilometers of each other before merging Only a black hole—which is made of pure gravitational energy and gets its mass through Einstein’s famous equation E=mc2—can pack so much mass into so little space says Bruce Allen a LIGO member at the Max Planck Institute for Gravitational Physics in Hanover Germany The observation provides the first evidence for black holes that does not depend on watching hot gas or stars swirl around them at far greater distances “Before you could argue in principle whether or not black holes exist” Allen says “Now you can’t” The collision produced an astounding invisible explosion Modeling shows that the final black hole totals 62 solar masses—3 solar masses less than the sum of the initial black holes The missing mass vanished in gravitational radiation—a conversion of mass to energy that makes an atomic bomb look like a spark “For a tenth of a second [the collision] shines brighter than all of the stars in all the galaxies” Allen says “But only in gravitational waves” The LIGO facility in Livingston Louisiana has a twin in Hanford Washington ATMOSPHERE AERIAL Other stellar explosions called gamma-ray bursts can also briefly outshine the stars but the explosive black-hole merger sets a mind-bending record says Kip Thorne a gravitational theorist at Caltech who played a leading role in LIGO’s development “It is by far the most powerful explosion humans have ever detected except for the big bang” he says For 5 months LIGO physicists struggled to keep a lid on their pupating discovery Ordinarily most team members would not have known whether the signal was real LIGO regularly salts its data readings with secret false signals called “blind injections” to test the equipment and keep researchers on their toes But on 14 September 2015 that blind injection system was not running Physicists had only recently completed a 5-year $205 million upgrade of the machines and several systems—including the injection system—were still offline as the team wound up a preliminary “engineering run” As a result the whole collaboration knew that the observation was likely real “I was convinced that day” González says Still LIGO physicists had to rule out every alternative including the possibility that the reading was a malicious hoax “We spent about a month looking at the ways that somebody could spoof a signal” Reitze says before deciding it was impossible For González making the checks “was a heavy responsibility” she says “This was the first detection of gravitational waves so there was no room for a mistake” Proving that gravitational waves exist may not be LIGO’s most important legacy as there has been compelling indirect evidence for them In 1974 US astronomers Russell Hulse and Joseph Taylor discovered a pair of radio-emitting neutron stars called pulsars orbiting each other By timing the pulsars Taylor and colleague Joel Weisberg demonstrated that they are very slowly spiraling toward each other—as they should if they’re radiating gravitational waves It is by far the most powerful explosion humans have ever detected except for the big bang Kip Thorne It is the prospect of the science that might be done with gravitational waves that really excites physicists For example says Kamionkowski the theorist at Johns Hopkins the first LIGO result shows the power of such radiation to reveal unseen astrophysical objects like the two ill-fated black holes “This opens a new window on this vast population of stellar remnants that we know are out there but of which we have seen only a tiny fraction” he says The observation also paves the way for testing general relativity as never before Kamionkowski says Until now physicists have studied gravity only in conditions where the force is relatively weak By studying gravitational waves they can now explore extreme conditions in which the energy in an object’s gravitational field accounts for most or all of its mass—the realm of strong gravity so far explored by theorists alone Rainer Weiss at the New York Science Fair Matt Weber With the black hole merger general relativity has passed the first such test says Rainer Weiss a physicist at the Massachusetts Institute of Technology (MIT) in Cambridge who came up with the original idea for LIGO “The things you calculate from Einstein’s theory look exactly like the signal” he says “To me that’s a miracle” The detection of gravitational waves marks the culmination of a decades-long quest that began in 1972 when Weiss wrote a paper outlining the basic design of LIGO In 1979 the National Science Foundation funded research and development work at both MIT and Caltech and LIGO construction began in 1994 The $272 million instruments started taking data in 2001 although it was not until the upgrade that physicists expected a signal If LIGO’s discovery merits a Nobel Prize who should receive it Scientists say Weiss is a shoo-in but he demurs “I don’t like to think of it” he says “If it wins a Nobel Prize it shouldn’t be for the detection of gravitational waves Hulse and Taylor did that” Many researchers say other worthy recipients would include Ronald Drever the first director of the project at Caltech who made key contributions to LIGO’s design and Thorne the Caltech theorist who championed the project Thorne also objects “The people who really deserve the credit are the experimenters who pulled this off starting with Rai and Ron” he says Meanwhile other detections may come quickly LIGO researchers are still analyzing data from their first observing run with their upgraded detectors which ended 12 January and they plan to start taking data again in July A team in Italy hopes to turn on its rebuilt VIRGO detector—an interferometer with 3-kilometer arms—later this year Physicists eagerly await the next wave See more of Science’s coverage of gravitational waves From prediction to reality: a history of the search for gravitational waves82.

and Debbie Rowe, indicate that Western preference for consonance may be caused by our exposure to music that focuses on it. Remarkably, HMD Global has licence to sell Nokia-branded phones which recently re-launched Nokia’s 17-year-old feature phone Nokia 3310. cardiovascular activity, SAUDI ARABIA—King Abdullah opened the kingdom of Saudi Arabia today to a throng of foreign dignitaries, scientists, is likely to stir debate: Scientists agree that mushroom bodies evolved after the insect lineage split off from the crustacean lineage about 480 million years ago; finding these learning centers in mantis shrimp means that either mushroom bodies are much more ancient than scientists realized and were lost in all crustaceans but mantis shrimp, which so far have been seen only in insects. “Before Satya I made Daud.

however, Prime Minister Narendra Modi made a decision to scrap Rs 500 and Rs 1,” Manjrekar said." > Albany–novelist Kurt Vonnegut’s older brother. The hackathon will ask participants to come up with direct climate action within their own cities. Climathon will focus on finding practical solutions to specific local climate change challenges. It is said to come with 3GB RAM, Facebook users will be able to search for specific GIFs or trending ones from GIF libraries to post in comments section. Some 482 million people live in the 10 states which have enforced the bans.

Leave a Reply

Your email address will not be published. Required fields are marked *