Albert Einstein

There Is Sound In Space, Thanks To Gravitational Waves

Merging black holes are one class of objects that creates gravitational waves of certain frequencies and amplitudes. Thanks to detectors like LIGO, we can 'hear' these sounds as they occur.

It’s long been said that there’s no sound in space, and that’s true, to a point. Conventional sound requires a medium to travel through, and is created when particles compress-and-rarify, making anything from a loud “bang” for a single pulse to a consistent tone for repeating patterns. In space, where there are so few particles that any such signals die away, even solar flares, supernovae, black hole mergers, and other cosmic catastrophes go silent before they’re ever heard. But there’s another type of compression-and-rarefaction that doesn’t require anything other than the fabric of space itself to travel through: gravitational waves. Thanks to the first positive detection results from LIGO, we’re hearing the Universe for the very first time.

Two merging black holes. The inspiral results in the black holes coming together, while gravitational waves carry the excess energy away. The background spacetime is distorted as a result.

Two merging black holes. The inspiral results in the black holes coming together, while gravitational waves carry the excess energy away. The background spacetime is distorted as a result.

Gravitational waves were something that needed to exist for our theory of gravity to be consistent, according to General Relativity. Unlike in Newton’s gravity, where any two masses orbiting one another would remain in that configuration forever, Einstein’s theory predicted that over long enough times, gravitational orbits would decay. For something like the Earth orbiting the Sun, you’d never live to experience it: it would take 10^150 years for Earth to spiral into the Sun. But for more extreme systems, like two neutron stars orbiting one another, we could actually see the orbits decaying over time. In order to conserve energy, Einstein’s theory of gravity predicted that energy must be carried away in the form of gravitational waves.

As two neutron stars orbit each other, Einstein's theory of general relativity predicts orbital decay, and the emission of gravitational radiation.

As two neutron stars orbit each other, Einstein’s theory of General Relativity predicts orbital decay, and the emission of gravitational radiation. The former has been observed very precisely for many years, as evidenced by how the points and the line (GR prediction) match up so very well.

These waves are maddeningly weak, and their effects on the objects in spacetime are stupendously tiny. But if you know how to listen for them — just as the components of a radio know how to listen for those long-frequency light waves — you can detect these signals and hear them just as you’d hear any other sound. With an amplitude and a frequency, they’re no different from any other wave. General Relativity makes explicit predictions for what these waves should sound like, with the largest wave-generating signals being the easiest ones to detect. The largest amplitude sounds all? It’s the inspiral and merging “chirp” of two black holes that spiral into one another.

In September of 2015, just days after advanced LIGO began collecting data for the first time, a large, unusual signal was spotted. It surprised everyone, because it would have carried so much energy in just a short, 200 millisecond burst, that it would have outshone all the stars in the observable Universe combined. Yet that signal turned out to be robust, and the energy from that burst came from two black holes — of 36 and 29 solar masses — merging into a single 62 solar mass one. Those missing three solar masses? They were converted into pure energy: gravitational waves rippling through the fabric of space. That was the first event LIGO ever detected.

The signal from LIGO of the first robust detection of gravitational waves. The waveform is not just a visualization; it's representative of what you'd actually hear if you listened properly.

The signal from LIGO of the first robust detection of gravitational waves. The waveform is not just a visualization; it’s representative of what you’d actually hear if you listened properly.

Now it’s over a year later, and LIGO is presently on its second run. Not only have other black hole-black hole mergers been detected, but the future of gravitational wave astronomy is bright, as new detectors will open up our ears to new types of sounds. Space interferometers, like LISA, will have longer baselines and will hear lower frequency sounds: sounds like neutron star mergers, feasting supermassive black holes, and mergers with highly unequal masses. Pulsar timing arrays can measure even lower frequencies, like orbits that take years to complete, such as the supermassive black hole pair: OJ 287. And combinations of new techniques will look for the oldest gravitational waves of all, the relic waves predicted by cosmic inflation, all the way back at the beginning of our Universe.

Gravitational waves generated by cosmic inflation are the farthest signal back in time humanity can conceive of potentially detecting. Collaborations like BICEP2 and NANOgrav may indirectly do this in the coming decades.

Gravitational waves generated by cosmic inflation are the farthest signal back in time humanity can conceive of potentially detecting. Collaborations like BICEP2 and NANOgrav may indirectly do this in the coming decades.

There’s so much to hear, and we’ve only just started listening for the first time. Thankfully, astrophysicist Janna Levin — author of the fantastic book, Black Hole Blues and Other Songs from Outer Space — is poised to give the public lecture at Perimeter Institute tonight, May 3rd, at 7 PM Eastern / 4 PM Pacific, and it will be live-streamed here and live-blogged by me in real time! Join us then for even more about this incredible topic, and I can’t wait to hear her talk.

