Search found 1911 matches

by Charlie!
Sat Jan 28, 2012 11:04 pm UTC
Forum: Science
Topic: Common Misconceptions within Physics and Astronomy
Replies: 98
Views: 18028

Re: Misconceptions within Physics and Astronomy

It can't- no one knows how to get a Born rule out of the theory. WIthout getting the Born rule, you either can't make predictions or you make wrong predictions. The same is true for all interpretations. The square of the amplitude is just put in. Well... there actually IS an idea how it could be th...
by Charlie!
Sat Jan 28, 2012 10:26 pm UTC
Forum: Science
Topic: [PHYSICS] Two questions whose solutions i dont understand
Replies: 19
Views: 3151

Re: [PHYSICS] Two questions whose solutions i dont understan

2.How does the (cos45)^2 term come in? Caution: I am a biologist with limited knowledge of physics, so I may be totally wrong. I intuitively think the term comes into play by combining the force vector from the two springs that are at a 135 degree angle to the downward springs. Combining those two ...
by Charlie!
Fri Jan 27, 2012 6:03 am UTC
Forum: Serious Business
Topic: Legitimate Faith vs Wacky Cult
Replies: 174
Views: 21959

Re: Legitimate Faith vs Wacky Cult

I do treat some people differently based on what they believe, for the fairly practical reason that what someone believes about religion informs you about how that person reasons. An earnest believer in FSM probably doesn't do so for sane reasons, so why should I expect them to be sane about other t...
by Charlie!
Sun Jan 22, 2012 11:01 am UTC
Forum: Science
Topic: Questions about Sulfur Hexafluoride
Replies: 30
Views: 5546

Re: Questions about Sulfur Hexafluoride

KrO2 wrote:What if you mix O2 and SF6 as originally suggested, but breathe it in zero-g? Then the heavier gas wouldn't just fill up the lungs from the bottom. Is that the only danger?

Eventual SF6 bad effects mentioned above.
by Charlie!
Thu Jan 19, 2012 12:06 pm UTC
Forum: Science
Topic: RPM vs Gas Consumption
Replies: 44
Views: 15961

Re: RPM vs Gas Consumption

Keep throttle constant when going uphill, don't keep speed constant. Public safety announcement: don't do this part on snow or ice. Potentially using less gas is not worth having trouble getting up the hill - drop into a lower gear and keep your speed consistent. This has been your regularly schedu...
by Charlie!
Tue Jan 17, 2012 2:39 am UTC
Forum: Science
Topic: Temperature on the Moon
Replies: 9
Views: 2553

Re: Temperature on the Moon

Well if he was just standing in one spot, he'd keep the moon warm beneath him :P But yeah, the only problem with your post I see is that you expect that the astronaut should come into equilibrium with the moon - humans are very non-equilibrium systems.
by Charlie!
Mon Jan 16, 2012 7:10 am UTC
Forum: Science
Topic: Airfoil/Airfoil comic
Replies: 3
Views: 1139

Re: Airfoil/Airfoil comic

Right. Air goes down, plane goes up. A lot of this comes from having the wing be at an angle to the oncoming air , sort of like waterskiing. If you think about where pressure comes from, you'll see that the "air goes down, plane goes up" and "difference in pressure" explanations ...
by Charlie!
Sat Jan 14, 2012 3:37 am UTC
Forum: Science
Topic: Science needs a symbol
Replies: 83
Views: 12920

Re: Science needs a symbol

The worldview that things can be explained, should be explained, that decisions and statements should be made with evidence. Also, that's not science. That is the view of almost every living person, ever Careful not to presume something is common just because it's a good idea, or to generalize from...
by Charlie!
Mon Jan 02, 2012 1:24 am UTC
Forum: Fictional Science
Topic: Being your own mother
Replies: 15
Views: 6252

Re: Being your own mother

There's an additional complication - her ovum would have to have 0 mutations as it was produced from itself! So we're really into the realm of magic powers here.
by Charlie!
Wed Dec 28, 2011 10:03 pm UTC
Forum: Serious Business
Topic: Does this image explain global warming?
Replies: 19
Views: 6696

Re: Does this image explain global warming?

