time travel possible for photons?

Of all the things science fiction has portrayed, time travel is by far the coolest. Sadly, reality and the laws of physics that come with it have basically eliminated all hope of a wormhole opening up and allowing us to travel through time… unless you’re a photon. Luke Butcher of the University of Cambridge has written a paper, describing a potential form of a wormhole that could be held open long enough to allow a photon to pass through. The paper has been submitted to the journal Physical Review D and has been published on arXiv.org in an open access format.

Wormholes were first suggested by Albert Einstein and Nathan Rosen in 1935. Essentially, it’s a hypothetical whirlpool-like passageway that would allow a traveler to escape the confines of the space-time continuum. While a wormhole could lead to a parallel Universe, it could also bend around and lead back to a different point of space and time in our current Universe. However, wormholes are regarded as remarkably unstable and would not hold open long enough to be used for travel purposes. 

Physicists then began to wonder if something could be used to strengthen the wormhole and keep it open. In 1988, a team from Caltech suggested that negative energy appeared to fit the bill. As positive energy would attract matter and pull the wormhole closed, negative energy would have the opposite effect and repel matter, holding it open.

Those researchers at the time began to explore the idea of using Casimir energy as the source of negative energy to stabilize the wormhole. In a vacuum (like space) parallel smooth plates that are near one another undergo quantum effects which trap energy (either positive or negative, depending on the circumstance) between them. If the wormhole vortex got started and negative energy was added to the center, it would brace the hole open and retard the collapse.

However, there was still one more problem: the wormhole itself would be tiny. When depicted in science fiction, wormholes are spacious openings that allow travelers in large spaceships to pass through with ease. In reality, even if a wormhole existed, humans still wouldn’t be able to get through because the passageway simply wouldn’t be wide enough. Butcher reasoned that while humans couldn’t pass through a wormhole, photons might be able to.

Butcher ran some new calculations, building off of previous research. His new design should be able to hold a wormhole open, but it would have to be very long and very narrow. There is also no good way to get the negative energy into the correct location, as the renormalized Casimir energy-density would be zero. “Nonetheless, the negative Casimir energy does allow the wormhole to collapse extremely slowly, its lifetime growing without bound as the throat-length is increased,” Butcher wrote in the paper. “We find that the throat closes slowly enough that its central region can be safely traversed by a pulse of light.”

Even if Butcher is completely correct in his calculations and he was able to hold a wormhole open long enough for a photon to pass through, that doesn't mean that your lifelong dream of going back in time and meeting Cleopatra is about to come true just yet. This paper only deals with holding the passage open, and doesn’t cover what would happen to the person—or photon—once inside. For now, you’ll have to get your time travel fix from Mr. Peabody & Sherman (let’s be honest, Ty Burrell is a treasure).

Scientists bounce water off superhydrophobic surfaces

Engineers from Brigham Young University (BYU) are developing extremely waterproof surfaces that they believe could dramatically improve the efficiency of both power plants and solar energy systems. These surfaces, called superhydrophobic surfaces, are extremely difficult to wet since they cause water to aggregate and form beads that sit on the surface.

If you turn to nature you can see numerous examples of naturally occurring superhydrophobic surfaces such as duck feathers, butterfly wings and lotus leaves. These surfaces efficiently repel water, causing it to clump together and form little beads because it is more attracted to itself than the surface. These surfaces have inspired many engineers in the field of biomimetics, where scientists attempt to imitate elements of nature to solve problems.

Superhydrophobic coatings such as these have numerous diverse applications in industry. They can be sprayed onto clothing such as boots and jackets to make them waterproof, or circuits and grids to keep them clean. They can also be applied to the hulls of ships to prevent the growth of organisms and reduce corrosion. But lead researchers of this study, Julie Crockett and Dan Maynes, see their research being applied to increase the efficiency of energy production systems.

The majority of power plants generate energy by burning either coal or gas to produce steam that rotates a turbine. The world’s largest solar farm that opened this year in the Mojave Desert, California, produces electricity in a similar manner by using giant mirrors to direct sunlight onto boilers which also creates high-temperature steam that drives generator turbines.