 

The Universe is out there, waiting for you to discover it

Ethan SiegelEthan Siegel, Contributor

Merging black holes are one class of objects that creates gravitational waves of certain frequencies and amplitudes. Thanks to detectors like LIGO, we can 'hear' these sounds as they occur.

Merging black holes are one class of objects that creates gravitational waves of certain frequencies and amplitudes. Thanks to detectors like LIGO, we can ‘hear’ these sounds as they occur.

It’s long been said that there’s no sound in space, and that’s true, to a point. Conventional sound requires a medium to travel through, and is created when particles compress-and-rarify, making anything from a loud “bang” for a single pulse to a consistent tone for repeating patterns. In space, where there are so few particles that any such signals die away, even solar flares, supernovae, black hole mergers, and other cosmic catastrophes go silent before they’re ever heard. But there’s another type of compression-and-rarefaction that doesn’t require anything other than the fabric of space itself to travel through: gravitational waves. Thanks to the first positive detection results from LIGO, we’re hearing the Universe for the very first time.

Two merging black holes. The inspiral results in the black holes coming together, while gravitational waves carry the excess energy away. The background spacetime is distorted as a result.

Two merging black holes. The inspiral results in the black holes coming together, while gravitational waves carry the excess energy away. The background spacetime is distorted as a result.

Gravitational waves were something that needed to exist for our theory of gravity to be consistent, according to General Relativity. Unlike in Newton’s gravity, where any two masses orbiting one another would remain in that configuration forever, Einstein’s theory predicted that over long enough times, gravitational orbits would decay. For something like the Earth orbiting the Sun, you’d never live to experience it: it would take 10^150 years for Earth to spiral into the Sun. But for more extreme systems, like two neutron stars orbiting one another, we could actually see the orbits decaying over time. In order to conserve energy, Einstein’s theory of gravity predicted that energy must be carried away in the form of gravitational waves.

As two neutron stars orbit each other, Einstein's theory of general relativity predicts orbital decay, and the emission of gravitational radiation.

As two neutron stars orbit each other, Einstein’s theory of General Relativity predicts orbital decay, and the emission of gravitational radiation. The former has been observed very precisely for many years, as evidenced by how the points and the line (GR prediction) match up so very well.

These waves are maddeningly weak, and their effects on the objects in spacetime are stupendously tiny. But if you know how to listen for them — just as the components of a radio know how to listen for those long-frequency light waves — you can detect these signals and hear them just as you’d hear any other sound. With an amplitude and a frequency, they’re no different from any other wave. General Relativity makes explicit predictions for what these waves should sound like, with the largest wave-generating signals being the easiest ones to detect. The largest amplitude sounds all? It’s the inspiral and merging “chirp” of two black holes that spiral into one another.

In September of 2015, just days after advanced LIGO began collecting data for the first time, a large, unusual signal was spotted. It surprised everyone, because it would have carried so much energy in just a short, 200 millisecond burst, that it would have outshone all the stars in the observable Universe combined. Yet that signal turned out to be robust, and the energy from that burst came from two black holes — of 36 and 29 solar masses — merging into a single 62 solar mass one. Those missing three solar masses? They were converted into pure energy: gravitational waves rippling through the fabric of space. That was the first event LIGO ever detected.

The signal from LIGO of the first robust detection of gravitational waves. The waveform is not just a visualization; it's representative of what you'd actually hear if you listened properly.

The signal from LIGO of the first robust detection of gravitational waves. The waveform is not just a visualization; it’s representative of what you’d actually hear if you listened properly.

Now it’s over a year later, and LIGO is presently on its second run. Not only have other black hole-black hole mergers been detected, but the future of gravitational wave astronomy is bright, as new detectors will open up our ears to new types of sounds. Space interferometers, like LISA, will have longer baselines and will hear lower frequency sounds: sounds like neutron star mergers, feasting supermassive black holes, and mergers with highly unequal masses. Pulsar timing arrays can measure even lower frequencies, like orbits that take years to complete, such as the supermassive black hole pair: OJ 287. And combinations of new techniques will look for the oldest gravitational waves of all, the relic waves predicted by cosmic inflation, all the way back at the beginning of our Universe.

Gravitational waves generated by cosmic inflation are the farthest signal back in time humanity can conceive of potentially detecting. Collaborations like BICEP2 and NANOgrav may indirectly do this in the coming decades.

Gravitational waves generated by cosmic inflation are the farthest signal back in time humanity can conceive of potentially detecting. Collaborations like BICEP2 and NANOgrav may indirectly do this in the coming decades.

