Okay, you want a reading list. I have one for you.
First brush up on your classical mechanics, you will need to study Lagragians and the Hamitonian formulation as they are both very important for the formation of Quantum Mechanics. Lets see, you could try:
Marion and Thorton, Classical Dynamics, Saunders College Publ., Philadelphia, 1995.
Now you have to start on Quantum Mechanics. There are many different books you could try; here are some of them:
Sakurai, Modern Quantum Mechanics
Dirac, Principles of Quantum Mechanics
Cohen-Tannoudji, Diu and Laloe, Quantum Mechanics
Merzbacher, Quantum Mechanics
Now that you have learned Quantum Machanics you can move onto some field theory:
Riazzudin & Fayazzudin, A Modern Introduction to Particle Theory, World Scientific.
Mohapatra, Unification and Supersymmetry, Springer Veriag.
Marshak, Conceptual Foundations of Particle Physics, World Scientific.
At this point you may want to deviate slightly and read some books on relativity and cosmology
Misner, Wheeler and Thorne, Gravitation,W H Freeman & Co, 1973.
Peebles, Principles of Physical Cosmology,Princeton Univ Press, 1993.
When I started college, I chose physics because I liked it. I soon realized that the physics you learn at a univeristy is not the physics a physicists does. Instead, everything you learn as an undergraduate classes are tools. These tools are to be used in graduate school as a foundation for more complex concepts.
It's been four years and I am about to go off to grad school to study elementry particle physics (experimental). I don't claim to have read any of the books above, but I hope it might show you that if you want to "*fully* comprehend stuff like particle physics, quantum phenomena, etc." it is not easy. Most popular science books you will find on a bookshelf do not contain much substance. Many are good reads. Brian Green's Elegant Universe and Stephen Hawking's A Brief History are good examples that are constantly recommended here on slashdot. But if you really (and I mean really) want to learn physics, you can do one of two things:
Read all the books above while doing most if not all the problems.
Spend a good amount of time (most people spend four undergraduate years) learning the "tools of the trade" and then spend five to six years in graduate studies, researching a single topic.
My purpose of this post is not to be harsh, but realistic. I am glad you are fasinated with physics. My fasination led me to the point where I want to spend years in school studying it. But I think many people don't realize that the subject is really difficult, and that it takes years of university education to even begin to understand it.
the beginning of the end for our dependence on oil
I guess I'll bite.
The problem with the dependence of oil isn't an alternative means. Someone has pointed/will point out that we have many alternative energy sources. Instead oil as a means of energy is dominant because it is cheap.
The world's energy infrastructure is based on using crude oil. There are oil power plants, oil refineries, gasoline engines, etc. Oil is simply cheaper to use. Companies spend billions of dollars researching new drill sites, lobbying Congress, etc. to maintain oil production because it is cheaper than investing in alternative energy sources; i.e. solar, nuclear.
Now what if this limitless source of Hydrogen comes on-line? What if we start using it instead of drilling for crude oil? At some point, the demand for oil begins to decline. Seeing as there is still a supply of oil (a diminishing supply, but still a supply) the price of oil will go down. Eventually, oil will be cheaper to use, and begin to rise in demand. A happy medium will be reached where crude oil drilling and this new hydrogen production will co-exist.
Admitidly, at this point there will no longer be a complete depedence on oil, but I would argue that we (the globe) are not as dependent as the media makes us out to seem. Alternative energies exist, but simply cost more. If we are willing to bear higher costs, we can reduce our oil dependence today.
As I see it the world's dependence on oil will not diminish with new energy sources. At least not until that source is so incredably inexpensive that it will replace all other energy supplies. Or all crude oil supplies run dry. Perhaps the correct question is not: will hydrogen reduce our oil dependence? But will this new hydrogen supply produce limitless inexpensive energy, so inexpensive that all other means of energy are outpriced?
It has a pdf version of the article in question. Here is the abstract.
In cavitation experiments with deuterated acetone,tritium decay activity above background levels was detected.In addition,evidence for neutron emission near 2.5 million electron volts was also observed,as would be expected for deute- rium-deuterium fusion.Control experiments with normal acetone did not result in tritium activity or neutron emissions.Hydrodynamic shock code simulations supported the observed data and indicated highly compressed,hot (10 6 to 10 7 kelvin)bubble implosion conditions,as required for nuclear fusion reactions.
I beleive that geographic isolation (punctuated equilibrium) differentiated species after a long (the longer the better) period of mutation. Are there any biology/ecology people out there who can correct me?
I believe that traditional evolutionary theories point toward the idea that isolated populations develop more rapidly. The example of Drawin's finches, usualy widely in high school textbooks, illustrates (among other things) that the isolated populations evolved more rapidly than their continental ancestors/contemporaries.
The selection pressures from living on small islands with limited food resources, a single (helpful) trait among an isolated finch population would most likely to be expressed. If these finches with a new trait were still on the mainland, the presence of so many other "unaltered" finches would eventaully "dilute" that genetic variation, because there is no selection pressure on the mainland for that trait, individuals with and without the modification survive.
However, on an island, there is a natural selection pressure for said trait to have an advantage over "unaltered" finches. These finches would not survive, leaving the new birds to multiply.
I would mod you up if I could. Not because I agree with you but because you have realized that fundamentally names are, well names. Ironically the politician who most acuratly fits your ideology is a liberal, defined in the classical sense: a so called Classical Liberal. John Lock comes to mind. Even more ironically a "true" conservative is the same sense is someone who wants government to push morality on the populus. (More or less, I am talking about Edmond Burke for instance). In the last 200 years the definitions have changed. Liberal today means a socialist liberaism while conservatism has moves toward the classical liberal view (I'm generalizing but you get my drift).
My real point is that we as a society assign names and labels arbitrary to classify. We group everyone on the left as liberal and everyone to the right as conservative. Libritarians will tell you they don't really fit in either. Even the definitions of left and right are arbitrary.
However, there is a good reason we do this. It is easier for us as humans to assign labels. Imagine if on the election ballot instead of Republican, Democrat, etc. we had a string of descriptive adjectives like (to quote you first):
believes government should leave the people alone, whether we're talking about guns, taxes, religion, family values, technology, etc.
believes government should do what it can to aid middle and lower middle income families by providing socal services and welfame programs.
believes in strong environmental policy to prevent futher damage to fragile ecology of planet.
Unfortunately by assigning names to group we deprive ourselves the valuable tool of critical thinking. Instead of analyzing exactly what a politician wants and will do we instead look towards the label assigned and imprint that label on the politician. Being able to think critically about a deicision is much harder than assigning labels, people do it all the time. I am gald to see that there are still some people who are willing to look past assigned names and, in this case, vote their conscience.
Being from the DC area, if you want inexpensive computer components I would urge you to actually try the Market Pro Computer Show and Sale. You can find information about the shows at this link.
Although they are advertised as you said "'Comptuer Show and Sale and Monster Truck Rally' events advertised constantly on cheapo UHF stations," they are mostly filled with local (DC/MD/VA) vendors and some out-of-area (PA/NY/NJ) sellers who sell computers and computer compenents. I would not recommend this show for any novice computer user. I do extensive research of the product(s) I want to buy before I go there; because the phrase caveat emptor is very appropriate.[1]
However, since you mentioned you wanted more of a swap fest, this may not be for you. You might try...
There are also fedral auctions at Goddard Space Flight Center (GSFC) which sell many components. However, most of them are really old government surplus. My step-father once picked up three 9 inch floppy drives there (it was part of a pallet where he wanted the plotter). I don't know the URL of the auctions but you can goto the GSFC Website and search for it. Google may work as well.
Finally there are HAMfests in the DC area you can go to. Not being a HAM operator/user I don't know of any. Once again, google may help.
[1] My friend once claims that he bought a motherboard from a computer show that was not FCC compliant (made in China) and interfered with radio devices. I have only bought a bad harddisk once which the (local) vendor was happy to replace. Again, caveat emptor.
In this setup plasma particles align themselves with the MAGNETIC field, which is threated through the magnetic rings (duh). The Electric field is generated in the center and radiated outward toward the edge of the bottle.
The tokamak reactor design uses a torus (donut) shaped ring to confine the plasma. Another design is one my (former) physics professor and the group he is in are currently working on. Basicaly the design consists of two magnetic rings, one above one another. The electric field is threaded through the bottom one and through the top one. The electric field bulges out between the two rings making a sort of "coat hanger" cross section between the rings. This forms the shape of the magnetic bottle.
