Category Archives: By Daniel Sternklar

Why X-Ray Astronomers Are Anxious For Good News From Troubled Hitomi Satellite

On February 16, the Japanese Space Agency (JAXA) successfully launched the ASTRO-H satellite from Tanegashima Space Center in Japan. The space telescope named Hitomi pupil in Japanese carried with it the hopes and dreams of astrophysicists from around the world.

Hitomi carried a number of scientific instruments, but the most revolutionary was a device called an X-ray microcalorimeter. Astrophysicists around the world were waiting with excitement for the first observations with this instrument, which was designed to see things like the million-degree gas sloshing around galaxy clusters stirred by relativistic jets from supermassive black holes.

But before anyone could see those first data from Hitomi, a possibly fatal misfortune struck. On March 26, while the spacecraft was executing its first test observations in orbit, JAXA lost contact. The U.S. Joint Space Operation Center detected five pieces of debris in the area and Hitomis orbit suddenly changed.

What happened? We dont know. Its possible that a piece of space junk, or perhaps a micrometeorite, hit the spacecraft. Or maybe an onboard piece of equipment a battery, a piece of scientific payload failed and exploded. Signs point to the latter, since the spacecraft appears to be rapidly spinning. If an explosion caused a leak allowing, say, coolant to escape, this would spin up the spacecraft.

Astronomers use all sorts of electromagnetic radiation to learn about the universe but X-ray spectra remain elusive. Philip Ronan, CC BY-SA

X-ray astronomy dreams

Astronomers use the electromagnetic spectrum including visible or infrared light to study stars, planets, galaxies and the universe as a whole. They have long used prisms and grisms to split the light into its components. Rather than just taking images, this spectroscopy allows astrophysicists to study the composition of objects in space and the conditions of the material that is emitting the light, including whether and how it moves around. Optical spectroscopy, for example, lets astronomers see how the stars in a galaxy move around and how old they are.

X-rays are near the far end of the eletromagnetic spectrum beyond the farthest ultraviolet, but not as far as Gamma rays.

Thanks to our atmosphere, X-rays from space dont reach us at the Earths surface. Thats actually good news, since wed all be in trouble: being constantly bombarded by X-rays leads to DNA damage, cancer and worse. But this also means we need to go to space to see X-rays from the cosmos. Astrophysicists have long wanted to put an X-ray high-resolution spectrograph into space but the goal has so far remained elusive.

Perseus cluster of galaxies as seen by the Chandra X-ray Observatory. The X-rays come from million-degree gases around the galaxy cluster. Giant bubbles and cavities show where the supermassive black hole blasted energy into the gas. NASA/CXC/IoA/A.Fabian et al., CC BY

X-ray astronomy got its start in the 1950s and 60s with the first X-ray telescopes being launched on sounding rockets and balloons. Space telescopes followed, and with these, astronomers could take X-ray images or low-resolution spectra and made amazing discovery after discovery: the first black hole in our Milky Way galaxy; clusters of galaxies bathed in the glow of million-degree gas; all the way to a mysterious X-ray background. Soon after its launch in 1999, the Chandra X-ray Observatory finally resolved that X-ray background into a multitude of growing supermassive black holes in the early universe.

But the history of X-ray spectroscopic measurements in space is somewhat star-crossed. Before Hitomi was ASTRO-EII, known as Suzaku. Suzaku carried an X-ray microcalorimeter, but just a few weeks after launch, the instruments cooling system suffered a series of failures and lost all its coolant. Before that came ASTRO-E, which was lost during launch in 2000 when its M-V-4 rocket failed. And before that, NASA planned to fly an X-ray microcalorimeter on a mission called AXAF-S, which got canceled.

Visions of the hot and energetic universe

With a true high-resolution X-ray spectrograph in space we could finally see so much: we could see the motion, the ebb and flow, of million-degree gas sloshing around galaxy clusters as the supermassive black hole in the galaxy at the center of the cluster shoots unimaginable amounts of energy into it with its relativistic jets. We could watch the final gasps of matter as it falls into a feeding quasar, and see the distortion of spacetime itself due to Einsteins general relativity. We could search for the missing matter which we believe must lurk in the vicinity of galaxies.

