Slashdot Mirror
Physics Problems For The New Age
In May, we ran a story on ten
"math problems for the new age."
ContinuousPark writes: "Last month, at the end of a conference on superstring theory at the University of Michigan, a group of physicists chose ten of the hardest problems in their field. They range from 'simple' ones like 'What is the lifetime of the proton and how do we understand it?' to obscure ones like 'Can we quantitatively understand quark and gluon confinement in quantum chromodynamics and the existence of a mass gap?' Resolve one today, get a Nobel Prize tomorrow. This
NY Times article
has the details." And unfortunately, says the Times,
"'Just because' is not considered an acceptable answer." Darn, there goes my Nobel.
The answer to any question in the universe is 3. You just need to figure out the units.
"Pinky, you've left the lens cap of your mind on again." - P&TB
"I can see my house from here!" - ST:
Surely you mean the answer is 42...
On a side note, does anyone have a login-free link for this? For reasons best known to itself, NYT have lost my login details, and I really can't be bothered to re-register.
"The invisible and the non-existent look very much alike." -- Delos B. McKown
Note that
and
are in part arguably physics questions (i.e., "how fast can you make transistors switch?", "how fast an optical switch can you make?", etc.).
The question
strikes me as being a more purely CS question (although with stuff such as Adelman's DNA computing it might not be pure CS either - toss in a little chemistry...).
Now, I'd put "is P = NP?" on the list....
Kepler's descriptive model of elliptical planetary orbits came before Newton's physics. Newton provided the theory that explained how Kepler's model worked.
Steven E. Ehrbar
Within a certain framework, yes. One of the most perplexing things about the Standard Model is that it doesn't contain gravity. There are many straightforward ways to extend it, all of them wrong (WRT gravity). Richard Feynman explored this in detail in "The Feynman Lectures on Gravity" (look for this in a library). But to really understand these lectures requires quite a bit of background knowledge. This is, for instance, why we think the "graviton" is spin-2. Extending the Standard Model in a straightforward way requires the graviton to be spin 2. Of course, it doesn't work. But within the framework of existing theories, you can rigorously prove that it has to be spin-2. There are a finite number of "actions" which can be written down in this framework. (action being the equation from which equations of motion are derived, by minimizing/maximizing the action) Each of these can be explored in turn, and rigorously proven to be wrong.
The next question is: "is our framework wrong?" The Standard Model is a set of "Gauge Theories", that is Quantum Field Theories which posess a certain gauge symmetry (represented by a Lie group). Now there's a mouthful to scare off the lay person. ;) String Theory/M-Theory is attempting to explore this, by starting from the simple assumption that particles, rather than being point entities, contain a continuous degree of freedom. (that is, parameterized by x,y,z,t and one extra, continuous, internal degree of freedom...hence "string") This theory has turned out to be significantly more complex than one might imagine at first, and we're not done trying to figure out the theory.
For instance, you can straightforwardly prove that string theory can only exist in 26 dimensions. If you add supersymmetry it requires 10 dimensions. If you go to M-theory (which still isn't well defined) it requires 11 dimensions. Each of these is rigorously provable.
Supersymmetry solves a nasty problem in field theories of renormalization in certain calculations. It turns out that by adding a fermion (1/2 integer spin) for every boson (integer spin) and vice-versa, that you exactly cancel many divergences. This is clearly desirable. A theory with divergences should be treated with skepticism. But where are these extra particles? Supersymmetry was discovered in the context of string theory and carried over into field theories because of this nice property. You can have a string theory without it, but it clearly does not correspond to our universe.
I often wonder if there is a better framework. The Standard Model/Gauge Fields framework was very confusing (because of certain apparent problems like renormalization...which turned out to be a calculational problem, rather than theoretical) when it was first introduced, but it has turned out to be extremely useful in calculation.
Gad, I'm rambling again...that's what I get for answering posts in my field. ;)
ah, books. I'm most familiar with graduate texts, so I'll give those. I don't read lay books because they frustrate me. (I need the math dammit!) These are the "canonical" texts in the field, those most respected in the physics community. There are others, I cannot speak for their quality, but I have used all in the following list, and can recommend them. I can handle the math: good luck, these are not easy reading, and often require a close examination of relevant equations. Note that this is the course regimen for a graduate degree in physics. If you make it through all these books, you should consider applying to a local university and getting a masters in Physics. This isn't light reading. Usual starting point for this material is an undergraduate degree in physics (though math or some engineering may suffice).
hep-th/####### and similar references can be obtained electronically at www.arxiv.org.
Hope this is useful, --Bob
1^2=1; (-1)^2=1; 1^2=(-1)^2; 1=-1; 1=0.
Perhaps there was something about his anatomy that caused him to continually confuse an infinitesimal particle with his hardon.
Did he also say "erectron" instead of electron?
If tits were wings it'd be flying around.
As the AC stated, there are patterns in the prime numbers, but what it seems you're asking is, is there a pattern that all the prime numbers fall into. Or, to put it another way, given all the prime numbers from 2 to n, find k=f(n) such that n+1 thru k-1 are composite but k is prime. Personally I doubt this one will ever be solved.
Heck, we haven't even been able to solve relatively minor prime-related problems, like the twin primes conjecture: Are there infinitely many pairs of primes of the form n and n+2? Or a followup, which I thought of but have no idea if anyone's done any research on, which I call 'quad primes': pairs of twin primes of the form n, n+2, n+6, n+8. It's easy to show that except for 3 and 5, all twin primes are of the form 6k-1 and 6k+1, and similarly that except for 5-7-11-13 all quad primes are of the form 30k+(11,13,17,19). But past that, who knows?
