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Mordred

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Everything posted by Mordred

  1. Not to the best of our knowledge, The energy-density of the cosmological constant is extremely low, to the point of being nearly immeasurable unless you measure it over an extremely large distance. Per cubic meter its energy-density is easily overpowered by the strong nuclear force and gravity. Its influence is primarily in the regions between large scale structures and is not known to cause any measurable influence in any gravitationally bound region. Nor is it known to cause any influence at the atom level.
  2. cool vid thanks for sharing
  3. I'm not sure where you read we can detect microwaves from the BB, considering we cannot directly view the BB due to the dark ages. The dark ages is the time when the mean free path is too short for photons to avoid interaction prior to reaching us. Secondly any microwave from the BB would be red shifted to the point of being undetectable. However lets assume your talking the CMB. I'm not clear on how you think that light traveling from point A to point B means that space itself has substance, that was once considered by the Ether/Aether theories. (Ether theories have been proved wrong, although nothing in physics is completely proven wrong so proposals will crop up from time to time) We can only measure interactions as they affect particles. You cannot measure the interaction of a void per se. http://en.wikipedia.org/wiki/Aether_theories Assuming your using the definition of void as "a completely empty space" If something is completely empty (has no energy, or matter) not that energy can exist by itself. At least not in physics. Then there is nothing for a photon to interact with. How would a photon interact with something that has no substance? How would it influence nothing? Energy does not exist on its own that's one of the first things they teach physics students all forces are mediates via a force carrier. Although in the case of gravity we haven't found the force carrier (graviton) but that doesn't preclude the possibility that it doesn't exist, it just means we haven't been able to produce a high enough of a temperature reaction to create a graviton. "In particle physics, quantum field theories such as the Standard Model describe nature in terms of fields. Each field has a complementary description as the set of particles of a particular type. A force between two particles can be described either as the action of a force field generated by one particle on the other, or in terms of the exchange of virtual force carrier particles between them. The energy of a wave in a field (for example, electromagnetic waves in the electromagnetic field) is quantized, and the quantum excitations of the field can be interpreted as particles. The Standard Model contains the following particles, each of which is an excitation of a particular field: Gluons, excitations of the strong gauge field. Photons, W bosons, and Z bosons, excitations of the electroweak gauge fields. (electro-weak field is the combination of electromagnetic force and the weak force) Higgs bosons, excitations of one component of the Higgs field, which gives mass to fundamental particles. Several types of fermions, described as excitations of fermionic fields. In addition, composite particles such as mesons can be described as excitations of an effective field." http://en.wikipedia.org/wiki/Force_carrier Now with everything I just stated above there is research ongoing to define the energy levels inherent in empty space as per se. Now to explain this with more clarity we need to look at a particular term. Zero point energy. Classical physics would state that zero point energy would be zero. However this isn't true in quantum mechanics. In quantum mechanics the zero point energy due to the Heisenburg uncertainty principle is [latex]e=\frac{hv}{2}[/latex] however as mentioned already this is essentially virtual particles popping in and out of existence Casimer effect is one such study http://en.wikipedia.org/wiki/Casimir_effect so fundamentally how you define space must work at all the applicable scales of measure. There is the space between particles and there is outer space for example. I just showed that interactions is essentially particle to particle and explained that a particle must interact with another particle (cannot interact with nothing, that makes no sense) so the only definition of space that applies at all levels of science and size scale is just a separation distance or volume.
  4. there is no competition the term force isn't restricted to just the 4 forces, you can also have force exerted by inertia, or force exerted by pressure. None of the latter 2 examples need to explain the cause of the force. How you define force depends on the system your examining "In physics, a force is any external effort that causes an object to undergo a certain change, either concerning its movement, direction, or geometrical construction. In other words, a force can cause an object with mass to change its velocity (which includes to begin moving from a state of rest), i.e., to accelerate, or a flexible object to deform, or both. Force can also be described by intuitive concepts such as a push or a pull. A force has both magnitude and direction" http://en.wikipedia.org/wiki/Force
  5. Just for clarity Hubble's law isn't the only reason we know space is expanding, We can also infer that the volume of space has increased due to the thermodynamic history of the universe. In and expanding universe, temperatures and energy-densities lower we know from measurements this is also true.
  6. good answer, couldn't have said it better myself The answer of why the body remains stationary when in free fall is rather complex in terms of GR, here is a quote from Lecture notes in General relativity by Mathius Blau. The article itself would do a far better job of it than I possibly ever could. I'm lousy at explaining GR related questions, so I would make too many mistakes at it. page 76 (the article itself is an excellent resource, I refer to it all the time) http://www.blau.itp.unibe.ch/newlecturesGR.pdf "Lecture Notes on General Relativity" Matthias Blau "How does this viewpoint of general relativity that there is no such thing as gravitational force square with the well known "fact" that there is a gravitational force field at the surface of the Earth of 980 cm s-Z? Recall that in the standard Newtonian viewpoint this gravitational force on an object placed on the Earth's surface is balanced by the force the surface exerts, leaving the body in equilibrium,i.e., "at rest." In the viewpoint of general relativity, the only force acting on the body is the force of the surface of the Earth. On account of this force, the body accelerates(i.e., deviates from geodesic motion) at the rate of 980 cm s-2. Nevertheless, it remains in a stationary state, because in the curved spacetime geometry in the vicinity of the Earth, the orbits of time translation symmetry differ from the geodesics of the metric." However as mentioned in the previous post there is no answer "to what is it really"
  7. the table exerts an equal force upon the cup as the downward force so the net force is zero.
