Posts Tagged ‘space’

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By Richard C. Lewis

Soon after the Big Bang, the universe went completely dark.

The intense, seminal event that created the cosmos churned up so much hot, thick gas that light was completely trapped. Much later—perhaps as many as one billion years after the Big Bang—the universe expanded; became more transparent; and eventually filled up with galaxies, planets, stars, and other objects that give off visible light. That’s the universe we know today.

How it emerged from the cosmic dark ages to a clearer, light-filled state remains a mystery.

In a new study, researchers at the University of Iowa offer a theory of how that happened. They think black holes that dwell in the center of galaxies fling out matter so violently that the ejected material pierces its cloudy surroundings, allowing light to escape. The researchers arrived at their theory after observing a nearby galaxy from which ultraviolet light is escaping.

“The observations show the presence of very bright X-ray sources that are likely accreting black holes,” says Philip Kaaret, professor in the UI Department of Physics and Astronomy and corresponding author on the study. “It’s possible the black hole is creating winds that help the ionizing radiation from the stars escape. Thus, black holes may have helped make the universe transparent.”

Kaaret and his team focused on a galaxy called Tol 1247-232, located some 600 million light years from Earth, one of only three nearby galaxies from which ultraviolet light has been found to escape. In May 2016, using an Earth-orbiting telescope called Chandra, the researchers saw a single X-ray source whose brightness waxed and waned and was located within a vigorous star-forming region of Tol 1247-232.

The team determined it was something other than a star.

“Stars don’t have changes in brightness,” Kaaret says. “Our sun is a good example of that.

“To change in brightness, you have to be a small object, and that really narrows it down to a black hole,” he says.

But how would a black hole, whose intense gravitational pull sucks in everything around it, also eject matter?

The quick answer is no one knows for sure. Black holes, after all, are hard to study, in part because their immense gravitational pull allows no light to escape and because they’re embedded deep within galaxies. Recently, however, astronomers have offered an explanation: The jets of escaping matter are tapping into the accelerated rotational energy of the black hole itself.

Imagine a figure skater twirling with outstretched arms. As the skater folds her arms closer to her body, she spins faster. Black holes operate much the same way: As gravity pulls matter inward toward a black hole, the black hole likewise spins faster. As the black hole’s gravitational pull increases, the speed also creates energy.

“As matter falls into a black hole, it starts to spin and the rapid rotation pushes some fraction of the matter out,” Kaaret says. “They’re producing these strong winds that could be opening an escape route for ultraviolet light. That could be what happened with the early galaxies.”

Kaaret plans to study Tol 1247-232 more closely and find other nearby galaxies that are leaking ultraviolet light, which would help corroborate his theory.

The paper, “Resolving the X-ray emission from the Lyman continuum emitting galaxy Tol 1247-232,” was published online Aug. 2 in the journal Monthly Notices of the Royal Astronomical Society.

Contributing author Liza Casella, an Iowa City native studying at Northwestern University, helped with the research while in high school through the UI’s Secondary Student Training Program. Matthew Brorby, a postdoctoral researcher in physics and astronomy at the UI, and Andrea Prestwich, of the Harvard-Smithsonian Center for Astrophysics, are the other contributing authors.

https://now.uiowa.edu/2017/08/researchers-hypothesize-how-universe-became-filled-light?utm_source=IANowFaculty&utm_medium=leaking_galaxies&utm_campaign=IANowFaculty-8-31-2017

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by Michael d’Estries

Mankind’s future exploration of other planets may come to depend on the very thing we all flush away every day.

Researchers from Clemson University, in collaboration with NASA, are studying ways to take advantage of human urine sweat, and carbon dioxide to create everything from polyester to nutritional supplements. The key to making this possible is a strain of yeast called Yarrowia lipolytica, which would feed off collected waste and convert it into useful oils and fats.

“One of the yeast strains produces omega-3 fatty acids, which contribute to heart, eye and brain health,” the team reported ahead of a presentation at the American Chemical Society. “Another strain has been engineered to churn out monomers and link them to make polyester polymers. Those polymers could then be used in a 3-D printer to generate new plastic parts.”

