One-sided debate [LWN.net]

One-sided debate

Posted Jun 24, 2007 14:36 UTC (Sun) by man_ls (subscriber, #15091) [Link]

Linus is known to be a good shepherd of cats, so once he is convinced the rest of the kernel world will probably follow suit. Thanks for not summarizing the details of the debate, not interested.

About the rest: what a wonderful display of condescension! Let me repay you in kind. Yes, I am dead serious; reality is not too consistent, even in Physics. Your typical Physics 101 course shows you a bunch of answers, but it doesn't even teach you the language to start making questions of your own. Once you delve deeper you are taught the real value of those answers (which is little) and how to question them, which is the truly scientific way of proceeding.

You are right that this is not the place to show you the cracks in reality; and anyhow, why should anyone want to make you question reality, if you feel comfortable with it? Let others face the voids of infinity and feel their stomachs turn and the ground under their feet open, so you can go back to your kernel code listings and feel all smug about it.

But all those onanistic references have earned you at least a little peek. The stumbling blocks in our knowledge of the physical world are the same that Heraclitus of Ephesus faced 2500 years ago: identity and infinity, which are subsets of the general problem of being. How can the the river keep being equal to itself, and yet it is ever changing? How can the arrow travel a distance which can be infinitely subdivided? In modern physics infinity rears its stomach-turning face in long series of infinities which should cancel each other but don't, or in a Universe which should be finite but doesn't seem to be. Meanwhile identity shows up in a zoo of subatomical particles which are constantly changing state and whose duration is often a matter of femtoseconds, but all equal to each other.

It is easy to predict that 2500 years from now Physics will be much changed, but mankind will still not have the answer to the fundamental questions: is the Universe finite or infinite? What are things made of? And the best of all: why is there anything instead of nothing? The words of Hippocrates of Kos will probably be as valid as they were 24 centuries ago:

But men do not have the science to examine those things which are veiled based on those which are apparent: using arts similar to the human way of being they do not recognize it: which is that the minds of the gods taught them to imitate their godly works, knowing what they do but not knowing that which they imitate.

Which means that the deeper we delve into the natural world the less we understand it, and the less valid our human concepts become. Yes, Physics works, some of the time, but it means little outside of Physics; it is a feeble justification for reality.

One-sided debate

Posted Jun 24, 2007 15:39 UTC (Sun) by viro (subscriber, #7872) [Link]

Sigh... So Sokal's affair hadn't taught you anything. How
unsurprising... Nobody says that Physics 101 gives one all
answers, correct answers or happens to be taught well. BTW,
you might want to continue your education past that - and not
into pseudo-phylosophical handwaving. That might at least
give you an understanding of difference between Zeno's stuff
and QED one and lack of relationship between those beyond the use
of the same word. And no, popular retellings do not count.

And learn real mathematics, please - again, not limited to freshman
courses. It's damn beautiful, beyond and above words. Again,
popular retellings miss that completely.

One-sided debate

Posted Jun 24, 2007 21:39 UTC (Sun) by man_ls (subscriber, #15091) [Link]

So Sokal's affair hadn't taught you anything.

That clowns can publish? That fools will swallow any kind of rubbish if it is neatly packaged? I already knew that, and I hope you did.

That might at least give you an understanding of difference between Zeno's stuff and QED one and lack of relationship between those beyond the use of the same word.

Good, that kind of disconnect is proof that your reality is solid.

And learn real mathematics, please - again, not limited to freshman courses.

Been there, done that. It is nice for a while but I wouldn't repeat it.

One-sided debate

Posted Jun 24, 2007 18:50 UTC (Sun) by bronson (subscriber, #4806) [Link]

I'm sure Al Viro is quite familiar with the philisophical void. Causality is an illusion! Descartes couldn't exit his empty room, Godel showed that there's no such thing as trust, 9.8 m/s/s is an unprovable convenience. Let's all throw up our hands in despair!

I realize that you were satirizing Viro's post mocking your own, but I'm not quite sure what you were trying to say... Maybe lay off the philosophy books for a bit until reality returns? :)

One-sided debate

Posted Jun 24, 2007 19:14 UTC (Sun) by bronson (subscriber, #4806) [Link]

> Godel showed that there's no such thing as trust

Bad editing on my part! Godel ostensibly showe that there is no such thing as *reason*. (which is sort of true, but philosophers carry it to absurd conclusions). Sorry bout that. :)

One-sided debate

Posted Jun 26, 2007 23:33 UTC (Tue) by roelofs (guest, #2599) [Link]

> Godel showed that there's no such thing as trust

Bad editing on my part! Godel ostensibly showe that there is no such thing as *reason*.

Yeah, it was Thompson who showed there's no such thing as trust.

;-)

Greg

One-sided debate

Posted Jun 24, 2007 21:40 UTC (Sun) by man_ls (subscriber, #15091) [Link]

Thank god for your opportune entrance!

I'm not quite sure what you were trying to say...

I guess Albert Einstein said it better:

As far as the laws of mathematics refer to reality, they are not certain; and as far as they are certain, they do not refer to reality.

One-sided debate

Posted Jun 24, 2007 22:02 UTC (Sun) by man_ls (subscriber, #15091) [Link]

Actually, that is a lousy translation. It can be better expressed as:

As far as the laws of mathematics refer to reality, they are not true; and as far as they are true, they are not real.

One-sided debate

Posted Jun 28, 2007 11:27 UTC (Thu) by forthy (guest, #1525) [Link]

How can the arrow travel a distance which can be infinitely subdivided?

The funny thing here is that current physics says basically that you can't infinitely subdivide neither the distance, nor the time - it's all quantized. If you could subdivide both distance and time infinitely, it works out ok again, as well (just that this type of mathematics was developed 2000 years later). But if you feel uncomfortable with infinity, take the current view of the universe, which is finite and quantized in time and space.

Why is there anything instead of nothing?

Now this is a real hard problem, but even in math you have to accept some assumptions before you can even ask a single question.

One-sided debate

Posted Jun 28, 2007 23:40 UTC (Thu) by man_ls (subscriber, #15091) [Link]

you can't infinitely subdivide neither the distance, nor the time - it's all quantized.

I'm not sure what you mean by this -- certainly, time and space could be subdivided infinitely when I studied QED. At the same time, too; the equations used to work just fine. It just doesn't make too much sense under a threshold.

If I remember correctly, one way to derive the equations of quantum mechanics was to suppose that particles could only be in the vertices of a lattice, and then make the separation between lattice nodes go to zero.

By the way, "quantized" doesn't mean that a magnitude cannot be infinitely subdivided; it means that it can only take certain values. Those values need not be equally spaced, and they can be determined to arbitrary precision too, like the energies for a particle. Particles will usually be in a superposition of states so their energy cannot be ascertained. The same happens for time and space; but those two magnitudes are not quantized and so the particle has a wave function which spreads over space.

Perhaps I misunderstood you? Are you talking about a different theory?

But if you feel uncomfortable with infinity, [...]

Maybe I gave the impression that I have a phobia to infinity or something. I don't, I'm probably like every other guy, I'm fascinated and scared by it. I was just suggesting that, now as 2500 years ago, infinities start at the point where we stop understanding things; a subtlety which was not very well expressed, it seems.

[...] take the current view of the universe, which is finite and quantized in time and space.

The Universe is only finite because we would like it to be. Cosmologists are still searching for "dark matter", a substance about which we have no proof, just so that the equations yield a finite Universe. This "dark matter" is more faith than substance, if you ask me.