Classical EM shows that the plasma particles will be confined to the electric field lines and helix around them. If there were no magnetic fields the particles would "escape" this system through the top and bottom of the E-fields.
The neat part is that when the magnetic fields change, the system imparts an angular momentum onto the plasma particles. The result is that the plasma spins (in the same plane as the magetic rings). Since the electric fields are in a bent, the centripetal force will push the plasma into the middle of the "bottle" and away from the top and bottom. The anaolgy he gave was take a bead and put it on the bent wire of a coat hanger. Now spin the hanger around its long axis. The centripetal force will push the bead to the "bulge" of the hanger. Similarly, the plasma should be pushed to the "bulge" of the magnetic bottle. Hopefully when enough energy is added to the system the plasma will fuse.
Last I heard the group this professor works in was trying to get funding to program a model of the reactor, so no working model is on the way soon. He claims that thoeretically this setup should be able to cross the energy in-energy out threashhold. Of course only time (and money) will tell.
How many people here would jump at the chance to work for NASA for free if it meant the possibility that they may, themselves, go into space?
I don't know about future of the space program or all the rules associated with working for NASA, but I was told that you are not allowed to work for the (US)Federal Government for free, i.e. volunteer your time. Of course you could argue that you are being "paid" with a trip into space. But for some reason all contracters and employees must be paid.
You are right, there are a number of accelerators around the world.
Here is a list of major accelerators with their corresponding experiments:
http://www.hep.net/experiments/all_sites.html
(Sorry, URLs don't work for me).
What is important to understand is that the overlap between the different experiments, even at the same accelerator, is very little. People do research an a myrid of physics at each site. In addition, accelerators around the world are constantly upgrading their hardware, software, and detectors to use at "capacity."
One of the reasons that scientists what a new accelerator built is because there are a number of areas of research that can only really be done with new equipment. While upgrading the old equipment does allow some of this new research, obviously someone (or someones) feel it would be better to build an accelerator with new hardware, software, and dectectors to conduct new research.
Historically, modern science has always been funded by someone else. In the 16th and 17th centuries, monarchs and other nobles funded science because they felt it was a sign that they were enlightened. They also hoped to reap any technological benefits that developed.
In the 18th and 19th centuries, science become the realm of the universities, who funded its members to research purely for the sake of research. Academic reputation had been established by societies such as the Royal Society in England and the Academie des Sciences in France. Scientists were pressured to generate research on the basis that their rewards would be academic fame.
In our time, science funding has returned to the realm of the state. Universities do fund the sciences, but to get significant funding you must petition the state. NASA is an extreme example. NASA must always petition the state for funds because no one else can put up that kind of money. All the academic institutions in the country would not be able to foot NASA's bill (and still function and universities). Therefore, because NASA is funded by the state, it is expected to return something to the state. After all, the state's money is the people's money right?
Personally I operate on the belief that my tax dollars (which I grudgingly pay every year) is not my money. It was my money, but as soon as I wrote a check to the "United State Treasury," I gave that money up. In effect, I gave the money to the government, which I have recognized as my state. It is up to the state to decide where the money should be spent. Now I can influence my congressman and my senators and the president to spend the money in a way in which I see fit, but that is an artifice of the system of government in which we live in. (Notice I am making a distinct difference in what a state is and what a government is.) If for some reason we lived in Soviet Russia in the 1960's, we would have no say in the government on how our state spends its funds (on space research or nuclear weapons).
Now we can get into an argument about governments and states and things like Jean-Jacques Roussea's Fundamental Rights and Freedoms and the interaction between the state and its people. My point is that Congress decides how much money NASA gets. Congress happens to expect a "return for its payment." This attitude is a result of our values as a society. As a scientist, I would rather see a society in where science funding can be given without any expectation of a return. Pure science is just as important to me as any technology for the citizenry.
Why would anyone want to go to a baseball game. I mean, why drive for miles and sit in a outdoor stadium for three (+) hours watching some guys throw and hit a ball around a field, then run around and around a dirt path? And pay for it! Why don't they just pick up a bat and a ball and play it themselves!
For me, I pay for to watch sporting events because I am a total geek and cannot play sports to save my soul, but I do enjoy watching them. While not all slashdot readers may be sports fans and not all slashdot readers may be first-person shooter (FPS) fans, there are people who are willing to pay real money to watch other people; whether it be baseball or basketball . . . or counter-strike (fortunately counter-strike is free).
Its rather ironically sad it has to be sold, and you have to wonder if Russia is that desperate for money.
The capsule is being sold by an American and Russian company, not the Russain Space program.
From the article:
"This sale is part of an agreement between Space Media Inc. and the S. P. Korolev Rocket and Space Corporation Energia (RSCE). Space Media and RSCE are promoting both American and Russian achievements in and contribution to peaceful space exploration."
And as for the customs issue (again from the article):
"The successful buyer should allow up to 24 weeks for delivery to allow for the necessary packing, shipping and customs paperwork requirements to go through official channels.
"
We have looked at both KDE and GNOME. There is some interesting work going on there. I personally feel it is too bad that the Linux community can't agree to build on one graphical environment.
It is absolutely necessary that Linux be built on gone graphical environment? I have gtk underneath KDE and run GNOME apps all the time. I can do the reverse under GNOME. What is important is that the underlying architecture the compatible, not the graphical interface.
I can change my shirt anytime, but it is what underneath that counts.
Two things: You are innocent until proven guilty in a court of law. Police departments and Law enforcement agencies are concerned with order and enforcement not justice. Anything you say to the police can be used again you (remember Miranda?). The police can search, seize, and presume, because they are not the ones who punish you. That job is for the district attorney's office.
Although it does not apply to this case, the Secret Service is the only law enforcement agency that can detain you for no reason, indefinately. They are allowed to do this if they feel you are a threat to the president. Obviously the "treasury arm" of the Sercret Service cannot do this, only the presidential protection branch.
Free speech only goes so far. I am all for free speech and expression in any form, but some of the other issues that the courts must decide on include:
Clear and Present Danger
It is illegal to yell "Fire!" in a crowded theater. The only case I can remember is a 1950's case where the Supreme Court ruled that inciteful speech is still protected. The case (Tortechelli vs. Chicago? something like that but spelled correctly) involved a man (T) who was holding a anti-"everyone except for white anglo-saxon males" rally in a Chicago theater. After a major riot broke out ouside theater, the police arrested the man. The court found that his speech is still protected and that the police did not have the right to arrest him.
Fighting Words
It is illegal to say, "I will kill you." If I actively say to your face that I hate you for whatever reason and say I am going to kill you, that speech is not protected under the 1st amendment. As you can see there is a fine line where this kind of speech crosses over. In this case, the judge decided that it the anti-abortion Web site was still on the Free Speech side and not the other.
Slander and Libel
If I post flagrantly incorrect information about you and you sue me (in a civil court), I cannot claim free speech because the speech is libel (slander is a verbal "lie"). The most famous case was a Hollywood actress who sued the National Enquirer for printed false information about her. The publication claimed freedom of speech, but the court ruled in favor of the actress. Note:this is a civil case, not a criminal one. There is nothing inherantly criminal about slander or libel that is contrary to the first amendment.
While the Supreme court often does rule in favor of the speaker in these cases, they must also weight into account the criteria above. I am sure there are even more subtler/obscure criteria that the court considers when ruling in a freedom of speech case.
While this convention shows off the newest and coolest gadgets, education budgets are shrinking. I for one would rather see people develop inexpensive experiments for high schools that would allow students to
learn science for a smaller price tag; it's win/win (except for the people who sell the cool gadgets...)
(story)
The other night my friend presented a neat toy he constructed, basically a Laser pen imbedded in a old Nintendo Zapper Light Gun. The trigger switch would trigger the laser. After playing with it for a while, someone suggested that we measure the wavelength of the light. Usually this lab is done with a diffraction grating. The laser beam is shined through the grating to produce a pattern on the wall. By measuring the pattern, the distance to the wall, and the width of the slits one can determine the wavelength of the laser beam. Usually, high schools have expensive He-Ne lasers and manufactured diffraction gratings; we had none of those things. It dawned on us that the opposite of a diffraction grating gives the opposite pattern against the wall. Since you get a interference pattern from a single narrow slit (see a physics text on why), we took the opposite of a single slit: a long, thin item. We eventually settled on a single staple and a.5 mm piece of (mechanical) pencil lead.