---
At least mafia-owned pizzarias make excellent pizza. Compare to Bill Gates.
Since when has alpha been different than 1/137? Man this really bums my day.
I have discovered a truly marvelous sig, unfortunately the sig limit is too small to contain i
The second law of thermodynamics says entropy
always increases, so this causes a bit of a problem.
No it doesn't. Substitute "planet" for "black hole" - gravitational potential energy is decreased, and entropy goes down. The second law refers only to closed systems.
If i have a solar-powered robot that organizes my sock drawer, that doesn't violate the second law because it's using energy to do so. A black hole sucking in an encyclopedia is using up energy (gravitational potential energy) to do so.
--
--
Mod up a post Rob doesn't like and you'll never mod again
Imagine the universe consisted of a bunch of rocks within a few million miles of each other. Soon they're all going to merge into one big planet, which is more orderly than lots of little rocks. The reason this doesn't violate the second law is because gravitational potential energy is lost as the rocks come together. The same is true with black holes.
--
--
Mod up a post Rob doesn't like and you'll never mod again
What would happen if you just burned the book? Or did some other ghastly thing to it, like explode it in a hydrogen bomb, how could you then retrieve the information? Can someone explain all this?
While it might not be technologically possible for humans to reassemble the information, it would be technically possible for, say, someone with root access to the universe, to look at the state of the entire universe, and follow the trajectories of the zillions of ash particles back to their original locations, and determine exactly what the book used to be like.
To explain another way: Pretend you're a fatalist. That means that given the state of everything in the universe at time t, it it possible to determine what the state will be at time t+1. Well, neglecting black holes, you could also say that given the state of the universe at time t, you could determine what it was at time t-1. But black holes screw that up.
--
--
Mod up a post Rob doesn't like and you'll never mod again
Some will take issue with these points. That is fine and arguably quite good. A healthy debate on the visibility of science is good for the country and the world.
Admittedly I am biased, as I am not an HEP person. My dissertation was on molecular dynamics studies of semiconductors. What I saw while in graduate school was projects like the SSC draining all the money out of science. When the NSF went before congress to ask for more money, congress balked, as it was after all funding this massive white albatross. Couldn't all scientists use it?
Arguably that was part of the problem, the lack of congressional education. The other part of the problem was the selling of HEP as Physics. It isn't, and it has demonstratably damaged the entire research community when that view was pushed. Yet there are still some that push it (see the article pointed to at the root of this thread).
No, the interesting problems in physics come from all the physics disciplines. The High Energy Physics (HEP) types still haven't learned that interesting physics to the public and interesting High Energy Physics are not identical. I would suspect that people in the U.K. are far less intrigued by the parity violation experiments as they are with protein folding diseases, specifically prions that are suspected to cause CJS. That is biophysics, biochemistry, biology, condensed matter physics, etc. The binding of small molecules to receptor sites to promote or inhibit life processes is arguably more interesting, and related to molecular dynamics, molecular recognition, statistical mechanics, etc. It is also the basis for drug discovery, without which we would have no pharmaceutical products.
And the universe, for the purposes of the second law, is assumed to be a closed system.
So, information 'disappearing' into a black hole *does* appear to violate the second law of thermodynamics. Which means something else must balance it out.
What about hawking radiation though? Could that not be seen as increasing the entropy in the universe?
It may be too late posting to this thread to get a reply, but oh well...
You say the current model of particle physics is the simplest model that is possible, and it's difficult to explain why.
That sounds a little like what we call a "hardness" proof in computer science.
I have a very good theoretical computer science background. Sometimes in computer science we can prove what we call "hardness" of a problem. That is, for some problem like multiplying two n-bit numbers, there is no algorithm that can do it in less than f(n) steps on some rigorously defined hardware (probably a virtual machine). These results are very difficult to obtain in general, and a lot the ones we do know aren't very good. For instance, it is easy to show that there is no way to sort n items in less than n steps, regardless of what algorithm you use, because you have to look at each item at least once.
Anyway...
When you say there is "no simpler theory" do you mean that it is possible to rigorously prove that? For instance, can you prove that any theory of particle physics that matches experimental results must be supersymmetric, or must have at least 11 spatial dimensions, or whatever?
If it's really too hard to explain in a Slashdot post, can you recommend a good book? I can handle the math - layperson stuff like "Shrodinger's kittens and the search for reality" is easy reading for me.
Thanks!
Torrey Hoffman (Azog)
Torrey Hoffman (Azog)
"HTML needs a rant tag" - Alan Cox
Multiplying all the primes below a certain number N, then adding one will either result in a new prime, or in a product of primes where at least one prime is greater than the largest prime in the original sequence. This is one of Euclid's theorems that proves that there are infinitely many primes.
BTW. 2*3*5*7*11*13 + 1 = 30031, which is non-prime because 30031 = 59 * 509.
"It's overkill, of course. But you can never have too much overkill." - Anonymous Slashdot Coward
- Yes, they are a direct by-product of the topological shape of spacetime, and that shape is the only possible shape.
- QG itself can't, but you can derive the creation of time from the topology of space. The perception of time is just a side-effect of the way our consciousness works.
- Protons are "wrapped" across the entire temporal dimension, like a loop, and thus appear to live forever, unless you radically distort spacetime.
- Yes, and it actually is not broken
- The "temporal dimension" is an illusion of consciousness. It is really just a highly expanded spatial dimension. Only three spatial dimensions have expanded because n-banes only need three dimensions of freedom to do all of the topologically possible transformations they can undergo.
