We've finally found gravitational waves, so can we time travel?
Physicists working with a powerful observatory on Earth announced Thursday that they have finally detected ripples in space and time created by two colliding black holes, confirming a prediction made by Albert Einstein 100 years ago.
(https://s.yimg.com/uu/api/res/1.2/5UnqznVhieqrMrAino_leQ--/aD0zMjM7dz01NzU7c209MTthcHBpZD15dGFjaHlvbg--/http://media.zenfs.com/en-US/homerun/mashable_science_572/574f64999a7e66379f553a5868df2756)
These ripples in the fabric of space-time, called gravitational waves, were created by the merger of two massive black holes 1.3 billion years ago. The Laser Interferometer Gravitational-Wave Observatory (LIGO) on Earth detected them on Sept. 14, 2015, and scientists evaluated their findings and put them through the peer review process before publicly disclosing the landmark discovery today.
SEE ALSO: Einstein was right: Scientists detect gravitational waves for the first time
While this finding potentially opens a up a new way to learn more about how the universe works, there's one question in particular non-scientists seem to want answered: Can we finally travel through time now?
First of all, it's not a bad question.
Think about space-time as a fabric that stretches through the universe and is affected by matter like stars, black holes, planets and other cosmic objects. Massive bodies warp space-time around them, creating what we feel as gravity on Earth.
It would follow that learning more about it could lead to some kind of understanding of how to manipulate space-time to somehow travel through time.
However, according to one well-known expert, this new gravitational wave discovery won't necessarily get us there.
"I don't think it [the detection of gravitational waves] is going to bring us any closer to being able to do time travel. I wish it would," said LIGO co-founder Kip Thorne during a press conference announcing the discovery.
Thorne should know, given that he was also an executive producer on the 2014 film Interstellar, which involved travel through a wormhole in space-time.
Even though we probably won't be able to surf a gravitational wave into the future or the past, this finding still means a lot for physics.
The merger of the two black holes "created a violent storm in space-time," Thorne said, allowing scientists to see the disruption in space-time as it passed through Earth's part of space.
By confirming that gravitational waves are produced by the extreme collisions of massive objects in the universe, it gives scientists a new way to explore space. Instead of just looking at the cosmos in infrared, optical and ultraviolet light, researchers can now use gravity as another way to investigate.
But the book isn't necessarily closed on the time travel question.
Some scientists haven't yet counted out the idea that this discovery could lead to something unexpected way down the line.
"The discovery will allow us explore space and time in a spectacular new way," physicist Brian Greene told Mashable. "Might that one day yield breakthroughs in space travel or perhaps even in time travel? Who knows. But deep understanding is the first step forward."
https://www.yahoo.com/news/weve-finally-found-gravitational-waves-221739243.html
============================
Revolution in physics as gravitational waves seen for first time.
(https://d1o50x50snmhul.cloudfront.net/wp-content/uploads/2016/02/howresearche-800x533.jpg)
We just turned the volume up on the sky. Gravitational waves, the booming echoes of massive objects moving all over the universe, have been detected for the first time by LIGO, the Laser Interferometer Gravitational-Wave Observatory, which was recently upgraded.
Gravitational waves are predicted by Einstein's theory of general relativity, which says that massive objects warp space-time around them. When these objects accelerate, they make gravitational waves: ripples in the fabric of space-time that spread outward, like the wake left behind a boat.
We have been pretty sure they exist for a while – their presence was inferred indirectly as far back as 1974 – but none had been observed directly.
In a press conference today at the National Press Club in Washington DC, which was simultaneously broadcast to the media and other members of the team that made the discovery, the LIGO collaboration announced that they had finally caught a wave.
"Ladies and gentlemen, we have detected gravitational waves," said David Reitze, the executive director of the LIGO Laboratory, at the press conference. "We did it!" The announcement accompanies a paper published in Physical Review Letters.
Double lucky
This historic signal was produced by a pair of black holes roughly 1.3 billion light years away, one 29 times the mass of the sun and the other 36 times, orbiting each other and then merging into a single black hole.
LIGO's dual detectors, based in Hanford, Washington, and Livingston, Louisiana, felt the tremors on 14 September 2015 at almost the same instant. Their sensors registered space-time expanding and contracting by as much as a thousandth of the size of a proton – a tiny distance, but 10 times larger than the smallest unit LIGO can measure.
This was a doubly lucky find: officially, the experiment wasn't scheduled to begin taking data until four days later, on 18 September, in a run that continued until 12 January 2016. The signal arrived while the detectors were in "engineering mode", making sure the instruments were running smoothly.
Black holes bumping
A second stroke of luck was the nature of the signal: it seems that black hole mergers happen more often than we expected.
All objects emit gravitational waves when they orbit each other, including Earth orbiting the sun. But as these two black holes circled each other, the energy they lost to gravitational waves was enough to bring them much closer together – causing them to distort space-time further and emit even more gravitational waves.
