leehin
Particle physics: "what is matter made of?". How to find out? Smash matter to find what is inside.
"We are now in the position of having the standard model of particle physics. We have figured out what the most basic elements of mater are. This quantum theory is our best description of Nature so far, and it works. Just one problem: in order to work theoretically, the particles need to have no mass."
Higgs field theory: Object weight is determined by how strongly it is interacting with the Higgs field. According to the standard model we are all swimming in the Higgs field. Its a vacuum field that doesn't have a source; it is present even in absolute vacuum; if you take out the Higgs field, particle become mass-less and everything starts to move at the speed of light. If you modify the Higgs field all particle properties will be different, atom will be completely different because of different electron mass. Really new elements could be created, far different from the 92 you have in the periodic table. We know that for a picosecond after t the Bigbang the Higgs field was turned of. Not even electron and protons could form in those days because everything was moving at the speed of light. Then the Higgs field turned on and things sudently became massive and slowed down. Is it really true? We don;t know the answer, because we haven't discover that field. This is what they are looking for in Cern. Tried for 10 years and haven't found it. 2 months before shutdown they annonced that they found 3 possible candidate for Higgs bosons.
Expension rate of vacum energy increase with expension of the universe. If the U is filled with normal energy then the expention rate should be slowing down (expansion does not create more particle), but if it is filled with vacuum energy then the expansion rate should be speeding up (expansion does create more vacuum, and hence more vacuum energy).
The Higgs field fill the U at a rate of more than a 3trillionT per cubic centimeters. "Something is terrybly wrong with this theory"
easy but ugly solution:There's another field that we'll create just for the occasion and that will also exist in vacuum and that will also fill the universe but its mass will be -3tT per cc and it will cancel out the Higgs filed.
Looking out in space, is looking back in time. 1999: Looking at supernova with Hubble telescope (Billions of years old, 'easy' to spot and practical to use as they are exploding stars with 'considerable' brightness. Measuring how fast they move away, and therefore the U's expansion rate. U's expansion is definitely speeding up. Which means vacuum energy drives the expansion. We are right now in an exponential expansion of vacuum the U. This was a shock for the scientific world. All were convinced that the expansion would be proven to be slowing down. We now know that vacuum energy, the energy of empty space, is the dominant substance in the Universe; it is driving the U and determining our fate.
Super string theory is the first model of a Unifying field theory (magnetism and gravity etc under one theory). It is very elegant but purely speculative. No experimental tests. Only 1 elementary particle and its not a particle at all, it is a loop of strings, and only 1 force: 2 strings can join and then they can slip apart. Particle can create gravity. Problem: the strings are so small that you'd need a particle accelerator the size of the galaxy in order to see them. Bad for physics because no data can be collected on them. 9 space and 1 time dimension. The 6 extra dimensions are hypothesized to be curled up so small that we cannot see them. The way these extra dimensions curled-up determine what kinds of particles are in the U. "I'm talking about empty space curling up, this sounds like S.F, but what is true is that the properties of the vacuum are turning out to determine many of the most important properties of the 'physical world' around us".
Does all this matters? Is it ever going to be of any practical use? "the honest answer is I don't know".
Zero point energy
9.2/10
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