- This is a direct fallout of the "shape" of the temporal dimension.
- No, it doesn't yet.
- The information does not go anywhere - it is stored in the topology of spacetime. This confusion comes from failing to consider time as a dimension capable of information storage.
- This is an artifact of only considering gravity in the 3 expanded dimensions
- Yes, again it is just an artifact of the shape of spacetime.
I have delightfully simple mathematical proofs for all of these, but alas, this text entry box does not allow me to paste in equations... =;-P>"given the state of the universe at time t, you could determine what it was at time t-1. But black holes screw that up"
Unfortunately, the universe doesn't work that way. Classical mechanics is deterministic, but quantum mechanics is not. We can't trace back to an earlier state of the universe, because we can only find the probability of one state evolving into another.
I'm not at all an expert, but I think this question is a lot more complex than most posts are making it sound. If problem #8 could be solved so easily by saying "the information is lost; the entropy difference is made up for by gravitational potential energy or Hawking radiation or some combination thereof," then the physicists who made this list would have said that.
It would be nice if someone who knows more about the underlying problems than I do could explain. However, this looks vaguely related to something known as the holographic principle, which seems to be important in string theory. My (very limited) understanding of it is that the equations of string theory could work on a smaller-dimensional subset... in other words, everything inside the universe might just be some sort of "reflection" of something on the "surface" of the universe. The theory that information inside black holes is reflected on the surface seems to be very similar. I'm fairly sure - correct me if I'm wrong - that the current theory is that a black hole's entropy is related to its surface area; i.e., when something falls into a black hole, the surface area increases by the same amount that the entropy of the rest of the universe decreases.
As I said, my understanding of this physics is limited, but one thing I do know is that quantum states can not be copied or destroyed. This is the source of some interesting differences between classical computers and quantum computers. Black holes seem to violate this.
By the way, if anyone reading this thread is unfamiliar with Hawking radiation, that's one thing I can explain... Black holes have a tendency to "evaporate." They give off particle/antiparticle pairs, so that they aren't entirely "black." On the other hand, these particles don't contain any of the information that actually goes into a black hole. They're more or less empty of information; black-hole radiation follows a statistical distribution that is roughly the same as the distribution of energy emitted from the sun (i.e., they work like blackbodies). As black holes emit this energy, they lose mass (remember E=mc^2?) and, correspondingly, "evaporate" over time. Because of this, every black hole can be said to have a temperature, which is determined from the Stefan-Boltzmann formula F=sigma*T^4, where F is the energy flux (watts per square meter) coming out of the black hole. So, a black hole shrinks over time. The question is: as it shrinks, does any information that was lost in it come back out?
If I get around to it, I might dig through some books later today and see if I can understand more about the issues involved here. I'm pretty sure it isn't a simple question, and there are very good reasons for it to be part of the list.
Matt Reece
So you'd rather have no science at all, because you feel that any logical framework used would be faulty?
I would rather that science be treated like the religion that it is, and like all religions have its problems talked about in a meaningful manner.
Or, the microscopic world is so different from the everyday macroscopic world where we live in, that we lack proper language to describe extremely small (or large) phenomena.
But what should scale have to do with anything? Any properly described event will happen the same way no matter how much, or how little, enery or matter is a part of the equation. That we recongize a difference is part of the problem.
Look at the bottle - see the number "57" right where the neck starts to bend to form the body? After shaking the ketchup, turn the bottle toward where you want to pour, and gently tap the number with the heel of your hand, and the ketchup will start to flow.
I support the EFF - do you?
Reason is the Path to God - Anon
Sorry my slip up.
Yes, the pions are mesons, composed of two quarks. When running simulations we tend to use both electrons and pions for detector simulations. The simulated data from pions tends to be very easy to compile and use to check whether one detector is better than another. I slipped up because I had been using pion simulationed events in my last project.
Disclamer - Opinion of Person
Perhaps but that rule only results in a subset of the primes at best.
2+1 = 3
(missed)= 5 (2x2+1)
2x3+1 = 7
11 (2x5+1)
13 (2x2x3+1)
17 (2x2x2x2+1)
19 (2x3x3+1)
23 (2x11+1)
29 (2x2x7+1)
2x3x5+1 = 31
His statement should have read more like, "no one has yet to discover *any* pattern that completely maps out the prime numbers."
:)
Veldrane
"Why does the Cambridge combinatorial hierarchy (a mathematics construct, pure and simple) generate the observed scale constants with great accuracy whereas standard theory does not?"
Seastead this.
"Why does the Cambridge combinatorial hierarchy (a mathmatics construct, pure and simple) generate the observed scale constants, such as vacuum energy, with great accuracy, whereas standard theory is off by 10 to the 120'th power?"
Seastead this.
6 double-quotes
8 single-quotes
I think we have a "winner"!
-----
Actually, he wrote that note in the margin of Arithmetica by Diophantus. In that book, the problem posed by Diophantus was to express a square rational number (a fraction), as the sum of 2 other square numbers.
Fermat's note stated that he had a marvellous proof of a related problem but that the margin was too small to contain it. I find it hard to believe that a mathemetician such as Fermat would make that sort of reference based on a specific case (n=4). More likely, he had a general case worked out which never saw the light of day. Considering the difficulty of the proof by Wiles, it is unlikely that Fermat's would have held up under scrutiny. But that is something which will probably remain a mystery :)
Best regards,
SEAL
Oh the invisible monster has lenses and retina that only affects wawelengths outside the visual spectrum, like infrared. How else would the hero be able to shield his own infrared emissions and detect the disturbance in those wawelengths caused by the monsters eyes, just in time for the final scene?