Artists conception of the ATHENA X-ray observatory. ATHENA/ESA

The next chance to fly such an instrument isnt for a while. Astronomers can next pin their hopes on the ATHENA satellite, which the European Space Agency has selected as a flagship large-class mission. ATHENA will carry two X-ray instruments, a Wide Field Imager for taking large X-ray images of the sky, and a true X-ray calorimeter which will let us do high-resolution X-ray spectroscopy.

But ATHENA is currently not slated to launch until 2028, and no spacecraft has ever launched on time.

In space, no one can hear you ping

There is still hope for Hitomi: it may be only mostly dead, On March 30, JAXA received two pings from the damaged satellite. This means that at least some onboard systems were still running. Perhaps over a few months, Hitomi can be recovered and still do science.

JAXA has an incredible record in saving troubled spacecraft: they lost and reestablished contact with Hayabusa as it was trying to land on an asteroid, and when Akatsuki failed to enter its planned orbit around Venus, JAXA spent five years flying it through the solar system for a second, successful attempt.

The good news is that before its troubles, Hitomi did take some observations and sent them back to Earth enough to amaze astrophysicists, but far too little to answer all the questions we have.

Kevin Schawinski, Assistant Professor of Galaxy & Black Hole Astrophysics, Swiss Federal Institute of Technology Zurich

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5 Digital Highlights From New York Fashion Week

5-digital-highlights-from-new-york-fashion-week-61fea41d28A model wearing Google Glass backstage at Diane von Furstenberg’s show in Lincoln Center.

Designers didn’t just bring new clothes to Lincoln Center during New York Fashion Week — several introduced new uses for digital technology as well.

Diane von Furstenberg led the pack, surprising in-person and online attendees by showcasing Google Glass — the futuristic eyewear device Google is building — down the runway. Photos were taken backstage using the device, and shared to DVF’s Google+ Page ahead of and during the show.

A short film compiled from video taken with glasses worn by models, Furstenberg and members of her team was released three days later. Tweets about the DVF show were up 160% from last season, making her the third most talked-about designer on Twitter during Fashion Week, according to third-party data from social media agency, Whispr Group.

Beyond DVF’s show, New York Fashion Week, which ended last Thursday, witnessed the appearance of stylish gadgets from the likes of HTC and Rebecca Minkoff. Reporters used short-form mobile video for new kinds of coverage, and several emerging designers teamed up with startup CutOnYourBias to let fans shape their collections. Live streams continued to grow in popularity, with new twists from Marc Jacobs and Oscar de la Renta. For a full roundup, check out the gallery below.

See Inside A Tiger Shark’s Mouth As It Gobbles A GoPro

It’s a pretty exhilarating feeling diving with sharks. As they curiously and elegantly glide by you, there’s that overwhelming sense of both fear and respect. Until they decide that a piece of your equipment is worth a nibble. And by nibble I mean envelop the whole darn thing in its whopping great, razor-sharp teeth lined mouth. But this diver’s GoPro camera survived to tell us the tale, and it’s pretty awesome to see inside the tiger shark’s mouth, even if it is only for a fleeting moment. You can even see the shark’s eyes roll back as it goes for the camera.



What’s particularly interesting is that the shark at first seems very disinterested in the equipment, but last minute he/she suddenly changes direction and ambushes the camera. While they may be highly evolved predators, behavioral observations have suggested that tiger sharks can be pretty lazy. Unlike some more swift and agile species, such as the mako shark, tiger sharks aren’t that maneuverable, and often have to “rely on surprise to catch things” according to marine biologist Mike Heithaus.

It may have come as an initial surprise to the unsuspecting diver, but the curious being gave up the camera pretty swiftly and carried on with his/her day, leaving the diver unscathed (as far as we’re aware) but probably with a racing heart.

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Extremely Tiny “Artificial Synapse” Mimics The Behavior Of Neurons

As we stand on the shoulders of giants, we’ve often looked to technological innovations to take us away from our biological beginnings. Nowadays, though, biology is often inspiring new artificial designs, and a new study led by engineers at MIT have taken this a step further than many others.

According to a new study published in Nature Materials, they’ve been tinkering around in the world of “neuromorphic computing”, which describes technological systems that replicate, to some degree, the human brain. Rather boldly, an accompanying MIT report on the paper explains that the team have created a new “artificial synapse”.

No, the researchers haven’t developed a fully operation human brain using nothing but mechanical and digital components, but they have taken a significant step toward such a lofty goal. Before we dive into what this study has actually accomplished, though, we need to get a few things straight.

