Archive for Science & Space
Physicists at the University of Glasgow, Scotland, have produced the first-ever image of a strong form of quantum entanglement, known as Bell entanglement.
To achieve this, they devised a system which fires a stream of entangled photons from a quantum source of light at “non-conventional objects” – which change the phase of the photons as they pass through.
Researchers then set up a super-sensitive camera capable of detecting single photons which would only take an image when it caught sight of both the photon and its entangled ‘twin’, creating a visible record of entanglement.
Black holes have been mysterious and elusive — until now. Astronomers using the Event Horizon Telescope (EHT) have, for the first time, photographed one.
“We’ve now seen the unseeable,” said Avery Broderick, a physicist at the University of Waterloo and the Perimeter Institute who was part of the international EHT research team. “Black holes are made real — they’re not just the scribblings on theorists’ chalkboards anymore, but they really are out there in the night.”
The image, which shows an orange ring around a round, black silhouette, is of the black hole at the centre of Messier 87 (M87), a galaxy 50 million light-years from Earth. This black hole is one of the most massive known: it’s six billion times more massive than our sun.
Black holes are so dense and have such strong gravity that anything that crosses their threshold — known as the event horizon — gets pulled into them, never to return. That includes both matter and light, making them black and invisible — and therefore very difficult to see and photograph.
An international team of more than 200 people spent more than a decade working to capture the image released today.
Scientists are about to restart the two giant facilities in the United States that register gravitational waves, the ripples in the very fabric of the universe that were predicted by Albert Einstein more than a century ago.
Einstein realized that when massive objects such as black holes collide, the impact sends shock waves through space-time that are like the ripples in water created by tossing a pebble in a pond.
In 2015, researchers made history by detecting gravitational waves from colliding black holes for the first time — and this was such a milestone that three U.S. physicists almost immediately won the Nobel Prize for their work on the project.
Since then, physicists have detected gravitational waves from other exotic smashups. The grand total is10 pairs of black holes colliding and a pair of neutron stars crashing together.
Now they’re getting ready to discover more of these cosmic events. On April 1, the twin facilities in Louisiana and Washington state that make up the Laser Interferometer Gravitational-Wave Observatory will start doing science again after being shut down for more than a year so that workers could install hardware upgrades.
The project is funded by the National Science Foundation and the improvements should dramatically increase the detector’s ability to sense some of the most mysterious and powerful events in the universe.
“So far, we’ve seen 11 things. Maybe we’ll see twice that many this year,” says Joseph Giaime, head of the LIGO Observatory in Livingston, La.
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Can NASA’s Dart spacecraft, a potential defensive weapon against incoming asteroids, hit one and change its course or speed? We should find out in 2022.
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Curiosity encountered a hurdle last Friday, when a hiccup during boot-up interrupted its planned activities and triggered a protective safe mode. The rover was brought out of this mode on Tuesday, Feb. 19, and is otherwise operating normally, having successfully booted up over 30 times without further issues.
Throughout the weekend, Curiosity was sending and receiving technical data, communicating with the team in order to help them pinpoint the cause of the issue.
“We’re still not sure of its exact cause and are gathering the relevant data for analysis,” said Steven Lee, Curiosity’s deputy project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California. JPL leads the Curiosity mission. “The rover experienced a one-time computer reset but has operated normally ever since, which is a good sign,” he added. “We’re currently working to take a snapshot of its memory to better understand what might have happened.”
Out of an abundance of caution, Lee said, science operations will remain on hold until the issue is better understood.
“In the short term, we are limiting commands to the vehicle to minimize changes to its memory,” Lee said. “We don’t want to destroy any evidence of what might have caused the computer reset. As a result, we expect science operations will be suspended for a short period of time.”
Modified left-over Shuttle engines will power NASA’s delayed Space Launch System (SLS), a giant launch vehicle intended for lunar missions and, eventually, Mars. An experimental autonomous DARPA spaceplane, called the Phantom Express, will also rely on a Shuttle engine. This vehicle is designed to offer swift, aircraft-like access to space. Both projects are being built by Boeing.
Now yet more Shuttle hardware is getting ready to fly again, also within Boeing’s empire. A Space Act Agreement signed in 2018 shows that the aerospace company wants to include a handful of the Shuttle’s smaller orbital maneuvering engines in a secret Department of Defense project. Known as the R40b, the engine was originally developed to allow Shuttles to adjust their speed and direction while in orbit, helping the iconic spacecraft to deploy the Hubble Telescope and parts of the International Space Station.
Under the $818,000 agreement, NASA will select eight engines that are currently mothballed at its White Sands Test Facility, in New Mexico. The agency will clean up, inspect, and test-fire them to identify the best four, before handing them over to Boeing for “return to service” in an unnamed DoD program.
The NASA agreement was signed in September by an engineer at Boeing’s facility in El Segundo, California. According to the LA Times, development work for DARPA’s Phantom Express spaceplane is being carried out there. Phantom Express is an uncrewed, reusable spaceplane that will take off vertically to deploy small satellites or other spacecraft, and then glide back down to land horizontally, like the Shuttle.
The Shuttle, which cost around $450 million per mission, was supposed to fly once a month but never got close to its goal. DARPA hopes the Phantom Express will be faster on its feet, able to launch, land, and launch again in as little as a day, with a price tag of just $5 million per flight. That would be a fraction of the cost of today’s SpaceX launches, though that company is also aiming to turn around its reusable rockets in about a day, which is expected to then shrink its price tag.
