Ask a Physicist Anything!

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UNITEDAIR
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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Sun Sep 06, 2015 9:44 pm

Since the server number (20?) is actually larger than the player number (-4ish) and time and space has not yet imploded, I'd say we're all safe.
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Re: Ask a Physicist Anything!

Postby Schubdüse » Tue Oct 20, 2015 1:23 am

Ask a Physicist Anything...
Yeah, yeah, I love you megalomaniac guys. Always thinking that they can explain the "world" without realizing that biology beats everything in complexity.
Don't get me wrong. You guys are important and the stuff you deal with is very complex. Still biology is much more complex.

But let's try: How do I move my index finger?
(Cut the crap and don't lecture me about actin, myosin, motoneurons, acetylcholine etc. Explain me the trigger? What is the "photon", the "soundwave", the ligand to the smell or taste receptor, the pressure or heat sensor which makes my finger move, if I WANT to?)
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Re: Ask a Physicist Anything!

Postby Colytic » Tue Oct 20, 2015 6:20 pm

Isn't it annoying when physicists demean biology as 'applied chemistry which is just applied physics' ;)
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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Tue Oct 20, 2015 7:16 pm

Schubdüse wrote:But let's try: How do I move my index finger?
(Cut the crap and don't lecture me about actin, myosin, motoneurons, acetylcholine etc. Explain me the trigger? What is the "photon", the "soundwave", the ligand to the smell or taste receptor, the pressure or heat sensor which makes my finger move, if I WANT to?)


Excellent question, but not really related to my field. Seems like you're asking it in a philosophical manner.
Now I can answer what a photon is or soundwave is if that is what your asking.
If you want to make a ask a biologist (if you are one), I have many questions I would like to ask.
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Re: Ask a Physicist Anything!

Postby xander » Tue Oct 20, 2015 8:06 pm

Colytic wrote:Isn't it annoying when physicists demean biology as 'applied chemistry which is just applied physics' ;)

Indeed. Especially when you consider that physicists don't even own the high ground on this one. I mean, physics is just applied mathematics. If anyone can look down on anyone else, it is definitely we mathematicians looking down on all the rest of y'all. :P

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Re: Ask a Physicist Anything!

Postby Mr.Megadeath » Tue Oct 20, 2015 9:37 pm

xander wrote:Indeed. Especially when you consider that physicists don't even own the high ground on this one. I mean, physics is just applied mathematics. If anyone can look down on anyone else, it is definitely we mathematicians looking down on all the rest of y'all. :P


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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Wed Oct 21, 2015 5:06 am

I agree with xander, mathematics blows every other field out of the water in terms of complexity (sorry biology) and purity. Philosophy may be purer as it can be argued that all of mathematics is logic which is just applied philosophy, perhaps mathematics is just theoretical reasoning, but that awesome discussion is for another thread. While I might joke a lot on academia, I don't seriously belittle any other field; I hold the utmost respect for my fellow scientists and their field of study.
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Re: Ask a Physicist Anything!

Postby kudayta » Thu Oct 22, 2015 2:36 am

UNITEDAIR wrote:I agree with xander, mathematics blows every other field out of the water in terms of complexity (sorry biology) and purity. Philosophy may be purer as it can be argued that all of mathematics is logic which is just applied philosophy, perhaps mathematics is just theoretical reasoning, but that awesome discussion is for another thread. While I might joke a lot on academia, I don't seriously belittle any other field; I hold the utmost respect for my fellow scientists and their field of study.


I studied bio in college, and maybe things are different where Schub is from, but around these parts we definitely had "physics envy". I mean, just read this:

"There is only one science, physics: everything else is social work." - James Watson

That dude helped to discover the structure of DNA. Definitely one of the luckiest biologists in history, if not one of the greatest.
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Re: Ask a Physicist Anything!

Postby trickser » Thu Oct 22, 2015 3:35 pm

The crown of scientific concepts belongs to evolution (see my avatar).

It even challenges the 2nd law of thermodynamics.