First, neuromorphic computing. Conventional computer chips transfer information to and fro at regular intervals. This works fine for the most part, but if we wanted to transfer information whenever we felt like it, rather than at a tick-tock constant pace, we need something else.

Enter, neuromorphic chips. These chips aren’t new, and in fact versions have been around since the 1980s. Instead of using logic gates – which express information using a binary (0 or 1) output, depending on the voltage level – these chips use neuron-inspired blocks.

These allow information to be transmitted in pulses and patterns, independent of any set pace. Information is transmitted on a spectrum, or a gradient, rather than through a binary yes/no system, much like real neurons.

These chips use a lot less energy overall than their conventional equivalents, which makes them more efficient at processing information. Intel have recently made headlines for using these chips to make computing components that “resemble the brain”, but they only resemble one aspect of the brain, to be fair.

So what have the team at MIT done that’s new? Well that all comes down to the aforementioned “artificial synapse.”

Within your brain, and the rest of your central nervous system, you have electrically conductive cells known as neurons. These send information to and from each other via neurotransmitters – biochemical signaling molecules. The junction that allows this connection to happen is called a synapse.

Synapses control the strength of the electrical connection – the flow of ions – between neurons. An artificial synapse would do much the same, and they do exist at present. Right now, though, the material in which they travel across aren’t that good at controlling the current, which leads to inaccurate information transference across neuromorphic chips.

MIT thought they could do one better. They designed an artificial neuron made of single-crystalline silicon, whose atoms are arranged in a particularly ordered way. They found that this allowed for a much more precise flow of ions, and in simulations using handwriting samples, the correct information was transferred accurately 95.1 percent of the time.

Making these synapses wasn’t easy. At just 25 billionths of a meter across, they’re smaller than the Ebola virus is wide.

As you may have noticed, neuromorphic chips aren’t widespread in computing right now. Despite existing for almost 40 years, their true potential hasn’t been realized, and until they can be scaled up, they’ve yet to replace conventional logic gate chips for the most part.

Research like this, however, may change that. Combining the tiny dimensions of these artificial synapses with the efficiency of neuromorphic chips may allow us to design portable neural networks: advanced artificial intelligences we can fit in our pockets.

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A Blob And A Bubble Tell Us The History Of A Supermassive Black Hole

Some astrophysical processes are so slow that we only see a snapshot of whats happing and it is up to astronomers to work out the full movie from it.

In the case of galaxy IC 2497, to help with its reconstruction the researchers had the help of a bubble of gas and a large green blob. The study, published in the Monthly Notices of the Royal Astronomical Society, used a new X-ray view of the galaxy to uncover the active past of its supermassive black hole.

IC 2497 became famous in the astronomy world for sporting a curious little green blob, discovered by Dutch school teacher Hanny van Arkel thanks to a citizen science project,Galaxy Zoo. The blob is called Hannys Voorwerp (Dutch for Hannys object) and the international team believes its the delayed response from a powerful emission from the supermassive black hole.

If the black hole at the center of IC 2497 was growing at a faster rate until 200,000 years ago, it might explain the glow in the distant blob. The voorwerp is like an after image of a cosmic flash.

The latest observationshows that the supermassive black hole is not dormant yet and probably just got quieter. The clue for this is in the bubble of gas that surrounds the center of the galaxy.

The astronomers were able to estimate the temperature of the gas and it is remarkably cool. When materials fallinto supermassive black holes, the gravitational forces heat it up and it begins to emit a lot of light. The light is powerful enough to push gas and dust into intergalactic space forming large spectacular jets.

The team believes the supermassive black hole was in a quasar phase and it was emitting so much energy that it pushed most of the hot gas out, and is now left with the cool gas. Without the hot gas, the supermassive black hole has lost its food source and is slowly going back to sleep.

Understanding all this from a snapshot is definitely not bad.

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How Migratory Birds Know Their Longitude

The calculation of longitude was one of the great scientific challenges of the 18th century. Very valuable prizes were offered for its solution, while countless sailors died from the delay. Yet birds solved the problem millions of years ago. Their solution, at least for reed warblers, has now been revealed as measuring magnetic declination – the angle between magnetic north and true north – as well as the more widely used intensity and inclination.

Calculating latitude is a relatively easy task, since (much to the annoyance of flat earthers) different stars can be seen depending on the distance from the equator. Longitude is much harder, and prior to GPS required very accurate clocks that could compare local time with that at a known location.

