A photograph of the Large Hadron Collider in the Science Museum. Photo: Getty
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Entangled in photons: the spooky behaviour of light particles

If you’re after science that makes you question your place in the universe, focus on that phrase “light years”, one that astronomers use so casually.

We are constantly making discoveries that reveal new wonders of the universe. Research presented in June, for instance, shows that some of its most spectacular features, such as the vast towers of gas and dust known as “the Pillars of Creation”, are a result of the way massive stars emit radiation that sculpts nearby gas clouds.

Those pillars are roughly four light years high and 7,000 light years away – which is close, compared to another discovery made recently. Scientists have found three black holes orbiting each other just over four billion light years away.

It’s an extraordinary thing to see things that distant, but in many ways this is just cosmic stamp collecting. These discoveries are informative – breathtaking, even – but they don’t cause you to question your place in the universe.

If that’s what you’re after, focus on that phrase “light years”, one that astronomers use so casually. Herein lies a truly discomfiting mystery.

Light years are a measure of the distance a photon – a packet of light energy – travels in a year. It’s a useful measure because light is the fastest thing in the universe. Yet we are still getting to grips with the properties of photons and it seems that they don’t experience distance in the same way as we do.

Fifty years ago, a Cern physicist called John Bell outlined the weirdness of photons. In a 1964 paper that built on some of Einstein’s work, Bell showed that they defy all ordinary notions of time and space. The phenomenon Bell explored is popularly known as “quantum entanglement”. It involves what Einstein once termed “spooky action at a distance” occurring between two particles. The spookiness begins when we make two photons interact in a way that leaves them entangled – the information about one is partly held in the other. The particles are “complete” only as a pair. Then we keep one on earth while sending the other to, say, the Pillars of Creation. It turns out that we can instantaneously influence the distant photon’s measured properties, such as its direction of spin.

That influence occurs because the spins of an entangled pair of photons are random but linked. You can think of it rather like knocking over two coins that are spinning on their edges. If we poke the one on earth, it might come up heads (entirely at random). If it does, we find, weirdly, that an immediate knock to the other one out there at the Pillars of Creation will give us a tail.

This cosmic connection can’t involve any signals passing between them: it would have to be quicker than light. The only explanation is that photons inhabit a reality beyond the space and time in which we live out our existence.

Entanglement’s delicate nature makes it a kind of tamper-proof seal. In the emerging science of quantum cryptography, entangled photons provide security guaranteed by the laws of physics. Financial institutions already use such measures and we are about to extend the network into space. A team of Italian researchers announced last month that they had bounced photons between satellites and earth without disturbing their quantum properties, laying the groundwork for “quantum communications on a planetary scale”. Here’s the wondrous fact: we are engineering a cosmic network that we may never fully understand. 

Michael Brooks’s “At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise” is published by Profile (£12.99)

Michael Brooks holds a PhD in quantum physics. He writes a weekly science column for the New Statesman, and his most recent book is At the Edge of Uncertainty: 11 Discoveries Taking Science by Surprise.

This article first appeared in the 02 July 2014 issue of the New Statesman, After God Again

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A quote-by-quote analysis of how little Jeremy Hunt understands technology

Can social media giants really implement the health secretary’s sexting suggestions? 

In today’s “Did we do something wrong? No, it was social media” news, Health Secretary Jeremy Hunt has argued that technology companies need to do more to prevent sexting and cyber-bullying.

Hunt, whose job it is to help reduce the teenage suicide rate, argued that the onus for reducing the teenage suicide rate should fall on social media companies such as Facebook and Twitter.

Giving evidence to the Commons Health Committee on suicide prevention, Hunt said: “I think social media companies need to step up to the plate and show us how they can be the solution to the issue of mental ill health amongst teenagers, and not the cause of the problem.”

Pause for screaming and/or tearing out of hair.