Unlike their larger brethren, though, the latest Shuttle engines to be resurrected may not be destined for the Phantom Express. El Segundo is also where Boeing builds most of its satellites, and the small engines could be used to boost large military satellites into geostationary orbits. NASA and Boeing both declined to comment on this story.
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NASA’s Voyager 2 probe, launched in 1977, is now more than 11 billion miles from Earth and has reached interstellar space, the agency said Monday. This is the second time a human-made object has reached this part of space. And it’s an incredible feat for a spacecraft designed to last five years.
Spanning three continents, the Deep Space Network hears all. And thank goodness, or you wouldn’t be seeing any photos of Pluto.
NASA’s New Horizons spacecraft is delivering amazing images of Pluto, but receiving them from 3 billion miles (4.8 billion kilometers) away is no easy feat.
The strength of the radio signals, the time it takes the signal to travel back and forth and the speed of the data flow all present challenges, but it’s all in a day’s work for NASA’s Deep Space Network. Think of it as the long-distance phone company for the solar system and beyond.
The DSN consists of a network of huge satellite dishes spread across three sites—near Barstow in California; near Madrid in Spain; and near Canberra in Australia. Those locations are about 120 degrees in longitude apart to give wide coverage of the skies, so before a spacecraft is lost by one antenna, another one can pick it up.
The sensitive antennas work alone or in groups and communicate with about 30 space probes each month, said Jeff Osman, contact technical manager for the Deep Space Network, in an interview.
For New Horizons, the first images of its closest Pluto fly-by will be received by 70-meter antennas at the Madrid and Barstow sites, he said.
Data is coming down at a speed of approximately 1,200 bits per second—about as fast as a dial-up Internet modem in the early Nineties—and it takes 4.5 hours for the signal to travel the distance from New Horizons to Earth.
The Deep Space Network isn’t confined to NASA craft. Because of its sensitivity, it also plays a supporting role to international missions, such as those launched by the European Space Agency and Japan’s space agency.
At any one time, the DSN is talking to between 12 and 15 craft. A real-time view of this setup can be found on the Web at DSN Now. The page details which antenna is talking to which space probe, and even the data rate and frequency in use.
Most spacecraft use a portion of the X-band at 8.4-8.5GHz, which is set aside globally for deep space communications. Because the signals coming back to Earth are so weak, agencies like NASA need a dedicated frequency band to avoid interference from terrestrial sources. Noise is also part of the reason space agencies are now eyeing even higher frequencies, around 32GHz, for future generations of craft.
There’s a forest in Massachusetts that for nearly 30 years has hosted the world’s longest running soil-warming experiment, measuring how hotter temperatures impact the tiny life-forms that live in the dirt.
With the way climate change is going, you could say the future itself is buried in that heated dirt. But our unknown tomorrows aren’t all that’s hiding there.
In this oversized outdoor research laboratory, scientists have made an unexpected discovery, finding 16 rare ‘giant’ viruses that are completely new to science.
“We were not looking for giant viruses,” says biologist Jeff Blanchard from the University of Massachusetts Amherst (UMass).
“Our goal was to isolate bacteria directly from the environment to understand how microbial communities are changing in response to soil warming.”
According to theoretical physicist Carlo Rovelli, time is an illusion: our naive perception of its flow doesn’t correspond to physical reality. Indeed, as Rovelli argues in The Order of Time, much more is illusory, including Isaac Newton’s picture of a universally ticking clock. Even Albert Einstein’s relativistic space-time — an elastic manifold that contorts so that local times differ depending on one’s relative speed or proximity to a mass — is just an effective simplification.
So what does Rovelli think is really going on? He posits that reality is just a complex network of events onto which we project sequences of past, present and future. The whole Universe obeys the laws of quantum mechanics and thermodynamics, out of which time emerges.
Rovelli is one of the creators and champions of loop quantum gravity theory, one of several ongoing attempts to marry quantum mechanics with general relativity. In contrast to the better-known string theory, loop quantum gravity does not attempt to be a ‘theory of everything’ out of which we can generate all of particle physics and gravitation. Nevertheless, its agenda of joining up these two fundamentally differing laws is incredibly ambitious.
Alongside and inspired by his work in quantum gravity, Rovelli puts forward the idea of ‘physics without time’. This stems from the fact that some equations of quantum gravity (such as the Wheeler–DeWitt equation, which assigns quantum states to the Universe) can be written without any reference to time at all.
Continue reading: https://www.nature.com/articles/d41586-018-04558-7
On April 5-14 2017, the team behind the Event Horizon Telescope hopes to test the fundamental theories of black-hole physics by attempting to take the first ever image of a black hole’s event horizon (the point at which theory predicts nothing can escape). By connecting a global array of radio telescopes together to form the equivalent of a giant Earth-sized telescope – using a technique known as Very Long Baseline Interferometry and Earth-aperture synthesis – scientists will peer into the heart of our Milky Way galaxy where a black hole that is 4m times more massive than our sun – Sagittarius A* – lurks.
A new glass electrolyte-based solid-state battery has been developed by the researchers at UT Austin. Led by the Li-ion battery inventor John Goodenough, the team demonstrated that their battery is better than Li-ion. It can hold an almost 3x charge, has more charging cycles, supports fast charging, and isn’t prone to catch fire.