As a new paper in Current Biology notes: “Birds do not appear to possess a time-difference clock sense.” Despite this, some manage to go on east-west migrations, as well as the more common north-south ones, homing in on specific sites. Moreover, the paper says “Night-migratory songbirds can correct for east-west displacements to unknown locations.”

The authors caught 15 reed warblers (Acrocephalus scirpaceus) in western Russia on their way to Africa. These were placed inside a magnetic field with the same strength as that of the Earth locally, but a declination differing by 8.5 degrees. The artificial field mimicked that near Edinburgh. The birds responded as if they were indeed now in Scotland, turning 151º to fly east-south-east, rather than west-south-west.

Reed warnbler’s breeding grounds (yellow) the path of migration for those from the eastern Baltic, lines of common magnetic declination (red) and common magnetic intensity (blue). Chernetsov et al/Current Biology

 “We’ve shown for the first time that magnetic declination may be a component of the magnetic navigational map, at least in some long-distance migratory birds,” said Dr Nikita Chernetsov of the Zoological Institute of the Russian Academy of Sciences, in a statement.

The research also revealed a learned component. Twenty-five birds too young to have undergone a migration through Western Europe became confused on exposure to the altered field, trying to fly in random directions.

“Reed warblers seem to learn the large-scale spatial pattern of the declination gradient during their annual movements, just like they learn other gradients, inclination, and total intensity,” Chernetsov said. “As magnetic declination mainly varies along the east-west axis, it provides the possibility to measure longitude.”

Unresolved questions include how reed warblers understand the implications of a gradient from a location they have never experienced, and whether all migratory birds use the same technique. The discovery could have been of great use to navigators in previous centuries, who might have found compasses that could measure magnetic declination easier to build than clocks that would keep time on a rolling ship. Nevertheless, it is not clear if there are any technological applications for which it could be used today.

Adult reed warblers responded to a different magnetic declination as if they were in Scotland. Juveniles didn’t know where they were and tried to fly in random directions. Ekaterina Chernetsova



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We’ll Survive 2012 Apocalypse, So Will Doomsday Fears


Humanity will survive the supposed December 2012 apocalypse, but, unfortunately, so will irrational doomsday fears, scientists say.

Doomsayers around the world are gearing up for armageddon on Dec. 21, based on predictions supposedly made by the Mayans more than 1,000 years ago. Even after the sun rises Dec. 22, however, many folks will be only momentarily reassured, quickly latching onto another scenario purported to bring about the apocalypse within their lifetime.

The persistence of these worries stems from a variety of factors, researchers say. The deluge of misinformation on the Internet, poorly developed or underutilized critical thinking skills and plain old human nature all contribute, convincing many people to fear the worst despite the lack of compelling evidence (and the poor track record of such dire predictions over the years).

“There have been end-of-the-world predictions every few years throughout history, really,” said astronomer David Morrison, head of the Carl Sagan Center for the Study of Life in the Universe at the SETI (Search for Extraterrestrial Intelligence) Institute in Mountain View, Calif. “We had two or three last year.”

Morrison spoke at the SETICon 2 conference in Santa Clara, Calif., on June 23 during a panel discussion called “Cosmophobia: Doomsday 2012 and Other Fiction Science.” [Don’t Panic: 2012 Doomsday Fears Debunked]

Flood of Misinformation

Though Morrison and other scientists work hard to tamp down fears of Comet Elenin, the mythical planet Nibiru and other supposed agents of impending doom, their voices of reason have a hard time being heard these days.

“We are completely drowned out by the doomsayers on the Internet,” Morrison said. “It’s very hard for the truth to even get a hearing.”

It’s especially hard to reach young people, most of whom seem unable to distinguish between reliable and unreliable sources, he added.

“At the best, they will just count numbers,” Morrison said. “‘Well, there are 83 websites that say the world will end in 2012, and one that says it won’t. So it must be true.'”

Not all of the misinformation is coming from altruistic folks who just want to get the worried word out, said fellow panelist Andrew Fraknoi, chair of the astronomy department at Foothill College in Los Altos Hills, Calif. Some of it is probably pumped out by people trying to make a buck.

“Today, it seems like money is much more important than truth, that anything goes,” Fraknoi said. “Fear-mongering has become a large and profitable industry.”

Data from the publishing world appear to back him up: A search for “Doomsday 2012” books on returns nearly 200 titles.