All opinions are my own - until criticized
Someone's already been working on it, actually:
Society for Interdisciplinary Studies
Very fascinating stuff. I first heard of them from the back of a James P. Hogan book.
-----
"You spilled my egg... I needed that egg."
The answer is: Yes. Now were's that Nobel prize when I need it????
kwsNI
Since when do you need proof to get a Nobel prize? And I was sooo looking forward to the fame associated with receiving that...
kwsNI
You can't prove me wrong.
kwsNI
No. Everyone knows first posts are faster than light. At least they appear faster.
----
When you toss a web server running slash into a black hole, will first posts finally get lost forever?
This is a method used to calculate *a* prime number. It's not unique in that manner. There are many others.
What it is *not* is a pattern to the prime numbers. Hell, there is no known pattern to the non-prime numbers either. Guess what though, I can take any power of two, and it won't be a prime number. Yes! I figured out the pattern!
Wait, here's another. Multiply the number five by any other number. Wow! I found another!
In short, the word pattern: You keep using that word. I do not think it means what you think it means.
Source code is a lot like a parachute; it needs to be open in order to function properly.
Science is about revising our view of the universe to be closer and closer to the way the universe actually acts.
Mathematics is a compression method. It compresses large amounts of explanation into small symbols which can be understood in an open-source kind of way. I use that term because 1. You can get your hands on the proofs for the mathematics we use today. 2. You are both allowed and encouraged to use and revise those proofs to show new principles. "Going back to first principles" is a much-lauded activity. Mind you, much like GPL, you are required (For some value of required) to point out the original data. If you built upon the theory of relativity, for example, and then claimed to have done all the work yourself, you would be professional crucified.
The big important thing to recognize is that as we form new theories we find ways to explain old behavior. Saying we shouldn't move on until we explain every open space in our logic today is like saying we shouldn't go to Mars when we still have hunger on our planet. Advances in space-based technology have consistently percolated down through the human strata to ensure a better way of life for [nearly] all mankind. (Sorry, I refuse to be PC.) My point is of course that by making advances in science, we solve old riddles. Some of those riddles would doubtless not be solvable without this new knowledge. So I think your initial exasperated expression of desire is at best uninformed.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Can somebody please explain how a "dimension" can be "curled up tiny"?
I'll try...
First, think of an infinite 1 dimensional surface ... a line. Now, as you know from geometry, the line has infinite extent. This is what we normally think of when we think of a "dimension". It is "1-dimension" since we need 1 parameter to describe a position along its length. It is an infinite dimension since the value of that position parameter can vary from -\infty to +\infty
Now, we'll think of a finite 1 dimensional surface. Take a line segment and connect the ends, and we get ... a circle! It is also "1 dimensional" since we need 1 parameter, and it is finite, since that parameter can vary from (say) 0 to 2\pi
When formulated in the right way, there is nothing that prevents you from doing physics where the dimensions are finite instead of infinite (I admit that it would be quite difficult using the techniques normally taught in an undergraduate setting). And, generally speaking, there is nothing that prevents you from doing physics with more than three space and one time dimension (although again, it is generally quite difficult using undergraduate techniques).
Now, we bring it all together; while a particular string theory requires that our universe be ten dimensional (for the mathematical consistency of the "supersymmetry algebra" of the theory), the theory itself doesn't specify which of those dimensions are finite, and which of them are infinite (eventually, we would hope to come up with a theory which DID make that specification, starting from basic assumptions, but we aren't there right now). What makes that specification right now is our experiments, which say that there are at least 3+1 "large" dimensions (nearly infinite). Thus, those extra 6 dimensions must be finite, or "curled up".
Incidentally, the fact that we can't see those extra dimensions (if they exist) tells us something (that "something" depends on exactly how you assume that they have compactified). Generally, it tells us that they must be smaller than a certain size, otherwise they would have manifested themselves in experiments, usually as deviations from the Newtonian gravitational force. The fact that we haven't seen any such deviations tells us that the "size" of the "dimension" must be very small.
Rereading what I just wrote, I'm not sure it helps, but I hope it does!
----
The most interesting "pattern" is the Prime Spiral. Get a sheet of graph paper. Write a "1" in the center square. Go one square to the right and write a "2". Move down and write "3". Continue in a clockwise pattern incrementing each number by one until you get to 100-200. Now circle all the prime numbers and you will see an interesting pattern. (or better yet, search for prime spiral on Google and see someone else do the hard work)
Everything in this post is false.
In any case, this is only potentially true for Einstein in the case of his work on the photoelectric effect. Special and general relativity were conceived as a world-famous, extremely prominent physicist.
-- the most controversial site on the Web
Firstly, they were backed by religion. Everything orbited the Earth, if you recall, and according to both the Church and Aristotle, they orbited in circles (aristotle claimed the solar system was geometrically perfect - each body orbited the earth on a sphere, inside of which was inscribed a regular polygon). One could argue that force of habit is as binding as religion, but probably not win that argument, in tht force of habit does not possess axemen.
Secondly, until Newton's gravity, epicycles were more accurate, ie, they gave results consistent with observation. Once Newton's gravity was on the field, Kepler showed how to compute the correct ellipses, and the simpler argument was more correct.