The result was the wavelength of the laser pen was about 750nm +/- 120nm. We suspect the laser pen is a cheap He-Ne laser with a (defined) wavelength of 632nm.
(/story)
The point is that we preformed a simple experiment with a significant amount of scientific value for about $20 ($15 for the laser; staples, pencil lead, ruler, etc. are all "free"). For a high school, this kind of experiment would be much more rewarding to the students that plugging things into calculators or Palm and churning out results. A science department could spend a minimal amount of money on laser pens (the $15 ones are good enough) and perform what my friends and I did. Rulers, pencil lead, and clamps are all equipment the school should already have.
As education budgets shrink, the experiment like the one above is a good example of what science can be done without a lot of money or without a lot of toys.
Being as dense as it supposedly is with such great gravitational attraction, how does it keep from folding in on itself like a black hole?
There are two answers:
1.
What determines the final stage of a collapsed star is its main sequence mass. Your sun's main sequence mass is 2 x 10^30 kg or one solar mass (Mo). Stars that are (less than)1-3 Mo become white dwarves, 3-10 Mo become neutron stars, >10Mo become black holes. Note, these numbers are approximate, look in a astronomy text for details.
2.
White dwarves are "held up" by what is known as degenerate electron pressure. To understand this phenomenon, I have to explain the Pauli-Exclusion Principle. The Pauli-Exclusion Principle states that no two electrons can occupy the same energy state. (In general the Pauli-Exclusion Principle says that no two identical fermions can occupy the same state. Fermions are particles with a spin of one-half.) A good analogy (which was given to me) is as follows: think of a classroom with 50 seats. Since only one student can occupy one seat, there are exactly fifty students in the room. If the room suddenly shrinks to 30 seats, 20 students must leave, and only 30 students remain.
As a main sequence star with mass (less than)1-3 Mo collapses, it reaches a point where every electron fills every energy state. At this point, there is an outward pressure because all the electron energy states are filled. This outward pressure balances against the inward pressure of gravitational collapse. At this point, we have a white dwarf.
If a star is sufficiently large, the gravitational pressure is enough to force electrons to bind with protons making neutrons. Neutrons are also fermions. So they also obey the Pauli-Exclusion Principle. Neutron stars are "held up" by degenerate neutron pressure.
Not that you asked but The Economist is a British publication that leans to the right.
What I got from this article was the basic conservative message about international trade. After all, it seemed to concentrate on why Japanese electronic firms might or will be declining. While the publication may be British, this article was written for the US publication of the magazine. The message seemed to be that the American Computer companies might reduce market share from the Japanese electronic firms. I hate to generalize but conservatives (in the US) support US industries with tariffs (to "protect" them). They also emphasize the "trade gap" between the US and foreign nations in an effort to boost their position against allowing more foreign trade. And they also fight for less foreign investment in US interests.
Now I may be reading too much into this article. After all most electronic firms are Japanese and most computer companies are American. Yet I get the feeling that there is a "Made in the USA" angle to what this column is saying. Anyone else agree? Or am I reading too much into what the article is saying?
PS After I wrote this comment, I had another look at the cartoon on the top of the page. Why does the computer have an American flag on it?
The final section = of the book gives sober and well thought out step-by-step directions to lift = people out of poverty and invisibility, again based on experience in field = programs, rather than ideology.
There are two main theories on how the developing world should move into the developed world. Currently, only 30 countries are considered "devloped," while the rest are divided among groups such as "developing," "not developing," and "less-developed."
developed countries = first-world = industrialized nations
developing countries = third-world
Modernization theory (MT)
MT prescribed that economic development requires the rejection of traditional behavior and orginizations, and acceptances of new behavior and orginizations that futher economic growth. The culture of a nation must change to the accepted western ideas of devlopment. A partial list of the requirements that Modernization theorists agree on include:
Education of the population
Acceptance of science, technology, and the scientific method
increased secularization/decreases religious tradition
urbanization
division of labor
rule of law
merit based system of rewards (as opposed to a system where people of a class or birthrite are rewarded)
social mobility
diversity
innovation and change
In a nutshell, a acceptance of western culture and western sytle economic and policital thought lays the foundation of economic development.
Dependency theory (DT)
DT is a ideology that critisizes the MT approach. Two main tennents of Dependency theory: The development of third-world nations did not resemble the development of the west. The west's development for instance did not have external influences. The second tennent is that developed countries exploited the third-world in their own economic rise. Therefore any economic structure that may exist in a developing country is set up to enrich the industialized nations, not develop the third-world nation.
Dependency theorists see the western exploitation of third-world nations as the primary roadblock to economic sucess. By removing the foundations rooted in imperialism, third-world nations and develop the economic structure that moves them forward.
I have not placed any value judgements on these two theories. All I can say is that I agree with the statement that there are no easy answers to how to develop the third-world.
Note to readers: For those who are not Star Trek fans, here is a quick guide to the acronyms/different series:
TOS: The Original Series
TNG: The Next Generation
DS9: Deep Space Nine
Voyager: Voyager
In my (humble) opinion, something is being overlooked. I have been a Star Trek fan for a while but never an ardent one (I havn't seen all the episodes). What makes Star Trek such a lasting and important part of our/American culture is not the technology, not the federation, nor the plots. Star Trek is sucessful because of the character development and character interaction.
I'll get back to this in a moment but think about this TNG couple: Worf and Troy. Who would have predicted that!
(I used "our/American culture" for a reason, I'll get back to is soon)
First I want to explain my views on why the other elements are not the reason for Star Trek's rise to fame.
Technology
Among my friends (yes we are all geeks), some of our favorite quips are: "Just reverse the polarity.","Activate the Heisenburg compensators.", or "Turn on the Reality compensators." There is a reason why new physics is invented constantly, the real stuff is too contraining. Hence an episode of Voyager where the ship falls into "Chaotic Space," where the law of physics (conveniently) don't hold. My point is that technology simply a tool used by the writers/producers to set the show in. Not much of the technology in Star Trek makes that much sense. As someone pointed out in another comment, "If a friend is fighting an enemy and you can't get a clear shot at the enemy, why not just stun them both?"
The Federation
What an ideal society. It's just that, and ideal society. Roddenberry wanted to set his show in some society that didn't have the social problems that were prevalent in the 1960's, when he conceptualized Star Trek. Look at TOS cast, a black woman Communication's Officer, a Japenese Helmsman, and Russian Tactial Officer, and a Scottish Engineer.
Yet at the same time women wore really short skirts and the three main characters were white males (Shatner, Nemoy, and DeKelly[sp?]). But that is another issue all together
I would like to point out that the main employer (or what looks to be) and/or main focal point of the Federation is not the ideal society but a military orginization. Let's face it, the Enterprise may have a mission "to go where no man has gone before," but they do it with phasers and photon torpedos. Again, my point is that the Federation plays the same role as technology does, a tool for the settting of the show.
Plot
Did you notice that you can save the (choose one: ship/planet/Federation/galaxy) in a single hour! Wow! I would argue that the plot of the episodes do not constitue a major part of the show's fame. Of course there are some exceptions. DS9's war with the dominion was a multi-season story that was well written and well produced. The reason plot is not important is tied into the culture behind the show, which I will now address.
Whether we like it or not, Star Trek is a part of American culture. The reason for this can be found in American history. In the 19th century, Americans moved west and covered the continent. That "western" era with cowboys and gunfights at the "OK Coral" inspired many American ideals and attitudes: the open frontier, the vast unknown, the cowboy hero. It also killed thousands of Native Americans and destroyed their culture but in the 1950's that was swept under the carpet.
I say 1950's because that is when television producers started making all the western shows that I have never seen. Roddenberry wanted to make a "western" style show set in the future, hence Star Trek was born. Think about the parallels: "to explore strange new worlds, to boldly go where no man has gone before." Sound like a cowboy western? Compare Captain James T. Kirk with Wyatt Erpp (sp) or The Lone Ranger. White men who are flamboyant and charasmatic. Although Roddenberry did not explicitly say, "I will make a western set in the future," the fact is that westerns were an ingrained part of American culture, and that culture unfluenced Roddenberry.
Star Trek TOS and TNG could easily inherent the western. Both has ships which ran around uncharted space exploring or fighting or discovering new conflicts that needed to be resolved (usually in an hour). DS9 had problems with this paradigm. A space station doesn't fly around space. To comensate the writers/produces introduced the Defiant. They also created a massive multi-threated plot (the Dominion war). Voyager has tried to mimic the TOS and TNG but for some reason is not as sucessful. That reason is because of the characters (my original point).