My favorite image is this one, though it's a bit out of date:

Image
by Charlie!
Tue Dec 27, 2011 5:43 pm UTC
Forum: Science
Topic: Why Chemistry?
Replies: 6
Views: 2086

Re: Why Chemistry?

Did you take a certain class that started your interest in Chemistry? What sort of stuff in chemistry do you enjoy most? (designing syntheses, doing syntheses, learning about cool compounds, analyzing unknown compounds, organic vs. inorganic and/or physics-ish vs. biology-ish) Do you have any intere...
by Charlie!
Mon Dec 26, 2011 8:34 pm UTC
Forum: Science
Topic: Pauli Exclusion Principle and Brian Cox
Replies: 16
Views: 8866

Re: Pauli Exclusion Principle and Brian Cox

The impression I'm getting is that we're discussing real systems where all of everything in the universe comes into play, and so you simply don't have an idealised lone hydrogen atom or 3d box or double well or other 'nice' solvable systems, and I'm not sure if theres any true symmetries that can b...
by Charlie!
Sun Dec 25, 2011 3:54 am UTC
Forum: Science
Topic: Pauli Exclusion Principle and Brian Cox
Replies: 16
Views: 8866

Re: Pauli Exclusion Principle and Brian Cox

So here's the issue: you are right, in the sense that /L> and /R> have the same distribution over the energy eigenstates- or, if you prefer, the same average energy. That should make Schroedinger happy. On the other hand, if you actually measure the energy of one or the other, you force yourself in...
by Charlie!
Thu Dec 22, 2011 9:12 pm UTC
Forum: Science
Topic: Pauli Exclusion Principle and Brian Cox
Replies: 16
Views: 8866

Re: Pauli Exclusion Principle and Brian Cox

Why accept something that's probably wrong, jut because someone's smart, or the subject is complicated? The claim seems pretty nobberish, anyhow. The exclusion principle keeps electrons from being in the same state, but many different states can have the same energy. For example, in a system with le...
by Charlie!
Wed Dec 14, 2011 9:07 pm UTC
Forum: Science
Topic: What textbooks would you recommend in the following courses?
Replies: 42
Views: 7024

Re: What textbooks would you recommend in the following cour

Minerva wrote:Jackson's Classical Electrodynamics is one of the most highly regarded CED books out there, but it might be a little too "hard" for the lower years of undergrad.

It also might be a little bit too deadly boring :P
by Charlie!
Sun Dec 11, 2011 11:59 am UTC
Forum: Science
Topic: Hawking radiation and conservation of charge
Replies: 20
Views: 3449

Re: Hawking radiation and conservation of charge

Feynman graphs do care. You can attach a photon with circular polarization to them. Try the same with linear polarization. Every single-photon process has a photon with spin 1, which corresponds to circular polarization. So you're saying that, for example, if 2 electrons interact, if you track the ...
by Charlie!
Sat Dec 10, 2011 6:22 am UTC
Forum: Science
Topic: Hawking radiation and conservation of charge
Replies: 20
Views: 3449

Re: Hawking radiation and conservation of charge

The photon doesn't measure itself - it doesn't have any preference at all for what state it's in. It's an electromagnetic field propagating through space, why should it care whether that field describes a line or a circle or an ellipse? Circularly polarized light can be written as a superposition o...
by Charlie!
Thu Dec 08, 2011 3:59 pm UTC
Forum: Mathematics
Topic: Labyrinth Puzzle
Replies: 15
Views: 3386

Re: Labyrinth Puzzle

If the proportion of truthful guards is at least (I think) 8/9 (for the worst case), and the proportion of safe doors is less than or equal to 1/2, it's always quicker to find a truthful guard and just ask which door is safe than it is to find a safe door. And of course it's on average faster more o...
by Charlie!
Tue Dec 06, 2011 11:31 pm UTC
Forum: Science
Topic: Infinity physical, theorhetical, and theological
Replies: 14
Views: 2757

Re: Infinity physical, theorhetical, and theological

My favorite place for infinities is the number of points between two different points. The universe looks pretty convincingly like that number is infinite.
by Charlie!
Tue Dec 06, 2011 11:16 pm UTC
Forum: Science
Topic: Calculating the error in an estimate of <x^2>
Replies: 5
Views: 1558