Once the turbines are going, the steam produced needs to be fed back into the system to be re-used which is achieved by condensing it back into a liquid. If the condensers were manufactured with super-hydrophobic surfaces this process could be a lot more efficient. “If you have these surfaces, the fluid isn’t attracted to the condenser wall, and as soon as the steam starts condensing to a liquid, it just rolls right off,” said Crockett in a news-release. “And so you can very, very quickly and efficiently condense a lot of gas.”

According to Maynes, if these surfaces were applied to photovoltaic cells the conversion of solar energy to electricity could also be improved because it would mean that the material is kept clean.

In order to produce their superhydrophobic surfaces, the researchers etched the micro posts or ridges onto materials that were then coated with a thin layer of a hydrophobic material such as Teflon. They then used high-speed cameras to record how water interacts with the surface. They’re currently tweaking the surfaces to gain a clearer understanding of why they are so hydrophobic, for example by changing the width and angles of the ribs.

“People know about these surfaces, but why they cause droplets or jets to behave the way they do is not particularly well know,” said Crockett. “If you don’t know why the phenomena are occurring, it may or may not actually be beneficial to you.” 

If you'd like to find out more, check out this YouTube video from BYU:

Read more at http://www.iflscience.com/technology/superhydrophobic-material-developed-makes-water-bounce-ball#kmMAH1KgDsgPocpe.99

4D printing?

These days, 3D printing seems to be at the core of most new new research ventures, whether it's developing ways to print entire meals or recreating facial features to repair a patient's face.

But Skylar Tibbits wants to up the ante: He's hoping 4D printing will be the thing of the not-so-far future.

The name for his concept, Tibbits admits, was a bit lighthearted at first. At the Massachusetts Institute of Technology, Tibbits and researchers from the firms Stratasys and Autodesk Inc were trying to come up with a way of describing the objects they were creating on 3D printers—objects that not only could be printed, but thanks to geometric code, could also later change shape and transform on their own.

The name stuck, and now the process they developed—which turns code into "smart objects" that can self-assemble or change shape when confronted with a change in its environment—could very well pop up in a number of industries, from construction to athletic wear.

“Normally, we print things and we think they’re done,” Tibbits says. “That the final output and then we assemble them.  But we want them to be able to transform and change shape over time.  And we want them to assemble themselves.”

Tibbits, a research scientist at MIT, was given the go-ahead last year to establish what’s known as the university's Self-Assembly Lab.  The challenge was to see how smart researchers could make an object without relying on sensors or chips; how fluid they could make something without wires or motors.

As luck would have it, when Tibbits shared this dilemma with acquaintances at Stratasys, a leading 3D printing firm, they told him the company had developed a printing material that expands by 150 percent when placed in water.  It sounded promising. But the real question was how to bring precision to that transformation so an object could unfold, curl and form specific angles instead of just swelling up like a bloated sponge.

Tibbits’ answer:  Geometry.

With a 3D printer, an operator plugs in a virtual blueprint for an object, which the printer uses to construct the final product layer by layer. To make something "4D," though, Tibbits feeds the printer a precise geometric code based on the object's own angles and dimensions but also measurements that dictate how it should change shape when confronted with outside forces such as water, movement or a change in temperature.

In short, the code sets the direction, the number of times and the angles at which a material can bend and curl. When that object is confronted with a change in environment, it can be stimulated to change shape. Pipes, for instance, could programmed to expand or shrink to help move water; bricks could shift to accommodate more or less stress on a given wall.

Tibbits demonstrated the concept of 4D printing at a TED talk last year, during which he showed how a single strand of printed material could be programmed to fold, on its own, into the word  “MIT.”

PS:Since the fourth dimension is time 4-D printing is basically printing 3-D objects that change their shape with time

for more info click here

matter from light?

Imperial College London physicists have discovered how to create matter from light - a feat thought impossible when the idea was first theorised 80 years ago.

In just one day over several cups of coffee in a tiny office in Imperial's Blackett Physics Laboratory, three physicists worked out a relatively simple way to physically prove a theory first devised by scientists Breit and Wheeler in 1934.

