Innovation and Technology Weekly – No. 28, 2017

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Issue 28, 2017

This week's headlines:

'Twisted light' could create ultra-fast wireless
October 31, 2017

A new method of using photons to carry information might provide a new wireless solution for communication. A collaborative team from the UK, Germany, New Zealand, and Canada have developed a way to 'twist' photons to improve on open-area quantum information transfer.

Photons already have seen use in a number of tests to determine the precision of quantum networks over long distances. While the advent of quantum communication might just well be on the horizon, the team has figured out a way to use photons to carry information and data wirelessly, potentially replacing today's fibre optics and creating a much faster internet.

The researchers call their new technique 'optical angular momentum' (OAM) which works by 'twisting' light across open spaces. Concretely, they twisted photons by passing them through a special kind of hologram to give the photons this OAM. Capable of travelling across open spaces, these twisted photons can carry more data in each transmission, while also becoming strong enough to withstand interference caused by turbulent air.

The hologram enables the photons to carry more than just the usual binary bits of 0s and 1s used in today's digital communications - the same way a quantum network relies on quantum bits (qubits) to relay information.

The method was shown to be effective across a 1.6 km free space link the research team built in Erlangen, Germany, an area that simulated an urban environment with all the potential sources for signal disruption.

Full story: Science Alert / Science Advances Back to top

Cosmic rays point to mysterious void in Great Pyramid of Giza
November 02, 2017

Scientists using an imaging method based on cosmic rays have detected a large and enigmatic internal structure in the last of the Seven Wonders of the Ancient World still standing, the massive Great Pyramid of Giza. The Great Pyramid, or Khufu's Pyramid, was built during the reign of Pharaoh Khufu (Cheops), who reigned from 2509 to 2483 BC.

The newly discovered void is located above a huge, known hall called the Grand Gallery. To peer inside the pyramid, the scientists used an imaging technique called muon tomography that tracks particles that bombard Earth at close to the speed of light and penetrate deeply into solid objects.

They said the newly discovered internal structure was at least 30 metres long, and located above a hallway called the Grand Gallery, one of a series of passageways and chambers inside the immense pyramid.

The findings come from a project called Scan Pyramids that relies on non-invasive scanning methods to probe the internal structure of the pyramids of ancient Egypt's glorious Old Kingdom period and understand how they were built.

Muon particles originate from interactions between cosmic rays from space and atoms of Earth's upper atmosphere. The particles can penetrate hundreds of metres into stone before being absorbed. Placing detectors inside a pyramid can discern cavities within a solid structure.

Full story: CBC / Reuters Back to top

Artificial intelligence smart enough to fool Captcha security check
October 27, 2017

Computer scientists have developed artificial intelligence that can outsmart the Captcha website security check system. Captcha challenges people to prove they are human by recognising combinations of letters and numbers that machines would struggle to complete correctly.

Researchers developed an algorithm that imitates how the human brain responds to these visual clues. The neural network could identify letters and numbers from their shapes.

The research as conducted by Vicarious - a Californian AI firm funded by Amazon founder Jeff Bezos and Facebook's Mark Zuckerberg.

The Captcha test was developed in the late 1990s to prevent people from using automated bots to set up fake accounts on websites. Computers usually struggle to pass such tests, and Google says that its reCaptcha test is so complicated that even humans can only solve it 87% of the time. However, researchers from Vicarious claim that their algorithm can pick out distorted letters and digits from images.

The team developed Recursive Cortical Network (RCN), a software which mimics actual processes in the human brain while requiring less computing power than a neural network. The RCN software was also able to solve reCaptcha tests from Captcha generator BotDetect at a 64.4% success rate, Yahoo Captchas at a 57.4% success rate and PayPal at a 57.1% success rate.

Full story: BBC News / Science Back to top

Cake-cutting game theory trick could stop gerrymandering
November 01, 2017

The method to fairly split a cake between two people is tried, tested, and mathematically proven. One person gets to cut the cake and the other gets to choose which slice they get. To get the biggest piece of cake, the cutter must split it fairly resulting in no hard feeling between the two eaters.

In American politics, however, cutting states into electoral districts doesn't have a similarly fair method. The political party in charge often decides where the electoral lines are drawn and does so in such a way to gain an advantage - a process called gerrymandering. But now researchers from Carnegie Mellon University have come up with a way to extend the cake cutting technique to electoral redistricting to make the system a lot fairer.

With the new approach, one political party gets to draw an electoral map that divides the state into the agreed number of districts. The second political party then chooses one district to freeze so that no more changes can be made to it by either side. They then get to redraw the rest of the map.

Once the new map is complete, the first political party freezes one of the new districts so that no further changes can be made to it, and is allowed to redraw the rest of the map again. This process goes back and forth until every district within the state is frozen. In Pennsylvania, for example, this would require 17 cycles as there are 18 districts.

Full story: New Scientist / arXiv Back to top

Earth's molten core could give earthquake warnings 5 years ahead
November 01, 2017

Changes in the flow of iron around Earth's outer core are thought to contribute to very small fluctuations in the length of our days. Now researchers say the sloshing of our planet's core could also be used for potential earthquake warnings, possibly even years ahead.

You've probably never noticed variations in the length of a day, as they're measured in milliseconds, but they represent very slight slowdowns in the speed that the world is spinning at. Geophysicists from the Universities of Colorado and Montana have found a correlation between day length variations over the last 100 years and major magnitude 7 earthquakes. They think the same root cause could be behind both - that molten iron sloshing around in Earth's core.

If the hypothesis holds up, it could provide a new earthquake predictor that could give as much as five years of advance warning about the risk of increased tremors.

No one's quite sure how this sloshing action works, though it also affects slight changes in Earth's magnetic field as well as day length, so we know it's happening. One idea is that part of the molten outer core sticks to the mantle above, changing the flow of liquid, and checking Earth's momentum.

The researchers found clusters of serious earthquakes happening at roughly 32-year intervals. They've matched those clusters with peaks in the fluctuation in day lengths - and so maybe also with activity deep within Earth. With Earth spinning at some 465 metres per second, the researchers say some kind of sloshing action could plausibly trigger a season of earthquake activity.

Full story: Science Alert Back to top

Secure your secret messages with printable invisible ink
October 31, 2017

A new invisible ink that you can print is harder to reveal than most common cyphers.

Researchers from Shanghai Jiao Tong University in China created this new ink accidentally while trying to synthesise a kind of glowing nanomaterial. In the process, they created a lead compound that was invisible to the human eye. When a mixture of a particular kind of salts was applied, the text became visible again. Without these salts, no one would suspect anything was on the page.

It's so much better than just using lemon juice. Most of the invisible inks we use now leave a residue behind as they become legible. This means that decrypting the message can be as easy as holding it up to a light. This compound can also be printed with a modified office printer, making it easy to fabricate a covert letter.

While it may seem antiquated or like a useless party trick, invisible ink can actually be used in anti-counterfeiting measures. US currency uses a variation on invisible ink to hide text or pictures on large denominations of money so that they're only visible in certain light.

This invisible ink can be used to record and protect confidential information by printing process. It could also be useful in devices that combine light with electronics. For instance, using these types of compounds in a television or tablet screen could lead to richer colours - the team's original motivation for studying them.

However, there are downsides. Lead is toxic, so the sender or recipient could end up harmed by the message. The team is exploring the possibility of swapping out the lead for tin, which is vastly less toxic.

Full story: New Scientist Back to top