CWL

Warp Drive and ‘Star Trek’: Physics of Future Space Travel

Excerpts from article: For starters, the technical goals ceased to be just science fiction decades ago with a legacy of pertinent publications. To be clear, this does not mean that these breakthroughs are on the threshold of discovery. What it does mean is that these notions have advanced to where they are now problems that are able to be attacked. A graduate-level treatise, along with next-step research options, is available as the compilation “Frontiers of Propulsion Science” (AIAA, 2009). For the rest of us, here is a short version.

Image Credit: Namco Bandai

Faster-than-light engines

Compared to the distances between stars, lightspeed is slow. The neighboring star system nearest to us (Alpha Centauri) is more than four years away at light speed (as measured from the perspective of an external observer). The nearest habitable planet might be anywhere from 25 light-years to 200 light-years away. And, to consider meeting new aliens for each week’s episode, our ship would need a naive cruise speed of at least 25,000 times light speed. The word “naive” is used to remind us that we don’t really know what happens to time and space beyond lightspeed.

Wormholes and warp drives— approaches to FTL flight — are theoretically possible, but the theory has not yet advanced to guide their construction. These theories are based on Einstein’s theory of generalrelativity. The ongoing progress mostly focuses on the energy conditions — how to lower the energy required and how to create and apply the required “negative energy.” One conclusion we have already found is that wormholes are more energy-efficient at creating FTL than warp drive. For more, see Eric Davis’ “Faster-Than-Light Space Warps, Status and Next Steps” paper from last year’s 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit.

Recent news regarding the work of Harold “Sonny” White at NASA’s Johnson Space Center has been exaggerated. That work is an attempt to measure space-time distortions caused by the presence of negative energy. Unfortunately, I do not have an article to cite about that hypothesis or the methods being used, since such information has not (yet?) been published. Although Eric Davis is tracking this for the Tau Zero Foundation, we do not yet know enough to render judgment.

Quantum physics also presents tempting phenomena relevant to FTL questions. A number of phenomena, such as tunneling and entanglement, fall under the header of “quantum non-locality” — a term I learned from physicist John Cramer at the University of Washington, Seattle. Cramer’s attempt to test the possible time-paradox implications of such phenomena still remains incomplete. The last update I saw was “Status of nonlocal quantum communication test” presented by Cramer and his colleagues.

Control of gravitational and inertial forces

Picture your favorite fictional starship, where the crew is walking around normally, as if in a studio back on Earth. This means that the ship is providing a gravitational field for the comfort and health of the crew — in the middle of deep space where such fields do not exist. This would be a profound breakthrough! This hugely important feature often gets neglected in the shadow of the difficulty of achieving FTL. It is so ubiquitous in science fiction that many people do not even realize it’s there and the extent of its implications. Unfortunately, it does not yet have a cool-sounding name to help champion and convey its essence.

Given such an ability to create acceleration forces inside a spacecraft, it is not much of a leap of imagination to suggest that forces could be created outside a spacecraft too, thus moving the spacecraft through the universe. Such a nonrocket space drive would be a profound breakthrough.

But wait, there’s more. The physics of being able to manipulate gravitational and inertial forces also implies the ability to have “tractor beams” for moving distant objects, “shields” to deflect nearby objects, plus the ability to sense properties of space-time that we cannot yet even fathom.

Researchers have published more than one way to generate such acceleration fields, and both methods are theoretically consistent with Einstein’s general relativity (Robert Forward’s 1963 paper cited below, and the Levi-Civita effect). Both of those have daunting theoretical and implementation challenges, similar to warp drives and wormholes.

However, there is more than one way to approach this challenge, as I presented last year in “Space Drive Physics: Introduction & Next Steps” in the Journal of the British Interplanetary Society. That is the challenge that piques my professional interest. I’m revisiting the works of Eddington and Mach, to test a different formalism of the coupling between space-time (inertial frames) and electromagnetism that can be experimentally tested. Wish me luck.

Unprecedented energy storage and power usage

Interstellar flight — even when in the context of foreseeable technology — requires enormous amounts of energy, more prowess than humanity has yet achieved. On “Star Trek,” they use matter-antimatter to provide energy (antimatter is existing physics), by fully converting matter into energy. Think Einstein’s E=mc2. Our fantastical spacecraft will need at least that much energy, perhaps more.

Nuclear power is a reality that, if used for spaceflight, would greatly increase the extent of space activities using foreseeable technology. The power levels required for FTL flight, values which were once astronomically high, have improved with continued research to where they are now just fantastically daunting.

Other science fiction has cited quantum zero point energy as an ample energy source. Though quantum vacuum energy is rooted in credible theoretical and experimental approaches, that research is still too young to answer the wishes for ample energy conversion. Today, minuscule energy conversions are possible using tiny electrode gaps. Though these experiments are not energy extractors, they do serve as excellent tools to empirically explore this young topic in physics.