That set them on track to collide and merge into one bigger black hole. "It's a runaway process," says Frans Pretorius, of Princeton University in New Jersey. "The closer they get, the faster they spin." Near the end, they were whirling so fast that each orbit lasted just a few milliseconds.
When they eventually merged, the single black hole that remained was 62 times the mass of the sun – three solar masses lighter than the two original black holes combined. That missing mass all went into creating gravitational waves that fluttered space-time like a sheet.
"The total power output of gravitational waves during the brief collision was 50 times greater than all of the power put out by all the of the stars in the universe put together," said Kip Thorne of Caltech, one of LIGO's founders. "It's unbelievable."
At first, the resulting bigger black hole was lumpy instead of round, and getting rid of the lumps caused it to emit more gravitational waves. It then settled into a sphere and grew quiet.
By translating the frequency of the gravitational waves into sound waves, you can actually hear the signal. Physicists call it a "chirp": a rise in pitch and volume as the black holes circle each other faster and faster.
The chirp from this new signal was very short – "just a thump", said LIGO spokesperson Gabriela Gonzalez at the press conference.
Listen to the pair of black holes colliding – as detected by LIGO:
Not a drill
There were lingering worries that this signal could have been a deliberate fake. The LIGO team is infamous for secretly introducing ersatz gravitational wave signals into the data stream to test the experiment's analysis procedures.
A previous "detection" in 2010 was sunk this way, but experienced team members knew something comforting this time around: fake signals aren't inserted into engineering runs.
Other false positives could come from the accidental insertion of a pattern that looks like a signal, or even from malicious tampering. But by following procedures to check each instrument and each step in the data analysis, the team ruled these out, too.
The big reveal, which team members call "opening the box", was on a conference call on 5 October. At the agreed-upon moment, a graph showing how likely it was that this signal was due to chance went live. The event was overwhelmingly likely to have been real.
Hello, gravitational sky
The groundbreaking discovery opens several doors, and has the potential to win a Nobel prize.
Since gravitational waves were predicted by general relativity, they offer a chance to verify that Einstein's theory really is the correct account of gravity. So far, general relativity is passing with flying colours: the observed signal is perfectly explained by Einstein's equations.
But the real excitement is that gravitational waves can show us a side of the night sky we've never seen before. Until now, there had been no sign of black holes in this size range – much less two of them.
Now that the first event has been detected, the era of gravitational wave astronomy is under way, says Avi Loeb of Harvard University in Massachusetts.
"I used to say, as they are building the instrument, they can be thought of as a physics experiment," he says. "But as soon they detect a single source, they will be thought of as an astronomical observatory." LIGO will be able to spot signals from massive objects that we are unable to observe with other techniques.
"It's been a very long road, but this is just the beginning," Gonzalez said. "This is the first of many to come. Now that we have detectors able to detect these systems, now that we know that binary black holes are out there, we begin listening to the universe."
All this time, the gravitational wave sky has been waiting for us patiently. We're about to tune in.
Want to know more? Learn about gravitational waves from one of the experts using LIGO data at our upcoming London event
https://www.newscientist.com/article/2077162-revolution-in-physics-as-gravitational-waves-seen-for-first-time
=====================
also ref to
Re: Einstein's most incredible prediction may be proven right on February 11 —
http://www.thelivingmoon.com/forum/index.php?topic=9090.msg121864#msg121864
Gravitational Waves vs. Gravity Waves: Know the Difference! -
http://www.thelivingmoon.com/forum/index.php?topic=9101.msg121968;topicseen#new
http://www.pbs.org/wgbh/nova/next/physics/gravitational-waves-discovered
Maybe...
"Time travel might be possible in situations that involve these very strong gravitational fields," another Princeton astrophysicist, Edwin Turner, tells The Daily Beast. "You would only get time travel in the strong-field gravity."
http://www.thedailybeast.com/articles/2016/02/15/hold-up-did-we-just-crack-time-travel.html
Cosmo
Not managed to look into or consider this topic as yet Cosmo..just initially posted the article/s..
here is another one related to it that just showed up..
---------------------------
Hold Up, Did We Just Crack Time Travel?
(https://s.yimg.com/lo/api/res/1.2/OGansgjxuFPGHJbTx7ro7w--/YXBwaWQ9eW15O3E9NzU7aD0zNDEuMzMzMzMzMzMzMzMzMzc7c209MQ--/http://slingstone.zenfs.com/offnetwork/89ca87d4936a08594125b8eea6f54bd3)
Astrophysicists famously proved Einstein's theory on the existence of gravitational waves last week. Here's the less covered part of it all: It might, down the line, bring us closer to moving through time.
A now-famous team of astrophysicists shocked the world Thursday after recording the gravitational waves of two black holes slamming into each other 1.3 billion light-years away.
This detection supports Einstein's general theory of relativity in a way that revolutionizes scientific understanding of how space and time behave in extreme environments, and astrophysics will never be the same.
That includes mankind's pursuit of time travel.
