Canadian prime minister Justin Trudeau's now-famous, possibly-not-so-impromptu, not-entirely-accurate explanation of quantum computing has unfortunately distracted attention from the real news behind the viral video: the announcement of $50 million in federal government funding for the Perimeter Institute, a research center affiliated with the University of Waterloo. Ignored amidst the Trudeaumania is the key question: will the money be well spent?
The Perimeter Institute is devoted to theoretical physics, an area whose enormous prestige, dating back to the days of Einstein and greatly enhanced by the terrifying grandeur of nuclear weapons, has gradually decayed over many decades. It hasn't had a true worldview-overturning breakthrough since the subatomic particle revolution of the 1960s, and has since spent several decades wrestling with a grand theoretical framework--string theory--which has yet to demonstrate any significant explanatory power. Once able to command cosmological-scale research budgets to build enormous experimental contraptions with which to smash particles together and announce suspiciously in-line-with-theory results, the field has found itself receiving less and less of the research funding pie, as more and more of it gets siphoned off by more fashionable fields with more recent tales of great impact.
Then, suddenly, along came quantum computing. In 1994, a computer scientist named Peter Shor discovered that a computer working according to the principles of quantum mechanics, rather than the classical physics that governs conventional computers, could--in theory, at least--break widely used cryptographic systems that are otherwise believed impervious to practical attacks. Now, this isn't a very practically useful result, unless you happen to be a spy agency interested in decrypting other people's secrets. The main consequence for most people is that they'll have to upgrade their software at some point in the future so that it uses cryptography that even a quantum computer can't break. (And as it happens, such cryptography doesn't appear to be all that hard to come up with.) Indeed, there's very little, beyond breaking the current generation of cryptography, that quantum computing appears to be particularly useful for. But it has two very important things going for it: the words "quantum" and "computing".
To the average person, the word "quantum" summons visions of impossibly complex, incomprehensible theories accessible only to the most brilliant scientific minds. (To quote Bernard Shaw, back in 1938, “You have nothing to do but mention the quantum theory, and people will take your voice for the voice of science, and believe anything.”) It's no coincidence that Trudeau, a politician with a reputation for thin intellect even by politician standards, chose to explain something with the word "quantum" in it--and that everyone was wowed by the spectacle.
As for "computing", no word screams "practical" (not to mention economically promising) quite as loudly. If you wanted to tie your abstruse, largely useless theoretical field of study to something eminently useful and profitable, you could do worse than try to figure out a way to connect it somehow with computing. And thanks to Peter Shor, quantum physicists have been able to do exactly that.
The result is a cash-strapped, out-of-fashion physics researcher's dream: a field tailor-made for a pretty-boy politician to make a grand show of handing a large wad of taxpayers' money to, while enhancing his gravitas and convincing an already-credulous press corps of his sound policy sense. I'm pretty sure that Shor had nothing like that in mind when he came up with his algorithm--but I also doubt that the delighted physicists at the Perimeter Institute waste too much time worrying about that, as they contemplate the many ways they might spend their unwisely-bestowed windfall.