Physics  

Rumors are swirling that the Laser Interferometer Gravitational-Wave Observatory experiment has actually observed gravitational waves predicted by Einstein's General Theory of Relativity over 100 years ago for the very first time and may be close to formally announcing the findings.

A major cosmological experiment designed to hunt for gravitational waves—ripples in the fabric of spacetime first predicted by Albert Einstein—has observed them directly for the very first time and may be close to formally announcing the findings. If confirmed, this would be one of the most significant physics discoveries of the last century. While no official announcement has been made, physicist Lawrence Krauss has posted a few Tweets that amount to a scientific spilling of the beans.

According to Einstein's general theory of relativity, gravity is how mass deforms the shape of space: near any massive body, the fabric of space becomes curved. But this curving does not always stay near the massive body. In particular, Einstein realized that the deformation can propagate throughout the Universe, just as seismic waves propagate in Earth's crust. Unlike seismic waves, however, gravitational waves can travel in empty space — and they do so at the speed of light.

My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting.

— Lawrence M. Krauss (@LKrauss1) January 11, 2016

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The Laser Interferometer Gravitational-Wave Observatory (LIGO) has been hunting for gravitational waves since 2002 with no luck. But a more powerful, advanced LIGO that's about three times more sensitive than the original detector started operating in just last fall.

"Gravitational waves may have been discovered!! Exciting."

LIGO is designed to open the field of gravitational-wave astrophysics through the direct detection of gravitational waves. The multi-kilometer-scale gravitational wave detectors use laser interferometry to measure the minute ripples in space-time caused by passing gravitational waves.

These phenomena could have been created from cataclysmic cosmic sources like the merging of pairs of neutron stars or black holes, or by supernovae. LIGO consists of two widely separated interferometers within the United States—one in Hanford, Washington and the other in Livingston, Louisiana—operated in unison.

The confirmed discovery of gravity waves would further support the theory of inflation — the idea that in the first few moments the universe existed, it underwent a rapid and incredibly massive expansion. That kind of rapid expansion would almost certainly leave behind ripples through spacetime and imprinting the cosmic background radiation.

The most important thing about this discovery, if proven, is that it could be a way to link up quantum and classical physics—a step to a Theory of Everything for physics.

SOURCE  Tech Insider Video Source: Nature

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Physics  

Summary Dark energy is cosmology's biggest mystery—an anti-gravitational force that confounds the conventional laws of physics. It makes up more than two-thirds of the cosmos, but science is still grappling to explain what dark energy actually is. In this program, top physicists search for clues to this mystery in both the earliest moments of the universe and far into the future of the cosmos.

SOURCE  World Science Festival

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 Quantum Computers  

In a new video from Big Think, physicist and author Lawrence Krauss describes quantum computing and the technical obstacles we need to overcome to realize this ambitious technological goal.

In the video above from Big Think, Lawrence Krauss describes quantum computing and the technical obstacles we need to overcome to realize this Holy Grail of processing.

According to Krauss, author of A Universe from Nothing, the difference between a quantum computer and a regular computer, is at some level. In a regular computer, you've got ones and zeros, which you store in binary form and you manipulate them and they do calculations.

In the quantum world, explains Krausss, particles like electrons are actually spinning in all directions at the same time, one of the weird aspects of quantum mechanics. We may measure, by doing a measurement of an electron, find it's spinning this way. But before we did the measurement, it was spinning this way and this way and that way and that way all at the same time.

This means, if the electron's spinning in many different directions at the same time, if we don't actually measure it, it can be doing many computations at the same time. "And so a quantum computer is based on manipulating the state of particles like electrons so that during the calculation, many different calculations are being performed at the same time, and only making a measurement at the end of the computation."

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If we could exploit that fact of quantum mechanics that particles could do many things at the same time, we would be able to do many computations at same time. And that's what would make a quantum computer so powerful.

"One of the reasons it's so difficult to make a quantum computer, and one of the reasons I'm a little skeptical at the moment, is that - the reason the quantum world seems so strange to us is that we don't behave quantum mechanically. I don't -- you know, you can - not me, but you could run towards the wall behind us from now 'til the end of the universe and bang your head in to it and you'd just get a tremendous headache," states Krauss. "But if you're an electron, there's a probability if I throw it towards the wall that it will disappear and appear on the other side due to something called quantum tunneling, okay."

Krauss is therefore in the camp that says the D-Wave system is not, in fact, a quantum computer. This despite the rising support that the Burnaby B.C.-based company's product is the real thing.  

Krauss maintains that the problem with a quantum computer is essentially quantum behavior.

"You want to make this macroscopic object, you want to keep it behaving quantum mechanically which means isolating it very carefully from, within itself, all the interactions and the outside world. And that's the hard part, Is isolating things enough to maintain this what's called quantum coherence. And that's the challenge and it's a huge challenge."

The potential of quantum computers is unbelievably great. Once you can engineer materials on a scale where quantum mechanical properties are important, a whole new world of phenomenon opens up.

Krauss says, "You might be able to say - as we say, if we created a quantum computer, and I'm not - I must admit I'm skeptical that we'll be able to do that in the near-term, but if we could, we'd be able to do computations in a finite time that would take longer than the age of the universe right now. We'd be able to do strange and wonderful things. And of course, if you ask me what's the next big breakthrough, I'll tell you what I always tell people, which is if I knew, I'd be doing it right now."


