
What is more fundamental: Physics or Computer Science? - prabodh
http://www.daniel-lemire.com/blog/archives/2009/10/05/what-is-more-fundamental-physics-or-computer-science/
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btilly
There is an old saying, "Anything with science in the name, isn't." That
applies here. Reading it I am reminded of the old linguistics argument that
every other field is a branch of linguistics because they have to use language
to express their discoveries. Fine, but is studying linguistics an effective
way to make progress in learning other subjects?

Have you noticed how seldom physicists bother arguing about how fundamental
they are? The value of what they do is so obvious to them that they don't need
to defend it.

For a more detailed contrasting view read
[http://bentilly.blogspot.com/2009/09/what-makes-it-
science.h...](http://bentilly.blogspot.com/2009/09/what-makes-it-
science.html). FWIW in the list of great science discoveries there I nearly
included several CS results (specifically the halting problem, the Church-
Turing hypothesis and the identification of NP-complete problems) but none
quite made the cut.

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robg
Replace linguistics with neuroscience (or more generally biology) and language
with the brain (or more generally the body). Does your conclusion change? What
does learning mean if we understand the biological processes that underlie it?

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btilly
I am puzzled why you would think that my conclusion would change.

You've fallen into a classic mistake. Science focuses on tractable problems,
not important ones. For instance no matter how wonderful world peace would be,
as long as there is no clarity about what lines of research are likely to
advance it, it simply can't be science. By comparison human happiness is
unlikely to change if we find the last particle predicted by the Standard
Model. However we know how to go about finding the Higgs boson, its discovery
would confirm our understanding of how mass arises, and understanding it could
help us towards reconciling GR and QM.

I fully grant the importance of understanding the human brain. I appreciate
the effort that is being spent, and that lots of progress is being made. I've
learned a lot by reading about what we have learned. However there is no
coherent story yet, and no sense of which lines of research are likely to lead
to fundamental improvements in understanding. As a result neuroscientists have
less of a shared paradigm than the hard sciences.

Incidentally your comment below about learning is ironic. Researchers into
memory learned a lot about how timely reminders improve long-term learning
ages ago. They have been trying to shout the news from the rooftops for
decades. There are computer programs that help people follow schedules that
really improve how you learn. But has it had a practical impact on, say,
classroom teaching?

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Tamerlin
"Science focuses on tractable problems, not important ones."

That doesn't make sense. Science isn't an entity for one thing, it can't focus
on anything... for another, do you really think that mechanics, immunology,
electricity, and ceramics, to pick a few examples, aren't important?

The reality is that scientists aim to solve tractable problems because they
know that they can't solve the whole thing at once. It's part of a simple
algorithm called "divide and conquer."

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MarkPNeyer
I'd say that you can't have computation without physics. I am willing to bet
that it'll eventually be proved that computation is inherently a physical
process: information is just one form of energy, and computation is the
process of converting energy and entropy into information. Computer Science is
then best viewed as a subset of Physics.

If I could study ANYTHING without worrying about getting funding, I'd study
computation as a physical phenomenon. I think the answer to P vs NP lies
somewhere in the laws of physics; solving NP-Complete problems in polynomial
time on the size of the problem input is either possible in our physical
universe, or it is not.

~~~
pavel_lishin
What about the people who'll come back and say that all physics is just the
result of the universe computing itself?

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nova
So physics = computing?

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MikeCapone
Am I the only one who thinks that this comparison is a bit pointless?

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jpwagner
Am I the only one who gets a funny feeling when upvoting something with a
rhetorical answer of "no"?

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_pius
Math.

~~~
Anon84
Math is a language, not a science. To quote Einstein "Math deals with the
relation between concepts. Physics deals with the relation between concepts
and reality."

~~~
_pius
_Math is a language, not a science._

If you dig into that statement, it turns out to be a very nihilistic view. We
should be careful not to fall into the trap of demoting math to a mere
notation. It isn't. It's the truth.

Green's Theorem, for instance, is no more just part of a mere language for
describing electromagnetic theory than the law of gravity is just part of a
mere language for describing, say, spacecraft propulsion.

In other words, if math is just a language for physics, physics is just a
language for engineering, and we don't have any "sciences" at all ... just
languages for higher level disciplines.

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reader5000
Physics is nothing but modeling phenomena found in the world. Usually
physicists use mathematical functions as their preferred class of models but
they are free to use whatever they please. I don't believe there is a
'fundamental' science since it's all just modeling. Maybe the science of
modeling is the most fundamental. Computer science, however, does seem to come
closer to the 'study of models' then physics.

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pbz
What's greener, blue or yellow?

~~~
jpwagner
The answer is obvious (to me): Without yellow there would be no blue! Blue is
built on the fundamental assumption that we can model the world using yellow.
Yellow is the most green.

~~~
bfung
care to elaborate? Red, Green, and Blue are the primary colors... the color
models I know of are RYB and CMYK, and

    
    
      >Without yellow there would be no blue!
    

in CMYK, without yellow, there is blue!

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ccc3
To a certain extent this really comes down to semantics. If someone is writing
a complex algorithm to describe a physical phenomenon that has been observed
in a lab, are they a physicist or a computer scientist?

I tend to disagree with the authors conclusion. I'll concede the theoretical
point that anything can be computed, but this doesn't make computer science
fundamental. By my definition, Physics is the study of the most fundamental
components of the universe and algorithms are an indispensible tool in that
study.

It is possible to write an algorithm that perfectly describes what happens
when you get hit by a car. This is not the same thing as you actually getting
hit by the car. In other words, algorithms are a description of what is
happening, not the actual events themselves.

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tel
I think at any level level of reasoning where you compare computer science and
physics they become pretty indistinguishable. At that point it's all about
which words you use to describe it.

Some pretty important ones seem to be: entropy, energy, information, logic,
and computability. Those seem to sit squarely between information theory,
physics, and math.

I think what this debate really means is that we're not yet going to find some
sort of nice hierarchy where every result in chemistry can be considered a
practical simplification of something squarely in physics. Instead perhaps
both physics and CS are attacking a problem so fundamental that eventually
there will be a new body of study that considers both CS and physics both to
be a practical simplification of its results.

Exciting, no?

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zeynel1
"We all live in the Matrix ... we live in a Turing machine."

Is the Matrix a Turing machine?

~~~
cperciva
_Is the Matrix a Turing machine?_

No, but it can be simulated on one.

