Ask a physicist anything. (2)

[Wiccan_Child]

The statement "1 apple +1 apple=2 apples" is a fact. The statement "1+1=2" isn't necessarily, personally I am not sure what "1+1=2" even means. This is even before we get to i*i=-1, what the hell is that?

e^pi*i+1=0!!!!!? That is insane.

Abstraction, abstraction, abstraction. Shape and number refined into pure concept!

My favourite quote about mathematics and logic is this:

Imagination does not breed insanity. Exactly what does breed insanity is reason. Poets do not go mad; but chess-players do. Mathematicians go mad, and cashiers; but creative artists very seldom. I am not, as will be seen, in any sense attacking logic: I only say that this danger does lie in logic, not in imagination.- G.K. Chesterton

That statement is more of a fact for me than "1+1=2". Look at Cantor!

It's a fact, but only because the human mind is too squishy to appreciate the firmaments of reality. Once you've upgraded your brain from organic to synthetic, like me, you see what I mean .

 

[Saving Hawaii]

My favourite quote about mathematics and logic is this:

Imagination does not breed insanity. Exactly what does breed insanity is reason. Poets do not go mad; but chess-players do. Mathematicians go mad, and cashiers; but creative artists very seldom. I am not, as will be seen, in any sense attacking logic: I only say that this danger does lie in logic, not in imagination.- G.K. Chesterton

It's a horribly mistaken quote. The greatest chess master in existence, Kasparov, is very sober and articulate to this day. The greatest of our country's heritage never really went insane; that's a figment of the imagination that's been propagated by our media. Bobby Fischer was a very close friend of a friend of mine; she was most familiar with Bobby after he'd dropped out of the international chess scene. If you're familiar with the history of chess, you might know who Bobby Fischer hung out with after he dropped out of chess (he spent a lot of time in SF) - there was a lady present during all of that who also incidentally earned the title of IWM.

Bobby Fischer's story is that of millions of sudden celebrities who wish they'd never been exposed to the public spotlight. He was a brilliant man who highlighted his brilliance in his ability to understand chess as a mathematical game where winners and losers are decided by their competency in understanding the odds of every move. That's the current human understanding of chess; pick up any book about the game and you'll learn that.

Bobby Fischer was not your average human being, this much is for certain. Chesterton is an absolute idiot to attack the media hyperbole though; it's completely inaccurate and makes his attack nothing more than a strawman.

 

[Wiccan_Child]

Bobby Fischer was not your average human being, this much is for certain. Chesterton is an absolute idiot to attack the media hyperbole though; it's completely inaccurate and makes his attack nothing more than a strawman.

Chesterton, you hear that? Stop attacking the media hyperbole!

 

[Chesterton]

Bobby Fischer was not your average human being, this much is for certain. Chesterton is an absolute idiot to attack the media hyperbole though; it's completely inaccurate and makes his attack nothing more than a strawman.

I'm not absolutely certain, but pretty sure that that quote was made before Fischer was even born. We can be certain he was not talking about Fischer.

Chesterton, you hear that? Stop attacking the media hyperbole!

Never!

 

[Maxwell511]

Abstraction, abstraction, abstraction. Shape and number refined into pure concept!

Pure madness.

It's a fact, but only because the human mind is too squishy to appreciate the firmaments of reality. Once you've upgraded your brain from organic to synthetic, like me, you see what I mean .

I don't care what your brain is made out of. All I care about is if you can figure out an analog to the Hamiltonian for SOC systems. That would help me (and humanity, but who cares about them) out alot.

 

[AV1611VET]

[Bobby Fischer] was a brilliant man who highlighted his brilliance in his ability to understand chess as a mathematical game where winners and losers are decided by their competency in understanding the odds of every move.

And what did this "brilliant man" think of the Jews and the U.S. Constitution?

And have you read, Bobby Fischer vs. the Rest of the World, by Brad Darrach?

 

[Chesterton]

I remember once reading something Fischer wrote to some newspaper, talking about the IRS sending him notices regarding owing back taxes. He said he was getting letters "from some outfit billing itself as the Government of the United States of America".