Sustainably peaceful society

An important element of “Star Trek” that went beyond technology is its society: creating a cooperative culture that can harness the power of starflight without killing themselves in the process. When considering the potency of the real energy levels required for starflight, that is critically important. This is not just a matter of inspiring fiction or feel-good notions. This is a matter of the survival of our species.

Although trends indicate that humanity is becoming more peaceful, overall, I am concerned that this challenge might turn out to be harder than creating the new physics for FTL and controllable gravity. The good news is that this is something we can all work toward by being more thoughtful about how each of us chooses to resolve conflicts of views, wants and needs.

(Full Article via SPACE)

Baked Exoplanet Gets Lab Treatment

Don’t get too excited, an exoplanet hasn’t really been captured from the cosmic wilds. And no, one of NASA’s boffins isn’t really taking a pair of tongs to the upper atmosphere of a strangely tiny “hot-Jupiter” being baked by a Bunsen burner. The doctored photo is actually a fun metaphor for this golden age of exoplanetary science. In particularly, it illustrates what one NASA space telescope is doing to understand the chemistry and dynamics of a particular Jupiter-sized exoplanet located some 385 light-years away.

Of course, it would be preferential if we could directly sample an exoplanet’s atmosphere in a lab, but as all exoplanets orbit stars many light-years from the nearest Bunsen burner, astronomers need to think up novel techniques by which the atmospheres of exoplanets can be remotely probed. Enter the Spitzer Space Telescope, NASA’s premier infrared observatory, the inadvertent hero of exo-atmospheric science!

Launched in 2003, Spitzer was designed to observe the infrared universe — particularly star-forming molecular clouds and distant galaxies — but in 2005 it became famous for detecting infrared emissions from extra-solar planets, namely HD 209458b and TrES-1. Since then, Spitzer has continued to notch up some impressive exoplanetary discoveries.

“When Spitzer launched in 2003, we had no idea it would prove to be a giant in the field of exoplanet science,” said Michael Werner, Spitzer project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Now, we’re moving farther into the field of comparative planetary science, where we can look at these objects as a class, and not just as individuals.”

In a new study published in the Astrophysical Journal, astronomers have used Spitzer to watch an exoplanet complete a full orbit around its host star.

Over 6 days, the hot-Jupiter HAT-P-2b passed in front of its star, behind and back in front again. Interestingly, HAT-P-2b’s orbit is highly eccentric, meaning its orbital path takes it only 2.8 million miles from the star’s surface at closest approach and out to 9.3 million miles at its most distant. As a comparison, the solar system’s innermost planet, Mercury, orbits the sun every 88 days and doesn’t come closer than 28 million miles — HAT-P-2b is therefore a roasted planet, where rapid changes in its atmosphere can be expected from extreme heating.

Fortunately, because HAT-P-2b’s orbit is not only compact but also eccentric, astronomers have a wonderful opportunity to see these changes occur over a very short timescale.

Full Article Over at Discovery News

How do rockets move in space?

If space is basically a vacuum and void of atmosphere, how do rockets alter the direction and speed of space craft? In other words, how do they “push off” against nothing?

This is a very good question. Isaac Newton worked out the solution and published it in 1687 in his Principia Mathematica. It is phrased as Newton’s 3rd law. I’ll include all 3 below just in case!

1st: A body will remain at rest or at motion with a uniform speed unless it is acted on my an external force. 2nd: The acceleration of a body with a force acting on it is that force divided by the mass of the body (F=ma) 3rd: Every action has an equal and opposite reaction.

So the third law basically says that if you shoot out stuff in one direction you will move in the other direction. This is how rockets work in a vacuum. They have a source of fuel which is heated up so that it expands and is pushed out of the rocket. In order to change direction in space rockets have to have little ‘thrusters’ on all sides (you need 6 in total to maneuver completely in 3 dimensions).

Newton’s 3rd law seems contrary to our intuition because on Earth there are lots of sources of friction - providing much easier methods of propulsion, however you might have seen it in action if you have ever blown up a balloon and then let go of it before tying it up. What pushes the balloon all around the room is the air you blew into in escaping.

Black Hole Caught Snacking on ‘Super Jupiter’ Planet

In a cosmic first, astronomers have discovered a black hole chowing down on what may be a giant rogue planet.

The supermassive black hole didn’t finish off its meal, which scientists say was either a huge Jupiter-like planet wandering freely through space or a brown dwarf, a strange object that’s larger than a planet yet still too small to trigger the internal fusion reactions required to become a full-fledged star.

