Ask a physicist anything. (6)

[Naraoia]

I do this daily. It's not that hard.

I guess I should have thought of mind-altering substances after four years in a university town

 

[Wiccan_Child]

It wasn't my thread. I just restarted it after the last got closed for some reason.

I'm not even a physicist, I'm more of a complexity scientist. Which is a such a young field we don't have a cool name for those that study it yet. How does Complexitist sound?

What about entropist?

 

[Wiccan_Child]

I think the majority would agree with you.

Huzzah! I knew they'd come around eventually

And the mathematics of the Caloric Theory. It is easier to make calculations on the assumption that heat is a substance that flows rather than trying to deduce things from the first principles from the Kinetic Theory.

Also Newtonian Mechanics is still extremely useful.

Yep! My brain uses it every day. Quantum mechanics, less so...

(Isn't Newtonian Mechanics the same as Classical?)

I dislike the use of your word "disproven". While I understand that some theories can be disproven, physical theories can very rarely be disproven. They can be superseded. Please use the word "superseded" from now on. CM was not disproven it was superseded by QM. Newtonian Mechanics was not disproven it was superseded by Special Relativity, and so on.

But, they were. There exists empirical evidence that contradicts Classical Mechanics, such as the Casimir effect or those recent Gravity Probe B experimental results.

QM did not show that CM was wrong. CM is theoretically derivable as special cases of QM. QM superseded CM, in the same manner that Maxwell's Equation superseded Ampere's Law.

Sure, but only as special cases. CM is still, ultimately, wrong.

Please, use the word superseded from now on. Mostly for my own sake, I will not have anything bad said about James Clerk's work. If you force my hand I will need to dedicate my life to proving that his equations are derivable from QM.

 

[Maxwell511]

Sure, but only as special cases. CM is still, ultimately, wrong.

If CM is a prediction of QM in special cases then that means that if CM is wrong so is QM. QM is not wrong as far as we can tell.

You have three chances at insulting James Clerk's work. You have taken two. If you do it again, I will get in a taxi to the airport, get a transatlantic flight and kick your ass. By ass kicking I mean read these books and share your opinions, until you realize that James was the greatest scientist to exist.

 

[mzungu]

If CM is a prediction of QM in special cases then that means that if CM is wrong so is QM. QM is not wrong as far as we can tell.

You have three chances at insulting James Clerk's work. You have taken two. If you do it again, I will get in a taxi to the airport, get a transatlantic flight and kick your ass. By ass kicking I mean read these books and share your opinions, until you realize that James was the greatest scientist to exist.

Nah! No one has even come close to Paul Adrien Maurice Dirac

 

[Wiccan_Child]

If CM is a prediction of QM in special cases then that means that if CM is wrong so is QM. QM is not wrong as far as we can tell.

CM is not a prediction of QM, QM is a refinement of CM. CM is a separate mathematical framework that is most accurate at medium size, low energy scales - but, ultimately, it's wrong. QM is a superior framework, and at the same scales that CM works best at, it makes largely the same predictions, to the extent that we just use CM for simplicity's sake.

But CM isn't QM. CM only approximates the more accurate QM at certain scales, and even then not exactly. Special Relativity is a special case of General Relativity, hence the name, but CM was never a special case of QM, it was a wholly separate thing that was summarily disproven in the early 20[sup]th[/sup] century.

You have three chances at insulting James Clerk's work. You have taken two. If you do it again, I will get in a taxi to the airport, get a transatlantic flight and kick your ass. By ass kicking I mean read these books and share your opinions, until you realize that James was the greatest scientist to exist.

Maxwell made great contributions, sure, but his theorems were still ultimately wrong - it's particles all the way down, baby.

 

[Maxwell511]

Maxwell made great contributions, sure, but his theorems were still ultimately wrong - it's particles all the way down, baby.

I'm sorry, what? Are you suggesting that James Clerk was ultimately wrong in uniting magnetism with electric phenomena?

 

[Wiccan_Child]

I'm sorry, what? Are you suggesting that James Clerk was ultimately wrong in uniting magnetism with electric phenomena?

I'm saying his unit of unification, the EM field, is wrong - it's photons, not waves. Like I said, great contributions, but just shy of the mark. Science has moved on.

 

[Maxwell511]

I'm saying his unit of unification, the EM field, is wrong - it's photons, not waves. Like I said, great contributions, but just shy of the mark. Science has moved on.

I think you must be using a weird version of the word "wrong".

Quantization of a EM field, and calling it a photon, does not prove EM fields to be wrong. In fact, it is the opposite.

 

[Maxwell511]

Nah! No one has even come close to Paul Adrien Maurice Dirac

Everybody loves Dirac. Especially those that have been trained as Engineers.

 

[chris4243]

I suppose an interesting problem then would be determining that the machine was actually sentient, rather than just appearing to be.

Yes it is possible, at least if the amount of observation/testing you do is limited (ie, we can have things that look superficially sentient, such as chat bots, but on deeper examination realize that they're just mindless bots).

A related question would be, are we sentient and how can we tell? I think sufficiently advanced non-sentience can be indistinguishable from sentience except to its creator or someone able to disassemble it. And defining sentient such as to exclude things that only "look" sentient runs the risk of declaring us potentially non-sentient.

 

[Wiccan_Child]

I think you must be using a weird version of the word "wrong".

Quantization of a EM field, and calling it a photon, does not prove EM fields to be wrong. In fact, it is the opposite.

