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Arch2008

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Everything posted by Arch2008

  1. The original “bang” is the energy you would get from one kilogram of matter. The “big” part came when the Superforce filled every part of the inflating universe. Then gravity and the other fundamental forces separated. The binding force that was freed up due to the separation is where you get the energy for everything in the observable universe. So the instanton particle or patch of negative pressure has a mass of around 1 kg. Also, this video is 5 years old. Perhaps Alan Guth is less embarrassed today. Also, galaxies collide for the same reason that meteors hit the Earth. Local gravity overcomes the inflation. Inflation is incredibly weak, but it's effect is everywhere. Only on immense scales does the DE overcome local gravity.
  2. Gravity waves are real and have been verified from observation. http://www.universetoday.com/97107/effects-of-einsteins-elusive-gravity-waves-observed/ Some groups are trying to detect the gravity waves that happened during the inflationary epoch after the Big Bang. They have not been successful...yet. In GR, gravity propagates at the speed of light. If the Sun vanished, the Earth would continue to orbit the spot where the Sun had been for around 8 minutes.
  3. Due to the pressure at the core of the Sun, friction heats that 100 kg of hydrogen to fifteen million degrees Fahrenheit. So the actual energy released by fusion may be less than that generated by a lizard, but it would be a well cooked lizard. The core of the Sun is a furnace, but fusion is not a magic wand. Our current fusion reactors use more energy than they produce.
  4. 1-Yes. 2-Yes. 3-No. You might want to try the Modern and Theoretical Physics section for a really detailed explanation. Three dimensions plus time exist in normal space. Inside the event horizon of a black hole, only one dimension exists, that which points to the singularity. So gravity “compactified” the other dimensions. After the Big Bang, the other dimensions that M-theory requires for strings to operate remained compactified.
  5. Pluto is a dwarf planet. This is a term that in its definition extends to small bodies around the Sun and no where else in the entire universe, i.e., no dwarf exoplanets will ever exist. However, objects like Pluto will exist around other stars, which still makes them exoplanets. Until we develop satellite telescopes linked together for interferometry to actually image some exoplanets, we will not know how many if any have large moons.
  6. Perhaps this should be asked in the Biology section? Other than the asteroid impact part, I don't see how this is astronomy or cosmology.
  7. http://www.eso.org/public/archives/releases/sciencepapers/eso1007/eso1007.pdf Gotta run.
  8. It is not possible to image individual stars in other galaxies unless they explode. So this is just the oldest star that can be imaged in the universe. The article explains how the star has an unusually low metallicity. This refers to the fact that its observed light spectrum displays the signature of fewer elements heavier than hydrogen. Normally, first generation giant stars fuse hydrogen into all the other elements during their lifetime and when they explode. The shock wave disperses these elements into the surrounding cloud of hydrogen and may even contribute to the collapse of this gas into stars like our Sun. This particular star was likely formed in a dwarf galaxy that was then torn apart as it approached the Milky Way. It may just be that this dwarf galaxy did not have enough mass for the statistically average number of first generation stars to form. So the lack of first generation stars gave this star fewer heavier elements in its make-up. No star can be older than the universe.
  9. DE only has a measured effect over distances of megaparsecs between supergalaxy clusters, so I would say no.
  10. This is a somewhat dated summary of Hawking Radiation: http://arxiv.org/pdf/hep-th/0409024v3.pdf Hawking originally described how virtual particle-antiparticle pairs can become real particles near an event horizon. The above paper shows how this extends to bosons and fermions, but only directly mentions neutrinos, photons and gravitons. So I am unable to confirm that quark-antiquark pairs, or any of the other particles you mention are a product of HR.
  11. To my knowledge, not one single primordial BH has ever been detected. As to CP violation, IIRC B meson decay rates give something like one bilion anti-particles and one billion plus one particles, which accounts for all the matter. I believe that the LHC should have some data on this.
  12. I would argue that "space" is misused in your statement. Einstein discovered that matter and energy are the same. If you mean the space between the planets, that is filled with the energy of the Sun and to a lesser extent some fraction of the energy from all the other stars in the observable universe. The space in and between galaxies is filled with this same energy. DE is also present and Dark Matter. If you only mean the space between my atoms' hadrons and electrons, that is filled with the EM force and at the nucleus by the strong force. So space is nowhere an empty space. Thus, the WMAP result is the only pertinent fact.