SOURCE  Big Think

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 Space Exploration  

NASA researchers have actually been testing actual faster-than-light warp drive practicality. By re-imagining of an Alcubierre Drive, it may eventually result in an engine that can transport a spacecraft to the nearest star in a matter of weeks — and all without violating Einstein's law of relativity.

Star Trek's warp drive may not be restricted to the world of science fiction after all.

Due a loophole in Einstein's general theory of relativity, a spaceship could travel galactic distances much faster than the speed of light.
To do this in practice the spaceship would not move; the space around it would warp.

Scientists at NASA are right now working on the first practical field test toward proving the possibility of warp drives and faster-than-light travel.

A few months ago, physicist Harold White shocked the aeronautics world when he announced that he and his team at NASA had begun work on the development of a warp drive. His proposed design, an ingenious re-imagining of an Alcubierre Drive, may eventually result in an engine that can transport a spacecraft to the nearest star in a matter of weeks — and all without violating Einstein's law of relativity.

Miguel Alcubierre

According to Einstein's theory, an object with mass cannot go as fast or faster than the speed of light. The original Star Trek series ignored this "universal speed limit" in favor of a ship that could zip around the galaxy in a matter of days instead of decades. The writers tried to explain the ship's faster-than-light capabilities by powering the warp engine with a "matter-antimatter" engine.

Antimatter was a popular field of study in the 1960s, when creator Gene Roddenberry was first writing the series. When matter and antimatter collide, their mass is converted to kinetic energy in keeping with Einstein's mass-energy equivalence formula, E=mc2.

In other words, matter-antimatter collision is a potentially powerful source of energy and fuel, but even that wouldn't be enough to propel a starship to faster-than-light speeds.

So, thanks to "Star Trek" that the word "warp" is now practically synonymous with faster-than-light travel. Alcubierre himself developed the model for warp drive after watching an episode of Star Trek.

Alcubierre used his knowledge of the Red Shift phenomenon to exploit a loophole in the "universal speed limit." In his theory, the ship never goes faster than the speed of light — instead, space in front of the ship is contracted while space behind it is expanded, allowing the ship to travel distances in less time than light would take. The ship itself remains in what Alcubierre termed a "warp bubble" and, within that bubble, never goes faster than the speed of light.

Since Alcubierre published his paper "The Warp Drive: Hyper-fast travel within general relativity" in 1994, many physicists and science fiction writers have played with his theory.

The Alcubierre warp drive is still theoretical for now. "The truth is that the best ideas sound crazy at first. And then there comes a time when we can't imagine a world without them." That's a statement from the 100 Year Starship organization, a think tank devoted to making Earth what "Star Trek" would call a "warp-capable civilization" within a century.

The first step toward a functional warp drive is to prove that a "warp bubble" is even possible, and that it can be artificially created.

That is what White and a team of researchers at NASA's Johnson Space Center in Texas are doing right now.

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According to Alcubierre's theory, one could create a warp bubble by applying negative energy, or energy created in a vacuum. This process relies on the Casimir effect, which states that a vacuum is not actually a void; instead, a vacuum is actually full of fluctuating electromagnetic waves. Distorting these waves creates negative energy, which possibly distorts space-time, creating a warp bubble.

To test if space-time distortion can occur by experiment, the researchers shine two highly targeted lasers: one through the site of the vacuum and one through regular space. White and his fellow researchers will then compare the two beams, and if the wavelength of the one going through the vacuum is lengthened, i.e. redshifted, in any way, they'll know that it passed through a warp bubble.

White and his team have been at work for a few months now, but they have yet to get a verifiable result. The problem is that the fields of negative energies are so minute, the laser so precise, that even the smallest seismic motion of the earth can throw off the results.

White, is now in the process of moving the test equipment to a building on the Johnson Space Center campus that was originally built for the Apollo space program. "The lab is seismically isolated, so the whole floor can be floated," White told TechNewsDaily. "But the system hadn't been [activated] for a while so part of the process was, we had the system inspected and tested."

White is now working on re-calibrating the laser for the new location. He wouldn't speculate on when his team could expect conclusive data, nor how long until fully actuated warp travel might be possible, but he remains convinced that it's only a matter of time.

Michio Kaku has dubbed Alcubierre's notion a "passport to the universe." Scientists speculate that such a drive could result in "speeds" that could take a spacecraft to Alpha Centauri in a mere two weeks — even though the system is 4.3 light-years away.  For now, this remains a theoretical idea, but the potential is truly  incredible.



SOURCES  IO9, Popular Science, NASA

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Join critically-acclaimed author and evolutionary biologist Richard Dawkins and world-renowned theoretical physicist and author Lawrence Krauss as they discuss biology, cosmology, religion, and a host of other topics.

The authors will also discuss their new books. Dawkins recently published The Magic of Reality: How We Know What's Really True, an exploration of the magic of discovery embodied in the practice of science. Written for all age groups, the book moves forward from historical examples of supernatural explanations of natural phenomena to focus on the actual science behind how the world works.

Krauss's latest book, A Universe from Nothing: Why There Is Something Rather than Nothing, explains the scientific advances that provide insight into how the universe formed. Krauss tackles the age-old assumption that something cannot arise from nothing by arguing that not only can something arise from nothing, but something will always arise from nothing.

Also, in case you missed it, here is Richard Dawkins uncut interview and laboratory tour with Craig J. Venter for "The Genius of Charles Darwin", the Channel 4 UK TV program which won British Broadcasting Awards' "Best Documentary Series" of 2008. Craig Venter founded The Institute for Genomic Research and has been credited with being instrumental in mapping the human genome. His team published the first complete genome of an individual human - Venter's own DNA sequence.