Similar to how Mars habitats will likely be created using resources already present on the Martian surface, spare tools and parts for long spaceflights will need to be sourced during the mission. According to Clemson University’s Mark Blenner, an assistant professor of chemical and biomolecular engineering, this conversion of waste will give birth to a new kind of economy.

“If astronauts are going to make journeys that span several years, we’ll need to find a way to reuse and recycle everything they bring with them,” he said in a statement. “Atom economy will become really important.”

While taking advantage of urine and sweat may sound justifiably gross, keep in mind that astronauts on the International Space Station today already convert their urine into clean drinking water. Using it for tools and other beneficial products won’t be much of a leap.

“It tastes like bottled water,” Layne Carter, water subsystem manager for the ISS at Nasa’s Marshall Space Flight Center told Bloomberg. “As long as you can psychologically get past the point that it’s recycled urine and condensate that comes out of the air.”

Despite only having managed to produce small amounts of polyesters or nutrients from Y. lipolytica in the lab, the Clemson researchers are hopeful that further studies will lead to increases in output.

“We’re learning that Y. lipolytica is quite a bit different than other yeast in their genetics and biochemical nature,” Blenner added. “Every new organism has some amount of quirkiness that you have to focus on and understand better.”


The first successfully captured photograph of a total solar eclipse, this daguerreotype was shot on July 28, 1851, by Prussian photographer Johann Julius Friedrich Berkowski.

Here’s a little history lesson to help you pass the time between now and the next total solar eclipse on August 21st. The photograph above, a daguerreotype captured almost exactly 166 years ago, is the first successfully-captured photograph of a total solar eclipse.

The photo was captured by master daguerreotypist Johann Julius Friedrich Berkowski, a Prussian photographer who was commissioned by the Royal Prussian Observatory at Königsberg to do what nobody else had managed up until that point: capture an appropriately-exposed photograph of a total solar eclipse.

Up until that point, every photograph taken had been over or under-exposed, and/or didn’t capture sufficient contrast between the bright corona and the obscuring disk of the moon.

According to a paper in the journal Acta Historica Astronomiae, the photograph was captured using a small refracting telescope attached to the hour drive of the 15.8-cm Fraunhofer heliometer. Berkowski began exposing the image shortly after totality, and the final daguerreotype took 84-seconds to capture.

To learn more about this photograph, click here: http://adsabs.harvard.edu/abs/2005AcHA…25..128S

Chinese scientists have teleported an object from Earth to a satellite orbiting 300 miles away in space, in a demonstration that has echoes of science fiction.

The feat sets a new record for quantum teleportation, an eerie phenomenon in which the complete properties of one particle are instantaneously transferred to another – in effect teleporting it to a distant location.

Scientists have hailed the advance as a significant step towards the goal of creating an unhackable quantum internet.

“Space-scale teleportation can be realised and is expected to play a key role in the future distributed quantum internet,” the authors, led by Professor Chao-Yang Lu from the University of Science and Technology of China, wrote in the paper.

The work may bring to mind Scotty beaming up the Enterprise crew in Star Trek, but there is no prospect of humans being able to materialise instantaneously at remote locations any time soon. The teleportation effect is limited to quantum-scale objects, such as fundamental particles.

In the experiment, photons were beamed from a ground station in Ngari in Tibet to China’s Micius satellite, which is in orbit 300 miles above Earth.

The research hinged on a bizarre effect known as quantum entanglement, in which pairs of particles are generated simultaneously meaning they inhabit a single, shared quantum state. Counter-intuitively, this twinned existence continues, even when the particles are separated by vast distances: any change in one will still affect the other.

Scientists can exploit this effect to transfer information between the two entangled particles. In quantum teleportation, a third particle is introduced and entangled with one of the original pair, in such a way that its distant partner assumes the exact state of the third particle.