Character development and interactions is what made Star Trek (TOS and TNG and to a partial extent DS9) successful. Kirk, Spock, and McCoy worked great together, playing off each others personalities. Picard, Ricker, Data, etc. wound up being a great combination. Why didn't Wesly Crusher work out? Not because the fans didn't like him (it didn't help), but because he didn't fit into the TNG universe. Picard was the Shakespearean captian, wise and philosophical. Riker, the cowboy (likely more popular than Picard). Data, the brains of the operation. Worf, the warrior who could be gentle and humane. Look at the relationships that developed. The friendship between Georde and Data developed when the writers realized the two worked great together in Engineering. Picard and Riker played off each other; one a flamboyant, almost reckless first officer, the other a stern, yet brilliant captian. Like I said before, Troy and Worf developing a realtionship? Although some people would agrue that was a stupid love story, I would look back and say the two worked well together.
What definatly helped TNG in its character development was good actors. Not to say the acting was award-winning or great, just good. This is partially the reason why Voyager doesn't seem to get anywhere. Voyager tries to develope character realtionships, but it isn't working very well. Plus the acting isn't much to speak of, which doesn't help. Try this, think of two characters which play off each other well in TNG (you can use the ones I've pointed out if you want). Now compare that relationship to another relationship in Voyager. Can you even think of a good two person relationship in Voyager?
DS9 managed to be the exception to this rule of character development. Since the "cowboy frontier" genre was not working, the writers/producers introduced the huge Dominion war, which succeded in overlaping the lack of character development. Again, think of a relationship, Kira and Odo? (I'd rather not think about it thank you). Sisko and ??? In fact Avery Brooks really played off himself. He is a pretty good actor. He did a good job being Captain Sisko. His character and force personality really didn't need a foil. He was Captian Sisko. I would say he alone helped make DS9 a sucess. The plot however is what really captured viewers. I must admit I have been arguing character this and character that, but when I watch DS9 I watch for the plot. This is why some DS9 episodes that don't deal with the Dominion War suck.
Think about the difference between a movie and a TV series. A movie is about a story, told in two hours. Star Trek runs once a week, so unless you have a huge plot like DS9, what are you going to intice the viewers with. Answer: the characters.
I haven't said much about the new show. I would hope that regardless of where or when it is set, the producers get some good actors and the writers generate good characters. Regardless of what they come up with, the fan base is so large that not everyone will be happy. But I'll still watch the first episode, and that is what the producers are hoping for.
Fossil Fuels such as oil run the world. The computer that I am writing this post on is powered by coal. What happens when (and if) all the fossil fuels are used up?
I would imagine that most/.-ers and people in general want a cleaner environment. I am no envirnmentalist, but I want clearer air and water. Unfortunalty, fossil fuels is not the cleanest scource of energy. The reason that we still use the is purely economical. After all, it is cheaper to mine/drill for coal,oil, and gas, burn them in our power plants and cars, than to use alternative scources of energy. We may want the electric car, but we don't want to play 10x the price for one.
I believe that the only way we will abandon fossil fuels is if they become too expensive to use. Exxon and other gas giants are always looking for newer scources of fuel (the Alaskan oil reserves for instance). Until the economic price of oil goes up, we will never start to use those "alternative" scources of energy that are cleaner.
Therefore, this discovery worries me. Sythetic rubber in tires are made from coal and petroleum. Basically, all we are doing is taking a fossil fuel that we already mined, and reusing it for energy. We are simply lengthening the overall "life-time" of these fossil fuels. I really believe that companies need to point their research at alternative energy sources, but there is no economic benifit for them to do so as long as we can extract more from our oil like this discovery has done.
Now I know that my agrument sounds kind of shoddy, but as long as there are cheap fossil fuels, the world will still use them and pollute. If we want to stop using fossil fuels we need to encourage economic benifits to research alternative energy sources; yes I know I sound like Gore. But I think he is right in the fact that the economic cost of alternative sources of energy are greater than the cost of using coal and oil.
Case and point. In the 70's during the energy crisis, there was a movement towards alternative energy sources. This was because oil cost so much that companies wanted to do the research. As soon as the energy cost of oil went back down, the motivation to develope alternative energy sources diminished.
In conclusion, I don't want us (society) to abandon fossil fuels. I personally like not having to pay lots of money for gas/electricity. But I also think that if we encourage alternative energy sources, we will be better off in the end.
And YES, you could come back from a mission to, say, Mars, using this technology. Travel between planets is accomplished by establishing yourself in an eccentric orbit that passes through the orbital path of both your origin and your destination. So you can use the magneto-sail to push out away from the planet, establish your orbit, then turn it off when you reach the "top" of your curve, and fall back in. Then turn the sail on again when you need to brake.
This is exactly what you would do. I think a lot of people posting seem to forget that the if this technology can be harnesses, we would have two forces from the sun.
Solar Wind
Gravity
Space travel isn't a point to point flight. To go from Earth to lets say Jupiter, stopping at Europa on the way, you launch your satelite in an ellipical orbit with a certain energy such that this new orbit would take your spacecraft out to the orbit of Jupiter. If you "missed" Jupiter (i.e. didn't slow down and and get captured by Jupiter/Europa) you would just continue traveling in that orbit. In fact you would eventually reach the point in Earth's orbit where you left the Earth (the earth wouldn't be there anymore since it moves).
By using the M2P2 as a propultion, you can change your orbit around the sun. Gravity does the rest. The great advantage of the M2P2 technology is that it unlike a chemical rocket it doesn't require as much fuel. After all, the amount of fuel dictates how much you can change your energy. With M2P2, the energy to change your orbit(s) comes from the sun.
It seems that there is a lot of hype with the discoveries of all these planets. Many of the comments about the prvious article on the finding of the Jupiter sized planet around Epsilon Eridani all seems to assume that we are close to finding the answers about planets and we can start searching for "earth-like planets" and that we will understand everything about extrasolar planets. In fact nothing could be further from the truth.
First of all, I am studying to receive my degree in Astronomy, so if any Astronomers out there want to correct me, please feel free to do so.
Let's take a quick look around our solar system:
The Earth and other inner planets are about 0-2 AU (1 AU = radius of Earth to Sun). Mars, the futhest inner planet is about 1.5 AU from the Sun.
The outer planets are (respectivly) 5, 9.5, 19, 30, and 40 AU from the Sun.
All the orbits of the planets (except Mercury and Pluto) are almost perfectly circular. The eccentricity of the orbits (where 0 is a perfect circle) range from.004 -.09 (Mercurey is.2, Pluto is.25).
These three facts are part of the theory of how our solar system formed, here is the short version. A large gas cloud collapes under gravity (Jean's Mass for those astronomers) and spins due to conservation of angular momentum. The spinning cloud's center begins fusion and the star is "born." The gas and other matter around the star forms into an acresion disk. When the disk cools, planetessials form which collide together to form planets. Inner (rocky) planets form within 2 AU because there is enough gravity to hold heavier elements and there is enough heat to let H and He escape (this is another discussion involving statisitcal mechanics). Outer planets form with gas and since there is not enough heat, H and He stay.
Now there are a lot of other things that may have happened. For example, capturing Pluto to make it a planet, Jupiter acting as the vaccuum cleaner sweaping up dust and small objects. Jupiter and Mars acting together to "form" the astroid belt.
But for the most part, this is the theory of how our Solar System formed.
Of course with now other planets being discovered until recently, this is also how we though other solar systems would possible form elsewhere is the galaxy. However, the after discovereing about 50 some planets it looks like we have some major rethinking to do.
ONE 90% or so of all stars in our galaxy are binary (or more) stars. Firstly, we don't have a good theory on how binary stars form. The spinning gas cloud theory I described above doesn't lend itself to form two stars. Secondly, how do you get planets with binary star systems? For those who know, N-body gravity problems are very difficult. With 3 bodies, two stars and one planet, the planet almost always flys out of the system!! Unless the two starts are very close together and the planet is orbiting far away, so that the two stars act as one. So, as we are discovereing new planets we run itno this problem that bianry stars don't seem like good "solar systems." I don't know the statistics, but I would like to know how many of these new planets are around binary systems.