 

[Spacewyrm]

Recently I had a discussion with Micheal in his thread about "an empircal theory of God", about said theory. Part of our discussion turned into a debate about "big bang" vs. "electric Universe" (I know, that subject hardly ever comes up, huh? ) Anyway, I was wondering if I could a second opinion about some of my arguments from one of the physicists on the board.

When I was asked to show evidence contradicting EU theory, I said this:

Eh, I'm not really sure. All I know is that most cosmologists don't agree with it. I'm not a physicist or a cosmologist, though I am very interested in astronomy and cosmology. In truth, I hadn't even heard of EU theory until a few months ago when it suddenly became the hot topic on the science forum here (mainly because Doveaman turns every thread into a debate of electric Universe vs. big bang Universe). I do know however that there is very good evidence that Universe is expanding (redshift of galaxies and such). This gives rise to the big bang theory. If I recall correctly, the big bang made at least two important predictions which verified it (and probably made more, but I don't remember anything else). One, the early conditions of the Universe proposed by the big bang theory along with the effects of fusion in stars would theoretically give rise to the proportion of elements that we see see in the Universe today. Another prediction was that we would find the cosmic microwave background radiation. (Of course, as I said, I'm no physicist, so if any of the physicists here see some horrible mistake in there, please correct me!)

Now, from what I've been reading from EU proponents here, it seems that EU theory and big bang theory can't really get along together. As far as I know, nothing has yet been found to falsify big bang theory, so this seems to be evidence against EU theory. But, I think until I learns more I'm just going to admit that mainly I'm basing my opinion on the overall opinion of cosmologists, who seem to be overwhelmingly in favor of big bang and overwhelmingly against EU. I suspect that if current cosmology is overturned it will not likely be in favor of EU theory but rather in favor of something completely new.

To which Micheal replied:

If I recall correctly, the big bang made at least two important predictions which verified it (and probably made more, but I don't remember anything else). One, the early conditions of the Universe proposed by the big bang theory along with the effects of fusion in stars would theoretically give rise to the proportion of elements that we see see in the Universe today.

That turns out to be based on some very questionable assumptions, starting with the concept that iron and nickel with stay "mixed" with light elements like hydrogen and helium over extend periods of time. If you take away that concept, the whole notion of elemental abundances comes into serious question. That turns out to be not so strong evidence actually.

Another prediction was that we would find the cosmic microwave background radiation. (Of course, as I said, I'm no physicist, so if any of the physicists here see some horrible mistake in there, please correct me!)

The problem however is that nobody ever demonstrated a "cause/effect" relationship between things like "inflation' or "dark energy" and that background signature. It's all "postdicted" to fit and there are some serious questions about the methods used in the WMAP program.

[1001.4643] Inconsistency between WMAP data and released map

There could be some "curve fitting" going on there.

Firstly, was I at all accurate in my assessment of evidence for the big bang?

Secondly, does Micheal's objection about assumptions about elements mixing have any merrit? How about that link about WMAP, I'm not quite sure what it's trying to say; there isn't anything nefarious going on there, right?



Finally, on the lighter side:

Is the following correct?

(from "Saturday Morning Breakfast Cereal")

 

[Assyrian]

Oh, this old world keeps spinning round It's a wonder tall trees ain't layin' down There comes a time.
Neil Young, Comes a Time, Greatest Hits CD, present from my son.

YouTube - Neil Young- Comes A Time Farm Aid '86
​

Now Neil as far as I know has his acceleration wrong. It isn't horizontal because we don't start from being stationary. If we are already spinning in a circle the acceleration is towards the center of the circle. However he does raise an interesting question, given the equivalence of gravity and acceleration, how much is g offset by the fact we are rotating? You don't experience g in free fall, so isn't rotating on the earth's surface the equivalent of a very slow orbit? So my first question is how much measurements of g are reduced at the equator? Of course most of us don't live in the equator, so is we lived at say a latitude of 45°, our acceleration is not toward the center of the earth like g, but is straight towards the earth axis at 45° to the force of gravity. So how much is the measurement of g changed and by what angle?

