Bill Angel

Oops! Fair enough.

If (big if) you could calculate the interactions in each and every atom in the prey and the predator why would you not be able to work out the relation between them?

In principle, it's physics.

That was my point. Where do you draw the line?

Or does the fact that some of these are, in principle, incalculable mean that physics really couldn't explain the predator prey relation?

 

In any event I agree it's silly to talk of any branch of science "winning".

If a purported theory cannot make meaningful refutable predictions about a phenomena that it purports to explain, then that theory really isn't making a scientific contribution to understanding that phenomena. Biologists would have every right to assert that since physicists who are experts in string theory cannot make refutable predictions relevant to understanding predator prey relationships, there is no reason for biologists to genuflect (i.e. pay deep homage and respect to) these string theorists.

I came across some interesting information about the element Bismuth:

"No other metal is verified to be more naturally diamagetic than Bismuth. It is the most diamagnetic of naturally occuring elements."

"Because bismuth is the most diamagnetic naturally occurring element, it is used for diamagnetic levitation."

Can someone supply an understandable explaination, or a reference to an understandable explaination, as to why bismuth is the most diamagnetic of naturally occuring elements?

And to make the question of more interest than the answer that one might be able to supply from a textbook: would molten (liquid) bismuth exhibit the same diamagnetic properties as is exhibited by its solid crystaline form?

Suppose "wormholes" actually exist. That seems an unwarranted assumption - we've no physical evidence of them. But if they did exist, they'd only be "shortcuts" across space.

I think that another issue should be mentioned. Even if wormholes did exist, while matter and energy could enter one end of the wormhole and then exit at some other point in space-time, information would not. Matter would be ripped apart into its most elementary constituents before being spit out of the wormhole's other end. I'm just extrapolating here what is expected to happen to matter when it falls into a black hole. Why would the physics of a wormhole in this regard be any different?

Accordingly to GR EM radiation follows the warp in space surrounding matter, but if not it would bend anyway under the influence of gravity based upon its mass-equivalence as Newton predicted

What you say is correct, but the AMOUNT that light bends is consistent with the predictions of Einstein's theory of GR, and not with Newton's theory. Newton's theory predicts an amount of bending of light from stars by our sun that is only half the amount that is experimentally observed.

A theory of everything would cover both general relativity and quantum mechanics. Biologists don't use Newtonian mechanics, relativity theory, or quantum mechanics to describe predator-prey relationships, and they would be even less likely to use this theory of everything. The same goes for sociologists and their descriptions of group dynamics. Different sciences operate at different levels of abstraction....

I agree. Physicists have explained quite well the ground state of the hydrogen atom, the thesis being that all hydrogen atoms in their ground state are identical. But there is no equivalent "ground state" description for a human being, let alone one that would allow scientific assertions to be made that assumed that all humans in such a "ground state" were identical.

The short answer: GR and QM are mutually incompatible.

I believe that quite a few theoretical physicists would disagree with you on this issue. A survey in the efforts of physicists to develop "loop quantum gravity" makes for interesting study.

Excuse me, are you suggesting that Science in general and Physics in particular can only define or describe things in terms of measurement?

 

Surely this is a bit restrictive?

I would also consider myself an Empiricist, meaning that I also believe that a valid scientific theory should make predictions that can be verified or refuted. But who pays attention to Empiricists anymore? The area of physics I have in mind is String Theory, which has been criticised as being useless for physical explainations as there is no basis in the theory for offering concrete predictions.

I encountered some really "outside of the box" thinking on time in the book "once before time: a whole story of the universe" by Martin Bojowald. According to the author, time is a real physical quantity and is quantized, i.e. time is only allowed to take on discrete values. It is not infinitely divisible into infinitely small increments. Is there a real world consequence to this assertion? According to the author, the singularity at the time of the "big bang" disappears from the equations of the general theory of relativity when time is quantized. This quantization of time also makes it possible for cosmologists to consider what happened BEFORE the big bang in ways that are consistent with the general theory of relativity, and also that the physical properties before the big bang has had consequences on the characteristics of our current universe. So, according to Dr. Bojowald, time and its quantization is a real physical aspect of the universe, and not simply a man made tool for making measurements!

