For the First Time, Astronomers Have Determined the Color of an Exoplanet. It is ...

 

 

Scientists have identified, at this point, more than 900 exoplanets -- planets that exist outside our solar system, orbiting other stars. We know those planets are out there; but we know that, in large part, through indirect measurements rather than through simply peering at them through telescopes.

One of them is HD 189733b, located 63 light-years away from us, and one of the nearest exoplanets to Earth that can be seen crossing the face of its star. Because of that, HD 189733b has been studied by teams of astronomers hoping to learn more about the bodies that orbit other stars.

Recently, the Hubble Space Telescope turned its attention to the planet, and they've announced a new discovery based on that research: they've determined the color of HD 189733b. Which marks the first time that scientists have determined the true color of a planet in another solar system.

"This planet has been studied well in the past, both by ourselves and other teams," says Frédéric Pont, leader of the Hubble observing program and an author of the paper announcing the find. "But measuring its color is a real first -- we can actually imagine what this planet would look like if we were able to look at it directly."

That color? Blue. Rich blue. If seen up close, the Hubble team puts it, HD 189733b "would be a deep azure blue, reminiscent of Earth's color as seen from space."

So how did the team make that determination? They measured the light reflected off the surface of HD 189733b. Since the planet is both faint and close to its star, the team needed to isolate the planet's light from its star's light -- which they did using Hubble's Space Telescope Imaging Spectrograph (STIS). They examined HD 189733b before, during, and after the planet passed behind its host star. And "we saw the brightness of the whole system drop in the blue part of the spectrum when the planet passed behind its star," Oxford's Tom Evans, first author of the paper, explains it.

"From this, we can gather that the planet is blue, because the signal remained constant at the other colors we measured."

That blue color does not mean, the team is quick to note, that the Earth-hued planet is earthly in other ways. This out-of-our-solar-system version of the "pale blue dot" is, in fact, an enormous gas giant -- think Jupiter, Saturn, Neptune, and Uranus -- that orbits very close to its host star (think Mercury). Its atmosphere clocks in at over 1,800 degrees Fahrenheit, and features periodic hazes and violent flares. Its winds whip at more than 4,000 miles per hour. Oh! And it rains glass. Yes, glass.

So HD 189733b is not habitable. But it is classifiable -- as, in particular, a "hot Jupiter," a gas giant that orbits closely to its host star. Our solar system lacks a hot Jupiter of its own -- Jupiter being, simply, Jupiter -- so we have to rely on studies of bodies like HD 189733b to learn more about that class of planets. And color is its own kind of data. While "it's difficult to know exactly what causes the colour of a planet's atmosphere, even for planets in the Solar System," Pont puts it, Hubble's new observations "add another piece to the puzzle over the nature and atmosphere of HD 189733b. We are slowly painting a more complete picture of this exotic planet."

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Soon, You May Download New Skills Stright to Your Brain

PROBLEM: Unlike Neo in The Matrix or the titular superspy in the comedy series Chuck, we can't master kung fu just by beaming information to our brain. We have to put in time and effort to learn new skills. 

METHODOLOGY: Researchers from Boston University and Japan's ATR Computational Neuroscience Laboratories designed a decoded functional MRI neurofeedback method that induces a pre-recorded activation pattern in targeted early visual brain areas that could also produce the pattern through regular learning. They then tested whether repetitions of the fMRI pattern caused an improvement in the performance of that visual feature.

RESULTS: The experiments successfully demonstrated that, through a person's visual cortex, decoded fMRI could be used to impart brain activity patterns that match a previously known target state. Interestingly, behavioral data obtained before and after the neurofeedback training showed improved performance of the relevant visual tasks especially when the subjects were unaware of the nature of what they were learning.

CONCLUSION: It may someday be possible to use brain technology to learn to play the piano, reduce mental stress, or even master kung fu with little or no conscious effort. Lead author and BU neuroscientist Takeo Watanabe says in a statement: "Adult early visual areas are sufficiently plastic to cause visual perceptual learning."

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How NASA might build its very first warp drive

A few months ago, physicist Harold White stunned the aeronautics world when he announced that he and his team at NASA had begun work on the development of a faster-than-light warp drive. His proposed design, an ingenious re-imagining of an Alcubierre Drive, may eventually result in an engine that can transport a spacecraft to the nearest star in a matter of weeks — and all without violating Einstein's law of relativity. We contacted White at NASA and asked him to explain how this real life warp drive could actually work.