TWOMost of the new planets are Jupiter sized planets. There is nothing strange about this, our instruments can only measure a Jupiter sized planet's wobble. But what is interesting is that many Jupiter sized planets have not been found at 5-30 AU, but all over. There are some that are as close as.5 AU! Once again, I haven' seem the statistics, but I would like to see a correlation between the distance of thuse Jupiter size planets and the type of star they orbit.
Jupiter size planets form because there is not enough heat for the H and He to escape the gravity
This finding seems to counter our original theory of solar system formation.
Some of the planets found have highly elliptical orbits. Without the statisitcs I cannot make any real guess on why but it does seem to refute the idea of the acresion disk forming planets, after all all of the planets in our system have near circular orbits (the.2 that mecury and pluto have isn't that ellipitcal either).
I would guess to say that we (science) need to rethink our theories of solar system formation. We need to figure out how thost extrasolar planets formed and come up with models ofhow our system could form in such a "untypical" manner. Of course we need to make many more observations to verify that we are not normal. After all, we could just be finding the fringle systems and al most all other systems are just like ours.
Slashdot Mirror
Okay, you want a reading list. I have one for you.
First brush up on your classical mechanics, you will need to study Lagragians and the Hamitonian formulation as they are both very important for the formation of Quantum Mechanics. Lets see, you could try:
For a good mathematical methods reference read:
You want to rigorously learn all of Electricity and Magentism; there is only one source:
Now you have to start on Quantum Mechanics. There are many different books you could try; here are some of them:
Now that you have learned Quantum Machanics you can move onto some field theory:
At this point you may want to deviate slightly and read some books on relativity and cosmology
When I started college, I chose physics because I liked it. I soon realized that the physics you learn at a univeristy is not the physics a physicists does. Instead, everything you learn as an undergraduate classes are tools. These tools are to be used in graduate school as a foundation for more complex concepts.
It's been four years and I am about to go off to grad school to study elementry particle physics (experimental). I don't claim to have read any of the books above, but I hope it might show you that if you want to "*fully* comprehend stuff like particle physics, quantum phenomena, etc." it is not easy. Most popular science books you will find on a bookshelf do not contain much substance. Many are good reads. Brian Green's Elegant Universe and Stephen Hawking's A Brief History are good examples that are constantly recommended here on slashdot. But if you really (and I mean really) want to learn physics, you can do one of two things:
My purpose of this post is not to be harsh, but realistic. I am glad you are fasinated with physics. My fasination led me to the point where I want to spend years in school studying it. But I think many people don't realize that the subject is really difficult, and that it takes years of university education to even begin to understand it.
the beginning of the end for our dependence on oil
I guess I'll bite.
The problem with the dependence of oil isn't an alternative means. Someone has pointed/will point out that we have many alternative energy sources. Instead oil as a means of energy is dominant because it is cheap.
The world's energy infrastructure is based on using crude oil. There are oil power plants, oil refineries, gasoline engines, etc. Oil is simply cheaper to use. Companies spend billions of dollars researching new drill sites, lobbying Congress, etc. to maintain oil production because it is cheaper than investing in alternative energy sources; i.e. solar, nuclear.
Now what if this limitless source of Hydrogen comes on-line? What if we start using it instead of drilling for crude oil? At some point, the demand for oil begins to decline. Seeing as there is still a supply of oil (a diminishing supply, but still a supply) the price of oil will go down. Eventually, oil will be cheaper to use, and begin to rise in demand. A happy medium will be reached where crude oil drilling and this new hydrogen production will co-exist.
Admitidly, at this point there will no longer be a complete depedence on oil, but I would argue that we (the globe) are not as dependent as the media makes us out to seem. Alternative energies exist, but simply cost more. If we are willing to bear higher costs, we can reduce our oil dependence today.
As I see it the world's dependence on oil will not diminish with new energy sources. At least not until that source is so incredably inexpensive that it will replace all other energy supplies. Or all crude oil supplies run dry. Perhaps the correct question is not: will hydrogen reduce our oil dependence? But will this new hydrogen supply produce limitless inexpensive energy, so inexpensive that all other means of energy are outpriced?
Here is a link Science Magazine is providing:
Science Magazine
It has a pdf version of the article in question. Here is the abstract.
I beleive that geographic isolation (punctuated equilibrium) differentiated species after a long (the longer the better) period of mutation. Are there any biology/ecology people out there who can correct me?
I believe that traditional evolutionary theories point toward the idea that isolated populations develop more rapidly. The example of Drawin's finches, usualy widely in high school textbooks, illustrates (among other things) that the isolated populations evolved more rapidly than their continental ancestors/contemporaries.
The selection pressures from living on small islands with limited food resources, a single (helpful) trait among an isolated finch population would most likely to be expressed. If these finches with a new trait were still on the mainland, the presence of so many other "unaltered" finches would eventaully "dilute" that genetic variation, because there is no selection pressure on the mainland for that trait, individuals with and without the modification survive.
However, on an island, there is a natural selection pressure for said trait to have an advantage over "unaltered" finches. These finches would not survive, leaving the new birds to multiply.
I would mod you up if I could. Not because I agree with you but because you have realized that fundamentally names are, well names. Ironically the politician who most acuratly fits your ideology is a liberal, defined in the classical sense: a so called Classical Liberal. John Lock comes to mind. Even more ironically a "true" conservative is the same sense is someone who wants government to push morality on the populus. (More or less, I am talking about Edmond Burke for instance). In the last 200 years the definitions have changed. Liberal today means a socialist liberaism while conservatism has moves toward the classical liberal view (I'm generalizing but you get my drift).
My real point is that we as a society assign names and labels arbitrary to classify. We group everyone on the left as liberal and everyone to the right as conservative. Libritarians will tell you they don't really fit in either. Even the definitions of left and right are arbitrary.
However, there is a good reason we do this. It is easier for us as humans to assign labels. Imagine if on the election ballot instead of Republican, Democrat, etc. we had a string of descriptive adjectives like (to quote you first):
Unfortunately by assigning names to group we deprive ourselves the valuable tool of critical thinking. Instead of analyzing exactly what a politician wants and will do we instead look towards the label assigned and imprint that label on the politician. Being able to think critically about a deicision is much harder than assigning labels, people do it all the time. I am gald to see that there are still some people who are willing to look past assigned names and, in this case, vote their conscience.
Being from the DC area, if you want inexpensive computer components I would urge you to actually try the Market Pro Computer Show and Sale. You can find information about the shows at this link.
Although they are advertised as you said "'Comptuer Show and Sale and Monster Truck Rally' events advertised constantly on cheapo UHF stations," they are mostly filled with local (DC/MD/VA) vendors and some out-of-area (PA/NY/NJ) sellers who sell computers and computer compenents. I would not recommend this show for any novice computer user. I do extensive research of the product(s) I want to buy before I go there; because the phrase caveat emptor is very appropriate.[1]
However, since you mentioned you wanted more of a swap fest, this may not be for you. You might try...
There are also fedral auctions at Goddard Space Flight Center (GSFC) which sell many components. However, most of them are really old government surplus. My step-father once picked up three 9 inch floppy drives there (it was part of a pallet where he wanted the plotter). I don't know the URL of the auctions but you can goto the GSFC Website and search for it. Google may work as well.
Finally there are HAMfests in the DC area you can go to. Not being a HAM operator/user I don't know of any. Once again, google may help.
[1] My friend once claims that he bought a motherboard from a computer show that was not FCC compliant (made in China) and interfered with radio devices. I have only bought a bad harddisk once which the (local) vendor was happy to replace. Again, caveat emptor.
(Slaps Forehead)
Your absolutely right. My bad.
In this setup plasma particles align themselves with the MAGNETIC field, which is threated through the magnetic rings (duh). The Electric field is generated in the center and radiated outward toward the edge of the bottle.
For more information on this containment theory please visit my professor's web page at: Centrifugally Confined Plasmas
You can also get a good scematic of the design at: This link
I apologize for the confusion.
The tokamak reactor design uses a torus (donut) shaped ring to confine the plasma. Another design is one my (former) physics professor and the group he is in are currently working on. Basicaly the design consists of two magnetic rings, one above one another. The electric field is threaded through the bottom one and through the top one. The electric field bulges out between the two rings making a sort of "coat hanger" cross section between the rings. This forms the shape of the magnetic bottle.
Classical EM shows that the plasma particles will be confined to the electric field lines and helix around them. If there were no magnetic fields the particles would "escape" this system through the top and bottom of the E-fields.