“This is the first time where we have seen the disruption of a substellar object by a black hole,” study co-author Roland Walter, of the Observatory of Geneva in Switzerland, said in a statement. “We estimate that only its external layers were eaten by the black hole, amounting to about 10 percent of the object’s total mass, and that a denser core has been left orbiting the black hole.”

Black Hole Firewall: Trouble On The Edge

Ever wondered what happens to things as they are consumed by the black hole, the left over matter of dead stars? For a time, it used to be okay to assume matter was destroyed once it entered into a black hole, spaghettified and all.. but it turned out that this couldn’t be further away from the truth. NewScientists Anil Ananthaswamy has a wonderful 3 page piece getting into full details of this history and what questions scientists are asking now. If you love black holes, this is a definite recommend. Although registration (completely free!) is required to view the whole article. It’s pretty insightful and accurately presents the problems currently being faced with how black holes do what they do:

“Paradoxes are good in physics,” reflects John Preskill. “They help to point the way towards important discoveries.” Quantum mechanics and Einstein’s theories of relativity offer plenty to choose from. There’s the cat that can be dead and alive at the same time. Or the Back to the Future-style time traveller who kills his own grandfather, rendering his own birth impossible. Or the twins who disagree on their age after one returns from a near light-speed trip to a neighbouring star. Each perplexing scenario forces us to examine the fine print of the problem, thereby advancing our understanding of the theory behind it. A case in point is Einstein, whose own theories came from trying to resolve the paradoxes of his time.

Image: Ring of fireSam Chivers

Now Preskill, a theoretical physicist at the California Institute of Technology in Pasadena, is scratching his head over the latest one to surface. Nicknamed the black hole firewall paradox, it comes about when you consider what happens to someone falling into a black hole.

With the nearest black hole more than 1000 light years away, the question is very much a theoretical one. Yet just by studying such a possibility, physicists are hoping to make a breakthrough in their efforts to combine general relativity and quantum mechanics into a theory of quantum gravity – one of the most intractable problems in physics today.

Black holes have long been fertile breeding grounds for paradoxes. Back in 1974, Stephen Hawking, along with Jacob Bekenstein of the Hebrew University in Jerusalem, Israel, famously showed that black holes are not entirely black. Instead, they radiate energy known as Hawking radiation comprising photons and other quantum particles – an agonisingly slow process that eventually causes the black hole to evaporate completely.

Hawking spotted a problem with this picture. The radiation seemed so random that he surmised it couldn’t carry any information about the stuff that had fallen in. So as the black hole evaporates, the information it holds must eventually disappear. Yet this is in direct conflict with a central tenet of quantum physics, which says that information cannot be destroyed. The black hole information paradox was born.

Over the decades, physicists have struggled with this paradox. Hawking thought that black holes destroyed information and the answer was to question quantum mechanics. Others disagreed. After all, Hawking’s idea came from his efforts to meld general relativity and quantum mechanics – a mathematical feat so elusive that he was forced to make approximations. Preskill even made a bet with Hawking that black holes don’t destroy information.

Several arguments suggest that Hawking was wrong. One of the most compelling comes from thinking about what happens as the evaporating black hole gets smaller and smaller. If information can’t escape or be destroyed, then more and more has to be stored in an ever-shrinking volume. But if this is the case, quantum theory says the probability for making a tiny black hole increases from virtually nothing to almost infinity wherever matter collides against matter. “You should have seen it at the Large Hadron Collider, you should have seen it at Fermilab, you should have seen it in tiny room-sized particle accelerators from the 1930s,” says Don Marolf, a theorist at the University of California in Santa Barbara (UCSB). “You should see it when you go and jump up and down on the grass.”

Obviously that hasn’t happened. The other possibility – that matter and the information it carries can leak out from a black hole – is unlikely. Any material that falls in would need to travel faster than light to escape the black hole’s fearsome gravity.

Perhaps, instead, the answer lies with the Hawking radiation itself. Maybe it isn’t so featureless. “A common reaction was that Hawking had simply been careless,” says Joseph Polchinski, also at UCSB. “It wasn’t that information was lost, it was that he hadn’t kept track of it enough.”

Yet all early efforts to do away with the paradox proved unsuccessful. “Hawking had identified a really deep problem,” says Polchinski.

As it happened, Hawking changed his mind in 2004, partly due to work by an Argentinian physicist called Juan Maldacena (see “Hawking’s change of heart”). Black holes don’t destroy information after all, he conceded. He honoured the bet he made with Preskill and presented him with an encyclopaedia of baseball, which Preskill likened to a black hole, because it was heavy and it took effort to get information out of it.

Into The Abyss..

[Full Article]

Man Arrested at Large Hadron Collider Claims He’s From the Future

A would-be saboteur arrested today at the Large Hadron Collider in Switzerland made the bizarre claim that he was from the future. Eloi Cole, a strangely dressed young man, said that he had travelled back in time to prevent the LHC from destroying the world.