Kip Thorne of the acclaimed Laser Interferometer Gravitational-wave Observatory (LIGO) researchers deflected such assertions about his team's finding at the press release by saying, "I don't think [our detection of gravitational waves] is going to bring us any closer to being able to do time travel. "
But two things are certain: Humility is essential in the path to a Nobel Prize, and other renowned astrophysicists are giving the LIGO team more credit than they give themselves.
David Spergel is a theoretical physicist and chair of Princeton University's astronomy and astrophysics department and he's one such admirer. Spergel concedes there is a long way to go before man comprehends the true plausibility of time travel, but he believes general relativity will be essential to that discovery, if the stars align for it.
"There are still a lot of ifs there, starting with the existence of negative mass particles and wormholes being stable," Professor Spergel tells The Daily Beast. "But general relativity's equations—which gave us black holes, and we see very strong evidence for them with LIGO—are telling us that that would permit time travel."
Whether or not they want to claim it, the LIGO researchers just made great strides toward understanding time travel.
A Brief Picture Of General Relativity
Einstein's general relativity explains gravity and how things move through space, and leading time-travel theories in the scientific community must account for it.
Einstein explains gravity as the product of mass manipulating the fabric of space-time. This fabric is known as "space-time" because the two concepts are inseparably woven together throughout the universe, much in the same way that a mile is roughly six minutes away from a good runner.
Like a bowling ball sitting amid a trampoline, black holes are massive objects that warp the fabric of space-time. Anything (say, a golf ball) that approaches a black hole (the bowling ball) gets faster the closer it gets because that is where the fabric of space-time (the trampoline) is most warped.
This warping is caused by any and everything with mass, but is especially intense around the greatest objects in the universe: black holes. And that's where the magic happens.
"Time travel might be possible in situations that involve these very strong gravitational fields," another Princeton astrophysicist, Edwin Turner, tells The Daily Beast. "You would only get time travel in the strong-field gravity."
LIGO's Proof Of Strong-Field Gravity
There's never been anything like LIGO's direct detection of strong-field gravity, which comes with a statistical significance of 5.1 sigma, meaning there's only a one in 6 million chance that the finding is an error.
It's proof.
It's proof that gravitational waves exist, that black holes exist, and that two of the fat monsters—at 29 and 36 times the mass of our sun—smashed into each other 1.3 billion years ago in a collision so violently it sent out ripples across the universe like a brick thrown into a pool. Most importantly, it's proof that Einstein's most radical prediction, which mathematically allows for time travel, was correct in a remarkably precise way.
Though this detection is the first of such, well, gravity, general relativity and even gravitational waves have been tested several times since Einstein's 1915 formulation of general relativity.
Sir Arthur Eddington launched Einstein to international stardom after his 1919 observations of a solar eclipse supported general relativity over classical Newtonian physics, and there have been myriad similar affirmations since. Most notably, Joseph Taylor and Russell Hulse won a Nobel Prize in 1993 for discovering the effects of gravitational waves generated from a binary pulsar's spin.
However, what LIGO's detection "did much better than anything that came before is test general relativity in what's called the 'strong-field limit,' meaning the involvement of things dominated by speed-of-light effects," Turner says. "These two black holes were approaching the speed of light."
Einstein says time stops for objects traveling at the speed of light and slows for anything nearing that speed.
Where Strong-Field Gravity Meets Time Travel
The greater the warping of space-time, the closer point A on one side of a black hole gets to point Z on the other side. Theoretically, gravity can be so intense around a supermassive black hole that points A and Z can actually touch, allowing for points B through Y to be bypassed altogether.
For time travel to be possible, "Trajectories through space-time have to be bent enough that they can close back on themselves—strong gravitational fields strongly distort the fabric of space and time," Turner explains. "If the field is strong enough and complicated enough, there can exist paths through that distorted space-time that intersect themselves at different times—meaning you could travel along a path that connects points in the future to points in the past."
What's that look like? Drop a heavy enough dumbbell in a leg of pantyhose, and you'll see the hose stretch so much that it contracts near the opening until the sides touch. If you have to spin the dumbbell to make it happen, so be it. Black holes are the most violent vortexes in the universe after all.
The ETA Of Time Travel
Innovations in astrophysics and our understanding of the universe are chugging along like never before, but don't hold your breath for George Carlin riding in on a magical phone booth anytime soon.
Spergel predicts at least another 50 years of discovery are necessary before the implications LIGO's findings can lead to any tangible advancement in how humans travel through space, but that's just the pace at which astronomy evolves. To say it functions on a geological time scale would quite literally be an understatement.
Whenever time travel does get proven or disproven, the discovery will have the LIGO researchers' proof of Einstein's 100-year-old prediction to thank for its path to logic.
"General relativity has some really interesting mathematically allowed features, which includes things like warp space-time that potentially allows very fast space travel—travel even faster than what looks locally like the speed of light," says Spergel. "Whether it's possible to take advantage of those solutions is not clear yet, but this observation tells us that we should use general relativity."
http://www.thedailybeast.com/articles/2016/02/15/hold-up-did-we-just-crack-time-travel.html