It’s Human Nature

But not all of the blame can be laid at the Internet’s feet. Doomsday fears have cropped up repeatedly throughout history, and in most cases they weren’t sustained by YouTube videos and “Nibiru” Google searches. [Oops! 11 Failed Doomsday Predictions]

The Millerites, for example, believed that Jesus Christ would return to Earth in 1843 or 1844, and that the world as we know it would be destroyed in the process. Another group called the Seekers thought a huge flood would ravage our planet on Dec. 21, 1954. The Seekers’ leader, a Chicago woman named Dorothy Martin, claimed to have gotten this information from aliens living on the planet Clarion.

We shouldn’t be too surprised whenever such cults grab the headlines, said Leonard Mlodinow, a Caltech physicist and author of such books as “The Drunkard’s Walk: How Randonmness Rules Our Lives” and “The Grand Design” (which he wrote with Stephen Hawking).

“I think it’s a very natural human phenomenon,” Mlodninow said. “People who we consider very rational believe such things all the time.”

He cited today’s major religions, saying that they would have seemed just as odd and irrational as the doomsday cults if we’d encountered them back in the early days, before they became so well established.

“I don’t consider those people particularly weird,” Mlodinow said of modern doomsayers. “I just think that they’re early adopters, you might call them.”

There’s likely some ego-boosting pyschology involved as well, said panelist Seth Shostak, a senior astronomer at the SETI Institute.

“To some extent, it’s a very empowering thought — that you know something very important that those nerdy, pointy-headed, tweed-jacketed academics down at the local university won’t acknowledge,” Shostak said. “I think you have to look for the answers there.”

Is Education the Answer?

Whatever their causes, doomsday fears are quite prevalent in the United States and abroad.

For example, a poll commisioned by the news agency Reuters earlier this year found that 15% of people worldwide — or roughy 1 billion folks — believe the apocalypse will come during their lifetime. In the United States, the figure is 22%.

Such worries aren’t just interesting sociological or psychological phenomena, Morrison said. They can have tragic consequences for believers.

“At least once a week, I get a question from a young person — usually 11, 12 years old — who says they are contemplating suicide before the end of the world,” Morrison said. “I know of several cases at least of reported suicides, of people who are obsessed with the end of the world in 2012.”

The best way to combat irrational doomsday worries — especially among the young — is education, Fraknoi said. We need to teach better critical thinking skills and instill a love of discovery that will inspire kids to seek out the truth — and make them less likely to be gulled by fanciful rumors.

“Ask yourself the question, ‘Why should I believe a word of this?'” Fraknoi said. “If you know how to answer, ‘Why should I believe a word of this?’ then you’re much closer to scientific truth.”

Artist’s conception of the rogue planet Nibiru, or Planet X courtesy of gilderm,

This article originally published at

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Oculus Rift Unveils New Virtual Reality Headset for Devs to Play With


The second generation Oculus Rift will be available for game developers this summer.

Game developers interested in creating games in virtual reality will get an upgraded set of tools from the Oculus Rift team this summer, the company announced Wednesday morning.

The second-generation Oculus Rift development kit is available for preorder starting Wednesday for developers. The virtual reality headset, which began as a Kickstarter campaign in 2012, now has 50,000 units in the hands of developers interested in creating games for it.

Oculus VR Vice President of Product Nate Mitchell said doesn’t resemble anything like consumers will eventually see, but is much farther along the company’s vision for virtual reality than the previous Oculus Rift model. A consumer version is still not under discussion, he added.

“We’ve learned a lot of lessons from our original vision,” Mitchell said.

The new Oculus Rift headset solves many users’ latency issues; it eliminates the motion blur problems that were easy to spot if you moved your head too quickly. It features a brighter, higher-resolution OLED screen with a 960 x 1080p resolution over each eye, rather than a 640 x 800p resolution over each eye on the current kit.


A straight on view of the updated Oculus Rift.

The new headset also boasts improved positional tracking, part of the Crystal Cove prototype the company showed off during CES 2014. Mitchell said that such new features will allow developers to bring many more complex elements into games they produce for virtual reality, including text and UI layouts. Previously, both were previously very difficult to add.

The new headset will cost $350 for developers and will ship sometime in July of this year.

