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

Joshua M. Jones for Emojipedia
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The emojis proposed for release in 2016 are faintly disturbing

Birds of prey, dead flowers and vomit: Emojipedia's vision for 2016. 

Since, as we're constantly being told, emojis are now the fastest growing languge in the UK, it seems only appropriate that its vocabulary should expand to include more commonly used images or ideas as its popularity increases. 

Next year, the Unicode Consortium, which decides which new codes can be added to the emoji dictionary, will approve a new round of symbols. So far, 38 suggestions have been accepted as candidates for the final selection. Emojipedia, an online emoji resource, has taken it upon itself to mock up the new symbols based on the appearance of existing emojis (though emojis are designed slightly differently by different operating systems like Apple or Android). The full list will be decided by Unicode in mid-2016. 

As it stands, the new selection is a little... well, dark. 

First, there are the faces: a Pinocchio-nosed lying face, a dribbling face, a nauseous face, an upset-looking lady and a horrible swollen clown head: 

Then there's what I like to call the "melancholy nighttime collection", including a bat, owl, fox, blackened heart and dying rose: 

Here we have a few predators, thrown in for good measure, and a stop sign:

There are a few symbols of optimism amid the doom and gloom, including a pair of crossed fingers, clinking champagne glasses and smiling cowboy, plus a groom and prince to round out the bride and princess on current release. (You can see the full list of mock-ups here). But overall, the tone is remarkably sombre. 

Perhaps as emoji become ever more popular as a method of communication, we need to accept that they must represent the world in all its darkness and nuance. Not every experience deserves a smiley face, after all. 

All mock-ups: Emojpedia.

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.