7 of Stephen Hawking's Most Provocative Moments
After being struck down with ALS in his early 20s, he would defy all projections about his potential lifespan. Before his death in March of last year, Hawking would lead a full and incredibly influential life - much to humanity's benefit.
His thoughts and inspirations on the wider Universe would inspire and provoke people in equal measures. Here are but 7 of them.
1. He showed that black holes aren't so black after all
One of Stephen Hawking's most provocative moments was when he, in the 1970s, proposed that black holes aren't that black. As it turns out, according to his theory, some light can actually escape them from their event horizons.
This announcement literally turned the physics world upside down and change the way we look at how black holes work forever.
Far from being all consuming marauding cosmic dustbins, black holes might actually lose energy over time.
This radiation comes from "virtual particles," which are constantly popping into and out of existence as predicted by quantum physics. They do so in matter-antimatter pairs, one of which has positive energy and the other negative energy.
One of the pairs, could, according to Hawking, escape the event horizon and whiz off into space. It's partner particle's fate, on the other hand, was sealed as it fell into the maw of the black hole.
Hawking completed his work in 1974, and his hypothesized black-hole light is known today as Hawking radiation, or Hawking-Bekenstein radiation. Nobody has spotted such emissions yet, but most physicists believe the emissions exist.
2. Stephen Hawking's actually lost a bet on a black hole
Stephen Hawking was no stranger to making bets throughout his life. In fact, most of these he lost, much to his amusement.
His most famous bet loss was one made Kip Thorne, a theoretical physicist at Caltech. In December of 1974, Hawking bet Kip that Cygnus X-1 (a massive x-ray source in our galaxy) was not, in fact, a black hole.
Whilst he was pretty sure it was, he decided to bet against the fact just in case.
“This was a form of insurance policy for me. I have done a lot of work on black holes, and it would all be wasted if it turned out that black holes do not exist,” wrote Hawking on the subject in his 1988 book A Brief History of Time.
“But in that case, I would have the consolation of winning my bet, which would win me four years of the magazine Private Eye.”
Today it is widely accepted by physicists that Cygnus X-1 is actually a black hole. Gravitational waves were also discovered emanating from it in 2016 - this pretty much sealed the deal.
3. Hawking also lost a bet on the Higgs Boson
Professor Stephen Hawking, not content with betting against his own ideas, also lost a £100 bet to Gordon Kane at Michigan University in 2012.
“I had a bet with Gordon Kane of Michigan University that the Higgs particle wouldn’t be found. It seems I have just lost $100.” Hawking's, whilst not questioning the groundbreaking work of Peter Higgs, was pretty sure it would never actually be discovered.
Far from being bitter over the subject, he suggested that Peter Higgs should be given a Nobel Prize for his work on the mysterious particle.
But Higgs was no stranger to skepticism from his peers. When he first proposed the idea in the 1960s he struggled to even get his work published by a journal.
4. Hawking also lost another big bet on black holes
In 1997, Hawking made a bet with John Preskill of Caltech, that information was lost at a black hole. Preskill argued to the contrary and believed that information could actually be preserved at a black hole.
The loser of the bet had to buy the winner an encyclopedia of their choice "from which information can be recovered with ease."
The main premise behind the bet is that, in the 1970s, Hawking showed that Black Holes appear to have a temperature. If this is the case, then it follows that the give off thermal radiation.
This would surely mean that Black Holes could eventually disappear over time - albeit very long timescales (depending on its size of course). If true, the information would be lost from the Universe as the hole vanishes (or evaporates). Thermal energy does not, after all, contain any "information".
But this appeared to be in conflict with what is allowed by quantum theory.
In 2004, Hawking finally conceded that he was actually wrong about this. His continued work on the subject revealed that information can, in fact, escape the hole and was therefore preserved.
“The way the information gets out [of a black hole] seems to be that a true event horizon never forms,” Hawking revealed at the 17th International Conference on General Relativity and Gravitation in Dublin, “just an apparent horizon.”
“The information remains firmly in our universe,” he said.
“I am sorry to disappoint science fiction fans, but if the information is preserved, there is no possibility of using black holes to travel to other universes. If you jump into a black hole, your mass energy will be returned to our universe, but in a mangled form which contains the information about what you were like, but in an unrecognizable state.”
5. Hawking's made stark warnings about AI
In his posthumously published book Brief Answers To The Big Questions, Hawking offered his hopes and fears for the future of AI. Like many other big thinkers in the world, he believed it should come as no surprise to man when AI inevitably outsmarts us all.
He, like others, believed that the rise of the AI could be either a blessing and a curse to its creators. Stephen hoped for the former but warned that we need to think carefully about how we develop and use it.
"Whereas the short-term impact of AI depends on who controls it, the long-term impact depends on whether it can be controlled at all,” Hawking warned.
It is very likely AI will develop quickly to such an extent to dwarf the intelligence of man.
Most people's concern is that it will become malevolent rather than benevolent. But Hawking isn't so sure, so long as we don't interfere too much.
“[The] real risk with AI isn’t malice, but competence.” He said. AI, in Hawking's view, will be very good at accomplishing its goals; if humans get in the way, we could be in trouble.
“You’re probably not an evil ant-hater who steps on ants out of malice, but if you’re in charge of a hydroelectric green-energy project and there’s an anthill in the region to be flooded, too bad for the ants. Let’s not place humanity in the position of those ants,” he wrote.
6. Hawking might have debunked the notion of God in his final book
It is no secret that Hawking was a strict Atheist. But many were confused by an apparent contradiction when he once stated that one day we would "know the mind of God".
Rather than taking this literally, like so many things in life, Hawking meant that as science provides us with more and more answers, the notion of God was fast becoming redundant.
"What I meant by 'we would know the mind of God' is, we would know everything that God would know if there were a God, which there isn't. I'm an atheist."
As a natural extension of this position, he also believed there is no afterlife or heaven for that matter.
"I believe the simplest explanation is, there is no God. No-one created the universe, and no one directs our fate. This leads me to a profound realization that there probably is no heaven and no afterlife either."
In his final book, Hawking would also go as far as to attempt to debunk the entire notion of God.
7. We are not alone in the Universe, let's hope they don't visit
"The idea that we are alone in the universe seems to be completely implausible and arrogant," he said. "Considering the number of planets and stars that we know exist, it's extremely unlikely that we are the only form of evolved life.
But he warned that they might not be very welcoming if we were to ever meet.
"If aliens ever visit us, I think the outcome would be much as when Christopher Columbus first landed in America, which didn't turn out very well for the Native Americans."