Some Thoughts On Quantum Computing

Some remarks by a speaker at a recent professional event inspired me to rant a bit on the topic of quantum computing. For sure, it's not my area of expertise, but I do have a dilettante interest in quantum physics, plus I took a short course at University of Denver a few months ago that was a kind of "Quantum Computing for Dummies", and it is the area of expertise by the Ph.D. physicist who taught it.

[1] Quantum computers will not replace conventional computers. There is a lot of interest in QCs because it is believed that they can do calculations that are not feasible for today's computers. But those calculations are only possible for problems for which there are known - or believed - to be QC-type algorithms. You will never be running a web browser or a spreadsheet on a QC.

[2] One example is Peter Shor's quantum algorithm for large number factorization, which could be used to break encryption schemes that rely on the difficulty of such factorization. Shor is a theoretical computer scientist who developed Shor's Algorithm while at Bell Labs. This is why governments are interested/concerned about QC. A lot of encrypted secrets have been stolen by hackers (theirs and ours), but are just useless bits until they can be decrypted.

[3] Not all encryption is based on large number factorization. Maybe there are as yet undiscovered QC algorithms for the "trap door functions" that those schemes use instead of large number multiplication and factorization. Maybe not. Until then - if ever - such schemes are described as quantum resistant. Switching to such schemes is probably a good idea for sensitive data, just in case QCs eventually work.

[4] QC may never work. Although scaling up quantum computers is talked about as if it were an engineering issue, the people trying to do it are - in my opinion, and whether they realize it or not - trying to solve what physicists call the measurement problem. What constitutes a "measurement" in a quantum system - an action that causes the wave function describing a superposition of states to collapse or decohere into one state - is unknown. QCs work by causing the superposition created by the quantum algorithm to collapse into a state representing the answer, possibly solving a problem what would take a conventional computer years, or centuries, or ... Engineers working on QCs are trying to prevent a measurement - whatever that is - from occurring and the system decohering until they want it to. Defining what constitutes a quantum measurement is Nobel Prize territory, a problem that reaches into the very definition of reality in the transition from the realm of the very small to the realm we perceive. It is a problem that may never be solved, despite what investors are told.

I hope quantum computers do come to fruition. Not just for the practical reasons of solving some very difficult optimization problems and such, but because of the light it would shed on the measurement problem in physics. But I remain cautiously pessimistic.

Real-Time versus Real Time

Interesting article from IEEE Spectrum: "How AI’s Sense of Time Will Differ From Ours" [Popovski, 2026-08-13].

Human cognition integrates events from different senses - especially seeing and hearing - using a temporal window of integration (TWI). Among other things, it's the ability that lets us see continuous motion with synchronized sound in old school films at 24 frames per second. But under the hood, everything is asynchronous with different sensing and processing latencies. Which is why we don't automatically integrate seeing distant lightning strikes with the thunderclap, even though intellectually we may know they're the same event.

Machines have to deal with this as well, especially AI in applications like self-driving vehicles. It's non-trivial. "Computers put timestamps, nature does not" as the author remarks. Anyone that develops real-time software - or has spent time analyzing log files - has already had to think about this. I talked about this issue in a prior blog article: "Frames of Reference".

I've also pointed out in a prior article, "Frames of Reference III", that our human sense of simultaneity continuously gives us a false view of reality. If I look towards the back of my kitchen, I see the breakfast table and chairs a few feet away. Since light travels about a foot per nanosecond, I'm actually seeing events that occurred a few nanoseconds ago (plus the communication and processing latency inside me). The back yard that I can see through the window: a few tens of nanoseconds ago. The house across the street: a hundred nanoseconds ago. The mountains to the west: microseconds ago. If I can see the moon on a clear evening: over a second ago. I see all of these things as existing in the same instant of time, but nothing could be further from the truth; my perception is at best an ensemble of many instants in the past, and the present is just an illusion.

AI perception of the real-world will have similar complications.

Events 2

I read a transcript of a science explainer by Dr. Sabine Hossenfelder about physicist David Deutsch's "Constructor Theory", which I had not heard of before, and how it accounts for time.