  8. Alright you have the Lorentz force equation here, now you want to calculate B the equation for B is on page 10 magnetic dipole, However there is different equations for B depending on the various factors in this article. So your going to have to define your problem with a lot more clarity http://www.ece.msstate.edu/~donohoe/ece3313notes8.pdf I still have no idea what the relation is to planets considering the motion of planets has nothing to do with electromagnetism.
  9. Judging from what I've read so far and I could be off on this he is looking for the dipole to dipole interactions of 2 charged particles. Might help if the OP can clarify which interaction specifically he is trying to define. probably not the best article but it has some of the basics http://chemwiki.ucdavis.edu/Physical_Chemistry/Quantum_Mechanics/Atomic_Theory/Intermolecular_Forces/Dipole-Dipole_Interactions problem is I'm not sure if he is looking for it in the more classical mathematics vs the QED metrics. His reference to Coulombs law makes me think he is looking for the former
  10. that I agree with. As long as we all agree the only aspects space itself has is volume and distance, the space-time itself as long as were clear it also does not refer to a fabric or substance then its usage to describe relations is agreeable. A term that may be handy to describe space including all its contents such as the various particles etc, is Intergalactic medium, or outside of large scale structure formation extra galactic medium. IGM for short. Its a nice science term to describe the totality of all the plasma etc that reside in space. the article below is a sample of its usage, highly technical though one of my favorites The Physics of the Intergalactic Medium http://arxiv.org/abs/0711.3358
  11. Inflation is a good area of research, One of the professors I know from another forum (though not personally) is also researching inflation here is his papers http://arxiv.org/find/all/1/all:+AND+Brian+Powell/0/1/0/all/0/1 he has given me permission to place one of his articles on my website see signature http://tangentspace.info/docs/horizon.pdf :Inflation and the Cosmological Horizon by Brian Powell (written for laymen hehe, he got tired of the same questions on the other forum lol) you should also have a copy of this if you haven't already, they regularly test various inflation models its 365 pages long so use it as a reference Encyclopaedia Inflationaris http://arxiv.org/abs/1303.3787 "ASPIC already has 74 different inflationary scenarios, a number that should be compared to the three or four models that are usually consi dered. The ASPIC library is an open source evolutive project and, although it already contains all the most popular inflationary scenarios, aims at including more models"
  12. How the universe expands or contracts depends on how the contents of the universe influence each other in terms of pressure. matter, radiation, exerts positive pressure, the cosmological constant exerts negative pressure. The relations is determined by their energy-density to pressure equation of state. The Universe is treated as a perfect fluid or ideal gas in terms of most metrics such as the FLRW metric. As such it follows all the ideal gas laws. http://en.wikipedia.org/wiki/Equation_of_state_%28cosmology%29 this is also used to determine the universes geometry. You can find more detail in this article. http://cosmology101.wikidot.com/universe-geometry page 2 covering distance measurements due to geometry http://cosmology101.wikidot.com/geometry-flrw-metric/ now our universe is extremely close to flat, but the question of if our universe is open or closed (infinite or finite is still an open question.) If the universe has a total positive pressure then the universe would contract, however the cosmological constant is the dominant influence of the universe today so the universe is expanding. your cosmology class will cover this soon enough, though I'm not sure how far your class has covered as of yet. Please also keep in mind that space is simply geometric volume that is filled with the contents of the universe.