For all intents and purposes, the distant particle takes on the identity of the new particle that its partner has interacted with.

Quantum teleportation could be harnessed to produce a new form of communication network, in which information would be encoded by the quantum states of entangled photons, rather than strings of 0s and 1s. The huge security advantage would be that it would be impossible for an eavesdropper to measure the photons’ states without disturbing them and revealing their presence.

Ian Walmsley, Hooke professor of experimental physics at Oxford University, said the latest work was an impressive step towards this ambition. “This palpably indicates that the field isn’t limited to scientists sitting in their labs thinking about weird things. Quantum phenomena actually have a utility and can really deliver some significant new technologies.”

Scientists have already succeeded in creating partially quantum networks in which secure messages can be sent over optical fibres. However, entanglement is fragile and is gradually lost as photons travel through optical fibres, meaning that scientists have struggled to get teleportation to work across large enough distances to make a global quantum network viable.

The advantage of using a satellite is that the particles of light travel through space for much of their journey. Last month, the Chinese team demonstrated they could send entangled photons from space to Earth. The latest work does the reverse: they sent photons from the mountaintop base to the satellite as it passed directly overhead.

Transmitting into space is more difficult as turbulence in the Earth’s atmosphere can cause the particles to deviate, and when this occurs at the start of their journey they can end up further off course.

The latest paper, published on the Arxiv website, describes how, more than 32 days, the scientists sent millions of photons to the satellite and achieved teleportation in 911 cases.

“This work establishes the first ground-to-satellite up-link for faithful and ultra-long-distance quantum teleportation, an essential step toward global-scale quantum internet,” the team write.

A number of teams, including the European Space Agency and Canadian scientists, have similar quantum-enabled satellites in development, but the latest results suggest China is leading the way in this field.

https://www.theguardian.com/science/2017/jul/12/scotty-can-you-beam-me-up-scientists-teleport-photons-300-miles-into-space#img-1

By Sarah Kaplan

Imagine you are a photon, a packet of light. You are a tiny blip of energy, hurtling through the universe on your own. But you have a twin, another photon to whom you have been intimately connected since the day you were born. No matter what distance separates you, be it the width of a lab bench or the breadth of the universe, you mirror each other. Whatever happens to your twin instantaneously affects you, and vice versa. You are like the mouse siblings in “An American Tail”, wrenched apart by fate but feeling the same feelings and singing the same song beneath the same glowing moon.

This is quantum entanglement. To non-physicists it sounds about as fantastical as singing mice, and indeed, plenty of physicists have problems with the phenomenon. Albert Einstein, whose own research helped give rise to quantum theory, derisively called the concept “spooky action at a distance.” Quantum entanglement seems to break some of the bedrock rules of standard physics: that nothing can travel faster than light, that objects are only influenced by their immediate surroundings. And scientists still can’t explain how the particles are linked. Is it wormholes? An unknown dimension? The power of love? (That last one’s a joke.)

Luckily for quantum physicists, you don’t always need to explain a phenomenon in order to use it. Ancient humans didn’t know about friction before inventing the wheel; doctors in medieval China didn’t know about antibodies when they began inoculating people against smallpox 600 years ago. Not knowing what’s behind quantum entanglement didn’t stop Jian-Wei Pan, a physicist at the University of Science and Technology of China in Shanghai, from rocketing it into space.

In a new study in the journal Science, Pan and his colleagues report that they were able to produce entangled photons on a satellite orbiting 300 miles above the planet and beam the particles to two different ground-based labs that were 750 miles apart, all without losing the particles’ strange linkage. It is the first time anyone has ever generated entangled particles in space, and represents a 10-fold increase in the distance over which entanglement has been maintained.

“It’s a really stunning achievement, and I think it’s going to be the first of possibly many such interesting and exciting studies that this particular satellite will open up,” said Shohini Ghose, a physicist at Wilfrid Laurier University in Canada. “Who knows, maybe there’ll be a space entanglement race?”