It sounds like just the 180º opposite of what I've been talking about: creating a model of physics that seems more like the kind of real-time systems I work on as a basis for reality. The shortest time period (Planck Time?) is the recycle time of a kind of null task, a term right out of Real-Time Operating Systems. That's basically how I think of the world around me - based solely on decades of professional experience - but it seems weird to think of it as a legitimate Theory of Everything.

Down deep, real-time computer systems - with their asynchronous, concurrent, and parallel behavior - are a lot more non-deterministic than people might think. It's one of the reasons that it's hard to debug such systems - a bug might only reveal itself under certain timing or certain order of events. Determinism is a kind of emergent property created by engineers who are hiding the details under the hood from the user - kind of like Newtonian physics layered on top of relativity and quantum mechanics.

Once you become accustomed to architecting, implementing, and debugging such systems, it's easy - it was for me, anyway - to start seeing the entire world through the same lens. Maybe I should not be surprised that there's one candidate for a Theory of Everything that takes this viewpoint.

Boom Town

In 1969, a forty-kiloton nuclear bomb was detonated underground in Colorado, near the town of Parachute, between Glenwood Springs and Grand Junction, west of Denver and a little south of what is now Interstate 70. The test shaft was over 8,400 feet deep. It was a test to see if small nuclear devices could free up natural gas deep underground, part of Project Plowshare. Edward Teller, one of the developers of the H-bomb, was there during the test.

In 1973, three thirty-kiloton nuclear bombs were detonated underground in Colorado, in Rio Blanco County, in the northwestern part of the state. It was another Project Plowshare effort to find peaceful uses for nuclear bombs.

These efforts to extract natural gas were a partial success. Partial because the gas was so radioactive it could not be sold, so was instead burned off.

As a result, Colorado passed an amendment to its state constitution such that approval for the detonation of a nuclear device in the state has to pass a state-wide popular vote. It is the only state in the U.S. with such a requirement.

This all happened before the Spousal Unit and I moved to the Denver area in 1989. But that's not the only adventure with radioactivity you may find in Colorado.

Given the depth of the H-bomb detonation near Parachute, the site is probably not nearly as radioactive as the site of the old Rocky Flats Nuclear Weapons Plant, between Denver and Boulder Colorado, just a few minutes drive from my home, and which I drove right past when I commuted to Boulder every day to work in the early 1990s. Rocky Flats - somewhat euphemistically - manufactured triggers for nuclear bombs; the trigger for a nuclear (fusion) bomb is an atomic (fission) bomb. Rocky Flats was an EPA superfund site for a long long time after it closed in 1992, following an FBI raid.

Radioactivity is a natural phenomena here in Colorado, thanks to decaying uranium ore underground that creates radioactive radon gas. Like a lot of folks in our neighborhood, we have radon mitigation in our home: a fan that runs 24x7 that pulls air (and presumably radon) out of our crawl space and exhausts it above the house.

Huge piles of mine tailings around Colorado mountain towns contain a lot of uranium ore, which was just a waste product when it was originally dug out during the gold and silver mining era. No one at the time had any idea they were creating an environmental hazard that would last, for all practical purposes, forever.

For reasons unrelated to any of this, my tiny little company owns a couple of geiger counters. One day, the Spousal Unit asked me if my watch with a tritium dial gave off enough radiation to be detectable. Good question. Tritium is a radioactive isotope of hydrogen. Its radioactive decay produces helium, an electron (a.k.a. beta particle), and an electron anti-neutrino. Tritium watch dials have hour and hand markers that are tiny vials containing tritium gas and a phosphorescent compound. The beta particles from the decaying tritium excite the phosphor, making it glow. No external light source is needed, although in time all the tritium will have decayed and the vial will stop glowing. Gun sights for use at night may use this mechanism too.

I swept one of my geiger counters close over the watch, and got a reading of normal background radiation. Beta particles from tritium decay are so feeble energetically that they typically can't penetrate more than about a quarter inch of air, much less human skin. Most probably can't make it past the wall of the vial.