So two points are worth remembering here - one, that epicycles were the best solution to a geocentric orbital model - a model which could not be discarded b/c of the catholic church; and two, more advanced (ie, complex) physics had to be invented to compute the simpler explanation.
Today there is no religious body powerful enough to squash disagreeable science. World views we have accepted a priori bind our perceptions, but we have learned to question all our instincts these days. Also, simpler explanations don't fall out of a system until we are mired inside a more complex explanation, and made familiar with the system we're trying to model. I recall what a professor once told me:
It's a good try, though.
Steve
Well, you won't get the nobel prize tomorrow, because if you solve the problem, nobody will realize how important your discovery was for another 40 years. Anyway, that's a good reason to start working on it.... :-)
Employee of Inrupt, Project Release Manager and Community Manager for Solid
This is what happened: Aristotelian physics required that all motions in the heavens to be circular, so some astronomers introduced epicycles to account for retrograde motion. Ptolemy incorporated this in his magnificient theory. Now, the story goes:
(taken from de Vaucouleurs, Gerard (1957)), it's just that this is wrong! First, where is the evidence that there was any significant observational progress. Have a good look, and you'll see that there wasn't any observational progress, so they had no reason whatsoever to introduce additional epicycles. The observational progress didn't come until Tycho Brahe, after Copernicus.
Now, the whole thing culminated in 1963, Robert Horace Baker wrote an article in the Encyclopedia Britannica stating that 40 to 60 epicycles were added to each planet, which is absurd, they would have needed a Beowulf cluster to compute the positions of the planets if they did that... ;-) At least with the math they had available.
Baker further said that Alfonso X stated that if he had been there at creation, he would have given the good lord a few hints. Alfonse X computed (well, as a patron) the Alfonsine Tables, that astronomers needed to determine the expected positions of the planets.
Owen Gingerich bashed the myth in 1968 by recomputing the Alfonsine Tables, and found that they were based on a pure Ptolemaic model with only minor corrections to the parameters used by Ptolemy.
I have been trying to figure out why this myth came to be and how it propagated. I haven't had time to do much research on it lately, and I won't tire you with my stuff, but I have an old essay about it for those interested.
Now, the myth has been uncritically accepted by a number of canons, most notably Thomas Kuhn. I have read a couple of his books, and I'm a bit uncertain how important it is for his philosophy, but it is clearly motivating him to go in the direction he does. Gingerich told me on the History of Astronomy Discussion List that Kuhn was very embarrased when he told him about it.
It is very important to note, IMHO, that Ptolemy went away from Aristotelian physics a long way, and that allready in the 10th century (i.e. before Aristotle was made compatible with Christianity by Thomas Aquinas), the criticism against him gained strength. Ptolemy had to introduce several concepts, among them, the equant. The epicycle itself is not consistent with Aristotelian physics, because the circular motion should be around the centre of the universe, namely the earth. Now, could it be that Copernicus was mainly motivated by lack of proper physics as opposed to merely mathematical constructs?
Finally, as others has mentioned, Copernican cosmology had no advantage over Ptolemaic cosmology in terms of accuracy, also as shown by Owen Gingerich. The breakthrough in accuracy came with Kepler.
Employee of Inrupt, Project Release Manager and Community Manager for Solid
The catch to all this is that in order for things to become simple, we must put them in the correct frame work. What made us realize that the orbit of the planets was simple? We had to find the correct framework, or rules, to apply to the orbits, and then the orbits became simple. We experience reality in 3 dimensions (4, if you want to toss in time as a dimension). But that's just the limitations of our perception of things. Adding higher dimension can vastly simplifiy mathematical propblems. Think of going from a list (one dimensional) to a table (two dimensional). With a table, organization and patterns can appear that were not evident in the one dimensional list. So... eleven dimensions ( or 24, or whatever) may sound messy, but if you can come up with on equation that describes all the forces (or just reality in general) within the framework of those dimension then that's simple.
The concept of special relativity had been in development for several years..
It was not the concept of relativity, it was the mathematics of what would later be called special relativity. The concept of relativity in this theory is mostly if not exclusively due to Einstein, who arrived at it from purely physical considerations. He did not need that mathematics.
As far as GRT and Gauss is concerned... What credit do you think deserves someone who even does not have guts to publish one's ideas. That's precisely what happened to Gauss who never published his idea that the space can be curved because he was afraid to be laughed at...Mach might have some impact on GRT, perhaps even negative. Einstein pursued Mach's ideas, but this turned out to be a blind alley: GRT does not realize the so called Mach principle that Einstein tried to incorporate in GRT. Poincare had nothing of substance to contribute to GRT at all, unlike to the mathematics of SRT. As far as Leibnitz is concerned- I can only guess that his ideas were very vague and certainly of no impact on Einstein.
So much about where the credit is really due...
Every man has one thing he can do better than anyone else - and usually it's reading his own handwriting. -G. Norman C
...whatever remains, however improbable, must be the case.
That's typically how the "logic" in science's attempts to describe reality functions, and it functions quite well that way, Godel be dammed.
Or in other words:
"I think X is so"
"This experiment foo tests X"
"If foo fails, X cannot be true"
"If foo succeeds, X may be true, and can probably be treated as true until something better comes along"
As far as the quantum mechanical property that observing changes the observed, that isn't as screwed up as you seem to think. Instead, consider how one might "observe" something at a quantum mechanical scale. Anything bounced off a quantum mechanical particle with sufficient energy to perform a "measurement" is locally "large" enough to affect whatever it is you're observing.