The neat part is that when the magnetic fields change, the system imparts an angular momentum onto the plasma particles. The result is that the plasma spins (in the same plane as the magetic rings). Since the electric fields are in a bent, the centripetal force will push the plasma into the middle of the "bottle" and away from the top and bottom. The anaolgy he gave was take a bead and put it on the bent wire of a coat hanger. Now spin the hanger around its long axis. The centripetal force will push the bead to the "bulge" of the hanger. Similarly, the plasma should be pushed to the "bulge" of the magnetic bottle. Hopefully when enough energy is added to the system the plasma will fuse.
Last I heard the group this professor works in was trying to get funding to program a model of the reactor, so no working model is on the way soon. He claims that thoeretically this setup should be able to cross the energy in-energy out threashhold. Of course only time (and money) will tell.
How many people here would jump at the chance to work for NASA for free if it meant the possibility that they may, themselves, go into space?
I don't know about future of the space program or all the rules associated with working for NASA, but I was told that you are not allowed to work for the (US)Federal Government for free, i.e. volunteer your time. Of course you could argue that you are being "paid" with a trip into space. But for some reason all contracters and employees must be paid.
You are right, there are a number of accelerators around the world. Here is a list of major accelerators with their corresponding experiments:
http://www.hep.net/experiments/all_sites.html
(Sorry, URLs don't work for me).
What is important to understand is that the overlap between the different experiments, even at the same accelerator, is very little. People do research an a myrid of physics at each site. In addition, accelerators around the world are constantly upgrading their hardware, software, and detectors to use at "capacity."
One of the reasons that scientists what a new accelerator built is because there are a number of areas of research that can only really be done with new equipment. While upgrading the old equipment does allow some of this new research, obviously someone (or someones) feel it would be better to build an accelerator with new hardware, software, and dectectors to conduct new research.
Historically, modern science has always been funded by someone else. In the 16th and 17th centuries, monarchs and other nobles funded science because they felt it was a sign that they were enlightened. They also hoped to reap any technological benefits that developed.
In the 18th and 19th centuries, science become the realm of the universities, who funded its members to research purely for the sake of research. Academic reputation had been established by societies such as the Royal Society in England and the Academie des Sciences in France. Scientists were pressured to generate research on the basis that their rewards would be academic fame.
In our time, science funding has returned to the realm of the state. Universities do fund the sciences, but to get significant funding you must petition the state. NASA is an extreme example. NASA must always petition the state for funds because no one else can put up that kind of money. All the academic institutions in the country would not be able to foot NASA's bill (and still function and universities). Therefore, because NASA is funded by the state, it is expected to return something to the state. After all, the state's money is the people's money right?
Personally I operate on the belief that my tax dollars (which I grudgingly pay every year) is not my money. It was my money, but as soon as I wrote a check to the "United State Treasury," I gave that money up. In effect, I gave the money to the government, which I have recognized as my state. It is up to the state to decide where the money should be spent. Now I can influence my congressman and my senators and the president to spend the money in a way in which I see fit, but that is an artifice of the system of government in which we live in. (Notice I am making a distinct difference in what a state is and what a government is.) If for some reason we lived in Soviet Russia in the 1960's, we would have no say in the government on how our state spends its funds (on space research or nuclear weapons).
Now we can get into an argument about governments and states and things like Jean-Jacques Roussea's Fundamental Rights and Freedoms and the interaction between the state and its people. My point is that Congress decides how much money NASA gets. Congress happens to expect a "return for its payment." This attitude is a result of our values as a society. As a scientist, I would rather see a society in where science funding can be given without any expectation of a return. Pure science is just as important to me as any technology for the citizenry.
Why would anyone want to go to a baseball game. I mean, why drive for miles and sit in a outdoor stadium for three (+) hours watching some guys throw and hit a ball around a field, then run around and around a dirt path? And pay for it! Why don't they just pick up a bat and a ball and play it themselves!
For me, I pay for to watch sporting events because I am a total geek and cannot play sports to save my soul, but I do enjoy watching them. While not all slashdot readers may be sports fans and not all slashdot readers may be first-person shooter (FPS) fans, there are people who are willing to pay real money to watch other people; whether it be baseball or basketball . . . or counter-strike (fortunately counter-strike is free).
Its rather ironically sad it has to be sold, and you have to wonder if Russia is that desperate for money.
The capsule is being sold by an American and Russian company, not the Russain Space program.
From the article:
"This sale is part of an agreement between Space Media Inc. and the S. P. Korolev Rocket and Space Corporation Energia (RSCE). Space Media and RSCE are promoting both American and Russian achievements in and contribution to peaceful space exploration."
And as for the customs issue (again from the article):
"The successful buyer should allow up to 24 weeks for delivery to allow for the necessary packing, shipping and customs paperwork requirements to go through official channels. "
We have looked at both KDE and GNOME. There is some interesting work going on there. I personally feel it is too bad that the Linux community can't agree to build on one graphical environment.
It is absolutely necessary that Linux be built on gone graphical environment? I have gtk underneath KDE and run GNOME apps all the time. I can do the reverse under GNOME. What is important is that the underlying architecture the compatible, not the graphical interface.
I can change my shirt anytime, but it is what underneath that counts.
Two things: You are innocent until proven guilty in a court of law. Police departments and Law enforcement agencies are concerned with order and enforcement not justice. Anything you say to the police can be used again you (remember Miranda?). The police can search, seize, and presume, because they are not the ones who punish you. That job is for the district attorney's office.
Although it does not apply to this case, the Secret Service is the only law enforcement agency that can detain you for no reason, indefinately. They are allowed to do this if they feel you are a threat to the president. Obviously the "treasury arm" of the Sercret Service cannot do this, only the presidential protection branch.
Free speech only goes so far. I am all for free speech and expression in any form, but some of the other issues that the courts must decide on include:
It is illegal to yell "Fire!" in a crowded theater. The only case I can remember is a 1950's case where the Supreme Court ruled that inciteful speech is still protected. The case (Tortechelli vs. Chicago? something like that but spelled correctly) involved a man (T) who was holding a anti-"everyone except for white anglo-saxon males" rally in a Chicago theater. After a major riot broke out ouside theater, the police arrested the man. The court found that his speech is still protected and that the police did not have the right to arrest him.
It is illegal to say, "I will kill you." If I actively say to your face that I hate you for whatever reason and say I am going to kill you, that speech is not protected under the 1st amendment. As you can see there is a fine line where this kind of speech crosses over. In this case, the judge decided that it the anti-abortion Web site was still on the Free Speech side and not the other.
If I post flagrantly incorrect information about you and you sue me (in a civil court), I cannot claim free speech because the speech is libel (slander is a verbal "lie"). The most famous case was a Hollywood actress who sued the National Enquirer for printed false information about her. The publication claimed freedom of speech, but the court ruled in favor of the actress. Note:this is a civil case, not a criminal one. There is nothing inherantly criminal about slander or libel that is contrary to the first amendment.
While the Supreme court often does rule in favor of the speaker in these cases, they must also weight into account the criteria above. I am sure there are even more subtler/obscure criteria that the court considers when ruling in a freedom of speech case.
From the article: Another concern is how penny stock boiler room operations and Ponzi schemes have benefited from using spam emails.
...now where will be able to hear about the latest oppurtunities to get rich; and quick too!
While this convention shows off the newest and coolest gadgets, education budgets are shrinking. I for one would rather see people develop inexpensive experiments for high schools that would allow students to learn science for a smaller price tag; it's win/win (except for the people who sell the cool gadgets...)
(story)
The other night my friend presented a neat toy he constructed, basically a Laser pen imbedded in a old Nintendo Zapper Light Gun. The trigger switch would trigger the laser. After playing with it for a while, someone suggested that we measure the wavelength of the light. Usually this lab is done with a diffraction grating. The laser beam is shined through the grating to produce a pattern on the wall. By measuring the pattern, the distance to the wall, and the width of the slits one can determine the wavelength of the laser beam. Usually, high schools have expensive He-Ne lasers and manufactured diffraction gratings; we had none of those things. It dawned on us that the opposite of a diffraction grating gives the opposite pattern against the wall. Since you get a interference pattern from a single narrow slit (see a physics text on why), we took the opposite of a single slit: a long, thin item. We eventually settled on a single staple and a .5 mm piece of (mechanical) pencil lead.
The result was the wavelength of the laser pen was about 750nm +/- 120nm. We suspect the laser pen is a cheap He-Ne laser with a (defined) wavelength of 632nm.