Don’t worry though; Hunt wasn’t simply trying to pass the buck, despite the committee suggesting he direct more resources to suicide prevention, as he offered extremely well-thought out technological solutions that are in no way inferior to providing better sex education for children. Here’s a quote-by-quote analysis of just how technologically savvy Hunt is.

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“I just ask myself the simple question as to why it is that you can’t prevent the texting of sexually explicit images by people under the age of 18…”

Here’s Hunt asking himself a question that he should be asking the actual experts, which is in no way a waste of anybody’s time at all.

“… If that’s a lock that parents choose to put on a mobile phone contract…”

A lock! But of course. But what should we lock, Jeremy? Should teenager’s phones come with a ban on all social media apps, and for good measure, a block on the use of the camera app itself? It’s hard to see how this would lead to the use of dubious applications that have significantly less security than giants such as Facebook and Snapchat. Well done.

“Because there is technology that can identify sexually explicit pictures and prevent it being transmitted.”

Erm, is there? Image recognition technology does exist, but it’s incredibly complex and expensive, and companies often rely on other information (such as URLs, tags, and hashes) to filter out and identify explicit images. In addition, social media sites like Facebook rely on their users to click the button that identifies an image as an abuse of their guidelines, and then have a human team that look through reported images. The technology is simply unable to identify individual and unique images that teenagers take of their own bodies, and the idea of a human team tackling the job is preposterous. 

But suppose the technology did exist that could flawlessly scan a picture for fleshy bits and bobs? As a tool to prevent sexting, this still is extremely flawed. What if two teens were trying to message one another Titian’s Venus for art or history class? In September, Facebook itself was forced to U-turn after removing the historical “napalm girl” photo from the site.

As for the second part of Jezza’s suggestion, if you can’t identify it, you can’t block it. Facebook Messenger already blocks you from sending pornographic links, but this again relies on analysis of the URLs rather than the content within them. Other messaging services, such as Whatsapp, offer end-to-end encryption (EE2E), meaning – most likely to Hunt’s chagrin – the messages sent on them are not stored nor easily accessed by the government.

“I ask myself why we can’t identify cyberbullying when it happens on social media platforms by word pattern recognition, and then prevent it happening.”

Jeremy, Jeremy, Jeremy, Jeremy, can’t you spot your problem yet? You’ve got to stop asking yourself!

There is simply no algorithm yet intelligent enough to identify bullying language. Why? Because we call our best mate “dickhead” and our worst enemy “pal”. Human language and meaning is infinitely complex, and scanning for certain words would almost definitely lead to false positives. As Labour MP Thangam Debbonaire famously learned this year, even humans can’t always identify whether language is offensive, so what chance does an algorithm stand?

(Side note: It is also amusing to imagine that Hunt could even begin to keep up with teenage slang in this scenario.)

Many also argue that because social media sites can remove copyrighted files efficiently, they should get better at removing abusive language. This is a flawed argument because it is easy to search for a specific file (copyright holders will often send social media giants hashed files which they can then search for on their databases) whereas (for the reasons outlined above) it is exceptionally difficult for algorithms to accurately identify the true meaning of language.

“I think there are a lot of things where social media companies could put options in their software that could reduce the risks associated with social media, and I do think that is something which they should actively pursue in a way that hasn’t happened to date.”

Leaving aside the fact that social media companies constantly come up with solutions for these problems, Hunt has left us with the burning question of whether any of this is even desirable at all.

Why should he prevent under-18s from sexting when the age of consent in the UK is 16? Where has this sudden moral panic about pornography come from? Are the government laying the ground for mass censorship? If two consenting teenagers want to send each other these aubergine emoji a couple of times a week, why should we stop them? Is it not up to parents, rather than the government, to survey and supervise their children’s online activities? Would education, with all of this in mind, not be the better option? Won't somebody please think of the children? 

“There is a lot of evidence that the technology industry, if they put their mind to it, can do really smart things.

Alas, if only we could say the same for you Mr Hunt.

Amelia Tait is a technology and digital culture writer at the New Statesman.