Virtual reality may be the belle of the ball at the Game Developers Conference this week. Sony also used the conference to announce its own virtual reality headset for the PlayStation 4, currently called Project Morpheus. Sony remained mum on setting a date for its headset to reach consumers.

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From Washing Machines To Computers: How The Ancients Invented The Modern World

True innovation is hard to find, as few things come out of nothing. Take the now ubiquitous selfie, for example. The format may have changed but the concept of making self-portraits is hundreds, if not thousands of years old. The same is true of many inventions that we typically think of as modern, some of which actually have precedents dating back over 1000 years.

A Roman Washing Machine

Did the Romans have machines like this? Wikimedia Commons

Fulling was a major occupation in the Roman world that involved cleaning cloth by trampling it in tubs containing an alkaline solution, such as water and urine or the mineral known as fullers earth. But in ancient Antioch, in what is now Turkey, evidence suggests the process may have been mechanised, meaning the Romans may have effectively created the worlds first washing machine as far back as the 1st century AD.

Traditionally thought of as a medieval invention, the mechanical fulling mill would likely have consisted of a waterwheel that lifted a trip-hammer, which would then drop to press the cloth. A fullers’ canal mentioned in an inscription in Antioch would have supplied an estimated 300,000m3 of water at almost a metre per second, far in excess of what was needed for regular foot-powered fulleries. The power this could generate means it could have supported fulling on an industrial scale with maybe 42 pairs of mechanical hammers.

An Ancient Greek Computer

Antikythera mechanism. Wikimedia Commons, CC BY

In 1900, divers off the coast of the Greek island of Antikythera discovered something that changed our view of ancient science. The Antikythera mechanism is a bronze system of 30 gears that models the cycles of the sun and moon. It is effectively the first-known analogue computer, dating back to the 1st century BC. Set in a wooden box, the internal gears would have turned dials on the outside that showed the position of the sun and moon, as well as the rising and setting of specific stars and possibly the positions of Mars and Venus, too. Another dial could be moved to take into account leap years.

Although we now know that the Babylonians discovered how to use geometry to track the course of Jupiter in around 1800 BC, the Antikythera mechanism is the earliest known device that automatically calculates astronomical phenomena. We know of no other similiar devices for several hundred more years until the 8th century AD, when mathematician Muhammed al-Fazari is said to have built the first Islamic astrolabe. And nothing as mechanically sophisticated would appear again until the European astronomical clocks of the 14th century.

The Great Roman Bake-Off

Tomb of Eurysaces the Baker. Livioandronico2013/Wikimedia Commons, CC BY-SA

Bread was big business in the Roman world. It was given out by the state as part of a dole known as the annona. This meant that it was possible for people to make substantial amounts of money as bakers. One such person was Marcus Vergilius Eurysaces, a freedman (ex-slave) from Rome, who was so proud of his successful baking business that he commemorated it on his tomb. Today it is one of the most striking monuments from ancient Rome.

The top of the monument is decorated with a series of scenes that show a range of baking activities including the mixing and kneading of dough, the forming of loaves and the baked loaves being stacked in baskets. The most curious part, however, is the cylinders that make up the bulk of the monument. These features have baffled scholars for quite some time. One convincing theory argues that it is likely that these cylinders are related to baking and may well represent an early dough-mixing machine. The idea is that a rotating metal arm would have been attached to each cylinder in order to mix the dough.

The First State Space Project

Starmen. Wikimedia Commons

Ninth-century Baghdad in what is now Iraq saw the rise of a growing scientific community, particularly in astronomy, centred around a library known as the House of Wisdom. The problem for these new scholars was that their books were written many centuries earlier and came from a wide range of different cultures including Persian, Indian and Greek that did not always agree. The Caliph al Mamun decided the only solution was to build an astronomical observatory so the citys scholars could determine the truth.

Observatories werent new but a state-sponsored scientific institution was. Its hard to be sure exactly which instruments were used in the al-Shammasiyya observatory, but they probably included a sundial, astrolabes and a quadrant set on the wall to measure the precise position of objects in the sky. The quadrant may have been the first of its kind to be used in astronomical observations. The scientists used these instruments to reassess Ptolemys Mathematical Treatise from the 2nd century AD, and to make numerous astronomical observations, including the latitudes and longitudes of 24 fixed stars.

Zena Kamash, Lecturer in Roman Art and Archaeology, Royal Holloway

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The Race To Hypersonic Speed: Will Air Passengers Feel The Benefits?