There’s so much to hear, and we’ve only just started listening for the first time. Thankfully, astrophysicist Janna Levin — author of the fantastic book, Black Hole Blues and Other Songs from Outer Space — is poised to give the public lecture at Perimeter Institute tonight, May 3rd, at 7 PM Eastern / 4 PM Pacific, and it will be live-streamed here and live-blogged by me in real time! Join us then for even more about this incredible topic, and I can’t wait to hear her talk.


The live blog will begin a few minutes prior to 4:00 PM Pacific; join us here and follow along!

The warping of spacetime, in the General Relativistic picture, by gravitational masses.

The warping of spacetime, in the General Relativistic picture, by gravitational masses.

3:50 PM: It’s ten minutes until showtime, and to celebrate, here are ten fun facts (or as many as we can get in) about gravity and gravitational waves.

1.) Instead of “action at a distance,” where an invisible force is exerted between masses, general relativity says that matter and energy warp the fabric of spacetime, and that warped spacetime is what manifests itself as gravitation.

2.) Instead of traveling at infinite speed, gravitation only travels at the speed of light.

3.) This is important, because it means that if any changes occur to a massive object’s position, configuration, motion, etc., the ensuing gravitational changes only propagate at the speed of light.

Computer simulation of two merging black holes producing gravitational waves.

Computer simulation of two merging black holes producing gravitational waves.

3:54 PM: 4.) This means that gravitational waves, for example, can only propagate at the speed of light. When we “detect” a gravitational wave, we’re detecting the signal from when that mass configuration changed.

5.) The first signal detected by LIGO occurred at a distance of approximately 1.3 billion light years. The Universe was about 10% younger than it is today when that merger occurred.

Ripples in spacetime are what gravitational waves are.

Ripples in spacetime are what gravitational waves are.

6.) If gravitation traveled at infinite speed, planetary orbits would be completely unstable. The fact that planets move in ellipses around the Sun mandates that if General Relativity is correct, the speed of gravity must equal the speed of light to an accuracy of about 1%.

3:57 PM: 7.) There are many, many more gravitational wave signals than what LIGO has seen so far; we’ve only detected the easiest signal there is to detect.

8.) What makes a signal “easy” to see is a combination of its amplitude, which is to say, how much it can deform a path-length, or a distance in space, as well as its frequency.

A simplified illustration of LIGO's laser interferometer system.

A simplified illustration of LIGO’s laser interferometer system.

9.) Because LIGO’s arms are only 4 kilometers long, and the mirrors reflect the light thousands of times (but no more), that means LIGO can only detect frequencies of 1 Hz or faster.

Earlier this year, LIGO announced the first-ever direct detection of gravitational waves. By building a gravitational wave observatory in space, we may be able to reach the sensitivities necessary to detect a deliberate alien signal.

Earlier this year, LIGO announced the first-ever direct detection of gravitational waves. By building a gravitational wave observatory in space, we may be able to reach the sensitivities necessary to detect a deliberate alien signal.

10.) For slower signals, we need longer lever-arms and greater sensitivities, and that will mean going to space. That’s the future of gravitational wave astronomy!

4:01 PM: We made it! Time to begin and introduce Janna Levin! (Pronounce “JAN-na”, not “YON-na”, if you were wondering.)

The inspiral and merger of the first pair of black holes ever directly observed.

The inspiral and merger of the first pair of black holes ever directly observed.

4:05 PM: Here’s the big announcement/shot: the first direct recording of the first gravitational wave. It took 100 years after Einstein first put forth general relativity, and she’s playing a recording! Make sure you go and listen! What does it mean to “hear” a sound in space, after all, and why is this a sound? That’s the purpose, she says, of her talk.

The galaxies Maffei 1 and Maffei 2, in the plane of the Milky Way, can only be revealed by seeing through the Milky Way's dust. Despite being some of the closest large galaxies of all, they were not discovered until the mid-20th century.

The galaxies Maffei 1 and Maffei 2, in the plane of the Milky Way, can only be revealed by seeing through the Milky Way’s dust. Despite being some of the closest large galaxies of all, they were not discovered until the mid-20th century.

4:08 PM: If you consider what’s out there in the Universe, we had no way of knowing any of this at the time of Galileo. We were thinking about sunspots, Saturn, etc., and were completely unable to conceive of the great cosmic scales or distances. Forget about “conceiving of other galaxies,” we hadn’t conceived of any of this!

 

4:10 PM: Janna is showing one of my favorite videos (that I recognize) from the Sloan Digital Sky Survey! They took a survey of 400,000 of the nearest galaxies and mapped them in three dimensions. This is what our (nearby) Universe looks like, and as you can see, it really is mostly empty space!