There’s good a reason world governments may soon race to test out quantum theory in orbit, and it’s not just so they can claim the title of “spookiest.” Entangled particles could one day be used for “quantum communication” — a means of sending super secure messages that doesn’t rely on cables, wireless signals, or code. Because any interference with an entangled particle, even the mere act of observing it, automatically affects its partner, these missives can’t be hacked. To hear quantum physicists tell it, entangled particles could help build a “quantum internet,” give rise to new kinds of coding, and allow for faster-than-light communication — possibilities that have powerful appeal in an era where hospitals, credit card companies, government agencies, even election systems are falling victim to cyber attacks.

But until Pan and his colleagues started their experiments in space, quantum communication faced a serious limitation. Entangled photons don’t need wires or cables to link them, but on Earth it is necessary to use a fiber optic cable to transmit one of the particles to its desired location. But fibers absorb light as the photon travels through, so the quantum connection weakens with every mile the particle is transmitted. The previous distance record for what’s known as quantum teleportation, or sending information via entangled particles, was about 140 kilometers, or 86 miles.

But no light gets absorbed in space, because there’s nothing to do the absorbing. Space is empty. This means that entangled particles can be transmitted long distances across the vacuum and not lose information. Recognizing this, Pan proposed that entangled particles sent through space could vastly extend the distance across which entangled particles communicate.

On board the Chinese satellite Micius, which launched last year, a high energy laser was fired through a special kind of crystal, generating entangled photon pairs. This in itself was a feat: the process is sensitive to turbulence, and before the experiment launched scientists weren’t completely sure it would work. These photons were transmitted to ground stations in Delingha, a city on the Tibetan Plateau, and Lijiang, in China’s far southwest. The cities are about 750 miles apart — a bit farther than New York and Chicago. For comparison, the fiber optic method for quantum teleportation couldn’t get a New York photon much farther than Trenton, N.J.

Multiple tests on the ground confirmed that the particles from the Micius satellite were indeed still entangled. Now Pan wants to try even more ambitious experiments: sending quantum particles from the ground to the satellite; setting up a distribution channel that will allow for transmission of tens of thousands of entangled pairs per second. ”

“Then the satellite can really be used for quantum communication,” he said.

The Micius satellite can also be used to probe more fundamental questions, Pan added. The behavior of entangled particles in space and across vast distances offers insight into the nature of space-time and the validity of Einstein’s theory of general relativity. Plus there’s the whole issue of what is going on with these bizarre linked photons in the first place.

“Mathematically we know exactly how to describe what happens,” Ghose said. “We know how to connect, physically, these particles in the lab, and we know what to expect when we generate and manipulate and transmit them.”

But as for how it all happens, how entangled photons know what their partner is doing, “that is not part of the equation,” she continued. “That’s what makes it so mysterious and interesting.”

https://www.washingtonpost.com/news/speaking-of-science/wp/2017/06/15/quantum-entanglement-sciences-spookiest-phenomenon-achieved-in-space/?utm_term=.0fefcba180de

By Leah Crane

HIDDEN dimensions could cause ripples through reality by modifying gravitational waves – and spotting such signatures of extra dimensions could help solve some of the biggest mysteries of the universe.

Physicists have long wondered why gravity is so weak compared with the other fundamental forces. This may be because some of it is leaking away into extra dimensions beyond the three spatial dimensions we experience.

Some theories that seek to explain how gravity and quantum effects mesh together, including string theory, require extra dimensions, often with gravity propagating through them. Finding evidence of such exotic dimensions could therefore help to characterise gravity, or find a way to unite gravity and quantum mechanics – it could also hint at an explanation for why the universe’s expansion is accelerating.

But detecting extra dimensions is a challenge. Any that exist would have to be very small in order to avoid obvious effects on our everyday lives. Hopes were high (and still are) that they would show up at the Large Hadron Collider, but it has yet to see any sign of physics beyond our four dimensions.

In the last two years, though, a new hope has emerged. Gravitational waves, ripples in space-time caused by the motion of massive objects, were detected for the first time in 2015. Since gravity is likely to occupy all the dimensions that exist, its waves are an especially promising way to detect any dimensions beyond the ones we know.