Breit and Wheeler suggested that it should be possible to turn light into matter by smashing together only two particles of light (photons), to create an electron and a positron – the simplest method of turning light into matter ever predicted. The calculation was found to be theoretically sound but Breit and Wheeler said that they never expected anybody to physically demonstrate their prediction. It has never been observed in the laboratory and past experiments to test it have required the addition of massive high-energy particles.

The new research, published in Nature Photonics, shows for the first time how Breit and Wheeler's theory could be proven in practice. This 'photon-photon collider', which would convert light directly into matter using technology that is already available, would be a new type of high-energy physics experiment. This experiment would recreate a process that was important in the first 100 seconds of the universe and that is also seen in gamma ray bursts, which are the biggest explosions in the universe and one of physics' greatest unsolved mysteries.

The scientists had been investigating unrelated problems in fusion energy when they realised what they were working on could be applied to the Breit-Wheeler theory. The breakthrough was achieved in collaboration with a fellow theoretical physicist from the Max Planck Institute for Nuclear Physics, who happened to be visiting.

Read more at: http://phys.org/news/2014-05-scientists-year-quest.html#jCp

For the third time this month there is bad news about ice melt in Antarctica. This time with consequences we will experience very soon. First we had the news that a small plug of ice is holding back vast glaciers in East Antarctica's Wilkes Basin. If the plug goes melting in that region will become unstoppable, adding 3-4m to the sea level rise already factored in from other causes. A week later there was the news that some West Antarctic glaciers have already passed the point of no return, and will melt faster than previously thought. While the first study is apocalyptic in its implications, little of the damage is likely to be seen this century – the worst could be a thousand years away. The second will raise sea levels by less, but on a shorter timescale. It can, though, still be ignored by those who, in John Oliver's words “cannot be trusted with the future tense.” However, the Centre for Polar Observation and Modelling at Leeds University has found that ice loss is happening right now, and at twice the rate estimated using an incomplete version of the same technique. The European Space Agency's Cryosat spacecraft uses radar to measure the height and extent of the Antarctic and Greenland ice sheets. Geophysical Research Letters reports the Leeds team found 159 billion tonnes is disappearing each year, 134 billion from West Antarctica, 23 billion from the Antarctic Peninsular and 3 billion from East Antarctica. While East Antarctica contains the most ice, and therefore will be most influential in the very long run, for the moment it is West Antarctica, and particularly the glaciers flowing into the Amundsen Seat, that is causing the problems. Previous studies had only been able to map portions of the continent, forcing extrapolations to the whole. Cryosat can penetrate obscuring clouds, allowing the team 96% coverage, leaving out only a small ring around the South Pole. The uncertainty is ±81 billion tonnes. “We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of between 4 and 8 metres per year near to the grounding lines of the Pine Island, Thwaites and Smith Glaciers,” says first author Dr Malcolm McMillan.

For the third time this month there is bad news about ice melt in Antarctica. This time with consequences we will experience very soon.
 
First we had the news that a small plug of ice is holding back vast glaciers in East Antarctica's Wilkes Basin. If the plug goes melting in that region will become unstoppable, adding 3-4m to the sea level rise already factored in from other causes. A week later there was the news that some West Antarctic glaciers have already passed the point of no return, and will melt faster than previously thought.
 
While the first study is apocalyptic in its implications, little of the damage is likely to be seen this century – the worst could be a thousand years away. The second will raise sea levels by less, but on a shorter timescale. It can, though, still be ignored by those who, in John Oliver's words “cannot be trusted with the future tense.”
 
However, the Centre for Polar Observation and Modelling at Leeds University has found that ice loss is happening right now, and at twice the rate estimated using an incomplete version of the same technique.
 
The European Space Agency's Cryosat spacecraft uses radar to measure the height and extent of the Antarctic and Greenland ice sheets. Geophysical Research Letters reports the Leeds team found 159 billion tonnes is disappearing each year, 134 billion from West Antarctica, 23 billion from the Antarctic Peninsular and 3 billion from East Antarctica. While East Antarctica contains the most ice, and therefore will be most influential in the very long run, for the moment it is West Antarctica, and particularly the glaciers flowing into the Amundsen Seat, that is causing the problems.
 