The Alcubierre Drive

The idea came to White while he was considering a rather remarkable equation formulated by physicist Miguel Alcubierre. In his 1994 paper titled, "The Warp Drive: Hyper-Fast Travel Within General Relativity," Alcubierre suggested a mechanism by which space-time could be "warped" both in front of and behind a spacecraft.

Michio Kaku dubbed Alcubierre's notion a "passport to the universe." It takes advantage of a quirk in the cosmological code that allows for the expansion and contraction of space-time, and could allow for hyper-fast travel between interstellar destinations. Essentially, the empty space behind a starship would be made to expand rapidly, pushing the craft in a forward direction — passengers would perceive it as movement despite the complete lack of acceleration.

White speculates that such a drive could result in "speeds" that could take a spacecraft to Alpha Centauri in a mere two weeks — even though the system is 4.3 light-years away.

 

In terms of the engine's mechanics, a spheroid object would be placed between two regions of space-time (one expanding and one contracting). A "warp bubble" would then be generated that moves space-time around the object, effectively repositioning it — the end result being faster-than-light travel without the spheroid (or spacecraft) having to move with respect to its local frame of reference.

"Remember, nothing locally exceeds the speed of light, but space can expand and contract at any speed," White told io9. "However, space-time is really stiff, so to create the expansion and contraction effect in a useful manner in order for us to reach interstellar destinations in reasonable time periods would require a lot of energy."

And indeed, early assessments published in the ensuing scientific literature suggested horrific amounts of energy — basically equal to the mass-energy of the planet Jupiter (what is 1.9 × 10²⁷ kilograms or 317 Earth masses). As a result, the idea was brushed aside as being far too impractical. Even though nature allowed for a warp drive, it looked like we would never be able to build one ourselves.

"However," said White, "based on the analysis I did the last 18 months, there may be hope." The key, says White, may be in altering the geometry of the warp drive itself.

A new design

In October of last year, White was preparing for a talk he was to give for the kickoff to the 100 Year Starship project in Orlando, Florida. As he was pulling together his overview on space warp, he performed a sensitivity analysis for the field equations, more out of curiosity than anything else.

 

"My early results suggested I had discovered something that was in the math all along," he recalled. "I suddenly realized that if you made the thickness of the negative vacuum energy ring larger — like shifting from a belt shape to a donut shape — and oscillate the warp bubble, you can greatly reduce the energy required — perhaps making the idea plausible." White had adjusted the shape of Alcubierre's ring which surrounded the spheroid from something that was a flat halo to something that was thicker and curvier.

He presented the results of his Alcubierre Drive rethink a year later at the 100 Year Starship conference in Atlanta where he highlighted his new optimization approaches — a new design that could significantly reduce the amount of exotic matter required. And in fact, White says that the warp drive could be powered by a mass that's even less than that of the Voyager 1 spacecraft.

That's a significant change in calculations to say the least. The reduction in mass from a Jupiter-sized planet to an object that weighs a mere 1,600 pounds has completely reset White's sense of plausibility — and NASA's.

Hitting the lab

Theoretical plausibility is all fine and well, of course. What White needs now is a real-world proof-of-concept. So he's hit the lab and begun work on actual experiments.

"We're utilizing a modified Michelson-Morley interferometer — that allows us to measure microscopic perturbations in space time," he said. "In our case, we're attempting to make one of the legs of the interferometer appear to be a different length when we energize our test devices." White and his colleagues are trying to simulate the tweaked Alcubierre drive in miniature by using lasers to perturb space-time by one part in 10 million.

Of course, the interferometer isn't something that NASA would bolt onto a spaceship. Rather, it's part of a larger scientific pursuit.

"Our initial test device is implementing a ring of large potential energy — what we observe as blue shifted relative to the lab frame — by utilizing a ring of ceramic capacitors that are charged to tens of thousands of volts," he told us. "We will increase the fidelity of our test devices and continue to enhance the sensitivity of the warp field interferometer — eventually using devices to directly generate negative vacuum energy."

He points out that Casimir cavities, physical forces that arise from a quantized field, may represent a viable approach.

And it's through these experiments, hopes White, that NASA can go from the theoretical to the practical.

Waiting for that "Chicago Pile" moment

Given just how fantastic this all appears, we asked White if he truly thinks a warp-generating spacecraft might someday be constructed.

"Mathematically, the field equations predict that this is possible, but it remains to be seen if we could ever reduce this to practice."

What White is waiting for is existence of proof — what he's calling a "Chicago Pile" moment — a reference to a great practical example.