The LHC successfully collided particles at record force earlier this week, a milestone Mr Cole was attempting to disrupt by stopping supplies of Mountain Dew to the experiment’s vending machines. He also claimed responsibility for the infamous baguette sabotage in November last year.

Mr Cole was seized by Swiss police after CERN security guards spotted him rooting around in bins. He explained that he was looking for fuel for his ‘time machine power unit’, a device that resembled a kitchen blender.

Police said Mr Cole, who was wearing a bow tie and rather too much tweed for his age, would not reveal his country of origin. “Countries do not exist where I am from. The discovery of the Higgs boson led to limitless power, the elimination of poverty and Kit-Kats for everyone. It is a communist chocolate hellhole and I’m here to stop it ever happening.”

This isn’t the first time time-travel has been blamed for mishaps at the LHC. Last year, the Japanese physicist Masao Ninomiya and Danish string-theory pioneer Holger Bech Nielsen put forward the hypothesis that the Higgs boson was so “abhorrent” that it somehow caused a ripple in time that prevented its own discovery.

Professor Brian Cox, a CERN physicist and full-time rock’n’roll TV scientist, was sympathetic to Mr Cole. “Bless him, he sounds harmless enough. At least he didn’t mention bloody black holes.”

Mr Cole was taken to a secure mental health facility in Geneva but later disappeared from his cell. Police are baffled, but not that bothered.

A Quantum Internet at the Speed of Light?

The realization of quantum networks is one of the major challenges of modern physics. Now, new research shows how high-quality photons can be generated from ‘solid-state’ chips, bringing us closer to the quantum ‘internet’.

Image: An artist’s impression of distributed qubits (the bright spots) linked to each other via photons (the light beams). The colours of the beams represent that the optical frequency of the photons in each link can be tailored to the needs of the network. Credit: Mete Atature

The number of transistors on a microprocessor continues to double every two years, amazingly holding firm to a prediction by Intel co-founder Gordon Moore almost 50 years ago. If this is to continue, conceptual and technical advances harnessing the power of quantum mechanics in microchips will need to be investigated within the next decade.

“We are at the dawn of quantum-enabled technologies, and quantum computing is one of many thrilling possibilities,” says Dr Mete Atature from University of Cambridge Department of Physics. “Our results in particular suggest that multiple distant qubits in a distributed quantum network can share a highly coherent and programmable photonic interconnect that is liberated from the detrimental properties of the chips. Consequently, the ability to generate quantum entanglement and perform quantum teleportation between distant quantum-dot spin qubits with very high fidelity is now only a matter of time.”

Developing a distributed quantum network is one promising direction pursued by many researchers today. A variety of solid-state systems are currently being investigated as candidates for quantum bits of information, or qubits, as well as a number of approaches to quantum computing protocols, and the race is on for identifying the best combination.

Ref: Laser-like photons signal major step towards quantum ‘Internet’

Betelgeuse

However you pronounce its name, the star Betelgeuse is hard to miss on a clear winter’s night. Representing the top left shoulder of Orion the Hunter it blazes a bright red colour. At over 600 light years away Betelgeuse is not particularly close, but it shines 100,000 times as brightly as our Sun.

Betelgeuse is a “red supergiant” star which is nearing the end of its life. As it has swelled in size over the past few hundred thousand years, currently measuring around 1000 times the size of our Sun, the massive star has been shedding its outer layers. This material is made of gas and dust, which has cooled over time and is seen here in far-infrared light by Herschel.

The ejected outer layers of the star expanded outwards until they hit the surrounding material, creating the arc-like structures seen to the left of the image. These arcs are a bow shock, similar to the wave that travels in front of a ship moving through water, and are caused by Betelgeuse’s motion through the surrounding gas cloud at around 30 km/s (70,000 mph).

Further to the left is what appears to be a straight wall of gas and dust, the origin of which is uncertain. It is very hard to measure distances in images such as this, so the wall could be much futher away or closer to Earth than Betelgeuse - essentially in the foreground or background.

Polarized Window Frost

The photo above shows both frost crystals and two curious multi-colored ribbons on a window of my home in Rimavska Sobota, Slovakia.

The variegated ribbons are actually drips of meltwater imaged using a circular polarizer lens. A polarizer filter or lens acts to recombine the two distinct rays of light that emerge when a beam of sunlight propagates through a slurry of partially frozen crystals as in this case.

Because the rays were out of phase when recombined, the new rays contain nearly every visible wavelength. It should be noted that these colors might also be attributable to diffraction processes caused by minute cracks in the window glass. — Photography / Summary: Daniela Rapava; Jim Foster