 

[thatbusfromspeed]

Dear physicists,

My understanding of thermodynamics and climate change is that it is physically impossible for climate change not to be anthropogenic. Because dS= w + q and the volume of the earth's atmosphere is constant (w=0) for entropy to increase q must increase. Furthermore, I know that for a system in equilibrium the energy in must = the energy out or else we see a change in temperature. For the earth, we receive energy in the form of UV and visible spectrum radiation from the sun, but because the earth is cooler we emit radiation in the IR spectrum. CO2 however absorbs IR radiation turning it into molecular vibrational energy which leads to an increase in the temperature of the gas and in turn the atmosphere. Essentially we receive more energy than we emit because CO2 (and other greenhouse gases) turn solar radiation into vibrational energy.

My question is, is this understanding accurate or over simplified, and do thermodynamics allow for any situation in which the increase of CO2 concentration in the atmosphere does not lead to an increase in temperature?

 

[Wiccan_Child]

Firstly, was I at all accurate in my assessment of evidence for the big bang?

Yes. The Big Two are the CMBR and the distribution of elements.

Secondly, does Micheal's objection about assumptions about elements mixing have any merrit? How about that link about WMAP, I'm not quite sure what it's trying to say; there isn't anything nefarious going on there, right?

No. The article basically pokes at minutiae that a) couldn't have been accounted for if they tried, and b) wouldn't make the slightest impact on the veracity of their data. It's like bemoaning the existence of an error of ±5, when your data are several orders of magnitude higher (when measuring in feet, the odd millimetre here and there doesn't matter).

Finally, on the lighter side:

Is the following correct?

(from "Saturday Morning Breakfast Cereal")

Yes. Her Kung Fu is indeed too powerful. I should know - I'm her.

 

[Spacewyrm]

Yes. The Big Two are the CMBR and the distribution of elements.

Ah good. I read a bunch of stuff and sometimes its hard to remember if I know what I'm talking about or making stuff up.

No. The article basically pokes at minutiae that a) couldn't have been accounted for if they tried, and b) wouldn't make the slightest impact on the veracity of their data. It's like bemoaning the existence of an error of ±5, when your data are several orders of magnitude higher (when measuring in feet, the odd millimetre here and there doesn't matter).

Yeah. I thought it was something like that. Good to know.

Yes. Her Kung Fu is indeed too powerful. I should know - I'm her.

Oh great... I think you just destroyed the Universe...

 

[Maxwell511]

Dear physicists,

My understanding of thermodynamics and climate change is that it is physically impossible for climate change not to be anthropogenic. Because dS= w + q and the volume of the earth's atmosphere is constant (w=0) for entropy to increase q must increase. Furthermore, I know that for a system in equilibrium the energy in must = the energy out or else we see a change in temperature. For the earth, we receive energy in the form of UV and visible spectrum radiation from the sun, but because the earth is cooler we emit radiation in the IR spectrum. CO2 however absorbs IR radiation turning it into molecular vibrational energy which leads to an increase in the temperature of the gas and in turn the atmosphere. Essentially we receive more energy than we emit because CO2 (and other greenhouse gases) turn solar radiation into vibrational energy.

My question is, is this understanding accurate or over simplified, and do thermodynamics allow for any situation in which the increase of CO2 concentration in the atmosphere does not lead to an increase in temperature?

I'm not a physicist so feel free to ignore everything I say.

We are not receiving more energy than we are emitting as a planet. It is that the pathways of the emission of energy from the planet are changing which will cause a change in the dynamics of the atmosphere i.e. climate change. So that part is incorrect in your understanding. The rest of your understanding seems fine to me.

Things that absorb energy without emitting it sufficiently tend to explode. We are not talking about global explosion.

 

[thatbusfromspeed]

I'm not a physicist so feel free to ignore everything I say.

We are not receiving more energy than we are emitting as a planet. It is that the pathways of the emission of energy from the planet are changing which will cause a change in the dynamics of the atmosphere i.e. climate change. So that part is incorrect in your understanding. The rest of your understanding seems fine to me.

Things that absorb energy without emitting it sufficiently tend to explode. We are not talking about global explosion.