Consider a basic thermometer. If I take your temperature, the amount of heat energy drawn off into the themometer is not enough to materially affect your overall temperature. But if I take that same thermometer and attempt to take the temperature as a drop of liquid nitrogen, the heat energy in the (room temperature) thermometer will boil off the nitrogen, and thus alter it.
It's just a question of scale, not metaphysics.
Want to learn about race cars? Read my Book
Investigators at a major research institution have discovered the heaviest element known to science. This startling new discovery has been tentatively named Administratium.
This new element has no protons or electrons, thus having an atomic number of zero. It does, however, have 1 neutron, 125 assistant neutrons, 75 vice neutrons and 111 assistant vice neutrons, giving it an atomic mass of 312.
These 312 particles are held together by a force called morons, that are surrounded by vast quantities of lepton-like particles called peons. Since it has no electrons, Administratium is inert. However, it can be detected as it impedes every reaction with which it comes into contact. According to the discoverers, a minute amount of Administratium causes a single reaction to take over four-days to complete when it would normally take less than a second.
Administratium has a normal half-life of approximately three years; it does not decay but instead undergoes a reorganization in which a portion of the assistant neutrons, vice neutrons and assistant vice neutrons exchange places. In fact, an Administratium sample's mass will actually increase over time, since with each reorganization some of the morons inevitably become neutrons forming new isotopes.
This characteristic of moron promotion leads some scientists to speculate that Administratium is spontaneously formed whenever morons reach a certain quantity in concentration. This hypothetical quantity is referred to as "Critical Morass".
You will know it when you see it.
try { do() || do_not(); } catch (JediException err) { yoda(err); }
I totally agree that it's hard to come up with other answers. Of course I don't think that scientists should stop doing physics.
The problem is, (and I should have made it clearer in my earlier post) I really get the impression that most physicists today are just trying to "patch up" these theories. And there are so many holes that there is lots to do, so they all keep pretty busy.
Is anyone (other than crackpots) even trying to come up with an alternative explanation? Or is it true, as another response to my post said, that "string theory IS the simpler theory.". If so, why are there so many different string theories, and what's with the M-theory "unifying" them but "adding complications"?
Are there physicists out there writing journal articles that say:
"Let's assume that all this string theory stuff is just wrong. Instead of patching holes in it (adding epicycles!) here's an alternative explanation..."
Torrey Hoffman (Azog)
Torrey Hoffman (Azog)
"HTML needs a rant tag" - Alan Cox
- True invisibility (not that refractive/ablative Predator-camo stuff) is complete transparency to light
- Human vision is transduction of light energy to electrochemical stimuli
- An invisible guy's lenses (light not refracted, focused, flipped) and retina (light not transduced) are transparent to light energy
wouldn't an invisible man be blind? Haven't heard this one discussed - just wondered.I find this rather hard to believe... can you give me any examples? Ideally, examples of original and/or important discoveries... My undergrad number theory prof told us an interesting story about when he was at Utah... seems one day the math dept got a packet in the mail from an amateur mathematician. It had several pages filled with Pythagorean triples. The person who sent them in said he did it because he thought they "might be helpful". Unfortunately, the problem of identifying Pythagorean triples has been completely solved, so all of his work was for nothing...
A few months ago I saw a list of unsolved mathematical problems that required no special knowledge to understand
Any chance you happen to remember where you saw it? Sounds interesting... My personal favorite is the Collatz problem (also called many other things...): define C(x) = 3*x+1 if x is odd, and C(x) = x/2 if x is even. Consider iterating C on a natural number N. Does C^n(N)=1 for some n? (Hint: it's true for N assuming Fermat wasn't bluffing or erred in his proof, then a simpler method awaits rediscovery.
I think it's pretty much assumed that Fermat didn't have a proof... partly because (as best as we can tell) he made that note several years before his death, and he had a proof in the case n=4. The generally accepted theory is that he thought this proof would work for the general case, and so he made that note in the margin. When he realized it didn't work, he didn't go back and scratch out that note...
Published lists of unsolved problems that can be comprehended by a layman may increase interest and make science "real" again for a lot of people who view things like physics and chemistry as voodoo.
It's not too hard to do for math, but are there any of these types of lists for physics or chemistry?
To within half a percent, pi seconds is a nanocentury. -- Tom Duff
The engineers proof that all odd numbers are prime.
...
1 is prime and odd, 3 is prime and odd, 5 is, 7 is, 9 isn't but that's probably just statisical error, 11 is, 13 is, well that's good enough for me.
The computer scientists proof that all odd numbers are prime.
1 is prime and odd, 3 is, 5 is, 7 is, 7 is, 7 is, 7 is
MSs proof that all odd numbers are prime.
1 is prime and odd, 3 is, 5 is, 7 is, [BSOD!]
Well it was holding true up until it crashed so it must be true.
Disclamer - Opinion of Person
Remember some of the basic rules of quantum mechanics? That because of the act of observation that the observed changes? Again, a clear sign that something, somewhere is screwed up so completely, but nothing is ever done. Nobody ever stops and says, maybe we need to rethink everything up to this point, because this just shouldn't be happening.
Although one could say that the problem must stem from the Schrodinger Equation, which is one of the four fundamental equations like F=ma, and therefore it must be changed, it also seems to be inexplicably correct. People have stopped and said, maybe we need to rethink everything up to this point, because this just shouldn't be happening. Einstein did, he questioned quantum mechanics until he died. Every question he threw at it, everytime he tried to throw a wrench in the gears, he failed. Some of his questions have only been answered in the past 20 years, but they have been answered.