Re: Calculating the error in an estimate of <x^2>

Don't worry If you want another option, you might look up the maxwell-boltzmann distributions for the energy and velocity, and cite the analogous characteristic scale of the distribution (related to the temperature in the case of maxwell-boltzmann) as the "spread" of your distribution...
by Charlie!
Tue Dec 06, 2011 10:27 am UTC
Forum: Science
Topic: Calculating the error in an estimate of <x^2>
Replies: 5
Views: 1558

Re: Calculating the error in an estimate of <x^2>

Standard deviation is usually a good measure of uncertainty. Sqrt[ <x^4> - <x^2>^2 ]
by Charlie!
Tue Dec 06, 2011 9:10 am UTC
Forum: Science
Topic: Hawking radiation and conservation of charge
Replies: 20
Views: 3449

Re: Hawking radiation and conservation of charge

I had never thought photons could have a spin. It appears photons have circular polarization, and that linear polarization can be achieved only by having two photons of opposite angular momentum, while I had always assumed it worked the other way around. Writing down the photon in terms of linearly...
by Charlie!
Tue Dec 06, 2011 8:53 am UTC
Forum: Science
Topic: What textbooks would you recommend in the following courses?
Replies: 42
Views: 7024

Re: What textbooks would you recommend in the following cour

Organic Chemistry My favorite was Clayden, Greeves, Warren and Wothers. A gigantic New York phonebook of a text, but fun to read. Special/General Relativity, Introductory For general relativity, D'Inverno seemed like a good first book. But that's for an actual general relativity course, of course.
by Charlie!
Sun Dec 04, 2011 9:37 pm UTC
Forum: Serious Business
Topic: "What's next, Bestiality?" revisited
Replies: 81
Views: 13212

Re: "What's next, Bestiality?" revisited

omgryebread wrote:
KrazyerKate wrote:What harm does sex with a cow do? What harm does marrying car do?
I've never met a cow nor a car that can consent to a contract.

Marriage is a contract, and contracts, by definition in order to avoid being either useless or unethical (or both!), require consent.

:P
by Charlie!
Wed Nov 30, 2011 5:32 am UTC
Forum: Science
Topic: Physics for beginners?
Replies: 8
Views: 2346

Re: Physics for beginners?

My favorite resource is hyperphysics. It's sort of like browsing through wikipedia, but with demonstrations of all the math.
by Charlie!
Tue Nov 29, 2011 9:02 am UTC
Forum: Science
Topic: Spring system, center of mass frame
Replies: 3
Views: 1436

Re: Spring system, center of mass frame

Radial kinetic energy:

So if R = r1 + r2 changes, and you're in the center of mass frame, how much does M1 move, and how much does M2 move (so that the center of mass doesn't move)? If that motion happens per 1 second, what is the kinetic energy of M1 and M2?
by Charlie!
Tue Nov 29, 2011 7:28 am UTC
Forum: Fictional Science
Topic: Some mechanism to locally reverse time
Replies: 22
Views: 8918

Re: Some mechanism to locally reverse time

The characters are actually living their lives inside a simulation, and the device has access to the control system. This is the less tame version of "the first run-through was a simulation, but the characters are from the real world." Or it could download their brain scan, send it back in...
by Charlie!
Sun Nov 27, 2011 2:37 am UTC
Forum: Science
Topic: "Longitudal Dielectric Waves"
Replies: 4
Views: 2545

Re: "Longitudal Dielectric Waves"

I was thinking it was bullshit, but I'm not sure how you can pull of things like this if it is. (I am told that the two lines are too far apart for it to work by radio/induction at that power, but like I said, I don't know my stuff here.) The main limiting factor is current. Voltage isn't that hard...
by Charlie!
Sat Nov 26, 2011 11:50 pm UTC
Forum: Science
Topic: "Longitudal Dielectric Waves"
Replies: 4
Views: 2545

Re: "Longitudal Dielectric Waves"

Yeah, looks like pretty pure bullshit.