I have discussed the energy balance part of what I said with my physics professors before and I am almost certain that is correct. I am more concerned with if thermodynamic laws allow for climate change to not be anthropogenic. The energy balance part that I described in my previous post is essentially the greenhouse effect which is a well documented and studied effect. It is a true that we recieve radiation in the visible and UV spectrums, it is true that the earth emits radiation in the IR spectrum, and it is true that CO2, H2O and to a much large extent methane absorb IR radiation turning it into vibrational energy, so I don't know how that could be wrong, however physicists prove me wrong if I am.

 

[Wiccan_Child]

Dear physicists,

My understanding of thermodynamics and climate change is that it is physically impossible for climate change not to be anthropogenic.

A very large heat sink or reservoir (e.g., a large asteroid) introduced into the climate would induce non-anthropogenic climate change. I'm wary of any claim that something is 'impossible'.

Because dS= w + q and the volume of the earth's atmosphere is constant (w=0) for entropy to increase q must increase.

I think you're thinking of W = PdV, which only relates the work required to change a volume of a fluid at a constant pressure. It doesn't tell us about work in its most general form; i.e., what the 'W' is in 'dS = W + Q'. In other words, a constant volume is no indication that W = 0. Work is, generally speaking, a change in the large, macroscopic properties of the system, not just a change in volume.

Moreover, the volume of the Earth's atmosphere isn't constant! It fluctuates as gas is lost and gained.

Furthermore, I know that for a system in equilibrium the energy in must = the energy out or else we see a change in temperature. For the earth, we receive energy in the form of UV and visible spectrum radiation from the sun, but because the earth is cooler we emit radiation in the IR spectrum. CO2 however absorbs IR radiation turning it into molecular vibrational energy which leads to an increase in the temperature of the gas and in turn the atmosphere. Essentially we receive more energy than we emit because CO2 (and other greenhouse gases) turn solar radiation into vibrational energy.

My question is, is this understanding accurate or over simplified, and do thermodynamics allow for any situation in which the increase of CO2 concentration in the atmosphere does not lead to an increase in temperature?

It depends entirely on how the CO[sub]2[/sub] reacts. It could very well send shockwaves through the atmosphere, vibrating things at their natural frequency and ablating all the oxygen till we suffocate.

But no, I don't see anything in the laws of thermodynamics that prohibit climate change being non-anthropogenic. The question isn't whether CO[sub]2[/sub] behaves the way we think it does, but rather the actual impact that behaviour has. Is it significant? Is if negligible?

 

[catzrfluffy]

Do all planets spin in the same direction?

 

[TerranceL]

YouTube - The Large Hadron Collider's Secret

 

[dewaddict84]

Do all planets spin in the same direction?

Yes and no? (The frame of reference for this post is far above the north pole of the planet, cause, you know, north is up...) All the planets orbit counter clockwise around the sun, which is the same direction the sun is rotating. This is due to how everything formed out of the space-soup.

All but two of the planets also rotate counter-clock-wise, except for Venus and Uranus. This is due to.... bad weather.... or something... It's called retrograde motion.

Another neat fact is that the moon orbits the earth at the same speed it rotates, so one side is always facing towards us and "the dark side" is unobserved.

 

[Wiccan_Child]

Yes and no? (The frame of reference for this post is far above the north pole of the planet, cause, you know, north is up...) All the planets orbit counter clockwise around the sun, which is the same direction the sun is rotating. This is due to how everything formed out of the space-soup.

All but two of the planets also rotate counter-clock-wise, except for Venus and Uranus. This is due to.... bad weather.... or something... It's called retrograde motion.

This is not due to 'bad weather'. Venus rotates clockwise (as viewed looking 'down' on the Earth's North Pole), and Uranus rotates laterally, due to large collisions in their history.

Another neat fact is that the moon orbits the earth at the same speed it rotates, so one side is always facing towards us and "the dark side" is unobserved.

That's the 'far side'. The 'dark side' is the side that is dark, and this changes over time. The 'far side' is, however, constant.

 

[Wiccan_Child]

Do all planets spin in the same direction?

No. Most of the planets and moons in our solar system spin in the same direction, because this is the way the original dust cloud span. The few exceptions arise from large collisions: spin a billiard ball and knock another one into its side in the right way, and it will spin in the other direction.