  13. I read that each cubic cm of intragalactic space has about one hydrogen atom. The space between galaxies has even less density. According to the WMAP, about 72% of the universe is Dark Energy, 24% is Dark Matter and the rest is the more traditional stuff.
  14. To clarify, space expanded faster than light, but a given point in space did not travel anywhere. The space between any two points inflated.
  15. Pauli's rule explains how electrons in orbit around a nucleus behave. No two electrons can have the same orbit normally. The gravity in a singularity overcomes this rule. Actually, this rule is already broken by gravity when a white dwarf star collapses into a neutron star. http://chandra.harvard.edu/xray_sources/white_dwarfs.html Nothing travels faster than light, so the point that it would move backward in time is a myth.  
  16. We cannot "see" or directly image the photons from Sagiatius*, the SMBH at the center of the Milky Way. The accretion disk is a busy place and too much interstellar dust absorbs the photons. However, radio telescopes can penetrate the cloud of dust and get an image this way. Here are some links to the event horizons of a rotating black hole: http://en.wikipedia.org/wiki/Rotating_black_hole http://en.wikipedia.org/wiki/Kerr_black_hole The ergosphere is the point where no particle can rotate opposite to the singularity.
  17. Einstein showed that energy and matter are two forms of the same thing. Both energy and matter have a property called mass which is affected by the fundamental force of gravity. To move a mass to orbit requires a lot of energy to overcome the gravity of the Earth. So, analytically, mass behaves like negative energy. Hypothetically, if one totaled up all the matter (negative energy) and energy in the universe, the sum might be zero. Thus the universe can start from nothing because it still is nothing.
  18. I believe that someone (quite) obviously is just trolling.
  19. This "site" in your link is poorly written trash.
  20. You may want to wait two weeks, because Dr. Lykken may or may not have found the decay paths of dark matter with the AMS. He is supposed to publish a paper about this.
  21. No scientific paper to back up this statement has been submitted to the arxiv yet, so we'll just have to wait and see.
  22. Alexro, everything you posted is about inflation. That is what the accelerated expansion is called. You are asking about inflation and that is what you are not understanding. Two scientists will observe the same thing. A prediction has to match the result no matter who does the test. That makes it science. Physics is the same no matter where you are. An observer somewhere else in the universe will see inflation occuring in every direction as well. The universe is not expanding here and contracting there. In between every super galaxy cluster the effect of gravity is overcome by DE as space inflates the way it did after the Big Bang. However, the matter within the gravity of a galaxy is not expanding. Within galaxies stars and planets are still forming. After a period of exponential (some would say epic) inflation, the universe expanded at a slower rate that allowed hydrogen to form into clouds and collapse into massive stars. These massive stars erupted after only a few million years releasing the elements that became planets and eventually you and me. It's not easy to percieve just from some posts. Would you prefer links to more detailed explanations?
  23. http://www.abc.net.au/science/articles/2013/02/19/3693584.htm Apparently, the mass of the Higgs Boson has determined the fate of the universe. Submitted for your discussion.
  24. Welcome alexro! Accelerated expansion actually creates a universe that is homogeneous (the same everywhere) and isotropic (a universe that can give rise to sentient creatures like us). Alan Guth proposed that the very early universe underwent inflation on an epic scale. This created a homogeneous effect that gave rise to stars and star stuff like planets and us. It is reflected in the Cosmic Microwave Background Radiation. The CMBR displays only a minute variation in the remaining background temperature throughout the observable universe. Inflation has met some predictions, so even if you cannot figure it out, it does not mean that it cannot happen. Take a Schwartzschild singularity at the center of a blackhole. It's a point because gravity has crushed everything, to include spacetime into a point. So too much gravity gets you no dimensions. Now take the opposite point. The predominance of anti-gravitational inflationary stuff, like Dark Energy, causes the original spacetime singularity to expand into three separate dimensions plus time. As the universe continued to inflate after about 7 billion years, the effect of gravity was supposed to slow the expansion. However, as the distance between super galaxy clusters increased, the effect of gravity in the regions in between was again overcome by the predominance of DE. The universe is undergoing accelerated inflation...again.
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