Then, I happened to sweep the geiger counter across one of my other watches, where it went completely nuts. It turns out an old mechanical French Army surplus watch from the 1960s that I own has a radium dial. I had no idea; that wasn't in the original description when I purchased it. Radium is a decay product of naturally occurring uranium, and radon gas is in turn a decay product of radium. As it decays, radium produces ionizing radiation in the form of helium nuclei (a.k.a. alpha particles) and gamma radiation.

That watch dial was hot. The watch now resides in a lead-lined envelope on a shelf in the basement, along with some samples of uranium ore.

In these parts, it's no accident that we all have a healthy glow.

References

Westword, "The Boom Years", 2023-07-30

Wikipedia, "Rocky Flats Plant", 2023-06-19

The Expanse of Cosmic Horror

(This blog article is a mash up of two long social media posts I made some time ago, so it might seem a little fragmented and repetitive, even though I've tried to edit it a little.)

The late H(oward) P(hillips) Lovecraft [1890-1937] is credited with inventing the genre of cosmic horror - one of my favorite genres in either print or visual media. I don't classify his iconic creation Cthulhu as comic horror. That gigantic octopus-headed other-worldly creature that lies dreaming deep under the sea in the impossibly ancient city of R'lyeh is way too anthropomorphic. Cthulhu is horrifying, sure, but cosmic horror is all about reality-bending stuff that comes from non-earthly realms and virtually defies description. Cosmic horrors aren't evil; they are indifferent, as uncaring about their impacts on us puny humans as a lawn mower is to ant hills. Cosmic horrors drive humans mad because of our inability to perceive and process their reality.

My affection for cosmic horror is one of the reasons my alter ego goes to science fiction conventions wearing pins or badges that identify him as a faculty member at Miskatonic University - that fictional university in an equally fictional Arkham County, Massachusetts situated on the banks of the still fictional Miskatonic River, where several Lovecraft stories take place.

(And in case you're wondering, there is absolutely no excuse for the terrible racism evident in some of H. P. Lovecraft's writing. In this respect he was wrong and ignorant, even for the time in which he lived and wrote, and that part of his work is repugnant and not to be admired. But I learned long ago that if I only love those who are perfect, I will come to love no one. So I celebrate his other work while decrying that part of his milieu.)

Cosmic horror is one of the reasons that, with some exceptions, I can't quite enjoy reading science fiction that casually features faster than light (FTL) travel or communication. (I'm just a little more forgiving of visual media in this respect, but not much.) My dilettante reading of physics leads me to interpret FTL as creating circumstances that would bend or break our very perception of reality, eliminating our ability to agree on basic cause and effect. It would lead to violations of the basic laws of physics - which is perhaps part of the definition of cosmic horror.

Here are some media - not intended in any way to be comprehensive - that I think fits the description of cosmic horror.

• John Carpenter's movie The Thing and John W. Campbell's novella "The Thing From Another World" on which it is based, is by far the best known example. (The Carpenter movie is also a great example of another horror genre, body horror).
• The movie Alien (but not so much the terrific sequel Aliens) shoots for a bit of cosmic horror, with an alien which could easily have been right out of Lovecraft's "Cthulhu Mythos", although it has the same anthropomorphic flaw as Cthulhu itself. [added 2023-06-19]
• The movie Event Horizon for sure has elements of "things man was not meant to know", all the result of the development of an FTL drive. [added 2023-06-19]
• Jeff VenderMeer's book Annihilation and the movie adaptation of the same name starting Natalie Portman was all about cosmic horror. (The book is part of a trilogy; I recommend the second and third books too.)
• The later books in James S. A. Corey's nine-novel series The Expanse are definitely cosmic horror. (The television adaptation didn't last long enough to really get to those parts.) The alien FTL technologies and nano-technology found by humans in the later parts of this epic series are not at all understood by the scientists, and they are appropriately horrified by their non-local behavior. (James S. A. Corey is the pen name of the authorial partnership of Daniel Abraham and Ty Franck.)
• And perhaps most controversially, even as most of it was based on the real science and technology of its day, I find Stanley Kubrick's movie 2001: A Space Odyssey to have elements of cosmic horror.