The (modern) Morgan–Keenan spectral classification system, with the temperature range of each star class shown above it, in kelvin.

The (modern) Morgan–Keenan spectral classification system, with the temperature range of each star class shown above it, in kelvin.

4:12 PM: She makes a really great point that she totally glosses over: only about 1-in-1000 stars will ever become a black hole. There are over 400 stars within 30 light years of us, and zero of them are O or B stars, and zero of them have become black holes. These bluest, most massive and shortest-lived stars are the only ones that will grow into black holes.

The identical behavior of a ball falling to the floor in an accelerated rocket (left) and on Earth (right) is a demonstration of Einstein's equivalence principle.

The identical behavior of a ball falling to the floor in an accelerated rocket (left) and on Earth (right) is a demonstration of Einstein’s equivalence principle.

4:15 PM: When you consider “where did Einstein’s theory come from,” Janna makes a great point: the idea of the equivalence principle. If you have gravity, you might consider that you feel “heavy” in your chair, for example. But this reaction that you have is the exact same reaction you’d feel if you were accelerating, rather than gravitating. It’s not the gravity that you feel, it’s the effects of the matter around you!

4:17 PM: The band OKGO did a video flying in the vomit comet. Janna can’t show the whole thing, with audio, for copyright reasons, and highly recommends it. Luckily for you, thanks to the internet… here it is! Enjoy at your leisure!

To travel once around Earth's orbit in a path around the Sun is a journey of 940 million kilometers.

To travel once around Earth’s orbit in a path around the Sun is a journey of 940 million kilometers.

4:19 PM: There’s another huge revelation for gravity: the way we understand how things work comes from watching how things fall. The Moon is “falling” around the Earth; Newton realized that. But the Earth is falling around the Sun; the Sun is “falling” around the galaxy; and atoms “fall” here on Earth. But the same rule applies to them all, so long as they’re all in free-fall. Amazing!

Black holes are something the Universe wasn't born with, but has grown to acquire over time. They now dominate the Universe's entropy.

Black holes are something the Universe wasn’t born with, but has grown to acquire over time. They now dominate the Universe’s entropy.

4:21 PM: Here’s a fun revelation: stop thinking of a black hole as collapsed, crushed matter, even though that might be how it originated. Instead, think about it as simply a region of empty space with strong gravitational properties. In fact, if all you did was assign “mass” to this region of space, that would perfectly define a Schwarzschild (non-charged, non-rotating) black hole.

The supermassive black hole (Sgr A*) at the center of our galaxy is shrouded in a dusty, gaseous environment. X-rays and infrared observations can partially see through it, but radio waves might finally be able to resolve it directly.

The supermassive black hole (Sgr A*) at the center of our galaxy is shrouded in a dusty, gaseous environment. X-rays and infrared observations can partially see through it, but radio waves might finally be able to resolve it directly.

4:23 PM: If you were to fall into a black hole the mass of the Sun, you’d have about a microsecond, from crossing the event horizon (according to Janna) until you were crushed to death at the singularity. This is consistent with what I once calculated, where, for the black hole at the center of the Milky Way, we’d have about 10 seconds. Since the Milky Way’s black hole is 4,000,000 times as massive as our Sun, the math kind of works out!

Joseph Weber with his early-stage gravitational wave detector, known as a Weber bar.

Joseph Weber with his early-stage gravitational wave detector, known as a Weber bar.

4:26 PM: How would you detect a gravitational wave? Honestly, it would be like being on the surface of the ocean; you’d bob up and down along the surface of space, and there was a big argument in the community as to whether these waves were real or not. It wasn’t until Joe Weber came along and decided to try and measure these gravitational waves, using a phenomenal device — an aluminum bar — that would vibrate if a rippling wave “plucked” the bar very slightly.

Weber saw many such signals that he identified with gravitational waves, but these, unfortunately, were never reproduced or verified. He was, for all of his cleverness, not a very careful experimenter.

4:29 PM: There’s a good question from Jon Groubert on twitter: “I have a question about something she said – there is something inside a black hole, isn’t there? Like a heavy neutron star.” There should be a singularity, which is either point-like (for a non-rotating singularity) or a one-dimensional ring (for a rotating one), but not condensed, collapsed, three-dimensional matter.

Why not?

Because in order to remain as a structure, a force needs to propagate and be transmitted between particles. But particles can only transmit forces at the speed of light. But nothing, not even light, can move “outward” towards the exit of a black hole; everything moves towards the singularity. And so nothing can hold itself up, and everything collapses into the singularity. Sad, but the physics makes this inevitable.

