Think that everything in a black hole gets swallowed up, never to be seen again? Well, you're half right

What happens to the information in a black hole once it disappears? Stephen Hawking thought he knew, betted on it, and lost.

Young people? Nothing but trouble. If you don’t believe the politicians, just look at physicists’ current anguish over the question of what is lost when stuff falls into a black hole. We are now in the middle of a huge crisis of confidence, just because the kids couldn’t keep their ideas to themselves.
 
If you think that stuff in a black hole just gets swallowed up, never to be seen again, you’re half right. The stuff is indeed gone. Yet the information about the stuff can’t be. In the 1970s, a young Stephen Hawking showed that, due to a quirk of quantum theory, black holes don’t just swallow; they also spit. A trail of particles is emitted from a black hole over its lifetime. As a result, the black hole eventually loses so much energy that it evaporates and disappears from the universe. According to Hawking’s theory, those particles contain no information of any kind, so the original information is lost once the black hole disappears.
 
However, a fundamental law of physics states that information can’t be destroyed. In 1997, John Preskill of the California Institute of Technology was so confident that Hawking must be wrong that the pair entered into a bet. That year, a young theorist called Juan Maldacena showed that, as stuff fell in, the information could be caught on the “event horizon”, the spherical surface of a black hole. With the information residing on the event horizon, it isn’t erased from the universe and might eventually leak back out.
 
Maldacena’s work was convincing enough for Hawking to concede. In 2004, he bought Preskill a baseball encyclopaedia (for reasons we won’t go into here) and the bet was considered settled.
 
Then, in 2010, along came the vibrant young mind of Mark Van Raamsdonk. His work has led to the new debate over the “cosmic firewall”. For information on the event horizon to leak back into the universe, there has to be a layer of ultra-high-energy particles – a firewall – just inside the event horizon. Each particle taking information from the event horizon has what Albert Einstein once termed a “spooky” link with a particle in the firewall. The link is called “entanglement” and it means that you can’t fully describe one of the particles unless you have information that resides in the other.
 
The problem is, the nature of Hawking’s original result shows that the particle on the outside of the event horizon also has to be entangled with another particle, one that carried away a little information from the black hole some time in the past. And a single particle can’t share that kind of entanglement with two others. So Maldacena’s idea doesn’t work. The best solution anyone can come up with involves another entanglement, this time between the particle inside the firewall and the particle that left the black hole all that time ago. That particular spooky link resolves the problem because those two entangled particles are actually one and the same.
 
It’s a classic Shakespearean twist. The whole problem has been a case of mistaken identity: the cosmic firewall story is the Twelfth Night of cosmology. However, most physicists don’t like this ending. Resolving all these entanglements stretches credulity too far, they say. The resolution they prefer is to acknowledge that this whole shebang exposes a gaping hole in our understanding of the universe. Maybe, they say, we need to start again.
 
While they scratch their heads and wonder what to do, Hawking could justifiably ask for his encyclopaedia back. If Preskill has any sense of how to play the foiled schemer, he’ll reluctantly hand it over while muttering something about those pesky kids. 
 
Michael Brooks’s “The Secret Anarchy of Science” is published by Profile Books (£7.99) 
In 1997 Hakwing made a bet with John Preskill of the California Institute of Technology - and lost. Photograph: Andrew Burman/Evevine/Contrasto.

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 September 2013 issue of the New Statesman, Syria: The west humiliated

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“A disaster waiting to happen”: Can you trust the government to digitise your personal data?

Privacy and security experts warn against the lesser-scrutinised Part 5 of the Digital Economy Bill, claiming bulk data sharing could be vulnerable to hacks.

Last week, the government’s Digital Economy Bill hit the news because of a proposed ban on pornographic websites that didn’t comply with its planned age verification rules. The news was just the right amount of shocking and yes, sexy, to grab the nation’s attention, but in the meantime other parts of the Bill remained unscrutinised. A distinctly un-sexy aspect of the Bill – Part 5, “Digital Government” – aims to completely revolutionise the way your personal data is shared.

In essence, Part 5 allows the government to digitise your data and bulk-share it without informing you or asking for your permission. This data includes your birth, death, and marriage certificates, as well as information on your taxes, court appearances, benefits, student loans, and even parking tickets. If the Bill passes, your information will be shared with local councils, charities, and even businesses – initially, gas and electricity companies.

Today, the Bill will undergo its third reading in the House of Commons. Last Friday, 26 privacy experts wrote to the Daily Telegraph to call for Part 5 to be removed from the Bill due to the lack of technical and legal safeguards in place.

“It's horrid and it's complex and it's going to impact all of us,” says Renate Samson, the chief executive of Big Brother Watch, an organisation that scrutinises the government to protect individual privacy. Big Brother Watch was invited by the government to work on the Bill as part of the government’s Open Policy Making, but Samson feels it was ignored when discussing the need for strong safeguards in the Bill. “Holding civil registration documents in bulk and sharing them in bulk is without a doubt a data disaster waiting to happen.”

Samson and her team worry that the Bill does not do enough to protect our personal data. “They tell a little story in one of their documents about mothers being able to click and access their baby’s birth certificate instead of having to go and get a copy, which sounds brilliant except they haven’t defined how they’ll know the mother is who she says she is, and how she will know who she can trust on the other end,” she says. “In a perfect, idyllic utopia, it works, but it doesn’t take hacking into consideration.”

According to the National Audit Office, in 2014-15, there were 9,000 data breaches across government departments. The subsequent inquiries revealed that many officials did not know how to report a breach and there was not enough guidance for the authorities involved. “The government is already failing to look after our data,” says Samson. “Fundamentally [Part 5] will lead to data breaches. People’s data will get lost and we won't ever know how or why.”

Though the government denies it, there are additional fears that this digitisation of data is the beginning of an ID database, a policy that was scrapped in 2011. At the time, then-Home Office minister Damian Green said that ending the proposed National Identity Register demonstrated “the government’s commitment to scale back the power of the state and restore civil liberties”.

Whether or not a register is created, however, Samson and other privacy experts, as well as the British Medical Association, take issue with the fundamental justifications for bulk data sharing. “The reason that they've given for wanting to do all this is ‘wellbeing’, which is crap, frankly,” she says. “In the summer, the Scottish Parliament dropped the Named Person Scheme because the supreme court found that ‘wellbeing’ is simply not a strong enough reason to share people’s personal information. Of course they’re trying to do something great but they’re going about it in a really cack-handed fashion.”

One example of this is that the government intends to share your personal information with the Troubled Families programme to identify people who may be at risk. Although this is ostensibly positive, this information will also be used to determine anti-social behaviour. “On the one hand, they’re saying that they’ll make sure that families who need help will get it, but on the other, if it transpires that you’re noisy or you’re difficult on your estate, they will now share that data so you can have an Asbo.”

Fundamentally, then, although the aims of the Bill seem admirable, there are simply not enough safeguards and rules in place currently for it to safely become law. While this partially might be a simple error on the government’s part, Samson argues that the language of the Bill is “as open and broad and woolly as you can possibly imagine”, causing concern about how it might actually be used in practice. In theory, hundreds or thousands of businesses and authorities could have access to your data without your consent.

“No one is opposing the idea of data sharing,” says Samson, “But a) tell us why, b) keep us informed if you’re using our data, and c) let us control our data. That’s the only way this is all going to move forward.”

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