The morality of quantum computing

This morning a humanities teacher named Richard Horan, having read my NYT op-ed on quantum supremacy, emailed me the following question about it:

Is this pursuit [of scalable quantum computation] just an arms race? A race to see who can achieve it first? To what end? Will this achievement yield advances in medical science and human quality of life, or will it threaten us even more than we are threatened presently by our technologies? You seem rather sanguine about its possible development and uses. But how close does the hand on that doomsday clock move to midnight once we “can harness an exponential number of amplitudes for computation”?

I thought this question might possibly be of some broader interest, so here’s my response (with some light edits).

Dear Richard,

A radio interviewer asked me a similar question a couple weeks ago—whether there’s an ethical dimension to quantum computing research.  I replied that there’s an ethical dimension to everything that humans do.

A quantum computer is not like a nuclear weapon: it’s not going to directly kill anybody (unless the dilution refrigerator falls on them or something?).  It’s true that a full, scalable QC, if and when it’s achieved, will give a temporary advantage to people who want to break certain cryptographic codes.  The morality of that, of course, could strongly depend on whether the codebreakers are working for the “good guys” (like the British breaking the Nazi codes during WWII) or the “bad guys” (like, perhaps, Trump or Vladimir Putin or Xi Jinping).

But in any case, there’s already a push to switch to new cryptographic codes that already exist and that we think are quantum-resistant.  An actual scalable QC on the horizon would of course massively accelerate that push.  And once people make the switch, we expect that security on the Internet will be more-or-less back where it started.

Meanwhile, the big upside potential from QCs is that they’ll provide an unprecedented ability to simulate physics and chemistry at the molecular level.  That could at least potentially help with designing new medicines, as well as new batteries and solar cells and carbon capture technologies—all things that the world desperately needs right now.

Also, the theory developed around QC has already led to many new and profound insights about physics and computation.  Some of us regard that as an inherent good, in the same way that art and music and literature are.

Now, one could argue that the climate crisis, or various other crises that our civilization faces, are so desperate that instead of working to build QCs, we should all just abandon our normal work and directly confront the crises, as (for example) Greta Thunberg is doing.  On some days I share that position.  But of course, were the position upheld, it would have implications not just for quantum computing researchers but for almost everyone on earth—including humanities teachers like yourself.

Best, Scott