Previous studies had only been able to map portions of the continent, forcing extrapolations to the whole. Cryosat can penetrate obscuring clouds, allowing the team 96% coverage, leaving out only a small ring around the South Pole. The uncertainty is ±81 billion tonnes.
 
“We find that ice losses continue to be most pronounced along the fast-flowing ice streams of the Amundsen Sea sector, with thinning rates of between 4 and 8 metres per year near to the grounding lines of the Pine Island, Thwaites and Smith Glaciers,” says first author Dr Malcolm McMillan.
 

amazing new battery cell

Power Japan Plus has announced an innovative new battery that charges up to twenty times faster and lasts longer than high-end lithium ion batteries. The company boasts that electric vehicles with the ability to drive 300 miles (480 km) on a single charge may soon be a reality. The Ryden dual carbon new battery is cheaper, safer, and 100% recyclable, making it an attractive option that could bring high-performance electric cars to market more quickly.

The battery was developed in partnership with Kyushu University in Japan. The beauty of the battery is in its simplicity. The anode and the cathode of the battery are both made out of carbon with an organic electrolyte solution that allows for ion current to flow separately. This also does not require the use of any rare Earth metals or other rare metals, significantly cutting down on the price of each unit.

Thermal stability means that this battery will not heat up while in use or during charging, and removes the threat of thermal explosion and making for a safer battery. This also means that expensive cooling systems do not need to be used, also driving down the price. The battery is stable enough to be discharged completely without harming the longevity of the product. Currently, the Ryden battery is rated for 3,000 charge/discharge cycles before the function of the battery begins to diminish. To put that into perspective, current electric cars advertise 300-500 charge cycles before the owner needs to think about replacing the battery.

Measles vaccine does NOT cure cancer

Media outlets, both traditional and social, are awash with the news that researchers in the US have apparently cured cancer with the measles virus – for example, the Washington Post, Daily Mail, Daily Mirror, Daily Telegraph and (with a much more measured headline) Reuters.

But while the story is dramatic – a 49-year old US woman’s myeloma blood cancer seems to have completely disappeared following treatment – the actual science is a lot more complex than simply injecting her with an armful of measles. A number of the stories implied that the woman had been treated with an extremely high dose of the regular measles vaccine, but we need to be absolutely clear here:

This treatment did not involve a standard measles vaccine or virus – the researchers used a genetically modified virus, and there’s no evidence that the regular measles or MMR jab can cure, prevent or cause any type of cancer.  

In fact, we’ve been here before – the approach is similar (although different in certain key respects) to the modified HIV-type virus used to successfully treat a young girl with leukaemia. Overblown headlines about her treatment also flew round the social media world before the scientific truth had got its boots on.

It’s also similar in that this is just one single success story from a very early stage trial, and a lot more work needs to be done to prove that it could be a safe and effective treatment for cancer.

What is this virus treatment?

The researchers at the Mayo Clinic in the US, led by Dr Stephen Russell, are using an approach called ‘oncolytic virus therapy’, which is generating a lot of excitement in the cancer research community around the world.  In fact, we’ve written about some of our work in this area a coupleof times already.

Briefly, it involves treating patients with viruses that have been genetically engineered to specifically infect cancer cells, rather than causing the particular illness that they usually bring. When injected into the body, the viruses seek out and destroy the tumour cells, multiplying inside them to create even more cancer-killing viruses. At least, that’s the theory.

To date, researchers have created oncolytic viruses from a number of different types of modified virus, including the herpes virus (which causes cold sores), poxvirus (chickenpox and related diseases) and adenovirus (common cold). But while tests in cancer cells grown in the lab and animals have been remarkably successful, this promise unfortunately hasn’t yet translated into success in clinical trials with actual cancer patients.

What did they do?

In this study, published in the Mayo Clinic Proceedings (the clinic’s own peer-reviewed journal), Dr Russell and his team were building on previous research they’d done using a genetically modified version of a ‘crippled’ (attenuated) measles virus, used in some vaccines, which could kill cancer cells.