“If there are extra dimensions in the universe, then gravitational waves can walk along any dimension, even the extra dimensions,” says Gustavo Lucena Gómez at the Max Planck Institute for Gravitational Physics in Potsdam, Germany.

Lucena Gómez and his colleague David Andriot set out to calculate how potential extra dimensions would affect the gravitational waves that we are able to observe. They found two peculiar effects: extra waves at high frequencies, and a modification of how gravitational waves stretch space.

As gravitational waves propagate through a tiny extra dimension, the team found, they should generate a “tower” of extra gravitational waves with high frequencies following a regular distribution.

But current observatories cannot detect frequencies that high, and most of the planned observatories also focus on lower frequencies. So while these extra waves may be everywhere, they will be hard to spot.

The second effect of extra dimensions might be more detectable, since it modifies the “normal” gravitational waves that we observe rather than adding an extra signal.

“If extra dimensions are in our universe, this would stretch or shrink space-time in a different way that standard gravitational waves would never do,” says Lucena Gómez.

As gravitational waves ripple through the universe, they stretch and squish space in a very specific way. It’s like pulling on a rubber band: the ellipse formed by the band gets longer in one direction and shorter in the other, and then goes back to its original shape when you release it.

But extra dimensions add another way for gravitational waves to make space shape-shift, called a breathing mode. Like your lungs as you breathe, space expands and contracts as gravitational waves pass through, in addition to stretching and squishing.

“With more detectors we will be able to see whether this breathing mode is happening,” says Lucena Gómez.

“Extra dimensions have been discussed for a long time from different points of view,” says Emilian Dudas at the École Polytechnique in France. “Gravitational waves could be a new twist on looking for extra dimensions.”

But there is a trade-off: while detecting a tower of high-frequency gravitational waves would point fairly conclusively to extra dimensions, a breathing mode could be explained by a number of other non-standard theories of gravity.

“It’s probably not a unique signature,” says Dudas. “But it would be a very exciting thing.”

https://www.newscientist.com/article/mg23431244-200-gravitational-waves-could-show-hints-of-extra-dimensions/

One of Nasa’s partners has said that he is “absolutely convinced” aliens exist – and that they are living on Earth right now.

Robert Bigelow, an entrepreneur who is working closely with Nasa on future space missions, has suggested that he knows that our planet has an alien presence that is “right under our noses”.

Mr Bigelow made the announcement during an episode of the show 60 Minutes that focused on his work with the space agency.

His company, Bigelow Aerospace, is developing an expendable craft for humans that can inflate and might provide the space habitats of the future.

They have already been tested out in journeys to the International Space Station. And the two organisations are working on further co-operation.

But during that episode Mr Bigelow began to talk about his belief in aliens – and his claim that UFOs have come to Earth and extraterrestrials have an “existing presence” here.

“I’m absolutely convinced [that aliens exist],” he told reporter Lara Logan. “That’s all there is to it.”

Asked by Ms Logan whether he also thought that UFOs had come to Earth, he said he did.

“There has been and is an existing presence, an ET presence,” Mr Bigelow said. “And I spent millions and millions and millions – I probably spent more as an individual than anybody else in the United States has ever spent on this subject.”

Ms Logan then asked if Mr Bigelow thought it was “risky” to say that he believes such things. He said that he doesn’t care what people think because it wouldn’t “change the reality of what I know”.

Mr Bigelow didn’t give any details about whether the research and private space travel that he is funding had revealed anything about aliens to him.

But he said that the hugely expensive work his company and Nasa are doing won’t be required to meet them – he said that people “don’t have to go anywhere”, because the aliens are “right under people’s noses”.

https://www.independent.co.uk/news/science/nasa-robert-bigelow-aliens-extraterrestrials-earth-aerospace-space-international-station-a7763441.html

Thanks to Kebmodee for bringing this to the It’s Interesting community.