2nd law of thermodynamics: "In the end everything will be equally dull."
evolution: "Uh, man! Sounds like a bad idea, mind if I try to have 1 or 2 better ones till then?"
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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Thu Oct 22, 2015 4:17 pm

trickser wrote:The crown of scientific concepts belongs to evolution (see my avatar).

It even challenges the 2nd law of thermodynamics.

2nd law of thermodynamics: "In the end everything will be equally dull."
evolution: "Uh, man! Sounds like a bad idea, mind if I try to have 1 or 2 better ones till then?"


Lovely opinion.
Also, this comment demonstrates you have a complete lack of understanding of thermodynamics.
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Re: Ask a Physicist Anything!

Postby trickser » Thu Oct 22, 2015 4:53 pm

I think the 2nd law just doesn't deal with regions(of system) that become subsytems with a lower entropy.
But it happens anyway.

(But yes, I dont really understand thermodynamics)
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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Sat Oct 24, 2015 4:07 am

The sun increases entropy by orders of magnitude higher than what all the life on earth can lower it by. If this were not the case, then life would not be possible.
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Re: Ask a Physicist Anything!

Postby Laika » Sat Oct 24, 2015 10:29 am

Explain me entropy, please.
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Re: Ask a Physicist Anything!

Postby xander » Sat Oct 24, 2015 8:03 pm

UNITEDAIR wrote:I agree with xander, mathematics blows every other field out of the water in terms of complexity (sorry biology) and purity. Philosophy may be purer as it can be argued that all of mathematics is logic which is just applied philosophy, perhaps mathematics is just theoretical reasoning, but that awesome discussion is for another thread. While I might joke a lot on academia, I don't seriously belittle any other field; I hold the utmost respect for my fellow scientists and their field of study.

I assume that the facetious tone of my previous comment was understood, but, just to be clear, let me echo this comment: I joke, but any disparaging comments about other fields are meant in good spirits. I would also hesitate to compare various fields, or to say that one is "more complex" or "more pure" than another. They are simply different.

Mathematics is a branch of philosophy, and deals with what conclusions can be obtained via a certain formulation of logic. In mathematics, a statement is either provably true, provably false, or undecidable. If we determine that something is true, then it absolutely is (at least, with respect to the axioms chosen). There is a notion of absolute proof. Unfortunately, this often has nothing to do with the real world---for instance, it is a mathematically verifiable fact (assuming the axiom of choice) that a ball can be decomposed into a small number of subsets, and that these subsets can be reassembled into two balls that are identical to the original ball using only translations and rotations (which are maps that don't change the sizes of the objects they act on). This is clear bonkers from an empirical point of view, but is definitely true in the world of mathematics.

On the other hand, the sciences are empirical. Any model or theory that is formulated is, ultimately, subservient to observed data. If the data contradict the theory, then either the data need to be verified (hey, mistakes and errors occur), or the theory needs to be discarded (or, more often, revised). All knowledge in the science is tentative, and it is always possible that new observations will fundamentally alter our understanding of the universe (this seems unlikely to happen, but, in principle, it could happen). The sciences often use mathematics as a tool (or, more accurately, they use the results of mathematics), but scientific truth is very different from mathematical truth.

Making a comparison between mathematics and the sciences is comparing apples and oranges. It can be done, but one has to give the proper context. ;)

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Re: Ask a Physicist Anything!

Postby UNITEDAIR » Sat Oct 24, 2015 9:12 pm

Entropy is the measurement of disorder or unusable mechanical energy in a system. Things in thermal equallibirum are said to be in a state of maximum entropy. There are several equations of entropy (S), here is the statistical mechanical one (probably the most important too) : S=k*ln(Q) where k is Boltzmann constant and Q is the number of possible microscopic arrangements of thermal flucuations. The unit of S is J/K or joules per kelvin. The second law of thermodynamics states that entropy always increases and will eventually cause the heat death.

[mod edit: corrected boltzmann's name]

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