The virus also contained an extra gene swiped from the human thyroid gland, containing the instructions to make a protein that shuttles iodine from the bloodstream into cells. This addition meant that the researchers could track exactly which cells in the body the virus had infected, by injecting small amounts of radioactive iodine into the blood and then monitoring using a CT scanner.

In this paper, the scientists describe the cases of two women, 49-year old Stacy Erholtz and another unnamed patient, who were part of a larger clinical trial started by the clinic a few years ago. Both had a type of blood cancer called myeloma that starts in the bone marrow – an ideal target for the measles virus, which particularly likes to infect bone marrow cells.

The women had received a range of treatments over nine and seven years, respectively, including a range of different chemotherapy drugs. Stacy had also had two bone marrow transplants. But while the treatments had held their cancers at bay for several years, they were now at the end of the road.

As part of an experimental, early-stage clinical trial, the researchers injected both patients with around 100 billion units of the measles virus – enough to vaccinate 10 million people if it had been a regular vaccine virus – over the course of an hour. Then they waited to see what would happen.

What were the results?

Almost straight away, the patients became feverish and unwell as their immune systems kicked into action against the massive virus load. They soon got better, and over the next few months the researchers watched as the levels of cancer cells in the patients’ bodies started to fall and their tumours shrank. For Stacy this was particularly noticeable as she had a large tumour on her forehead, which melted away as the virus got to work.

Although the initial responses were impressive, the two women had very different outcomes. Stacy’s cancer seemed to completely disappear for nine months, although her forehead tumour has apparently now come back and is being controlled with radiotherapy.

However, the other woman was less lucky and after just two months her cancer had come back worse than before. But on a more positive note, the researchers managed to use the iodine-shuttling protein to see where the virus infection had taken hold in her body. It revealed that the virus had indeed infected all her tumours, even though it hadn’t managed to eradicate them.

Why did it work?

As we mentioned, many cancer-killing viruses have not been as successful in human trials as they have been in the lab. One reason that the measles virus might have worked in Stacy’s case is that it was injected at such high doses.

The Mayo Clinic team have been testing their modified measles virus over several years, and initially started testing doses around 100,000 times lower than in these two patients. This suggests that there may be some kind of ‘critical level’ of virus in the body that has to be reached before it can take effect – knowledge that may be useful for other virus researchers around the world.

One other thing to note about the two patients in this trial – neither of them had antibodies against the measles virus in their blood that might have ‘mopped it up’ and made it less effective. This may have been because they had not been exposed to the virus or vaccinated against it, or their previous cancer treatment could have wiped them out.

Today, many people are vaccinated against measles as children, which involves injecting a very small amount of non-infectious measles virus, so are likely to have antibodies against it. So one of the next steps for the Mayo Clinic team is to work out how to get round this problem – perhaps by only giving the treatment to people who don’t have measles antibodies, by masking the virus in some way (like our own researchers’ approach with adenovirus), or by modifying the virus so it looks suitably different from the real thing that it can’t be recognised by measles antibodies.

However, it’s certainly not a good reason to suggest skipping the measles or MMR vaccine in childhood – measles is an unpleasant disease at best and fatal at worst, and is still one of the leading global causes of death among young children.

Where next?

Stacy’s story is certainly an impressive result from an exciting field of research, and we look forward to seeing more results from the Mayo Clinic team’s trial as they come through.

But these are just two patients, only one of whom is still alive, and one success story does not make a miracle cure. We need to see results from many more patients to know whether the virus is safe and effective at treating cancer and that Stacy’s incredible outcome wasn’t just a fluke.

It’s also important to note that the measles virus approach won’t work for all cancers. Myeloma was chosen for this trial as the measles virus specifically targets the bone marrow. It would need significant genetic modifications before it could be persuaded to attack other types of cancer cells, and other oncolytic viruses are being designed to target different types of cancer.

In this short video about the research, Dr Russell is hopeful about the prospects for his modified measles virus, saying “We believe it can become a single shot cure.”

But despite the bold words and headlines, which might make you think that a measles-based cancer cure is just around the corner, the best approach to this new study is cautious optimism. It’s incredible science – and a fantastic outcome for one woman and her family – but (as ever) more work still needs to be done.

This article originally appeared on the Cancer Research UK website and is reproduced here with permission.