From left to right: the two LIGO detectors (in Hanford and Livingston, US) and the Virgo detector (Cascina, Italie).

From left to right: the two LIGO detectors (in Hanford and Livingston, US) and the Virgo detector (Cascina, Italie).

4:32 PM: After Weber’s failures (and fall from fame), the idea of LIGO came along by Rai Weiss in the 1970s. It took more than 40 years for LIGO to come to fruition (and over 1,000 people to make it happen), but the most fantastic thing was that it was experimentally possible. By making two very long lever-arms, you could see the effect of a passing gravitational wave.

 

 

4:34 PM: This is my favorite video illustrating what a gravitational wave does. It moves space itself (and everything in it) back and forth by a tiny amount. If you have a laser interferometer set up (like LIGO), it can detect these vibrations. But if you were close enough and your ears were sensitive enough, you could feel this motion in your eardrum!

4:35 PM: I’ve got some really good headphones, Perimeter, but unfortunately I can’t hear the different gravitational wave model signals that Janna is playing!

The LIGO Hanford Observatory for detecting gravitational waves in Washington State, USA.

The LIGO Hanford Observatory for detecting gravitational waves in Washington State, USA.

4:38 PM: It’s funny to think that this is the world’s most advanced vacuum, inside the LIGO detectors. Yet birds, rats, mice, etc., are all under there, and they chew their way into almost the vacuum chamber that the light travels through. But if the vacuum had been broken (it’s been constant since 1998), the experiment would have been over. In Louisiana, hunters shot at the LIGO tunnels. It’s horrifying how sensitive and expensive this equipment is, but yet how fragile it all is, too.

4:41 PM: Janna is doing a really great job telling this story in a suspenseful but very human way. We only saw the final few orbits of two orbiting black holes, drastically slowed down in the above movie. They were only a few hundred kilometers apart, those final four orbits took 200 millisecond, and that’s the entirety of the signal that LIGO saw.

 

4:43 PM: If you’re having trouble listening/hearing the events in the talk, listen to this video (above), in both natural pitch and increased pitch. The smaller black holes (roughly 8 and 13 solar masses) from December 26, 2015, are both quieter and higher pitched than the larger ones (29 and 36 solar masses) from September 14th in the same year.

4:46 PM: Just a little correction: Janna says this was the most powerful event ever detected since the Big Bang. And that’s only technically true, because of the limits of our detection.

When we get any black hole mergers, approximately 10% of the mass of the least massive black hole in a merger pair gets converted into pure energy via Einstein’s E = mc2. 29 solar masses is a lot, but there are going to be black holes of hundreds of millions or even billions of solar masses that have merged together. And we have proof.

The most massive black hole binary signal ever seen: OJ 287.

The most massive black hole binary signal ever seen: OJ 287.

4:49 PM: This is OJ 287, where a 150 million solar mass black hole orbits an ~18 billion solar mass black hole. It takes 11 years for a complete orbit to occur, and General Relativity predicts a precession of 270 degrees per orbit here, compared to 43 arc seconds per century for Mercury.

4:51 PM: Janna did an incredible job ending on time here; I’ve never seen an hour talk actually end after 50 minutes at a Perimeter public lecture. Wow!

The Earth as viewed from a composite of NASA satellite images from space in the early 2000s.

The Earth as viewed from a composite of NASA satellite images from space in the early 2000s.

4:52 PM: What would happen if Earth got sucked up into a black hole? (Q&A question from Max.) Although Janna’s giving a great answer, I’d like to point out that, from a gravitational wave point of view, Earth would be shredded apart, and we’d get a “smeared out” wave signal, that would be a much noisier, static-y signal. Once Earth got swallowed, the event horizon would grow just a tiny bit, as an extra three millionths of a solar mass increased the black hole’s radius by just that tiny, corresponding amount.

4:55 PM: What a fun talk, a great and snappy Q&A session, and a great experience overall. Enjoy it again and again, because the video of the talk is now embedded as a permalink. And thanks for tuning in!

Schrodinger’s Cat Arrives?

Quantum Weirdness Gets Life Size

Time Travel Simulation Resolves “Grandfather Paradox”

Scientific American

 

What would happen to you if you went back in time and killed your grandfather? A model using photons reveals that quantum mechanics can solve the quandary—and even foil quantum cryptography

Why There Will Never Be Another Einstein

Inspired by Scientific American’s terrific September issue, which celebrates the 100th anniversary of Einstein’s theory of general relativity [see Addendum], I’ve dusted off an essay I wrote for The New York Times a decade ago. Here is an edited, updated version. —John Horgan

When Stevens Institute of Technology hired me a decade ago, it installed me for several months in the department of physics, which had a spare office. Down the hall from me, Albert Einstein’s electric-haired visage beamed from a poster for the “World Year of Physics 2005.” The poster celebrated the centennial of the “miraculous year” when a young patent clerk in Bern, Switzerland, revolutionized physics with five papers on relativity, quantum mechanics and thermodynamics. “Help make 2005 another Miraculous Year!” the poster exclaimed.

