# Please explain Justin Trudeau and Quantum Computing to me

April 15, 2016 5:59 PM Subscribe

I somewhat understand Trudeau and I somewhat understand quantum computing but I don't understand either well enough to parse this video. And so I turn to you Metafilter. Please make sense of this of this for me or explain why it is just not so?

I didn't think this was a particularly good answer to the question asked, or a good explanation of quantum computing, but I'm by no means expert enough to judge on either. Mefites with relevant knowledge please enlighten me.

I didn't think this was a particularly good answer to the question asked, or a good explanation of quantum computing, but I'm by no means expert enough to judge on either. Mefites with relevant knowledge please enlighten me.

He's making a joke in response to the reporter's joke, "I was going to ask you to explain quantum computing, but..." by actually explaining (vaguely) quantum computing. Presumably (since he's there to announce funding for a physics think tank) someone on the stage had recently mentioned the subject.

posted by bethnull at 6:25 PM on April 15, 2016 [1 favorite]

posted by bethnull at 6:25 PM on April 15, 2016 [1 favorite]

I agree entirely with Chaussette, but I think there's another point Mr. Trudeau was making. Given the two issues, Canada's involvement in the war on ISIL and quantum computing, quantum computing is easier to understand.

My older son was 22 during the last federal election and he said that Mr. Trudeau was the only one of the three major party leaders (the others being Stephen Harper and Thomas Mulcair) who could connect with my son's generation. I think Mr. Trudeau's performance on this question gives some insight into that connection. I certainly can't imagine either Mr. Harper or Mr. Mulcair giving a sensible answer with as much aplomb.

posted by angiep at 6:28 PM on April 15, 2016 [6 favorites]

My older son was 22 during the last federal election and he said that Mr. Trudeau was the only one of the three major party leaders (the others being Stephen Harper and Thomas Mulcair) who could connect with my son's generation. I think Mr. Trudeau's performance on this question gives some insight into that connection. I certainly can't imagine either Mr. Harper or Mr. Mulcair giving a sensible answer with as much aplomb.

posted by angiep at 6:28 PM on April 15, 2016 [6 favorites]

Thank you for those answers. They have certainly explained to me why

posted by roolya_boolya at 7:19 PM on April 15, 2016 [3 favorites]

*politically*it was a good answer. I am still curious as to whether it was a scientifically accurate answer. And, if it was, a detailed explanation of*why*it was would be very much welcome.posted by roolya_boolya at 7:19 PM on April 15, 2016 [3 favorites]

It was not an in-depth answer, but everything he said was accurate and -- taken together -- constituted a succinct and simple explanation of quantum computing, yes.

posted by trip and a half at 7:29 PM on April 15, 2016 [8 favorites]

posted by trip and a half at 7:29 PM on April 15, 2016 [8 favorites]

Computer scientist here: trip and a half is right; it was a very shallow answer (as is appropriate for a crowd of primarily non-engineers) but a totally accurate one.

posted by Itaxpica at 7:41 PM on April 15, 2016 [5 favorites]

posted by Itaxpica at 7:41 PM on April 15, 2016 [5 favorites]

Ok, so not to threadsit and to be totally clear this isn't a politically motivated question - I'm a European and, as philistine as it sounds, Trudeau and his political career are a tiny blip on my radar. What I'm really asking for here is a more thorough explanation of what he described. If it helps for pitching the depth of an answer, I've studied pure maths and (elements of) computer science at university but have only been exposed to quantum physics/computing through popular accounts.

posted by roolya_boolya at 7:49 PM on April 15, 2016 [1 favorite]

posted by roolya_boolya at 7:49 PM on April 15, 2016 [1 favorite]

complete novice here but my understanding of quantum-ness is it is the "everything", and thusly information could be put into the everything making it possible to have ie smaller computers because all that is available- theeverythingness - is used to hold the information needed to run the computer, now bring on the experts and omg i love our mr t!

posted by RelaxingOne at 8:09 PM on April 15, 2016 [2 favorites]

posted by RelaxingOne at 8:09 PM on April 15, 2016 [2 favorites]

There are a ton of YouTube videos that attempt to explain how quantum computers would actually work. This one is almost grokable to me as a person with very little pure math background but significant understanding of classical computing.

posted by jacquilynne at 8:24 PM on April 15, 2016 [1 favorite]

posted by jacquilynne at 8:24 PM on April 15, 2016 [1 favorite]

There is a pretty good explanation of quantum computing in the most recent Economist Technology Quarterly.

Trudeau is really saying several things at the same time. I get:

- Your question is snarky, so I'm giving you a snarky answer in response.

- I'm not just a pretty face; I do know what quantum computing is.

- Quantum computing is much more complicated than traditional computing. I identify with the scientists and researchers in this room who want to pursue quantum computing because it's so exciting.

It's not clear whether Trudeau addresses the reporter's question about ISIL after the point where the clip ends.

posted by Multicellular Exothermic at 9:29 PM on April 15, 2016 [4 favorites]

Trudeau is really saying several things at the same time. I get:

- Your question is snarky, so I'm giving you a snarky answer in response.

- I'm not just a pretty face; I do know what quantum computing is.

- Quantum computing is much more complicated than traditional computing. I identify with the scientists and researchers in this room who want to pursue quantum computing because it's so exciting.

It's not clear whether Trudeau addresses the reporter's question about ISIL after the point where the clip ends.

posted by Multicellular Exothermic at 9:29 PM on April 15, 2016 [4 favorites]

The other political thing J-deau is saying here is "We do science again."

