
In what sense is quantum computing a science? - Osiris30
http://cognitivemedium.com/qc-a-science
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klyrs
Speaking from experience, as somebody who works in quantum computing.

* Theoretical physicists make hypotheses, and find abstract circuits to accomplish a goal; experimental physicists work closely to validate those circuits -- a cycle of experimentation, hypothesis testing, and lots of statistics (aka science).

* Circuit designers find concrete implementations of those circuits, and work closely with fab to produce them. Fab employs chemists and physicists to test, characterize, and refine their processes through experimentation, hypothesis testing, and lots of statistics (aka, science).

* When experiment-laden chips come back from fab, the circuit designers and theoretical physicists work with experimental physicists and lab technicians to characterize/validate the implementation through experimentation, hypothesis testing, and lots of statistics (aka, science).

* Individual devices are assembled into processors by an architect, who has a high-level understanding of the circuits, fab processes, and algorithms that use the processors -- coordinating a larger feedback loop with algorithm researchers involving experimentation, hypothesis testing, and lots of statistics (aka, science).

Scienceless design is a myth worthy of quashing. Our process isn't much
different than those employed in the classical computing realm. I'd claim that
quantum computing isn't even groundbreaking, in this regard: there's probably
a billion person-hour trail of scientific studies that took us from the
Antikythera device to the 7nm node ( _cough cough_ , or 10nm; who's counting?)
and the architectures built thereupon.

If you're doing "design" without "science" as a subroutine; you're probably
just following a recipe.

~~~
phkahler
A lot of what you describe is also done by people going by the engineer label.
How much overlap do you see?

~~~
klyrs
Plenty; as far as I can tell, an engineer is an applications-oriented
scientist who works with macroscopic objects...

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porpoisely
It isn't a science. It doesn't delve into natural laws. Quantum computing,
like computer science, is mathematics. The applied versions of quantum
computing and computer science is engineering. One of my professor's biggest
pet peeves was the misnomer "computer science". He always said that he was a
mathematician and not a scientist. Turing was a mathematician, not a
scientist.

~~~
Koshkin
Outside the US mathematics is a science. (Because deduction is part of the
scientific method.)

~~~
dragonwriter
> Outside the US mathematics is a science. (Because deduction is part of the
> scientific method.)

That's a reason for math to be recognized as an important _tool for_ science
(and a certain level of it a _prerequisite for_ certain science work), but
lacking an empirical component, it makes no sense to consider it _a_ science.

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Buldak
I tend to view "science" as quintessentially a "success term." We call a
discipline a science if we have a high degree of confidence in its results. In
this sense, math is a science, and whether psychology or economics are
scientific has less to do with their subject matter than whether we think they
produce real knowledge.

I like this notion of science because it helps to account for the broader
sense of "science" you see in earlier periods of history, before it became
more narrowly associated with experimental science. More importantly, I think
it gets at what actually interests us in the designation of "science."

~~~
claudiawerner
On the other hand, whether or not philosophy is a science is also up for
question; if we go by what you're saying, we can approximate "real knowledge"
to be "progress", but whether or not philosophy makes progress is hotly
debated in metaphilosophy. There are some interesting arguments on this[0]
site about it. In particular, as you note, the notion that science is purely
empirical/"experimental" is relatively new, and outside of the Anglosphere, at
least, it was common to see philosophy take up the name of science through
words such as Wissenschaft - both Kant and Hegel published works which had
their titles translated as the "Science of Logic", for instance.

But most people seem to agree that the crudest formulation of science as that
which is falsifiable (a la Popper) is inadequate; as the SEP notes, astrology
is falsifiable and would thus qualify as a science! Furthermore, research has
shown that what we regard as "science" published in the Nature journal
actually _doesn 't_ usually come in the form of starting with a falsifiable
hypothesis, but the research is exploratory in the first place.

Defining science is tricky, and I think we should reconsider how much weight
we assign to the term as a proxy for the concepts of rigor, progress,
replicability, ability to provide new knowledge, to confirm old knowledge etc.

[0] [http://www.philosophyisscience.com/](http://www.philosophyisscience.com/)

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throwawaymath
How is astrology falsifiable?

~~~
claudiawerner
Astrology makes definite claims, and the claims have shown to be false. Check
out Shawn Carlson's 1985 piece "A Double Blind Test of Astrology" in Nature.

~~~
msla
The final part of science, then, is _giving up_ paradigms which have been
falsified.

Astrologers... refuse to do this, to put it politely.

~~~
claudiawerner
I agree! But the popular conception of science as merely something falsifiable
doesn't include that condition - my whole point here (which for some reason
people are downvoting me for...?) is that Popper's definition isn't
sufficient, because it both includes pseudoscience (astrology) and excludes
legitimate (exploratory) science.

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kickopotomus
Perhaps I am misunderstanding the author or simply not fully grasping the
concept of "design science"[0], but it seems as if they are simply trying to
reclassify engineering with a term that sounds more "science-y".

[0]: [https://en.wikipedia.org/wiki/Design_science#cite_note-
cross...](https://en.wikipedia.org/wiki/Design_science#cite_note-cross2001-20)

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wybiral
Quantum computing boils down to unitary matrix operations over complex space.
It's very straightforward. But the way those pieces behave in more complicated
systems and the emergent properties they give rise to can be studied...
Scientifically.

Some of it will be encompassed by computer science in that algorithms will
still have the same metrics, but there may be other metrics for which to study
quantum algorithms.

~~~
reikonomusha
You really can’t boil down quantum computing to something that doesn’t include
probability distributions and measurement.

~~~
wybiral
Those probability distributions are typically represented as complex vectors
and quantum gates as unitary matrix operations on those vectors.