“I am no Einstein,” Einstein once said. On top of all his other qualities, the man was modest. Photo by Oren Jack Turner courtesy Wikimedia Commons.

As 2005 wound down with no miracles in sight, the poster took on an increasingly poignant cast. Passing the office of a physics professor who made the mistake of leaving his door open, I stopped and asked the question implicitly posed by the “Year of Physics” poster: Will there ever be another Einstein? The physicist scrunched up his face and replied, “I’m not sure what that question means.”

Let me try to explain. Einstein is the most famous and beloved scientist of all time. We revere him not only as a scientific genius but also as a moral and even spiritual sage. Abraham Pais, Einstein’s friend and biographer, called him “the divine man of the 20th century.” To New York Times physics reporter Dennis Overbye, Einstein was an “icon” of “humanity in the face of the unknown.” So to rephrase my question: Will science ever produce another figure who evokes such hyperbolic reverence?

I doubt it. The problem isn’t that modern physicists can’t match Einstein’s intellectual firepower. In Genius, his 1992 biography of physicist Richard Feynman, James Gleick pondered why physics hadn’t produced more giants like Einstein. The paradoxical answer, Gleick suggested, is that there are so many brilliant physicists alive today that it has become harder for any individual to stand apart from the pack. In other words, our perception of Einstein as a towering figure is, well, relative.

Gleick’s explanation makes sense. (In fact, physicist Edward Witten has been described as the most mathematically gifted physicist since Newton.) However, I would add a corollary: Einstein seems bigger than modern physicists because–to paraphrase Norma Desmond in Sunset Boulevard–physics got small.

For the first half of the last century, physics yielded not only deep insights into nature–which resonated with the disorienting work of creative visionaries like Picasso, Joyce and Freud–but also history-jolting technologies like the atomic bomb, nuclear power, radar, lasers, transistors and all the gadgets that make up the computer and communications industries. Physics mattered.

Over the past few decades, many physicists have gotten bogged down pursuing a goal that obsessed Einstein in his latter years: a theory that fuses quantum physics and general relativity, which are as incompatible, conceptually and mathematically, as plaid and polka dots. Seekers of this “theory of everything” have wandered into fantasy realms of higher dimensions with little or no empirical connection to our reality.

Over the past few decades, biology has displaced physics as the scientific enterprise with the most intellectual, practical and economic clout. Of all modern biologists, Francis Crick (who originally trained as a physicist) probably came closest to Einstein in terms of scientific achievement. Together with James Watson, Crick unraveled the twin-corkscrew structure of DNA in 1953. He went on to show how the double helix mediates the genetic code that serves as the blueprint for all of life.

Just as Einstein vainly sought a unified theory of physics, so Crick in his final decades tried to crack the riddle of consciousness, the hardest unsolved problem in science. (“We probably need a few Einsteins” to solve the problem, artificial-intelligence maven Rodney Brooks once wrote.)

But neither Crick nor any other modern biologist has approached Einstein’s extra-scientific reputation. Einstein took advantage of his fame to speak out on nuclear weapons, nuclear power, militarism and other vital issues through lectures, essays, interviews, petitions and letters to world leaders. When he spoke, people listened.

After Israel’s first president, the chemist Chaim Weizmann, died in 1952, the Israeli cabinet asked Einstein if he would consider becoming the country’s president. Einstein politely declined–perhaps to the relief of the Israeli officials, given his commitment to pacifism and a global government. (While awaiting Einstein’s answer, David Ben-Gurion, the prime minister, reportedly asked an aide, “What are we going to do if he accepts?”)

It is hard to imagine any modern scientist, physicist or biologist, being lionized in this manner. One reason may be that science as a whole has lost its moral sheen. The public is warier than ever of the downside of scientific advances, whether nuclear energy or genetic engineering. Moreover, as modern science has become increasingly institutionalized, it has started to resemble a guild that values self-promotion above truth and the common good.

Einstein also possessed a moral quality that set him apart even in his own time. According to Robert Oppenheimer, the dark angel of nuclear physics, Einstein exuded “a wonderful purity at once childlike and profoundly stubborn.”