  13. The reasons you mentioned is precisely why I like the article, lets just say I'm a very well studied long term amateur. In that I've been studying physics for over 20 years. As well as buying and studying a huge collection of the textbooks, however I've never taken institutional training. Luckily though I do have a few professors in the field that I personally know that help me along. (as well as correct my mistakes lol) they have even had me do some of their exams. My actual stock and trade is an Industrial electronics controls tech. In other words design, program and repair robotics and automated systems. (requires a high degree of mathematics, makes understanding physics easier).. If you ever watched "How its made" I design and repair the equipment that makes those items needless to say cosmology has come a long ways in the past 20 years, I recall arguments on whether the universe was flat,curved etc before LCDM became strong and the WMAP data.(it was funny as people were trying to invent their own shapes and show the metrics for it) The MOND vs quintessence,vs BB,string debates were also amusing. That was when Space.com used to have a forum Another related paper Fred Jegerlehner wrote http://arxiv.org/abs/1406.3658 "About the role of the Higgs boson in the evolution of the early universe" related by different author Multifield Dynamics of Higgs Inflation http://arxiv.org/abs/1210.8190
  14. You keep wanting to apply some magical attribute to space, space has no energy it has no matter, it has no property other than volume. I'm sorry if you want to believe otherwise but space itself is just volume. That volume is simply filled with everything else if it has no traits of its own then it cannot interact with anything, it is the particles that reside in the volume of space that interacts whether virtual or real
  15. "quantum foam can be used as a qualitative description of subatomic space-time turbulence at extremely small distances," http://en.wikipedia.org/wiki/Quantum_foam again this is a visualization tool to describe the wave function turbulence at extremely small scales via virtual particle production. In essence its no different than the volume of space being filled with particles. Try to keep in mind there is plenty of empty space between particles at any level. We can only measure how particles and fields interact with each other. Space itself is volume, that volume simply is filled with energy and matter. Hence for example in Cosmology when the volume of space increases, the energy-density of matter and radiation also decreases as well as the temperature. This shows that the volume is filled as more volume becomes available
  16. read this from above, The fabric, sheet,warping terms are all just visualization aids used by GR to help others understand what is occurring much like the balloon analogy used in Cosmology. The sheet in that image is merely a 2D visualization aid, in a sense a 2D coordinate map. Doesn't mean the map itself is part of the universe. The map is only a representation of relations the Calibi-Yau space is also a mathematical representation of interactions for example (string theory) doesn't mean that space at the string level has a substance itself or that the term manifold has a substance. These are all geometry relation terms http://en.wikipedia.org/wiki/Calabi%E2%80%93Yau_manifold
  17. Thanks Beefpatty, just making sure I couldn't think of any reason why the B-E wouldn't be appropriate. Much like the papers you have posted the only examples I've usually read deals with the Higg's in terms of its TeV metastabiltiy above 1011 GeV. I have easily been able to find papers dealing with the Higg's at high temperature ranges. SO(10) papers have numerous examples and relies on the Higg's for the seesaw 1 and seesaw II mechanism. However I've yet to find any papers covering the Higg's below the standard model 246 VEV. So I'm not looking at the Higg's mechanism itself but rather the Higg's bosons contributions (if any) to the thermodynamics after spontaneous symmetry breaking. Which is where I'm hoping the B-E can be used to give an approximation of the energy density and pressure contributions below the VeV. (I've never read or seen any papers covering Higg's below the 246 VeV, so I'm not sure if there is any further contributions below that range in terms of thermodynamics, the fact I never see any papers dealing with the Higg's interactions temperatures of the universe from the CMB to today) makes me wonder if there is or isn't an influence in current times cosmology. I'll have to see if I can locate a copy of the paper by Krauss, thanks for these. This is specifically what I am looking for (currently studying the 39 page article) lol at least I'm not the only one that had that idea just glancing over the 39 page paper it looks like it has the information I was curious about including the related formulas much thanks for that "What is at our disposal is essentially only the value of the Higgs field at the Planck scale, since in the experimentally accessible low energy region the Higgs field is not an observable and we only know its vacuum expectation value." this statement explains, why finding papers covering current influence is so tricky. awesome paper lol (my apologies if I'm acting like a kid with a new toy hehe)
  18. The intention of this post is not a speculation, its an ideal I wish to test out. So I don't want replies based on speculation or personal theories. Now here is the Cosmic inventory http://arxiv.org/pdf/astro-ph/0406095v2.pdf "The Cosmic energy inventory" The one value missing from this inventory is the energy contribution of the Higg's field itself. So I wish to use the Bose-Einstein statistics, based on the only confirmed Higg's Boson we have confirmed (reasonably). As the Higg's particle is a boson this statistic should work, for fermions we use the fermi-dirac statistics. The purpose of this research is to see if I can further constrain the cosmological constant itself. (possibly) The two time periods I will examine is via the temperature of the CMB and the temperature of the universe today However I have a couple of questions. 1) first does anyone know of a reason why the Bose-Einstein statistics cannot be used in this case, if not what statistic is more appropriate ? 2) The cosmological constant is a positive energy, with a negative pressure contribution determined by its equation of state. Has anyone come across or seen an equation of state relating to the 126 GeV Higg's. (or knows if it is a positive or negative pressure contributor) (I would assume the Higg's field EoS may be the same as the relativistic radiation, however thats an assumption)(may be more appropriate to use the scalar field EoS, though via the standard model the vacuum expectation value is 246 Gev considerably less than the CMB) any professional peer review papers are welcome in terms of the thermodynamic properties of the Higg's itself are welcome.
  19. a large part of that uncertainty is due to not knowing how soon Early structure formation occurs due to inhomogeneities in the uniformity of the universe after or during inflation. There is no strong agreement on this aspect. However as you stated it does not conflict with the BB
  20. Ok I can offhand think of a few situations that can be used to support this, so I agree with you on that aspect. Might help if you provide a few examples
  21. The universe from nothing model, is one of many possible beginning models. Though not the only one other models include a bounce from a previous collapsed universe. Universes from black holes etc. The universe from nothing model is one of the few that doesn't involve a previous universe. The idea has merit, but then so do the others.
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