(/story)
The point is that we preformed a simple experiment with a significant amount of scientific value for about $20 ($15 for the laser; staples, pencil lead, ruler, etc. are all "free"). For a high school, this kind of experiment would be much more rewarding to the students that plugging things into calculators or Palm and churning out results. A science department could spend a minimal amount of money on laser pens (the $15 ones are good enough) and perform what my friends and I did. Rulers, pencil lead, and clamps are all equipment the school should already have.
As education budgets shrink, the experiment like the one above is a good example of what science can be done without a lot of money or without a lot of toys.
There are two answers:
1.
What determines the final stage of a collapsed star is its main sequence mass. Your sun's main sequence mass is 2 x 10^30 kg or one solar mass (Mo). Stars that are (less than)1-3 Mo become white dwarves, 3-10 Mo become neutron stars, >10Mo become black holes. Note, these numbers are approximate, look in a astronomy text for details.
2.
White dwarves are "held up" by what is known as degenerate electron pressure. To understand this phenomenon, I have to explain the Pauli-Exclusion Principle. The Pauli-Exclusion Principle states that no two electrons can occupy the same energy state. (In general the Pauli-Exclusion Principle says that no two identical fermions can occupy the same state. Fermions are particles with a spin of one-half.) A good analogy (which was given to me) is as follows: think of a classroom with 50 seats. Since only one student can occupy one seat, there are exactly fifty students in the room. If the room suddenly shrinks to 30 seats, 20 students must leave, and only 30 students remain.
As a main sequence star with mass (less than)1-3 Mo collapses, it reaches a point where every electron fills every energy state. At this point, there is an outward pressure because all the electron energy states are filled. This outward pressure balances against the inward pressure of gravitational collapse. At this point, we have a white dwarf.
If a star is sufficiently large, the gravitational pressure is enough to force electrons to bind with protons making neutrons. Neutrons are also fermions. So they also obey the Pauli-Exclusion Principle. Neutron stars are "held up" by degenerate neutron pressure.
I don't understand how black holes form...
Not that you asked but The Economist is a British publication that leans to the right.
What I got from this article was the basic conservative message about international trade. After all, it seemed to concentrate on why Japanese electronic firms might or will be declining. While the publication may be British, this article was written for the US publication of the magazine. The message seemed to be that the American Computer companies might reduce market share from the Japanese electronic firms. I hate to generalize but conservatives (in the US) support US industries with tariffs (to "protect" them). They also emphasize the "trade gap" between the US and foreign nations in an effort to boost their position against allowing more foreign trade. And they also fight for less foreign investment in US interests.
Now I may be reading too much into this article. After all most electronic firms are Japanese and most computer companies are American. Yet I get the feeling that there is a "Made in the USA" angle to what this column is saying. Anyone else agree? Or am I reading too much into what the article is saying?
PS After I wrote this comment, I had another look at the cartoon on the top of the page. Why does the computer have an American flag on it?
The final section = of the book gives sober and well thought out step-by-step directions to lift = people out of poverty and invisibility, again based on experience in field = programs, rather than ideology.
There are two main theories on how the developing world should move into the developed world. Currently, only 30 countries are considered "devloped," while the rest are divided among groups such as "developing," "not developing," and "less-developed."
MT prescribed that economic development requires the rejection of traditional behavior and orginizations, and acceptances of new behavior and orginizations that futher economic growth. The culture of a nation must change to the accepted western ideas of devlopment. A partial list of the requirements that Modernization theorists agree on include:
In a nutshell, a acceptance of western culture and western sytle economic and policital thought lays the foundation of economic development.
DT is a ideology that critisizes the MT approach. Two main tennents of Dependency theory: The development of third-world nations did not resemble the development of the west. The west's development for instance did not have external influences. The second tennent is that developed countries exploited the third-world in their own economic rise. Therefore any economic structure that may exist in a developing country is set up to enrich the industialized nations, not develop the third-world nation.
Dependency theorists see the western exploitation of third-world nations as the primary roadblock to economic sucess. By removing the foundations rooted in imperialism, third-world nations and develop the economic structure that moves them forward.
I have not placed any value judgements on these two theories. All I can say is that I agree with the statement that there are no easy answers to how to develop the third-world.
Note to readers: For those who are not Star Trek fans, here is a quick guide to the acronyms/different series:
In my (humble) opinion, something is being overlooked. I have been a Star Trek fan for a while but never an ardent one (I havn't seen all the episodes). What makes Star Trek such a lasting and important part of our/American culture is not the technology, not the federation, nor the plots. Star Trek is sucessful because of the character development and character interaction.
I'll get back to this in a moment but think about this TNG couple: Worf and Troy. Who would have predicted that!
(I used "our/American culture" for a reason, I'll get back to is soon)
First I want to explain my views on why the other elements are not the reason for Star Trek's rise to fame.
Among my friends (yes we are all geeks), some of our favorite quips are: "Just reverse the polarity.","Activate the Heisenburg compensators.", or "Turn on the Reality compensators." There is a reason why new physics is invented constantly, the real stuff is too contraining. Hence an episode of Voyager where the ship falls into "Chaotic Space," where the law of physics (conveniently) don't hold. My point is that technology simply a tool used by the writers/producers to set the show in. Not much of the technology in Star Trek makes that much sense. As someone pointed out in another comment, "If a friend is fighting an enemy and you can't get a clear shot at the enemy, why not just stun them both?"
What an ideal society. It's just that, and ideal society. Roddenberry wanted to set his show in some society that didn't have the social problems that were prevalent in the 1960's, when he conceptualized Star Trek. Look at TOS cast, a black woman Communication's Officer, a Japenese Helmsman, and Russian Tactial Officer, and a Scottish Engineer.
Yet at the same time women wore really short skirts and the three main characters were white males (Shatner, Nemoy, and DeKelly[sp?]). But that is another issue all together
I would like to point out that the main employer (or what looks to be) and/or main focal point of the Federation is not the ideal society but a military orginization. Let's face it, the Enterprise may have a mission "to go where no man has gone before," but they do it with phasers and photon torpedos. Again, my point is that the Federation plays the same role as technology does, a tool for the settting of the show.
Did you notice that you can save the (choose one: ship/planet/Federation/galaxy) in a single hour! Wow! I would argue that the plot of the episodes do not constitue a major part of the show's fame. Of course there are some exceptions. DS9's war with the dominion was a multi-season story that was well written and well produced. The reason plot is not important is tied into the culture behind the show, which I will now address.
Whether we like it or not, Star Trek is a part of American culture. The reason for this can be found in American history. In the 19th century, Americans moved west and covered the continent. That "western" era with cowboys and gunfights at the "OK Coral" inspired many American ideals and attitudes: the open frontier, the vast unknown, the cowboy hero. It also killed thousands of Native Americans and destroyed their culture but in the 1950's that was swept under the carpet.
I say 1950's because that is when television producers started making all the western shows that I have never seen. Roddenberry wanted to make a "western" style show set in the future, hence Star Trek was born. Think about the parallels: "to explore strange new worlds, to boldly go where no man has gone before." Sound like a cowboy western? Compare Captain James T. Kirk with Wyatt Erpp (sp) or The Lone Ranger. White men who are flamboyant and charasmatic. Although Roddenberry did not explicitly say, "I will make a western set in the future," the fact is that westerns were an ingrained part of American culture, and that culture unfluenced Roddenberry.
Star Trek TOS and TNG could easily inherent the western. Both has ships which ran around uncharted space exploring or fighting or discovering new conflicts that needed to be resolved (usually in an hour). DS9 had problems with this paradigm. A space station doesn't fly around space. To comensate the writers/produces introduced the Defiant. They also created a massive multi-threated plot (the Dominion war). Voyager has tried to mimic the TOS and TNG but for some reason is not as sucessful. That reason is because of the characters (my original point).
Character development and interactions is what made Star Trek (TOS and TNG and to a partial extent DS9) successful. Kirk, Spock, and McCoy worked great together, playing off each others personalities. Picard, Ricker, Data, etc. wound up being a great combination. Why didn't Wesly Crusher work out? Not because the fans didn't like him (it didn't help), but because he didn't fit into the TNG universe. Picard was the Shakespearean captian, wise and philosophical. Riker, the cowboy (likely more popular than Picard). Data, the brains of the operation. Worf, the warrior who could be gentle and humane. Look at the relationships that developed. The friendship between Georde and Data developed when the writers realized the two worked great together in Engineering. Picard and Riker played off each other; one a flamboyant, almost reckless first officer, the other a stern, yet brilliant captian. Like I said before, Troy and Worf developing a realtionship? Although some people would agrue that was a stupid love story, I would look back and say the two worked well together.