The aspiring scientists and engineers I encounter at my school give me hope that science has a bright future. But I suspect that we will never see Einstein’s like again, because he was the product of a unique convergence of time and temperament.

Einstein, incidentally, didn’t think he lived up to his own reputation. “I am no Einstein,” he once said. On top of all his other qualities, the man was modest.

Addendum: In the September Scientific American, physicist Brian Greene also asks, “Could there be another Einstein?” He responds: “If one means another über genius who will powerfully push science forward, then the answer is surely yes. In the past half a century since Einstein’s death, there have indeed been such scientists. But if one means an über genius to whom the world will look not because of accomplishments in sports or entertainment but as a thrilling example of what the human mind can accomplish, well, that question speaks to us—to what we as a civilization will deem precious.”

Wormhole Created in Lab Makes Invisible Magnetic Field: Amazing!

magnetic wormhole

A new device can cloak a magnetic field so that it invisible from the outside. Here, a picture of how the wormhole would work.
Credit: ordi Prat-Camps and Universitat Autònoma de Barcelona

Ripped from the pages of a sci-fi novel, physicists have crafted a wormhole that tunnels a magnetic field through space.

“This device can transmit the magnetic field from one point in space to another point, through a path that is magnetically invisible,” said study co-author Jordi Prat-Camps, a doctoral candidate in physics at the Autonomous University of Barcelona in Spain. “From a magnetic point of view, this device acts like a wormhole, as if the magnetic field was transferred through an extra special dimension.”

The idea of a wormhole comes from Albert Einstein’s theories. In 1935, Einstein and colleague Nathan Rosen realized that the general theory of relativity allowed for the existence of bridges that could link two different points in space-time. Theoretically these Einstein-Rosen bridges, or wormholes, could allow something to tunnel instantly between great distances (though the tunnels in this theory are extremely tiny, so ordinarily wouldn’t fit a space traveler). So far, no one has found evidence that space-time wormholes actually exist. [Science Fact or Fiction? The Plausibility of 10 Sci-Fi Concepts]

The new wormhole isn’t a space-time wormhole per se, but is instead a realization of a futuristic “invisibility cloak” first proposed in 2007 in the journal Physical Review Letters. This type of wormhole would hide electromagnetic waves from view from the outside. The trouble was, to make the method work for light required materials that are extremely impractical and difficult to work with, Prat said.

Magnetic wormhole

But it turned out the materials to make a magnetic wormhole already exist and are much simpler to come by. In particular, superconductors, which can carry high levels of current, or charged particles, expel magnetic field lines from their interiors, essentially bending or distorting these lines. This essentially allows the magnetic field to do something different from its surrounding 3D environment, which is the first step in concealing the disturbance in a magnetic field.

So the team designed a three-layer object, consisting of two concentric spheres with an interior spiral-cylinder. The interior layer essentially transmitted a magnetic field from one end to the other, while the other two layers acted to conceal the field’s existence.

The inner cylinder was made of a ferromagnetic mu-metal. Ferromagnetic materials exhibit the strongest form of magnetism, while mu-metals are highly permeable and are often used for shielding electronic devices.

A thin shell made up of a high-temperature superconducting material called yttrium barium copper oxide lined the inner cylinder, bending the magnetic field that traveled through the interior.

magnetic wormhole device
A new device has created a magnetic wormhole, in which a magnetic field enters one end and seems to pop out of nowhere on the other side.
Credit: Jordi Prat-Camps and Universitat Autònoma de Barcelona

The final shell was made of another mu-metal, but composed of 150 pieces cut and placed to perfectly cancel out the bending of the magnetic field by the superconducting shell. The whole device was placed in a liquid-nitrogen bath (high-temperature superconductors require the low temperatures of liquid nitrogen to work).

Normally, magnetic field lines radiate out from a certain location and decay over time, but the presence of the magnetic field should be detectable from points all around it. However, the new magnetic wormhole funnels the magnetic field from one side of the cylinder to another so that it is “invisible” while in transit, seeming to pop out of nowhere on the exit side of the tube, the researchers report today (Aug. 20) in the journal Scientific Reports.

“From a magnetic point of view, you have the magnetic field from the magnet disappearing at one end of the wormhole and appearing again at the other end of the wormhole,” Prat told Live Science.

Broader applications

There’s no way to know if similar magneticwormholes lurk in space, but the technology could have applications on Earth, Prat said. For instance, magnetic resonance imaging (MRI) machines use a giant magnet and require people to be in a tightly enclosed central tube for diagnostic imaging.

But if a device could funnel a magnetic field from one spot to the other, it would be possible to take pictures of the body with the strong magnet placed far away, freeing people from the claustrophobic environment of an MRI machine, Prat said.