The previous Canadian government was notorious for being anti-science -- they shut down government research projects and destroyed existing documents, they cancelled the long form census, they ordered government scientists to never speak to the press directly about anything. Having the new PM offer an off-the-cuff explanation of a cutting edge area of scientific research and do it with humour and excitement about the topic is in keeping with that philosophical shift.

posted by jacquilynne at 9:49 PM on April 15, 2016 [22 favorites]

The previous Canadian government was notorious for being anti-science -- they shut down government research projects and destroyed existing documents, they cancelled the long form census, they ordered government scientists to never speak to the press directly about anything. Having the new PM offer an off-the-cuff explanation of a cutting edge area of scientific research and do it with humour and excitement about the topic is in keeping with that philosophical shift.

posted by jacquilynne at 9:49 PM on April 15, 2016 [22 favorites]

I only have the most basic understanding of quantum computing, but I'll try to elaborate on Trudeau's answer and why it was generally accurate.

Normal or classical computation, which is what our current processors do, relies on bits. Each bit can be on (1) or off (0). If it takes 32 bits to store one number, it takes 32n bits to store

Quantum bits (qubits) also have 1 and 0 states. However, each qubit also has another state called superposition. So, a single qubit can represent a 1, 0, or a superposition of those states that is usually described as being in both states at once. Two qubits can be in any one of 4 states, three qubits can be in any one of 8 states, and so on. If each qubit is in superposition (a state called coherence in quantum computing), you can perform a calculation of all possible inputs simultaneously, in parallel. Qubits can also exist in "entangled" states, which means that two qubits will be doing the exact same thing at the exact same time no matter how physically distant they are from one another. Einstein called this "spooky action at a distance." Which is like my favorite name for a thing ever. In order to do calculations, you perform a certain type of transformation on the qubit states. (This is where you get into Hilbert curves, inner product conservation, and other mathematical insanity that I can't even begin to understand.) Quantum calculations are probabilistic, meaning that the results can vary and be assigned a confidence value. The reason quantum calculations are probabilistic has to do with the Heisenberg uncertainty principle--we can either know the exact momentum of a particle OR the exact position, but not both at the same time. So to assign confidence, you would want to run the same calculation a number of times in succession.

In, uh, "practical" terms, quantum computers are only extra useful for applications where parallelism would increase the speed of calculation. Great for AI, complex modelling, virtual physics experiments, encryption/prime numbers, that sort of thing.

(Interestingly, we don't necessarily have to throw out all of our silicon and transistor smarts to get going on making affordable qubits. Recently some Australian researchers used a silicon wafer and phosphorus atoms to make a CNOT quantum logic gate, which requires 2 qubits. I mean, the operating environment has to be at 1 Kelvin, which is pretty chilly. But they claimed to maintain coherence for 30 seconds, which is an eternity for quantum computing purposes.)

posted by xyzzy at 10:54 PM on April 15, 2016 [14 favorites]

Normal or classical computation, which is what our current processors do, relies on bits. Each bit can be on (1) or off (0). If it takes 32 bits to store one number, it takes 32n bits to store

*n*numbers. In order to perform calculations, you instruct the processor to do pretty much the same thing you would do on a piece of paper. The answers are predictably deterministic, meaning that you will always get x result for y input and that's it.Quantum bits (qubits) also have 1 and 0 states. However, each qubit also has another state called superposition. So, a single qubit can represent a 1, 0, or a superposition of those states that is usually described as being in both states at once. Two qubits can be in any one of 4 states, three qubits can be in any one of 8 states, and so on. If each qubit is in superposition (a state called coherence in quantum computing), you can perform a calculation of all possible inputs simultaneously, in parallel. Qubits can also exist in "entangled" states, which means that two qubits will be doing the exact same thing at the exact same time no matter how physically distant they are from one another. Einstein called this "spooky action at a distance." Which is like my favorite name for a thing ever. In order to do calculations, you perform a certain type of transformation on the qubit states. (This is where you get into Hilbert curves, inner product conservation, and other mathematical insanity that I can't even begin to understand.) Quantum calculations are probabilistic, meaning that the results can vary and be assigned a confidence value. The reason quantum calculations are probabilistic has to do with the Heisenberg uncertainty principle--we can either know the exact momentum of a particle OR the exact position, but not both at the same time. So to assign confidence, you would want to run the same calculation a number of times in succession.

In, uh, "practical" terms, quantum computers are only extra useful for applications where parallelism would increase the speed of calculation. Great for AI, complex modelling, virtual physics experiments, encryption/prime numbers, that sort of thing.

(Interestingly, we don't necessarily have to throw out all of our silicon and transistor smarts to get going on making affordable qubits. Recently some Australian researchers used a silicon wafer and phosphorus atoms to make a CNOT quantum logic gate, which requires 2 qubits. I mean, the operating environment has to be at 1 Kelvin, which is pretty chilly. But they claimed to maintain coherence for 30 seconds, which is an eternity for quantum computing purposes.)

posted by xyzzy at 10:54 PM on April 15, 2016 [14 favorites]

This journalist from the Guardian wishes we could raise our expectations of scientific literacy among the political and commentating classes.

posted by Coaticass at 6:12 PM on April 16, 2016

posted by Coaticass at 6:12 PM on April 16, 2016

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posted by Chaussette and the Pussy Cats at 6:11 PM on April 15, 2016 [40 favorites]