That's the point.

Is it really true that Americans don't understand irony?

Could you or someone else explain to this dumb American the element of irony present in this cartoon?

I thought that the use of Albert Einstein's Image in this political cartoon to be disturbing and inappropriate:

See: http://www.charlotteobserver.com/2012/05/16/3244059/jpmorgan.html

The image the cartoonist used is clearly derived from a well known portrait of Albert Einstein by Yousuf Karsh:

So what are some of the problems that I see this political cartoon's usage of Einstein's image?

Einstein was a theoretical physicist, not an experimental chemist.

Einstein never wore a white lab coat while working.

Einstein was not pre-occupied with money, and never worked for a bank.

Einstein was not dumb.

There is an interesting article in the May 31, 2012 issue of ScienceDaily titled "Clash of the Titans: Milky Way is Destined for Head-On Collision With Andromeda Galaxy". So here is a speculation: galactic collisions are a well studied occurance in the observable universe. Might it be possible to confirm the existence of dark matter by observing how these collisions play out? Cosmologists model how these galactic collisions evolve. Would the models improve if "dark matter" is included in the calculations? If two galaxies are each surrounded by spherically shaped concentrations of dark matter, how might each of these spherical distributions be distorted as the two galaxies approach each other and then merge?

The BH only masses about 4 million solar masses. We know this by the periods of stars that orbit closely around it. But even if we to assume that it was massive enough to account for the Sun's orbital speed, it wouldn't account for the flatness of the rotation curve. If all that mass were concentrated at the center, the orbital speeds of the stars would pretty much drop of by the inverse of the squareroot of their distance from the center. What we see instead is that the orbital speeds remain close to the same as you move out. This means that the extra mass must be more or less evenly distributed. (so that as you move further away, the amount of mass you are orbiting increases.)

 

Black holes can capture dark matter, it is just not as easily a "normal" matter. As normal matter circles a BH, it collides with other matter causing it to radiate away some of its energy, causing it to fall in closer. DM doesn't react with itself or other matter this way. So it holds on to all of its original energy.

 

The other factor is that while 80% of the Galaxy's mass is DM, is spread out into a much larger volume than the visible disk of the galaxy. Imagine the galactic disk as being imbedded in a spherical "ball" of DM that is much larger than it is. This much larger volume means that, in any given part of the visible disk, the density of DM is much less than visible matter (This also explains why 80% of the Solar system isn't made of DM).

Still, some issues about the characteristics of Dark Matter come to mind. The idea that the galactic disk is imbedded in a spherical "ball" of DM that is much larger than the disk itself would suggest that near the beginnings of the universe ordinary matter and dark matter were uniformly distributed, and in the region of space containing our galaxy the ordinary matter coalesced into our spiral galaxy, while the dark matter associated with this region of space did not. One can also imagine a simply physics experiment. Suppose one suspended at the ends of two strings a ball of ordinary matter, and a ball of dark matter. Now it is postulated that the two balls will attract each other gravitationally. Assuming that the balls are of equal mass, would the ordinary ball move slightly towards the dark matter ball, while the dark matter ball remained motionless in space? Wouldn't one expect the equal forces on each of the balls to cause them to move equally towards each other?

Huh? Why do you think the Earth's orbit relies on the gravity of any other stars that it's own?

That was a mis-statement on my part. What I meant to say was about the orbit of the SUN about the galactic center. I did not intend to make an assertion about the orbit of the Earth about the sun.

Janus's analysis as to why the amount of visible matter falls short of the amount of matter needed to constrain the sun in its galactic orbit certainly seems reasonable to me, but I would suggest an alternative possibility. If the analysis that determines that the gravitational pull of 160 billion stars located at the galactic center was insufficient to hold the earth in its orbit (without the existance of dark matter), then what would be the effect of incorporating the gravitational pull of the black hole located at the galactic center into the result? How much gravitational pull would that black hole contribute, as compared to this theorized dark matter. And if this dark matter does exist, would not the black hole be sucking it in as well as sucking in ordinary matter? And if so, isn't 80% of the purported mass of this black hole attributable to its dark matter component, rather than to ordinary matter ?

