Justin Trudeau explains the basics of quantum computing to reporters • Hacker News Board

Re: Justin Trudeau explains the basics of quantum computing to reporters

#21

Post by fragsworth » Sat, Apr 16, 2016, 4:54 PM UTC

daeken wrote: post #5

fragsworth wrote: post #2

I see no evidence that his knowledge is any better than a layman's, and this really feels like a promotional piece. It's pretty sad that people are surprised or impressed when a politician has a layman's understanding of something in science.

Do you honestly believe that the majority of people (hell, even 10% of people) could explain it to even the level he did? It's still a layman's level -- his response is clearly over-simplified and I doubt he could show the math behind any of it -- but it's far and above what the average person could tell you about the subject.

> Do you honestly believe that the majority of people (hell, even 10% of people) could explain it to even the level he did?

No, and what I said came across wrong. I was surprised, and I think that is sad, because things would be a lot better if most of our politicians understood science and technology.

The surprise should only be when they really, deeply understand something like this.

Re: Justin Trudeau explains the basics of quantum computing to reporters

#22

Post by galadran » Sat, Apr 16, 2016, 4:55 PM UTC

osweiller wrote: post #7

While this seems planted and trite (much like the "because it's 2015" answer), I have to confess that I don't get quantum computing. A qubit can hold multiple values, it seems. Okay, that's a data density improvement (presuming a quibit is as dense as a traditional bit). How does that improve computing power (especially by the many magnitudes)? Do you multiply a qubit of infinite values against a quibit of infinite v…

Note: This explanation is FAR from precise and is only trying to give an intuition

The key point is that qubits aren't limited to finite "multiple values", they can express an uncountable number of values. The best "short" answer is that a qubit can exist in a superposition (QM Term) of states. LOOSELY put it can have a probability of being a 0 and a probability of being 1 (with both probabilities adding to 1). This ability to encode information as the probability is the key to quantum computing.

When you measure (QM Term) the qubit, it takes on either the value 0 or 1 according to the probabilities you set it up with. This is computationally useful because with clever constructions you can make these probabilities meaningful.

For example Grover's Algorithm allows you to search an unsorted database for a particular item in O(sqrt(N)) time rather than the classical best O(N). The algorithm is successful with very high probability, note that because it uses the probabilistic nature of qubits, it itself can only be probabilistically correct, it just so happens you can make the probability of error very low (in theory lower than the chance your classical computer has a bit flip or similar)

The unfortunate restriction on QC is that you need enough qubits to encode your problem, if you can't hold the database in your "qubit memory" then you can't perform algorithm. In practice, building systems of qubits is extremely difficult and the current record is about 1000 as of 2015 I believe.

Re: Justin Trudeau explains the basics of quantum computing to reporters

#23

Post by [deleted] » Sat, Apr 16, 2016, 4:57 PM UTC

osweiller wrote: post #7

While this seems planted and trite (much like the "because it's 2015" answer), I have to confess that I don't get quantum computing. A qubit can hold multiple values, it seems. Okay, that's a data density improvement (presuming a quibit is as dense as a traditional bit). How does that improve computing power (especially by the many magnitudes)? Do you multiply a qubit of infinite values against a quibit of infinite v…

[deleted]

Re: Justin Trudeau explains the basics of quantum computing to reporters

#24

Post by return0 » Sat, Apr 16, 2016, 4:58 PM UTC

osweiller wrote: post #7

While this seems planted and trite (much like the "because it's 2015" answer), I have to confess that I don't get quantum computing. A qubit can hold multiple values, it seems. Okay, that's a data density improvement (presuming a quibit is as dense as a traditional bit). How does that improve computing power (especially by the many magnitudes)? Do you multiply a qubit of infinite values against a quibit of infinite v…

I couldn't recommend enough Michael Nielsen's on quantum computation. He has also written many articles:

http://michaelnielsen.org/blog/quantum-computing-for-the-det...