"In late 1942, humanity activated the first nuclear reactor in Chicago generating a whopping half Watt — not enough to power a light bulb," he said. "However, just under one year later, we activated a ~4MW reactor which is enough to power a small town. Existence proof is important."

His cautious approach notwithstanding, White did admit that a real-world warp drive could create some fascinating possibilities for space travel — and would certainly reset our sense of the vastness of the cosmos.

"This loophole in general relativity would allow us to go places really fast as measured by both Earth observers, and observers on the ship — trips measured in weeks or months as opposed to decades and centuries," he said.

But for now, pursuit of this idea is very much in science mode. "I'm not ready to discuss much beyond the math and very controlled modest approaches in the lab," he said.

Which makes complete sense to us, as well. But thanks to these preliminary efforts, White has already done much to instill a renewed sense of hope and excitement over the possibilities. Faster-than-light travel may await us yet.

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DNA storage breakthrough: 700TB of data in one gram

A bioengineer and geneticist at Harvard’s Wyss Institute have successfully stored 5.5 petabits of data – around 700 terabytes – in a single gram of DNA, smashing the previous DNA data density record by a thousand times.

The work, carried out by George Church and Sri Kosuri, basically treats DNA as just another digital storage device. Instead of binary data being encoded as magnetic regions on a hard drive platter, strands of DNA that store 96 bits are synthesised, with each of the bases (TGAC) representing a binary value (T and G = 1, A and C = 0).

To read the data stored in DNA, you simply sequence it – just as if you were sequencing the human genome – and convert each of the TGAC bases back into binary. To aid with sequencing, each strand of DNA has a 19-bit address block at the start (the red bits in the above image) – so a whole vat of DNA can be sequenced out of order, and then sorted into usable data using the addresses.

Scientists have been eyeing up DNA as a potential storage medium for a long time, for three very good reasons. Firstly, it’s incredibly dense – you can store one bit per base, and a base is only a few atoms large. Secondly, it’s volumetric (beaker) rather than planar (hard disk). And finally, it’s incredibly stable – where other bleeding-edge storage mediums need to be kept in sub-zero vacuums, DNA can survive for hundreds of thousands of years in a box in your garage.

It is only with recent advances in microfluidics and labs-on-a-chip that synthesising and sequencing DNA has become an everyday task, though. While it took years for the original Human Genome Project to analyse a single human genome (some 3 billion DNA base pairs), modern lab equipment with microfluidic chips can do it in hours. Now this isn’t to say that Church and Kosuri’s DNA storage is fast – but it’s fast enough for very-long-term archival.

Just think about it for a moment: One gram of DNA can store 700 terabytes of data. That’s 14,000 50-gigabyte Blu-ray discs… in a droplet of DNA that would fit on the tip of your pinky. To store the same kind of data on hard drives – the densest storage medium in use today – you’d need 233 3TB drives, weighing a total of 151kg. In Church and Kosuri’s case, they have successfully stored around 700 kilobytes of data in DNA – Church’s latest book, in fact – and proceeded to make 70 billion copies (which they claim, jokingly, makes it the best-selling book of all time!) totalling 44 petabytes of data stored.

Looking forward, they foresee a world where biological storage will allow us to record anything and everything without reservation. Today, we wouldn’t dream of blanketing every square metre of Earth with cameras, and recording every moment for all eternity/human posterity – we simply don’t have the storage capacity.

There is a reason that backed up data is usually only kept for a few weeks or months – it just isn’t feasible to have warehouses full of hard drives, which could fail at any time. If the entirety of human knowledge – every book, uttered word, and funny cat video – can be stored in a few hundred kilos of DNA, though… well, it might just be possible to record everything (hello, police state)!

It’s also worth noting that it’s possible to store data in the DNA of living cells – though only for a short time. Storing data in your skin would be a fantastic way of transferring data securely…

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You can use a hot spoon to instantly relieve itchy bug bites

The season for annoying bug bites? Maybe, but a surprisingly simple remedy exists that can eliminate all of the itch within minutes.

All you have to do is heat up a metal spoon under hot tap water for a minute or so, then press it directly against the bite. Hold it tight against your skin for a couple of minutes, and when you take it off, the itch should be gone for good.

When mosquitoes bite you, they inject proteins under your skin to keep your blood from clotting. It's this protein that causes you to itch, but it can't survive at the moderately high temperatures a hot spoon can create. The bump might linger for a few days, but the uncomfortable itching should be gone for good!

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'Pillars of creation' destroyed by supernova 6000 years ago!