Quantum mechanics has been poked, prodded, attacked, and verbally abused and yet it keeps on showing us that it is correct. All of the scientific data taken to try and disprove things like the Uncertainty Principle has failed. We cannot do any better than hbar. We have to deal with the duality of waves and particles. All of the evidence shows that it is correct.
Sure there are holes, the standard model for particles is full of them. People are trying their hardest to patch them, a good example is question #4. Supersymmetry was theorized as a fix for the standard model, and it wasn't the first, there were others with funny names like Technicolor.
Einstein placed the cosmological constant into his relativity equation because he wanted the universe to be static rather than expanding or collapsing. Now there is talk of re-introducing the cosmological constant, in a slightly different form, but never less it has been talked about to try and explain some of the holes.
Superstring theory is just another patch, a way of trying to understand the universe. Other theories don't cut it, they have gapping holes. Superstring theory surfaced because something wasn't quite right and someone tried to fix it.
Most of the physics done today is patch work. Something isn't working right so we need to find out why.
Disclamer - Opinion of Person
Casting a wide net and exposing the worlds problems to everyone in the population is the scientific comunities way to seek out people thay haven't previously considered. Let's not forget that the theory of relativity was concieved by one man, all alone, without contact to the "greatest minds of the day". He was a loner, an outsider, a rebel that took conventional wisdom and bent it around space time.
note that the definition of "physics" being used here is pretty broad. :-)
There are many ways to calculate prime numbers, yes. Calculations are not patterns.
To help you out a bit, there is a pattern to the following series: 1, 4, 9, 16, 25,
Can you guess this pattern? Good job. Know what the 1000th number in this list would be? Good job. Did you have to know the values of any other elements in the list, or did you just need to know the pattern? I think you understand.
Oh, and the 1000th prime number is 7919. Useful stuff to know.
Source code is a lot like a parachute; it needs to be open in order to function properly.
Why didn't they try harder to find a simpler explanation?
I'm a grad student in particle theory, so take what I say with a grain of salt. In a sense that isn't easy to relate to a lay person (because they are technical and require acquisition of a vocabulary and rigorous definitions that I'm not well equipped to explain), the current model of particle physics IS the simplest theory that is possible (meaning anything simpler gets the wrong answer). Whether it be within the Standard Model or with M-theory, you start by writing down the simplest mathematical description you can, and then check the consequences.
The complications all arise in the last step, checking the consequences. Those calculations are often horrifically difficult. This is not unlike the example you cite of Newtonian gravity: you COULD write down a more complicated model that agrees with experiments, but the inverse square law works very well, and is incredibly simple. Unfortunately, even this simplest possible model becomes calculationally intractable when you try to do something as seemingly simple as the three body problem, which is unsolvable (in a technical sense) except in a few highly contrived circumstances.
String theory is the same thing. Write down the absolutely most trivial and general equations you can that are consistent with the known "properties" of the universe, turn the crank, and see what comes out....but you get stuck in the process of turning the crank.
As to whether there are physicists trying to come up with a simpler set of explanations; yes, there are, but anything that has been tried that IS simpler is KNOWN to be wrong. Since these theories are mathematical, you can convince yourself that there AREN'T simpler theories that you have missed (in a certain highly technical sense....), because those classes of theories makes predictions which are wrong.
Of course, it may turn out that a more complicated fundamental theory may turn out to be simpler to calculate with, and hence be simpler in a different sense.
This question could be resolved by checking your reference frame. If I am someone outside of the black hole, dropping my copy of Webster's in, I never actually see that copy of Webster's hit the event horizon. Instead, it approaches it more and more slowly, the image growing ever redder and ever dimmer. From my reference frame, it never actually enters the black hole. It may be very red and very dim, but just 'cause I can't read it, doesn't mean that it is not there. Locking that Webster's in a box doesn't count as information loss. Thus, no information loss.
From the reference frame of someone (someone due to die a quick and short death) inside the event horizon, I would see a Webster's plunging in towards me. Still, no information loss.
Black holes were also once called "frozen stars," due to the fact that the "history" of a black hole (as Thorne puts it) is contained just above the event horizon -- the star's surface would appear to be there, if it weren't so red(-shifted) and dim. Somewhere in Wheeler's gravitation there's a nice calculation on how long it takes something to become practically invisible (red/dim) as it plunges towards the event horizon.
What is troubling for my two cent explanation is the problem of the matter that was there when the collapse began, which would be the neutron-laden core of a supernova. That definitely seems like lost information.
Black holes do all kinds of fun things, like violate baryon conservation and lepton conservation, in big ways. They do pose some very interesting questions. Of course, we don't have any really handy to test out stuff like Hawking radiation and whatnot on, so we won't know if our theory meets reality. We've detected black holes, but we haven't gotten up close enough to really know if what we predict about them in regards to particle production is true.
Average American male loses 4 socks per year. Call it 125,000,000 million males in US. That is about a billion socks every 2 years. This has been going on for at least 50 years.
Do you think you could hide 25,000,000,000 socks without the odd one showing up every once in a while? With that many socks missing you would think we'd be tripping over them regularly.
...as everyone knows, is 42.
The real question, of course, is how much wood would a woodchuck chuck if a woodchuck could chuck wood. Now _there's_ some Nobel material!
You owe Slashdot a copy of the best Oracularities...
Tongue-tied and twisted, just an earth-bound misfit, I
Learning to fly, Pink Floyd.
haven't figured out where my other matching sock goes everytime I do the wash. Seems like a blackhole or something is created with all the water rushing around a metal cylander.