When Concorde entered service 40 years ago, it more than doubled the speed of air travel at a stroke. Following Concordes retirement, airliners today fly once more at subsonic speeds, but engineers worldwide are looking to a future in which high-speed flight is an everyday occurrence. Except they want to go one better: not at supersonic, but hypersonic speeds.

Aerospace giant Airbus was last year awarded a patent that details how a future hypersonic aircraft, with delta wings reminiscent of Concorde, could travel at Mach 4.5 fast enough to carry passengers between Paris and Tokyo in just three hours.

But inevitably, technology that has reached the commercial realm will already have been investigated by the military. The US, Russia and China have all carried out test flights of hypersonic vehicles those which travel at around five times the speed of sound with varying degrees of success. Each also has plans for weapons systems that could be developed from them.

Because while these are often referred to as fighter jets, in truth the machines are more similar to missiles. Without pilots, they sit atop rockets which boost them to high supersonic speeds (Mach 4 and above), at which point they start up their own engines (if equipped) and accelerate to even faster cruise speeds – but not for long, as they usually run out of fuel quickly, and most of their flight time is spent in a glide, albeit an extremely fast one.

Current missiles have operated in this fashion for decades. Intercontinental ballistic missiles (ICBM) and some shorter-range versions use the same sort of flight path, with the missile formed of multiple rocket stages to provide enough power to arc high into the atmosphere, only flying faster and higher. The now retired US AIM-54 Phoenix air-to-air missile had a top speed of Mach 5. What makes the current generation of hypersonic aircraft designs different is their capability to manoeuvre, making them harder to intercept.

X-43 rocket plane dropped from a B-52, seconds before igniting its scramjet engines and reaching a world record-holding 10,000km/h (Mach 9.8). NASA

The Need For Speed

Why bother? There are two main reasons for the fresh interest shown by the military in hypersonic aircraft. The first is that a very fast, highly manoeuvrable weapon is not easy to counter: it can be difficult to detect and its speed means that there is little time for defences to react, much less to actually take any action to stop it. This makes it a threat to supposedly heavily defended targets and most discussion of the Chinese hypersonic craft, dubbed Wu-14, and the Russian equivalent, the Yu-71, mention penetrating US missile defence systems as a primary aim.

The second relates to a requirement that has become more urgent in recent years, namely to shorten response time and to attack mobile targets. While drones, satellites and the like can locate them easily enough, highly mobile enemy units anything from terrorist groups to Scud missile launchers will not hang around waiting for the inevitable airstrike to be called in. A very fast weapons platform with the ability to manoeuvre means that once found, a target will have little time and less opportunity to escape.

Material Shortfall

Of course, to create a workable hypersonic vehicle, engineers have to overcome, or at least cope with, the severe environment encountered by something moving that fast. The main problem (from which most if not all the others stem) is heat heat from air friction and from the shock waves generated by moving faster than the speed of sound.

The temperatures a hypersonic vehicle encounters are so high that conventional materials cant withstand them and maintain their strength. There are materials that can insulate a structure from the heat, but they tend not to be very strong in themselves, and so any breach of insulation can quickly lead to catastrophic failure as demonstrated by the tragic loss of the space shuttle Columbia in 2003, and also of some current test vehicles. Research into new heat-resistant materials and suitable manufacturing techniques is therefore a priority.

High air temperatures also reduce the thrust of an air-breathing jet engine, so new propulsion concepts are also needed relying on rocket engines tends to lead to overly large and heavy aircraft. Among the companies leading the way on propulsion technology is British company Reaction Engines, which is testing the revolutionary Sabre variable-cycle engine.

Travelling at very high speeds will also require advanced sensors and controls. New materials will be needed again, as conventional radomes and antennae would never withstand the heat. Conformal antennae where the crafts fuselage skin is used as the transmitter and receiver are a possibility, though this is not guaranteed to work. Depending on just how fast the vehicle is designed to travel, ionisation of the air around it could interfere with radio-frequency sensors and communications.

Hypersonic Flight For All?

Whether its possible to create a crewed or passenger hypersonic aircraft is still up for debate. But producing any sort of hypersonic vehicle is a long-term project that will take a lot of time and effort and a whole lot of money. Patents mark the ground as to where some may follow. But who out there has the will, the persistence and the funds to do so?

Phillip Atcliffe, Senior Lecturer in Aeronautical Engineering, University of Salford

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