The famous "pillars of creation" - clouds of dust and gas imaged by the Hubble Space Telescope, are no more - a supernova blast wave has blown them apart. But their ghostly image will linger for another thousand years because of the time it takes for light to travel from them to Earth.

The pillars have been astronomical icons since Hubble imaged them in 1995 (scroll down for Hubble image). They are part of a larger star-forming region called the Eagle Nebula, which lies 7000 light years away. That means we are seeing the pillars as they were 7000 years ago, when the light first left them.

Now, an infrared image from the Spitzer Space Telescope has revealed a previously unseen supernova blast wave that was advancing towards the pillars at that time, threatening to ultimately sweep them away.


Nicolas Flagey of the Institut d'Astrophysique Spatiale in Orsay, France, led a team that obtained the image. It shows a cloud of hot dust thought to have been heated by a supernova blast that likely occurred between 1000 and 2000 years earlier.

Based on the cloud's position, the blast wave looked set to hit the pillars in 1000 years. Taking into account the 7000-year time lag for their light to reach the Earth, that means the pillars were actually destroyed 6000 years ago, Flagey says.

We will not see their obliteration from Earth for another 1000 years, however. And when we do, they will be in tatters - Flagey says only a few patches of the pillars are dense enough to survive the blast. "All the other parts will crumble when the shock wave arrives," he says.

Now, his team is searching through historical records to see if ancient astronomers spotted the supernova responsible for the pillars' destruction. It should have become visible on Earth 1000 to 2000 years ago, but while a few candidate events have been found in the right time frame, so far none has been confirmed as the culprit.


But Stephen Reynolds of North Carolina State University in Raleigh, US, is not convinced the hot dust cloud is the result of a supernova explosion. The expanding gas, or remnant, from the event should emit much stronger radio waves and X-rays than have been observed, he says.

"I believe that a supernova remnant less than 2000 years old at a distance of less than 6000 light years would have to have quite unusual properties to have avoided detection to this point," he told New Scientist.

Instead, he suggests that hot, high-speed winds from massive stars in the region could have heated up the dust grains in the cloud. If so, the presence of this hot gas would still erode the pillars of creation over time, he says.

The results were presented on Tuesday at a meeting of the American Astronomical Society in Seattle, Washington, US.

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Starfish eyes are good enough to show them the way home

Starfish use the light-sensitive organs at the tips of their arms to form images, helping the animals find their way home if they stray from the reef.

We have known about the sensors that starfish have at the ends of their arms for 200 years, but no one knew whether they are real eyes that form images or simply structures that detect changes in light intensity.

We finally have an answer: they appear to act as real eyes. The discovery is another blow to creationist arguments that something as complex as a human eye could never evolve from simpler structures.

The blue sea star (Linckia laevigata), which is widely sold as dried souvenirs, lives on shallow rock reefs in the Indian and Pacific oceans. It can detect light, preferring to come out at night to graze on algae.

The light sensitivity has recently been found to be due to pigments called opsins, expressed in cells close to the animal's nerve net.

What has not been clear, says Anders Garm at the University of Copenhagen in Denmark, is whether these cells simply tell the starfish about ambient light levels, as happens in more primitive light-sensitive animals, or whether they actually form spatial images.

To find out, Garm collected healthy starfish and removed the arm-tip photoreceptors from a third of them. He made similar incisions on another third of the starfish but left the eyes intact, for a control "sham" operation. The remaining starfish were left untouched. He then took the starfish off their rocks, and put them on the sandy bottom – where they would starve if they didn't get back to the reef.

He told the Society for Experimental Biology meeting in Valencia, Spain, this week that intact starfish promptly scuttled back to the rocks. Eyeless starfish scuttled just as fast, but in random directions – demonstrating that the starfish needed the photoreceptors to recognise and move towards the reef. To do this, Garm says, they had to be able to form an image of the reef, meaning that their simple nerve net must be able to process visual information.

"Amazingly, image vision in starfish has not been investigated before," says Dan-Eric Nilsson at Lund University in Sweden, who collaborated with Garm on the study.

In evolutionary terms, says Garm, it is interesting because starfish eyes are structurally close in form to the hypothesised first image-forming eyes.

For instance, light receptors in more advanced eyes are built either out of modified cytoplasmic projections called microvilli, or out of filament-shaped cell organelles called cilia. Starfish eyes contain both structures, so "have features that look a bit ancestral", says Nilsson.

"This shows what visual task drove this important step in eye evolution," says Garm. "Navigation towards large stationary objects – here the reef – that were preferred habitats." In other words, he thinks our eyes may have first evolved so we could find our way home.

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