Re: Justin Trudeau explains the basics of quantum computing to reporters

#25

Post by DanBC » Sat, Apr 16, 2016, 5:00 PM UTC

mgiannopoulos wrote: post #6

fragsworth wrote: post #2

I see no evidence that his knowledge is any better than a layman's, and this really feels like a promotional piece. It's pretty sad that people are surprised or impressed when a politician has a layman's understanding of something in science.

Watching dozens of videos of Americans answering geography questions would lead me to disagree with you on what the average person knows about quantum physics.

Look at how engineering students answer a question about gravity.

http://www.falstad.com/gravity.html

> Physics 324 - Modern Physics for Engineers

> "A body is at rest tends to stay at rest, plus there's no gravity"

> "The gravity of the moon can be said to be negligible, and also the moon's a vacuum, there is no external force on the pen. Therefore it will float where it is."

> "The pen will float away because the gravitational pull of the moon, being approximately 1/6 that of the earth, will not be enough to cause the pen to fall nor remain stationary where it is. The gravatational pull of other objects would influence the pen"

Re: Justin Trudeau explains the basics of quantum computing to reporters

#26

Post by [deleted] » Sat, Apr 16, 2016, 5:00 PM UTC

osweiller wrote: post #7

While this seems planted and trite (much like the "because it's 2015" answer), I have to confess that I don't get quantum computing. A qubit can hold multiple values, it seems. Okay, that's a data density improvement (presuming a quibit is as dense as a traditional bit). How does that improve computing power (especially by the many magnitudes)? Do you multiply a qubit of infinite values against a quibit of infinite v…

[deleted]

Re: Justin Trudeau explains the basics of quantum computing to reporters

#27

Post by a_imho » Sat, Apr 16, 2016, 5:04 PM UTC

fragsworth wrote: post #2

I see no evidence that his knowledge is any better than a layman's, and this really feels like a promotional piece. It's pretty sad that people are surprised or impressed when a politician has a layman's understanding of something in science.

Agree 'Normal computers work, either there’s power going through a wire or not. It’s 1 or a 0.'

I believe power does not go through the wire, it is current or charges, and usually voltage is used to signal states. We can have wires depending how you define a computer, but in most cases it just feels wrong.

Re: Justin Trudeau explains the basics of quantum computing to reporters

#28

Post by Reedx » Sat, Apr 16, 2016, 5:04 PM UTC

daeken wrote: post #5

fragsworth wrote: post #2

I see no evidence that his knowledge is any better than a layman's, and this really feels like a promotional piece. It's pretty sad that people are surprised or impressed when a politician has a layman's understanding of something in science.

Do you honestly believe that the majority of people (hell, even 10% of people) could explain it to even the level he did? It's still a layman's level -- his response is clearly over-simplified and I doubt he could show the math behind any of it -- but it's far and above what the average person could tell you about the subject.

Right. In fact I'd bet that 10% is a very generous estimate. I'd be surprised if it's even 1%.

Re: Justin Trudeau explains the basics of quantum computing to reporters

#29

Post by [deleted] » Sat, Apr 16, 2016, 5:04 PM UTC

osweiller wrote: post #7

While this seems planted and trite (much like the "because it's 2015" answer), I have to confess that I don't get quantum computing. A qubit can hold multiple values, it seems. Okay, that's a data density improvement (presuming a quibit is as dense as a traditional bit). How does that improve computing power (especially by the many magnitudes)? Do you multiply a qubit of infinite values against a quibit of infinite v…

[deleted]

Re: Justin Trudeau explains the basics of quantum computing to reporters

#30

Post by Torgo » Sat, Apr 16, 2016, 5:04 PM UTC

Trudeau is reasonably smart, and admitted his knowledge was basic. It's everyone else that's acting ridiculous.

>“I was flabbergasted,” Laflamme says. “I don’t know how he does in other subjects, but in quantum physics, he knows the basic pieces and the important questions.”

Maybe he read a single article about quantum theory in an issue of Popular Science. Maybe, before an event at a facility where he knew he would be speaking, he spent fifteen minutes reading something he asked an aide to give him, so he could speak intelligently about it.