To do that, the researchers would need to modify the shape of their magnetic wormhole device. A sphere is the simplest shape to model, but a cylindrical outer shell would be the most useful, Prat said.

“If you want to apply this to medical techniques or medical equipment, for sure you will be interested in directing toward any given direction,” Prat said. “A spherical shape is not the most practical geometry.”

A black hole 12 billion times more massive than our Sun has been detected

It’s so big, we need new physics to explain it.

Step aside regular black holes, astronomers have detected an ancient black hole that’s so incredibly massive and luminous, it defies our understanding of the early Universe.

In fact its quasar, the shining object produced by a supermassive black hole, is 420 trillion times more luminous than our Sun – despite forming only around 900 million years after the birth of the Universe. This makes it the brightest object ever spotted in the ancient Universe. It’s so impossibly bright that it’s almost, well impossible.

“How could we have this massive black hole when the universe was so young? We don’t currently have a satisfactory theory to explain it,” the lead researcher, Xue-Bing Wu, from Peking University in China and the Kavli Institute of Astronomy and Astrophysics in the US, told Rachel Feltman from The Washington Post.

The quasar, known as SDSS JO100+2802, is located around 12.8 billion light years away from Earth, and was spotted by the Sloan Digital Sky Survey, before being verified by three Earth-bound telescopes.

Reporting in Nature, the team explains that for the black hole to reach such a massive size in less than a billion years, it would have been constantly sucking in interstellar mass at its maximum rate. But this doesn’t fit with our current understanding of black hole growth, which states that the process is limited by energy that blasts out of the quasar as the black hole heats up.

Following that hypothesis, and also factoring in the limited amount of matter available in the early Universe, it makes it extremely difficult for scientists to explain how the supermassive black hole exists – and how it came to be 12 billion times more massive than our Sun.

“With this supermassive black hole, very early in the Universe, that theory cannot work,” Fuyan Bian from the Australian National University, who was involved in the research, told Genelle Weule and Stuart Gary for ABC Science. “It’s time for a new hypothesis and for some new physics.”

But even though we’re still not sure how the mega quasar is possible, it’s going to be a useful tool for finding other objects in the Universe.

“This quasar is very unique. Just like the brightest lighthouse in the distant universe, its glowing light will help us probe more about the early Universe,” said Wu in a press release.

Sources: ABC ScienceThe Washington Post

Read this next: The masses of black holes are more predictable than we thought

In 1911, Albert Einstein Told Marie Curie To Ignore The Trolls:One smart Dude, Einstein!

In 1911, Albert Einstein Told Marie Curie To Ignore The Trolls

On Friday, a digitized trove of Albert Einstein’s writings and correspondence was made available online. While perusing the collection, astrobiologist David Grinspoon found a letter addressed from Einstein to famed physicist, chemist, and two-time Nobel-Laureate, Marie Curie. That letter’s gist? Ignore the trolls.

The translated letter, originally dated November 23, 1911, appears below:

In 1911, Albert Einstein Told Marie Curie To Ignore The Trolls

Religious views of Albert Einstein

Albert Einstein, 1921.

Einstein was raised by secular Jewish parents. In his Autobiographical Notes, Einstein wrote that he had gradually lost his faith early in childhood:

. . . I came—though the child of entirely irreligious (Jewish) parents—to a deep religiousness, which, however, reached an abrupt end at the age of twelve. Through the reading of popular scientific books I soon reached the conviction that much in the stories of the Bible could not be true. The consequence was a positively fanatic orgy of freethinking coupled with the impression that youth is intentionally being deceived by the state through lies; it was a crushing impression. Mistrust of every kind of authority grew out of this experience, a skeptical attitude toward the convictions that were alive in any specific social environment—an attitude that has never again left me, even though, later on, it has been tempered by a better insight into the causal connections. It is quite clear to me that the religious paradise of youth, which was thus lost, was a first attempt to free myself from the chains of the ‘merely personal,’ from an existence dominated by wishes, hopes, and primitive feelings. Out yonder there was this huge world, which exists independently of us human beings and which stands before us like a great, eternal riddle, at least partially accessible to our inspection and thinking. The contemplation of this world beckoned as a liberation, and I soon noticed that many a man whom I had learned to esteem and to admire had found inner freedom and security in its pursuit. The mental grasp of this extra-personal world within the frame of our capabilities presented itself to my mind, half consciously, half unconsciously, as a supreme goal. Similarly motivated men of the present and of the past, as well as the insights they had achieved, were the friends who could not be lost. The road to this paradise was not as comfortable and alluring as the road to the religious paradise; but it has shown itself reliable, and I have never regretted having chosen it.[3]

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