Not that induction isn't cool, but it's more fun when not surrounded by bullshit.
by Charlie!
Fri Nov 25, 2011 3:28 pm UTC
Forum: Science
Topic: Climate Emails
Replies: 3
Views: 726

Re: Climate Emails

Context? What's context? From the actually proving things perspective, if you don't have context you ain't got nothin', and I somehow suspect that there will be a shortage. But this was never intended to actually prove things, but to have a political impact, so I suppose we should think about the po...
by Charlie!
Sat Nov 19, 2011 1:34 am UTC
Forum: Science
Topic: photon size
Replies: 61
Views: 12086

Re: photon size

Xami wrote:There are exactly the same number of right answers as wrong answers to any question.

This bald assertion cannot withstand the power of... Multiple Choice Exaaaaaaaaams!
by Charlie!
Fri Nov 18, 2011 9:48 pm UTC
Forum: Science
Topic: photon size
Replies: 61
Views: 12086

Re: photon size

Wouldn't the photon's "size" be approximately the plank length? A string would vibrate to create a particle, and a string is at the minimum a plank length in diameter. Being massless I would hope that a photon holds the minimum size. If a photon behaved like a wavepacket with a diameter o...
by Charlie!
Fri Nov 18, 2011 4:19 am UTC
Forum: Science
Topic: 2 "point" 4 dimethyl valeronitrile - why no comma?
Replies: 4
Views: 1513

Re: 2 "point" 4 dimethyl valeronitrile - why no comma?

It's not even consistently used.

Maybe it's one o' them odd holdovers from pre-IUPAC.
by Charlie!
Thu Nov 17, 2011 1:36 am UTC
Forum: Serious Business
Topic: The Assumptions of Searle’s Chinese Room Thought Experiment
Replies: 349
Views: 43091

Re: The Assumptions of Searle’s Chinese Room Thought Experim

My whole point was that there are problems that are solvable that are not "computable" in the strict sense of the term. So far, no-one's ever found one . Busy beaver function for a 4-state, 2-symbol machine. Or, more generally, because proving theorems is not computable, there are things ...
by Charlie!
Wed Nov 09, 2011 2:37 pm UTC
Forum: Science
Topic: Cosmology Question
Replies: 21
Views: 2950

Re: Cosmology Question

Locust wrote:am I the exact center of time as well?

Nope.
by Charlie!
Fri Oct 28, 2011 7:29 am UTC
Forum: Science
Topic: Reconstructing an accident; Vomhof method?
Replies: 3
Views: 1446

Re: Reconstructing an accident; Vomhof method?

It's probably because there's some characteristic length over which the car itself bends. If it hits a wall, the whole front of the car will be crushed, but if it hits a pole, it won't just be a pole-shaped slice of the car that gets crushed - the whole front of the car will crumple to some extent, ...
by Charlie!
Thu Oct 27, 2011 10:22 pm UTC
Forum: Science
Topic: One thing that has always bugged me about evolution.
Replies: 48
Views: 7985

Re: One thing that has always bugged me about evolution.

Dr.Buck wrote:So, in that case, what would you call a deer with no antlers?

A doe?
by Charlie!
Tue Oct 25, 2011 7:27 am UTC
Forum: Science
Topic: Goodbye dark matter?
Replies: 18
Views: 3692

Re: Goodbye dark matter?

Tass wrote:Why is the topic about dark matter when the link is about dark energy?

The link also claims that the author claims to eliminate the need for dark matter in gravitational lensing.
by Charlie!
Thu Oct 20, 2011 9:32 am UTC
Forum: Science
Topic: Wait, can free will exist?
Replies: 247
Views: 26439

Re: Wait, can free will exist?

I feel like you're making one big category error, Ben. You're treating "free-willed" as if it has to be the same sort of thing as deterministic and random. But it cannot be that sort of thing - deterministic and random just mean "does the same thing when in the same configuration"...
by Charlie!
Wed Oct 19, 2011 3:52 am UTC
Forum: Science
Topic: Wait, can free will exist?
Replies: 247
Views: 26439

Re: Wait, can free will exist?

I agree that there is nothing in the definition of a random model and a deterministic model that makes those two options exhaustive Imagine that you could repeatably generate some system at some point in time - like a pendulum pulled back to a certain height, or a human at birth. There would be som...

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