Two men walk into a bar and sit down. The barman asks them what they would like to drink. The first man says, "I'll have some H20 please. The other man said, "I'll have some H20 too". The second man died.

I for one had not heard this joke before, and I think it's funny, as "H2O too" sounds like H2O2 i.e. Hydrogen peroxide, which is poisonous.:-D

Here is a potentially positive consequence of the existence of the human race:

There was an event known as the Cretaceous extinction that occurred approx 65 million years ago. It supposedly wiped out 85% of all species on the planet. One theory was that it was caused by the impact of a large meteorite. If another such large meteorite were headed towards earth, I'm certain that scientists and engineers would divert it from striking, thereby preventing a re-occurance of a similar mass extinction of life. So the human race may yet be of positive value, in terms of its relationship to the rest of the animal species on the planet, by preventing their extinction from a natural catastrophic event similar to the one that caused the Cretacious extinction.

Surface tension will also tend to narrow it.

I think that a short video I shot illustrates the effect of surface tension on water flow. It is a slow motion video of water flowing in a fountain. See:

A recent book (published in 2010) with an excellent discussion of black holes is "once before time: a whole story of the universe" by martin bojowald. The author is a theoretical physicist, but the book is aimed at a broader audience.

In which case it wouldn't be "doomed to failure".

 

The other objection I have is that you've given us a False Dilemma. It's entirely possible that al Qaeda's goals will not be realized, and neither will we win the War on Terror. In fact, it's my fear that the War on Terror has been designed to be an ongoing source of economic and political opportunity, much as the unwinnable War on Drugs.

I agree with the point you are making. It's also disheartening that the USA has been turned into the world's policeman, via its War on Terror and also the War on Drugs. While the resources of the USA are being eaten up by these activites (successful or not) other countries (like China) will devote more of their own resources to the areas of technological and scientific innovation.

The original question was who or what are you likely to defend or to attack. I've thought about that issue a lot, off and on, as the most significant activity in my life has been my service in the US Military (but not as a combatant). As an American, the thing I think most important to defend is the right of myself and my fellow citizens to sustain their personal freedom in their beliefs. To paraphrase someone notable: "I may not agree with what you think, but I would defend to the death your right to think it".

The production values of the video are good, but I don't think that the student comes away understanding combustion any better than they did before watching the video. I think you need to add a stronger narrative pertaining to what is being demonstrated. You might challenge the student to consider and choose which of several explainations that you would offer is the valid one in terms of why a match lights when struck on dry concrete, but not on wet concrete.

I know some groups aren't so secrete about paving the way for the end of the world, some religious fundamentalists are actively promoting bringing about the end of the world they consistently warn us about...

I'm uncertain which fundamentalist groups you could be referring to. The Christian fundamentalists I am familiar with believe Jesus is on his way back, his return is imminent, and all Christians need do to prepare for His return is believe in the Salvation that awaits them. They don't have to kill any infidels, let alone engage in acts of terrorism and mayhem.

of course, he could also be displaying that christian trait that is prized above all others: tolerance.

Fundamentalist Christians believe that we are all sinners in the eyes of God, and the acceptance of the offer of Salvation offered by Jesus garantees entry and eternity in paradise for anyone who believes in Him. How one had conducted one's life "morally" does not enter into the issue. That said, I think that gays desire a level of social acceptance by straight Christians beyond having them holding their noses while assuring them (gays) that Jesus loves them and will take care of them in paradise.

Okay, so I tried to google what would eventually happen to a neutron star and nothing showed up, so i'm gathering either no one knows or we think that it will remain a neutron star, I thought that they may become pulsars but I don't know what happens to the others, some people say they become invisible but does anyone know why this is?

My understanding is that if a neutron star is heavy enough, about twice as massive as the sun or greater, it will collapse to form a black hole.