--
You're a unique individual, just like everyone else.
Sig it.
--
Linux MAPI Server!
http://www.openone.com/software/MailOne/
(Exchange Migration HOWTO coming soon)
Question #4 discusses Supersymmetry. The lab group that I am part of is working with simulating supersymmetry, if you want more information on supersymmetry then go to the University of Colorado NLC group site.
We only hope that the NLC, or Tesla, is built. Right now particle physicists around the world are trying to scrape up the ~$9 billion that it would require to build one of them.
I know that some of you will say, "We already have particle accelerators that can reach TeV (Tera Electron Volts), why do we need the NLC?" The particle accelarators today that can reach TeV, like the Tevatron at Fermilabs, accelerate Hadrons like protons. Although the physics gained from accelerating Hadrons is very useful, it cannot give us the information necessary for supersymmetry. Hadrons are composed of three quarks, and therefore when they collide not all six quarks are hitting at the same time, generally only one quark hits one quark. These kind of reactions are useful but not what we need. We need a particle accelerator that can accelarate leptons, like electrons and pions, to the TeV scale. When electrons hit we are getting the entire center of mass energy at one point at one time. This allows for physics that is extremely useful to supersymmetry.
I am just an undergrad so my understanding of this next aspect is kind of shakey. From what I have been able to understand, hadron colliders are really good for understanding the forces between particles, whereas lepton colliders are really good for discovering new particles. In order to prove, or disprove, supersymmetry we need to see if sparticles (supersymmetric particles) exist, therefore we need lepton colliders. Today the most powerful lepton collider in the US is SLAC (Stanford Linear Accelerator).
Disclamer - Opinion of Person
Ask Jeeves!
Mike Roberto
- GAIM: MicroBerto
Berto
My favorite unanswered questions like this are those which are easy to explain but relatively impossible to figure out. For example, no one has yet to discover *any* pattern in the prime numbers. I can explain that question to my grandmother. Difficult questions aren't always complicated to explain.
Source code is a lot like a parachute; it needs to be open in order to function properly.
'Can we quantitatively understand quark and gluon confinement in quantum chromodynamics and the existence of a mass gap?'
People PLEASE! Do I have to spell out everything for you? The answer is obviously 'NO'.
This is 3rd grade stuff, people.
D
The first, last, and only tech news site on the net
I have only a laypersons understanding of quantum physics, so feel free to ignore me.
Whenever I read about these incredibly complex theories, like 11 dimensional superstrings, the M-theory, "sparticles", and what have you, it just reminds me of the "theories of planetary motion" that people used to come up with before they realized the earth goes around the sun.
To explain the observed motion of the planets in a way consistent with the sun going around the earth, they invented "epicycles", which were essentially loops within loops on the hypothical orbits. This went on for years, with the epicycles getting more and more complicated. They built amazing geared machines to simulate the motion of the planets. Now we look back at them and shake our heads, thinking "Why didn't they look for the simpler explanation? Why did it take so long for a Copernicus to come along?"
I don't mean to dis modern physics... but I can't help thinking that in 100 years, people will look back on M-theory and sparticles and laugh, saying "Why didn't those people realize how ridiculous those theories are? Why didn't they try harder to find a simpler explanation?"
Maybe the real world really is that complicated. But history would indicate otherwise.
Torrey Hoffman (Azog)
Torrey Hoffman (Azog)
"HTML needs a rant tag" - Alan Cox
This was quite an interesting list, but let's not forget who came up with it -- a group of string theorists. The list reflects a certain... severe bias, in that ALL of the problems lie in the fields of high energy physics and cosmology. They completely ignore the equally fascinating (and much more rapidly growing) fields of condensed matter physics, biophysics, geophysics, and astrophysics (apart from cosmology). These fields promise to change our world, both in terms of the gadgets we use, to our very genetic essence, and contain problems of significant scientific merit as well.
This point reminds me of a listing posted to slashdot a couple of months ago of the top ten algorithms of all time. It just so happened that all ten were numerical algorithms, reflecting the bias of the poster in that case as well. A more objective list requires a more universal panel.
Science, like Nature, must also be tamed, with a view turned towards its preservation.
What they mean by information disappearing is that we would never be able to find out about what's in the black hole again. It would cease having an effect on the universe. Particles lost in a black hole take their history with them. You have to be realistic about this; how much information would anyone have spent time extracting from those particles anyway?
But the point is that the singularity means, for all we can tell, the complete destruction of everything except the raw mass of the particles that fall into it.
Using the encyclopedia is a bad pun; imagine dropping something simpler, like a salt grain down instead. The salt grain contains information about its structure and if you were clever enough you could figure out where it came from and how long ago. That information vanishes in a black hole.
I think this type of think is what's needed to get the average person interested in math and science again. Math used to be a hobby for a lot of people, and many discoveries were made by people in their spare time, but unfortuneately the outer boundaries of math and science are generally too specialized and complex for the average person to understand.
A few months ago I saw a list of unsolved mathematical problems that required no special knowledge to understand and I thought it was a really good idea since it might get your average person interested in solving one of these problems. For example, Fermat's last theorem has been proven, but using very complex math that was unknown at the time he wrote his little note in the margin. The concept behind the theorem is pretty intuitive, and assuming Fermat wasn't bluffing or erred in his proof, then a simpler method awaits rediscovery.
Published lists of unsolved problems that can be comprehended by a layman may increase interest and make science "real" again for a lot of people who view things like physics and chemistry as voodoo.
Actuaries - making accountants look interesting since 1949