what were the 2 reasons the Mir experiment was so important?
541536
Wasn't that the Mars landing?  Looking for life out there.
752091
Go read this article from the Whitehead Institute for Biomedical Research \nhttp://www.wi.mit.edu/news/archives/1996/pk_0828.html
418207
Both are important, but the proper ratio of each is the most important.  I haven't had physics for so long...maybe you should also try the physics section so that some smart physicist will sit down and figure it out for you.
701402
No - we've been doing fusion research for a long time. The ITAR test device JET has managed to crack most of the problems that needed be cracked before we ploughed big money into the project. There are also some side development that have helped, like improved computing power to control the field shape and strength needed to control the plasma  plus High Temperature superconductors.
1125359
I think the author of the article linked to in your referenced web page (it's the link below) explains it well. One of the many  fundamental constants, the Fine Structure Constant, may have changed very slightly -- or it may not have. The data acquired so far is not conclusive, especially as decided by the scientific establishment, which generally demands pretty overwhelming proof of such a radical idea. And as the author says, confirming evidence must be obtained not merely from more iterations of the same experiment, but from totally different kinds of experiment, and he adds that precision in these other experiment types is not yet high enough to be useful as a proof.
991385
Experimenting with magnetorheological fluids.\nSuspending a magnet in mid-air.\nLevitating pyrolytic graphite.\nA Gauss Rifle: A Magnetic Linear Accelerator.\nBuilding a Curie-effect heat engine.\nGoing further:\n\nSuperconductors.\n\n \n \n \nThe Gauss Rifle:\nA Magnetic Linear Accelerator\n \n \n This very simple toy uses a magnetic chain reaction to launch a steel marble at a target at high speed. The toy is very simple to build, going together in minutes, and is very simple to understand and explain, and yet fascinating to watch and to use.  \n \n gauss rifle Click on image for animated view  \n \n The photo above shows six frames of video showing the gauss rifle in action. Each frame shows 1/30th of a second. In the first frame, a steel ball starts rolling towards a magnet taped to a wooden ruler. In the second frame, a second ball can be seen speeding between the rightmost two magnets. By the third frame, the accelerator has sped up so much that the ball that is seen leaving the left side of the device is just a blur as it smashes into the target. One ball, starting at rest, has caused another ball to leave the device at a very high speed.  \n \n gauss rifle materials Click on image for larger view  \n \n The materials are simple. We need a wooden ruler that has a groove in the top in which a steel ball can roll easily. Any piece of wood or aluminum or brass with a groove will work. We chose the ruler because they are easy to find around the house or at school or at a local stationery store.  \n \n We need some sticky tape. Again, almost any kind will do. Here we use Scotch brand transparent tape, but vinyl electrical tape works just as well.  \n \n We need four magnets. Most any type will do, but the stronger the magnets are, the faster the balls will go. Here we use the super strong gold-plated neodymium-iron-boron magnets we have made available in our catalog for the other projects. They work great.  \n \n We will also need nine steel balls, with a diameter that is a close match to the height of the magnets. We use 5/8 inch diameter nickel plated steel balls from our catalog.  \n \n The only tool we will need is a sharp knife for trimming the tape.  \n \n gauss rifle first\nClick on image for larger view  \n \n We start by taping the first magnet to the ruler at the 2.5 inch mark. The distance is somewhat arbitrary -- we wanted to get all four magnets on a one foot ruler. Feel free to experiment with the spacing later.  \n \n gauss rifle tape\nClick on image for larger view  \n \n With the sharp knife, trim off any excess tape. Be careful, since the knife will be strongly attracted to the magnet.  \n \n It is very important that you keep the magnets from jumping together. They are made of a brittle sintered material that shatters like a ceramic. Tape the ruler to the table temporarily, so that it doesn't jump up to the next magnet as you tape the second magnet to the ruler.  \n \n gauss rifle two\nClick on image for larger view  \n \n Continue taping the magnets to the ruler, leaving 2.5 inches between the magnets.  \n \n When all four magnets are taped to the ruler, it is time to load the gauss rifle with the balls.  \n \n gauss rifle all\nClick on image for larger view  \n \n To the right of each magnet, place two steel balls. Arrange a target to the right of the device, so the ball does not roll down the street and get lost.  \n \n To fire the gauss rifle, set a steel ball in the groove to the left of the leftmost magnet. Let the ball go. If it is close enough to the magnet, it will start rolling by itself, and hit the magnet.  \n \n gauss rifle ready\nClick on image for larger view  \n \n When the gauss rifle fires, it will happen too fast to see. The ball on the right will shoot away from the gun, and hit the target with considerable force. Our one foot long version is designed so the speed is not enough to hurt someone, and you can use your hand or foot as a target.
745178
What is known comes from experiment.
1178573
a) a nuclear disaster falls under physics, not chemistry\nb) Yahoo Answers does not exist to do your homework for you.
801568
I did an experiment with this in graduate school.  When a plant has limited to no light, it invests all of its energy and growth into finding a light source.  In my experiment, the plant grew very tall and had very few leaves (since it could not go through photosynthesis anyway, why bother).  It was a very interested experiment and proved that even plant have priorities.
135532
You can either look it up or determine it experimentally.\nI cant get much more specific without additional details.
739847
Please go to this website for a full explanation.  It doesn't make sense for me to restate what it says in the article.\n\nhttp://gemini.tntech.edu/~tfurtsch/scihist/avogadro.htm
17379
The focus in the 21st century for the forefront of physics is understand the connection between General Relativity and Quantum Mechanics. No question about this. The results could be a string theory, or loop gravity, or something completely different.\n\nAlso up there I think is a better understanding of a property we all know and love: mass. There is a search for the Higgs Boson. We need to find it and study it. Or, if it can't be observed try and determine what that means.\n\nOther challengs include being able to use the EPR phenomena of quantum entanglement to produce the first prototypes of an actual encrypted signal over a reasonable distance.\n\nNanotechnology is another challengs, in how to work those little parts into ways that form mini-computers, and also in ways that allow for various medical uses.
