How close are we to quantum computing being a thing that I have to actively think about? My understanding is that it's on the horizon but not all that close.

I'm impressed at the heavy investment in tooling and education by microsoft -- they've often laid the groundwork for market segments that they've gone on to dominate by making development really easy.

Practical Quantum Computing is in a quantum state where it's at the same time around 10 years away and never gonna happen.

(To be serious: That's roughly true, you'll get credible scientific opinions on both. What's not true is what you occasionally read: That we're almost at a state where quantum computing will be a mass application.)

Indeed, it's not on the near horizon. I found this article illuminating:

The Case Against Quantum Computing - https://spectrum.ieee.org/computing/hardware/the-case-agains...

> I argue that they can’t. In the physical world, continuous quantities (be they voltages or the parameters defining quantum-mechanical wave functions) can be neither measured nor manipulated exactly. That is, no continuously variable quantity can be made to have an exact value, including zero. To a mathematician, this might sound absurd, but this is the unquestionable reality of the world we live in, as any engineer knows.

Wasn't this problem addressed just recently? https://www.unibas.ch/en/News-Events/News/Uni-Research/The-g...

Dyakonov‘s opinions have been rebutted by many prominent quantum information scientists and physicists. To put it charitably, his arguments don’t agree with the consensus. Check out [1] as an example criticism of his writing.

[1] https://scirate.com/arxiv/1903.10760

The article is indeed interesting. I find this one addressing it https://www.hpcwire.com/2019/01/09/the-case-against-the-case...

As a researcher in the field, I think you should think about it because it's fun to think about... but I don't think you "have" to think about it yet.

Thanks. That's a pretty neat and tidy summary.

At this point most of the “practical” work seems to be proactive in nature; e.g., financial firms (such as GS) developing quantum solutions that aren’t currently useful, but will be extremely valuable if and when quantum computing can scale up to practical levels. In the meantime, general-purpose quantum languages (hybrid wrappers) are fun and genuinely interesting hobbies, but not much else.

From a pricing perspective it looks like the first two chapters out of seven are free, and then it would cost 30$ a month to continue (or 12$/month yearly).

I'm guessing that includes all of their courses, not just Quantum?

That's correct. Their course offerings are all you can eat with that subscription.

I predict that all of the money that these big companies are pouring in to quantum computing (which is motivated by a fear of missing out on the next big thing) will turn out to be a mistake from their perspective, not because quantum computing never works out, but because the next big thing turns out to be something else and blindsides them.

Does anyone know of a relatively accessible book that introduces quantum mechanics well?

We (Brilliant) do have an introductory course on quantum mechanics as well. It goes into more of the phenomena (like spin, photons, etc.) than this computing course that mostly focuses on information. Let us know what you think: https://brilliant.org/courses/quantum-objects/

If Brilliant isn't your cup of tea – check out mcintyre's spin-first treatment. Generally speaking avoid any textbooks with cats on the cover (ie. Griffith's is popular but only so-so IMO). That being said, we went with a cat on our course ¯\_(ツ)_/¯.

Depends how much maths you already know. I've liked Griffiths' Introduction to Quantum Mechanics- the first chapter goes into the Schrodinger equation.

> For a limited time following the release of this blog post, the first two chapters of Quantum Computing, including an interactive introduction to coding in Q# will be available to all registered Brilliant users for free.

I wish these strings were not attached and the course was published on free platform. More people learning QC is itself a benefit then minor revenue generated by few.