Here's a quantum computer simulator [1] I wrote years ago that allows you to
construct quantum circuits using the most common quantum gates found in
literature. This is all done by the application of complex matrices. On the
right there is the probability distribution that taking a measurement would
result in.

[1]
[https://github.com/qcsimulator/qcsimulator.github.io](https://github.com/qcsimulator/qcsimulator.github.io)

Edit: It's worth noting that we can study quantum computing without a quantum
computer, just as we can study computing without a classical computer.

Edit 2: Here's Grover's Algorithm in my simulator where you can see that the
probability of measuring the correct "hidden" oracle value is 96% after only
three applications of the diffusion operator:
[https://qcsimulator.github.io/?example=Grover%27s%20Algorith...](https://qcsimulator.github.io/?example=Grover%27s%20Algorithm)

~~~
urgoroger
I think the commentor's point is that measurement (which is a key component of
quantum computation) is not a unitary operation.

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peteradio
The fundamentals of quantum computing are absolutely a science. The
hypothesis, discovery and characterization of useful quantum systems is done
in Physics labs all over the world. Beyond that, is Computer Science not
considered a fundamental science?

~~~
reikonomusha
“Proper” computer science as studied and understood in academia is really a
branch of mathematics, not science.

~~~
mkirklions
The last 10 years of seeing Academia decide what is a valid has convinced me
Academia has limited weight in the real world.

Don't sweat their opinion, Industry drives the world.

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goatlover
Let us hope that commercial interests don't drive science.

~~~
msla
Let us hope that _as many things as possible_ drive science, as serendipity is
the heart of new discovery.

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whatshisface
> _Up to now, physics has for the most part not been a design science. But my
> guess is that’s going to change in the coming decades. There are more and
> more examples where design seems the right way to think: topological quantum
> computers; new designer phases of matter; the Alcubierre warp drive and
> other designer spacetimes; constructor theory and universal constructors;
> programmable matter and utility fog._

I'm not sure if the author realizes what the difference between physics and
engineering really is. In the 1800s, concepts like entropy and pressure (and
the foundations of mechanics) were considered to be exciting fields of
research, right alongside the construction of the first steam engines.
Although the inventors building the first steam engines were exploiting the
cutting-edge physics of the day, they were not in doing so acting as
physicists. Engineering is not "the study of heat transfer and classical
mechanics," engineering is "the application of physics (or whatever other
science is helpful) to practical design problems." If a physicist were to
construct or design a physical system to meet some requirements, they would be
by definition engineering, whether they were a mechanical engineer, an
electrical engineer, or a quantum field engineer. Likewise, if an engineer
were to decide that the laws of the system they were working with were not
fully understood, they might spend some time working out what they were, and
in doing so they would be acting as a scientist.

~~~
C1sc0cat
An Engineer is a Scientist with thumbs is how it was explained to me.

~~~
checkyoursudo
My dad was a aeronautical engineer and my father-in-law is an electrical
engineer. I would say their work was not really like my wife's (when she was a
scientist).

The scientists in my life have seemed more like chefs coming up with the
recipes and the engineers more like line cooks making the operation of the
restaurant actually happen. That's probably a really terrible analogy.

I don't mean at all to say that the engineers don't understand the science (I
have no idea! and it probably varies from eng to eng), but the actual work I
hear or heard them talk about over the course of decades seems very different,
whereby "scientist with thumbs" doesn't really seem accurate.

Although maybe that is more true now than in the past? For the last 10 years
or so, my f-i-l's main complaint is that newly graduated engineers _only_
understand theory and models and have zero practical experience coming out of
a degree program. Though, he ... let's just say, he exaggerates a lot, so I
don't know how accurate that is.

My engineer-for-45-years father seems very little like a scientist.

~~~
C1sc0cat
Depends where you worked :-) my first job was at a world leading hydrodynamics
research place on campus at CIT (Cranfield)

Our Boss was Presediuent of the Mech engineers and the boss of CIT The civil's

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scottlocklin
The author never used the phrase "glass bead game" -which pretty well
describes quantum computing's relation to anything you could consider science
or engineering. I guess he does use the words "Alcubierre warp drive" which is
about right, except we don't have 1000s of Alcubierre warp drive experts
running around publishing papers and pretending like they're not playing make
believe.

~~~
jackfraser
You do realize you can sign up for D-Wave Leap and execute programs on a
quantum annealer ten minutes from now, right?

It's far from a glass bead game. Just because you and I don't know how to make
an annealer do something useful doesn't mean others aren't already getting
exciting and useful results from it.

~~~
scottlocklin
It is a glass bead game. D-Wave is a LARP.

FWIIW I use annealing all the time in non-gradient optimization problems. My
X220 thinkpad from 2012 is faster than d-wave's thing.

The only interesting quantum computer is one which achieves actual quantum
supremacy. There's a really obvious reason why this will never happen (well
really obvious to me). It's the same reason you can't solve NP-hard problems
using soap bubbles.

~~~
tmvphil
Quantum computing is not analog computing. It is discretized in the process of
quantum error correction.

~~~
scottlocklin
Show me an actual quantum error corrected qubit in the physical world. There
is no time limit, unless you die first, in which case "time's up!"

FWIIW there are 0 error corrected qubits in the history of the human race so
far. Might happen some day! Kinda funny how regular digital computers didn't
have such problems as not existing in the world, even in the very early days.

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trhway
In the same as exobiology - we can make models compatible with our current
physics/chemistry/etc and study those models, write papers, have conferences,
grants... ie. do a science. One day it may happen to be useful upon
encountering a life on another planet matching the models.

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justicezyx
Theoretical quantum computing is a science.