What definatly helped TNG in its character development was good actors. Not to say the acting was award-winning or great, just good. This is partially the reason why Voyager doesn't seem to get anywhere. Voyager tries to develope character realtionships, but it isn't working very well. Plus the acting isn't much to speak of, which doesn't help. Try this, think of two characters which play off each other well in TNG (you can use the ones I've pointed out if you want). Now compare that relationship to another relationship in Voyager. Can you even think of a good two person relationship in Voyager?
DS9 managed to be the exception to this rule of character development. Since the "cowboy frontier" genre was not working, the writers/producers introduced the huge Dominion war, which succeded in overlaping the lack of character development. Again, think of a relationship, Kira and Odo? (I'd rather not think about it thank you). Sisko and ??? In fact Avery Brooks really played off himself. He is a pretty good actor. He did a good job being Captain Sisko. His character and force personality really didn't need a foil. He was Captian Sisko. I would say he alone helped make DS9 a sucess. The plot however is what really captured viewers. I must admit I have been arguing character this and character that, but when I watch DS9 I watch for the plot. This is why some DS9 episodes that don't deal with the Dominion War suck.
Think about the difference between a movie and a TV series. A movie is about a story, told in two hours. Star Trek runs once a week, so unless you have a huge plot like DS9, what are you going to intice the viewers with. Answer: the characters.
I haven't said much about the new show. I would hope that regardless of where or when it is set, the producers get some good actors and the writers generate good characters. Regardless of what they come up with, the fan base is so large that not everyone will be happy. But I'll still watch the first episode, and that is what the producers are hoping for.
Fossil Fuels such as oil run the world. The computer that I am writing this post on is powered by coal. What happens when (and if) all the fossil fuels are used up?
I would imagine that most /.-ers and people in general want a cleaner environment. I am no envirnmentalist, but I want clearer air and water. Unfortunalty, fossil fuels is not the cleanest scource of energy. The reason that we still use the is purely economical. After all, it is cheaper to mine/drill for coal,oil, and gas, burn them in our power plants and cars, than to use alternative scources of energy. We may want the electric car, but we don't want to play 10x the price for one.
I believe that the only way we will abandon fossil fuels is if they become too expensive to use. Exxon and other gas giants are always looking for newer scources of fuel (the Alaskan oil reserves for instance). Until the economic price of oil goes up, we will never start to use those "alternative" scources of energy that are cleaner.
Therefore, this discovery worries me. Sythetic rubber in tires are made from coal and petroleum. Basically, all we are doing is taking a fossil fuel that we already mined, and reusing it for energy. We are simply lengthening the overall "life-time" of these fossil fuels. I really believe that companies need to point their research at alternative energy sources, but there is no economic benifit for them to do so as long as we can extract more from our oil like this discovery has done.
Now I know that my agrument sounds kind of shoddy, but as long as there are cheap fossil fuels, the world will still use them and pollute. If we want to stop using fossil fuels we need to encourage economic benifits to research alternative energy sources; yes I know I sound like Gore. But I think he is right in the fact that the economic cost of alternative sources of energy are greater than the cost of using coal and oil.
Case and point. In the 70's during the energy crisis, there was a movement towards alternative energy sources. This was because oil cost so much that companies wanted to do the research. As soon as the energy cost of oil went back down, the motivation to develope alternative energy sources diminished.
In conclusion, I don't want us (society) to abandon fossil fuels. I personally like not having to pay lots of money for gas/electricity. But I also think that if we encourage alternative energy sources, we will be better off in the end.
And YES, you could come back from a mission to, say, Mars, using this technology. Travel between planets is accomplished by establishing yourself in an eccentric orbit that passes through the orbital path of both your origin and your destination. So you can use the magneto-sail to push out away from the planet, establish your orbit, then turn it off when you reach the "top" of your curve, and fall back in. Then turn the sail on again when you need to brake.
This is exactly what you would do. I think a lot of people posting seem to forget that the if this technology can be harnesses, we would have two forces from the sun.
Space travel isn't a point to point flight. To go from Earth to lets say Jupiter, stopping at Europa on the way, you launch your satelite in an ellipical orbit with a certain energy such that this new orbit would take your spacecraft out to the orbit of Jupiter. If you "missed" Jupiter (i.e. didn't slow down and and get captured by Jupiter/Europa) you would just continue traveling in that orbit. In fact you would eventually reach the point in Earth's orbit where you left the Earth (the earth wouldn't be there anymore since it moves).
By using the M2P2 as a propultion, you can change your orbit around the sun. Gravity does the rest. The great advantage of the M2P2 technology is that it unlike a chemical rocket it doesn't require as much fuel. After all, the amount of fuel dictates how much you can change your energy. With M2P2, the energy to change your orbit(s) comes from the sun.
It seems that there is a lot of hype with the discoveries of all these planets. Many of the comments about the prvious article on the finding of the Jupiter sized planet around Epsilon Eridani all seems to assume that we are close to finding the answers about planets and we can start searching for "earth-like planets" and that we will understand everything about extrasolar planets. In fact nothing could be further from the truth.
First of all, I am studying to receive my degree in Astronomy, so if any Astronomers out there want to correct me, please feel free to do so.
Let's take a quick look around our solar system:
The Earth and other inner planets are about 0-2 AU (1 AU = radius of Earth to Sun). Mars, the futhest inner planet is about 1.5 AU from the Sun.
The outer planets are (respectivly) 5, 9.5, 19, 30, and 40 AU from the Sun.
All the orbits of the planets (except Mercury and Pluto) are almost perfectly circular. The eccentricity of the orbits (where 0 is a perfect circle) range from .004 - .09 (Mercurey is .2, Pluto is .25).
These three facts are part of the theory of how our solar system formed, here is the short version. A large gas cloud collapes under gravity (Jean's Mass for those astronomers) and spins due to conservation of angular momentum. The spinning cloud's center begins fusion and the star is "born." The gas and other matter around the star forms into an acresion disk. When the disk cools, planetessials form which collide together to form planets. Inner (rocky) planets form within 2 AU because there is enough gravity to hold heavier elements and there is enough heat to let H and He escape (this is another discussion involving statisitcal mechanics). Outer planets form with gas and since there is not enough heat, H and He stay.
Now there are a lot of other things that may have happened. For example, capturing Pluto to make it a planet, Jupiter acting as the vaccuum cleaner sweaping up dust and small objects. Jupiter and Mars acting together to "form" the astroid belt. But for the most part, this is the theory of how our Solar System formed.
Of course with now other planets being discovered until recently, this is also how we though other solar systems would possible form elsewhere is the galaxy. However, the after discovereing about 50 some planets it looks like we have some major rethinking to do.
ONE 90% or so of all stars in our galaxy are binary (or more) stars. Firstly, we don't have a good theory on how binary stars form. The spinning gas cloud theory I described above doesn't lend itself to form two stars. Secondly, how do you get planets with binary star systems? For those who know, N-body gravity problems are very difficult. With 3 bodies, two stars and one planet, the planet almost always flys out of the system!! Unless the two starts are very close together and the planet is orbiting far away, so that the two stars act as one. So, as we are discovereing new planets we run itno this problem that bianry stars don't seem like good "solar systems." I don't know the statistics, but I would like to know how many of these new planets are around binary systems.
TWOMost of the new planets are Jupiter sized planets. There is nothing strange about this, our instruments can only measure a Jupiter sized planet's wobble. But what is interesting is that many Jupiter sized planets have not been found at 5-30 AU, but all over. There are some that are as close as .5 AU! Once again, I haven' seem the statistics, but I would like to see a correlation between the distance of thuse Jupiter size planets and the type of star they orbit.
This finding seems to counter our original theory of solar system formation.Some of the planets found have highly elliptical orbits. Without the statisitcs I cannot make any real guess on why but it does seem to refute the idea of the acresion disk forming planets, after all all of the planets in our system have near circular orbits (the .2 that mecury and pluto have isn't that ellipitcal either).
I would guess to say that we (science) need to rethink our theories of solar system formation. We need to figure out how thost extrasolar planets formed and come up with models ofhow our system could form in such a "untypical" manner. Of course we need to make many more observations to verify that we are not normal. After all, we could just be finding the fringle systems and al most all other systems are just like ours.
Then we can go out and find other "Earths."