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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"Death to all Jews": Why Disney dropped YouTube's biggest star PewDiePie

The Minecraft vlogger turned internet celebrity's taste for shock comedy was too much for the family-focused corporation. 

Disney has cut ties with YouTube’s most-subscribed star after he paid two Sri Lankan men five dollars to hold up a sign that read “DEATH TO ALL JEWS”.

Feel free to read that sentence again, it’s not going anywhere.

A still from PewDiePie's video, via YouTube

PewDiePie, real name Felix Kjellberg, has over 53 million subscribers on YouTube, where his videos about gaming earned him over $15m last year. The 27-year-old, whose content is popular with children, came under fire this month after the Wall Street Journal investigated anti-Semitic comments in his videos. In one video, a man dressed as Jesus says “Hitler did absolutely nothing wrong”, while in another Kjellberg used freelance marketplace Fiverr to pay two men to hold up the offensive sign. The videos have since been deleted.

Jumpcut.

The Walt Disney Company became affiliated with PewDiePie after they bought Maker Studios, a network of YouTube stars, for nearly $1bn in 2014. Following the WSJ’s investigation, Maker dropped the star, stating: “Although Felix has created a following by being provocative and irreverent, he clearly went too far in this case and the resulting videos are inappropriate. Maker Studios has made the decision to end our affiliation with him going forward.”

When you sack a YouTube Star, makes no difference who they are.

Via Wall Street Journal

But why should the story stop there? Neo-nazi website The Daily Stormer are now defending PewDiePie, while the notoriously politically-incorrect 4Chan forum /pol/ have called him “our guy”.  

In his defence, Kjellberg wrote a blog post denying an affiliation with anti-Semitic groups and explained his actions, writing: “I was trying to show how crazy the modern world is, specifically some of the services available online.” In a video last December the star also said: "It's extremely annoying how I can't make jokes on my channel without anyone quoting it as actual facts, like something I actually said", before dressing as a soldier and listening to one of Hitler's speeches while smiling. 

Pause.

(If all of this sounds familiar, recall when disgraced YouTuber Sam Pepper claimed a video in which he groped unsuspecting females was a “social experiment”).

Play.

And yet the story still isn’t over. Disney have learned a hard lesson about assuming that YouTubers are the squeaky clean fairy-tale princes and princesses they often appear to be. Shay Butler, one of the original founders of Maker Studios, yesterday quit the internet after it was alleged he sent sexual messages to a cam girl via Twitter.

Butler is one of the original "family vloggers", and has spent nine years uploading daily videos of his five children to YouTube. A practicing Mormon, Butler has become emblematic of family values on the site. “My heart is sick,” he wrote on Twitter, neither confirming nor denying the allegations of his infidelity, “I have struggled with alcoholism for years… My purpose is to rehab.” 

The result is a very dark day for YouTube, which has now dropped Kjellberg from its premier advertising network, Google Preferred, and cancelled the second series of the star's reality show, Scare PewDiePie

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