409458
Here is the first paragraph of a review article answering your question, see the source below...\n\nLike the discovery of splicing three decades ago, the unearthing of RNA interference (RNAi) and microRNAs (miRNAs) once again has everyone’s attention focused on posttranscriptional phenomena. During RNAi, dsRNA formed in cells by DNA- or RNA-dependent synthesis is processed to ∼20 bp small interfering RNAs (siRNAs) containing 2 nt (nucleotide) 3′ overhangs. These siRNAs are then incorporated into an R NA-i nduced s ilencing c omplex (RISC), which mediates the degradation of mRNAs with high sequence complementarity to the siRNA. MiRNAs are ∼21 nt regulatory RNAs excised from genome-encoded precursors folding into dsRNA-like hairpins. With few exceptions, animal miRNAs base pair imperfectly to the 3′-untranslated region of target mRNAs and inhibit protein accumulation by an unknown mechanism, while plant miRNAs show nearly precise complementarity to their targets and trigger mRNA degradation. This miRNA dualism and observations that miRNAs can act under some circumstances as siRNAs, and vice versa, highlight similarities between the siRNA and miRNA pathways. Indeed, maturation of both RNA classes involves Dicer proteins, and, like siRNAs, miRNAs function as RNP particles, miRNPs or miRISCs, whose composition and, probably, assembly are related to those of the RISC (Sontheimer [2005]; Tomari and Zamore [2005] [ Sontheimer, 2005, Tomari and Zamore, 2005]; consult these reviews when discussed findings are not specifically referenced).
377216
Russia, then the U.S.S.R., uses graphite based fission reactors, as opposed to the U.S. design.  Human error caused the incident.  The second post to your question is a decent description as to the chain of events.
32339
FACT FACT FACT.\n\nMy physics professor gave the unbeatable argument on this one.  If the USA had lied, the USSR WOULD HAVE SAID SOMETHING.  The USSR was very technologically advanced, and it would have taken very little effort on their part to look up and see if there really was a metal box hurling toward the moon sending high-amplitude radio transmissions back to Houston.  If this hadn't been the case, the USSR would have called our bluff, I guarantee you.\n\nIf they didn't doubt the moon landing, why the hell should we?  Defrauding the American people might have been a comparably easy task, but there's no way they could have fooled the USSR.  The USSR did, after all, have the technology to beat us in the first two stages of the space race (the first satelite and the first human in space).
592883
Have you ever heard the term "critical mass" as it applies to inanimate and animate entities? It's the point when enough systems come together to form a working entity that something is considered alive.\n\nAs for not being able to create life forms, I have heard of experiments where scientists were able to create a primitive cell using simple chemicals. In the same way that soap has a hydrophilic (attaracted to water) end and a hydrophobic end (repelled from water), a cell wall has an interior layer in which the hydrophobic ends face each other and the hydrophilic ends form the inner and outer walls of a cell. There is also a mathematical point where the cell wall is the most stable with respect to voulme- any larger and the cell tends to split, and any smaller and the cell will burst with internal osmotic pressure.\n\nAs for the argumant that DNA is too complex to come about by simple random selection, RNA is easily created using just nitrogen, carbon, oxygen, and hydrogen. An RNA molecule is the precursor to DNA and has some interesting properties- it can exist as a single chain and although more difficult to copy, the development of the double helix did away with the difficulties of copying and issues of heritability and mutation (both beneficial and harmful). Interestingly enough, viruses use RNA almost exclusively, and they are almost considered alive, yet they lack some of the major requirements of biological life. RNA is also self-replicating and forms quite easily under the right conditions- one of the major factors of DNA.\n\nIn one of my College Biology classes, we learned of an experiment where the scientists put carbon dioxide gas, water, and ammonia in a flask which was slightly heated, stirred, and subjected to a high voltage spark. After a while, the flask was opened and the contents were chemically tested for what was formed. Several simple proteins and short chains of these proteins were detected- some of the proteins detected was the proteins used to construct RNA and DNA. The conclusion of the experiment was that if these proteins are so easy to form under these conditions, life created spontaneously was not an impossibility but inevitable under the right circumstances.\n\nIf the earth was 100 degrees hotter, a lot drier, covered in oceans, a primarily ammonia or methane atmosphere, we would have adapted as we developed and changed (evolved).\n\nWho knows? If we developed on a planet where the average surface temperature was 200 degrees below the freezing point of water and we breathed ammonia, the earth we now know would probably be considered a oxygen-poisoned too hot hell hole- surely no life could have evolved there- but here we are.\n\nAs for creating biological life from a copy, the DNA code for a human would reach to the moon (360 million miles). A lot of the DNA code we have no clue what it is used for, how much of it is actually used (like the brain, we might only need about 10% of our DNA to operate on a daily basis), and the fact that most of the DNA we have is only used while we are in the womb to develop from a single cell to a multicellular organism.\n\nOne of my favorite sayings is "ontogeny recapitulates phylogeny", which means that as the fetus develops, the organism goes through what appears to be different stages of our evoultion to get to where we are today. Interestingly enough, a chicken, pig, and a lizard ova and a hman ova at identical stages of development look surprisingly identical to one another. This is where geneticists and evolutionists agree that humans must have hada common ancestor with proto-hominids, or pre-apes.\n\nI hope this helps.
90666
Here are some experiments.