It proves them to be other than what Maxwell envisioned. A refinement of a scientific theory is still a supercession - Darwin's ideas have been refined, and thus, the originals are wrong. The EM field, as described by Maxwell, was described as a wave - not a particle. True, there's some contention as to whether photons are waves, particles, or both, but Maxwell's original set of equations have been replaced, in principle, by quantum electrodynamics. Broadly similar, but QE supersedes Maxwell just as QM and GM supersede CM.

Maxwell is classical electrodynamics, with all the usefulness and shortcomings of any other classical, non-quantum description.

 

[Maxwell511]

It proves them to be other than what Maxwell envisioned. A refinement of a scientific theory is still a supercession - Darwin's ideas have been refined, and thus, the originals are wrong. The EM field, as described by Maxwell, was described as a wave - not a particle. True, there's some contention as to whether photons are waves, particles, or both, but Maxwell's original set of equations have been replaced, in principle, by quantum electrodynamics. Broadly similar, but QE supersedes Maxwell just as QM and GM supersede CM.

Maxwell is classical electrodynamics, with all the usefulness and shortcomings of any other classical, non-quantum description.

Thank you using the word "superseded".

On a small pedantic point; Maxwell did not envision EM fields as being waves. His theory predicted that they could be. This caused many monocles to break and virtuous women to faint at such nonsense, but it was ultimately proven true by Hertz and his experiments. James did not say that an EM must be wave, he said it can be.

 

[Wiccan_Child]

Thank you using the word "superseded".

On a small pedantic point; Maxwell did not envision EM fields as being waves. His theory predicted that they could be. This caused many monocles to break and virtuous women to faint at such nonsense, but it was ultimately proven true by Hertz and his experiments. James did not say that an EM must be wave, he said it can be.

Fair enough. Still, QE is what we use nowadays .

 

[mzungu]

Yes it is possible, at least if the amount of observation/testing you do is limited (ie, we can have things that look superficially sentient, such as chat bots, but on deeper examination realize that they're just mindless bots).

A related question would be, are we sentient and how can we tell? I think sufficiently advanced non-sentience can be indistinguishable from sentience except to its creator or someone able to disassemble it. And defining sentient such as to exclude things that only "look" sentient runs the risk of declaring us potentially non-sentient.

If one uses your argument then one may call a severely cerebrally handicapped person a non sentient being and technically be right.

So you see; Biological physiology is not a prerequisite for the title "sentient life form"

The physical does not the sentience define.

 

[selfinflikted]

WiccanChild,

Over in E&M we've been discussing in a couple of threads the idea of free will vs an omniscient deity (again).

The way I see it, if "god" has total and complete knowledge and knows every decision one will ever make in life, can one have free will if one can never make a decision contrary to the known outcome?

What are your thoughts on this?

(Sorry for busting this up with a philosophical question. But I'm going to defer to our resident "expert" on this. lol)

 

[Wiccan_Child]

WiccanChild,

Over in E&M we've been discussing in a couple of threads the idea of free will vs an omniscient deity (again).

The way I see it, if "god" has total and complete knowledge and knows every decision one will ever make in life, can one have free will if one can never make a decision contrary to the known outcome?

What are your thoughts on this?

(Sorry for busting this up with a philosophical question. But I'm going to defer to our resident "expert" on this. lol)

Well all philosophy boils down to physics, so I suppose this falls under my jurisdiction

I used to be of the belief that omniscience precluded genuine free will, but I've since changed my mind. Though I don't believe any omniscience exists, and I'm on the fence about free will, I don't see the two as mutually exclusive.

Omniscience means that your decisions are known. But they're still just that: your decisions. What you freely choose may be known by God (or whatever entity is omniscient), but he isn't forcing you to choose the decision you will make, the choice is still yours. If we have some 'soul' or 'spirit' that solves the problem of how we can be truly creative or spontaneous in our decision making*, that still wouldn't necessarily preclude an omniscient being from foreknowing what it is we will freely decide. The 'free' part means its our decision, not that it's unknowable.

That's my take, at least

*From a scientific point of view, a highly complex quantum mechanical interaction in the brain's synapses may result in a very sophisticated sorting algorithm, much like the sophisticated computer programmes that arise ultimately from rather basic logic gates, could give rise to a 'genuine free will' algorithm. Maybe, in contrast to epiphenomenalism, that's the reason why the concious mind evolved - to act as a decision making tool of such sophistication that conciousness was the inevitable outcome of such a collation of sensory data. Maybe

 

[chris4243]

I used to be of the belief that omniscience precluded genuine free will, but I've since changed my mind. Though I don't believe any omniscience exists, and I'm on the fence about free will, I don't see the two as mutually exclusive.

To be fair, we were discussing responsibility of the creator for the evil in the world and how free will relates to that, so if you subscribe to the idea of deterministic free will as compatible with omniscience than (I think) responsibility still carries through.

A more physics related question: is "non-determinism" still non-deterministic if you know the result ahead of time (eg via time machine or "omniscience")?

 

[mzungu]

WiccanChild,

Over in E&M we've been discussing in a couple of threads the idea of free will vs an omniscient deity (again).

The way I see it, if "god" has total and complete knowledge and knows every decision one will ever make in life, can one have free will if one can never make a decision contrary to the known outcome?

What are your thoughts on this?

(Sorry for busting this up with a philosophical question. But I'm going to defer to our resident "expert" on this. lol)

Free will and Omniscience are mutually exclusive!

 

[Assyrian]

Free will and Omniscience are mutually exclusive!

All you need is someone outside our universe, outside our space time, who knows what we are going to choose because because he has already seen us do it. That doesn't change whether we make the decisions with free will or not. You know the decisions you and your friends made last weekend, but knowing the decisions from your perspective now doesn't mean you didn't have free will, (at least before that thing with the rabbit and the toothpaste).