I’ve been thinking about this for some time now: The Expanse is obviously a great hard-SF saga of humans colonizing the solar system - and, eventually, beyond. Both the books and the television adaption are careful to obey the laws of physics, e.g. no FTL, no artificial gravity, and force, inertia, and momentum are all a bitch. But it’s not just that. In my opinion, it’s fused with a great story of cosmic horror, in the Lovecraft tradition, if H. P. Lovecraft had had some physics courses. (Lovecraft was in fact a great fan of astronomy in his time.)

I like to say that we really don’t want faster than light travel. When Einstein wrote

E = mc²

E was energy, m was mass, and c was… the speed of light in a vacuum? Not really.

The speed of light isn’t fixed. It has a top speed in a vacuum, but travels more slowly - indeed, sometimes more slowly than other particles - when going through a transparent medium. (That’s what causes the glow, called Cherenkov Radiation, in water-immersed reactors; particles that are the result of atoms fissioning travel through the water faster than photons, which in turn produces more photons.) But more weirdly: the speed of light is a particular medium is a constant for all observers in inertial reference frames (that is, moving but not accelerating), regardless of how fast each observer is moving relative to one another.

This is what special relativity is all about. If that weren't the case, stuff like the chemical reactions in our bodies that are necessary for life wouldn't work reliably. And keep in mind, we are all in motion, all of the time: we move on the surface of the Earth, the Earth orbits the Sun, the Sun travels through the Milky Way galaxy gravitationally dragging all of its planets along with it, the Milky Way moves through its local galactic cluster, the cluster... well, as far as we know, there's no end to it. All in motion, all of the time. There's no such thing as standing still. And if there were... standing still relative to what?

The variable c isn’t really the speed of light, in a vacuum or otherwise; it’s the speed of causality, the maximum speed at which cause-and-effect can travel. In a vacuum, light travels at this speed.

(Update: as far as I know, there is no definitive answer as to what Einstein and his peers had in mind when they chose c to stand for the speed of light in a vacuum; some have suggested it stands for constant.)

Special relativity is strange enough, in that observers, in different locations and traveling at different speeds in different directions, may legitimately disagree on the order of two independent events, “independent” meaning that those events are not connected directly or indirectly by cause and effect. There is no correct answer as to which event occurred first; it all depends on your point of view.

If we had faster than light travel, or faster than light communication, this gets even worse. Really, our basic perception of reality would come into question. We might not just disagree on the objective order of events, but information about events could arrive before the events apparently occurred. This is actually kinda scary.

Scary in a cosmic horror kind of way.

As I said before, while I’m a fan of H. P. Lovecraft - my alter ego has Miskatonic University business cards he uses for non-work related stuff - I find the popular conception of Lovecraft's creation Cthulhu to be way too anthropomorphic. The mere fact that we can describe Cthulhu - it (apparently) has an octopus head, a humanoid body, wings - means it's really not a cosmic horror. A true cosmic horror would be more of what Lovecraft meant when he wrote of people being driven insane because they could not possibly comprehend, much less describe, what they were witnessing and experiencing.

One of the things I liked about The Expanse books is that the scientists experimenting with the protomolecule and with the ring gates - both extraterrestrial technologies which humans manifestly did not understand any more than my cat understands my laptop - were actually deeply disturbed by the protomolecule's non-local behavior, and by the gates’ faster than light travel. And rightfully so. Lovecraft fans in The Expanse universe would have known that it would not end well. Technology that enables faster than light travel, and non-local behavior, is inevitably going to be a kind of cosmic horror, driving people mad with its non-Euclidian geometries.

So I have come to think of The Expanse series as a fusion of the hard-SF genre and the cosmic horror genre (with a little bit of body horror thrown in for good effect). I would not be surprised to find that the authors Daniel Abraham and Ty Franck had that in mind from the very beginning.