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Everything posted by Mordred
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A connection between entropic gravity and the vacuum catastrophe ?
Mordred replied to stephaneww's topic in Speculations
Here is a paper that better explains and argues against entropic gravity. https://www.google.com/url?sa=t&source=web&rct=j&url=http://philsci-archive.pitt.edu/8383/1/Why_gravity_is_not_an_entropic_force.pdf&ved=2ahUKEwj0nKux_KznAhUhPn0KHbyIC-UQFjADegQIBRAB&usg=AOvVaw3nvC6cU5cIzrPFyA-LCIFo Hrrm so how do I put this. The reason your seeing connections with the numerous formulas your using to those used in entropic gravity is simple yet fundamental. F=ma the laws of inertia. All viable physics theories apply these laws of inertia. So every viable theory must at some point show that they are correctly applying these laws. This includes thermodynamics, relativity, (weak field limit), QM, QFT, string theory and the holographic principle. Now this goes even deeper into what is called action. The action will correspond to the effective degrees of freedom which is how they are applying entropy though done through statistical mechanics (thermodynamics). The holographic principle is a methodology to reduce the number of degrees of freedom. That is where the holographic surface and the information contained in that surface comes into play. -
A connection between entropic gravity and the vacuum catastrophe ?
Mordred replied to stephaneww's topic in Speculations
If this was me I would start with the research papers on entropy gravity. -
A connection between entropic gravity and the vacuum catastrophe ?
Mordred replied to stephaneww's topic in Speculations
That although you can show certain relations that match. You are not digging deep enough into entropy gravity to find out where the contentions are with the standard model. You will notice for example entropy gravity forms the basis behind MOND and in MOND the gravitational coupling constant will vary in different mass distributions so some of the relations above will also vary accordingly. -
No you need a graph that directly applies the creation and annihilation operators. Here https://en.m.wikipedia.org/wiki/Second_quantization
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One can mathematically formulate the effect of lensing on a GW waves however as you mentioned testing would be problematic as the detector would have to be in location and a suitable size to detect the correct range of frequencies. Might be cheaper to build a colony on the Moon lol. Anyways the curvature can lead to GW tails.
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Second quantization itself is a methodology to handle large multiparticle states. In essence using the Schrodinger or Klien Gordon equation for gets inconvenient when you have 10^(20) particles. So you apply an occupation density through the creation and annihilation operators. Those operators are used in second quantization.
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All fields share the same space or more accurately under GR, spacetime. Some fields affect other fields, while some only affect certain other fields. Good example is the limited fields the Neutrino family of particles. As they are weakly interactive they do not affect the strong or EM fields. As your asking about QM specifically and want help understanding particle production under either QM or QFT. You will want to study "action" as in the principle of least action but more involved. The action of a field describes the (Observable) ie measurable quantities. In QM or QFT the creation and annihilator operators are used to determine probable particle number densities of a field. https://en.m.wikipedia.org/wiki/Creation_and_annihilation_operators You will see it mentions the Uncertainty principle.Those operators will correspond to the external lined on Feymann diagrams. Now the virtual particles individually cannot cause action. So they are described in the internal lines as part of the propogators. Now QFT works well under SR the reason being gravity is so weakly interactive. However all matter and force fields contribute to the Stress energy momentum of GR so they all contribute to the spacetime curvature. The stress energy tensor is how we describe the influence of mass using the four momentum and four velocity. Mass being described as resistance to inertia change. In essence the action of a field or collection of fields will correspond to the kinematics of all interactions. We describe that using the those vectors. In QM your operators being position and momentum. Under QFT we use field and momentum.
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Both the harmonic oscillator and anharmonic oscillator are lessons in QM. Particularly with the HUP and quantum harmonic oscillator. Though you will find oscilators in probability functions.
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No energy is a property it doesn't exist on its own. Energy is defined as the ability to perform work. So when someone states field energy simply think of it as the fields ability to perform work. Keep in mind a field is an abstract object that describes a collection of mathematical values/objects such as scalar quantities/ vectors/spinors or tensors at each coordinate.
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Every field fluctuates through the quantum harmonic oscillator. This involves to an extent the uncertainty principle. Zero point energy is based on this. Any field can generate particles as all particles are field excitations. If the particle exceeds a quanta then the particle is real instead of virtual. If the particle is below a quanta then it's oft denoted virtual. The number density of particles in a field will correspond to the energy density of the field on a probability function. To get a complete answer then QFT and path integrals will lead you there however there is a significant learning curve.
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Sergupstart it's best to start with gravity being spacetime curvature described by the energy momentum tensor. You really are not ready for particle production via field strength for particle number density. In essence any location of a field is capable of particle production. The number density is in direct ratio with the field energy density at a given locale. So no gravitons do not need to escape a BH. Secondly gravity as spacetime itself as Marcus mentioned is static.
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Universal Concept of Time (Is the Big Bang wrong?)
Mordred replied to lucien216's topic in Modern and Theoretical Physics
Correct we are close to the fundamental time afiak in so far as to being a good estimate. Though there is research showing we may be in an underdense region which leads to the discrepancy of the Hubble parameter it isn't conclusive at this point of research. -
Universal Concept of Time (Is the Big Bang wrong?)
Mordred replied to lucien216's topic in Modern and Theoretical Physics
Cosmology using the FLRW uses what is called a fundamental observer which is an observer whose time would be based on the mean average mass density of the universe. The universe we refer to is our Observable universe. -
When you start dealing with Acceleration and curvature you can often get counter intuitive results. It's one of the reasons it's a good policy to be able to do the calculations where those calculations are viable. Bells paradox is a good example in order to maintain the seperation distance one would think rocket a and b must have the same proper acceleration. However this isn't true as the lead ships proper acceleration must be lower than the trailing ship to maintain seperation distance
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What is defined as the four forces involve whether or not that field has a gauge boson. Example the gauge boson for the EM field is the photon. Gravity if it is a force would need the graviton as it's gauge boson. We haven't discounted the possibility yet. Keep in mind were talking force fields.
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Ah charge polarity got it. The experiment is also done with photons using a beam splitter to entangle photons. Edit just noticed Swansont described that above.
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Just to add some details to the above. Let's look at how photons contribute to the stress tensor. Due to their momentum photons have a high momentum to pressure relation. Matter often described as dust exerts zero pressure. Pressure in the stress energy tensor is described as flux in a given direction (think of the classical container walls). Gravity is also defined by its flux influence in the same manner as pressure. The pressure terms are the diagonal terms the off diagonal terms being shear stresses. [math]T=\begin{pmatrix}-\rho&0&0&0\\0&p&0&0\\0&0&p&0\\0&0&0&p\end{pmatrix}[/math] The [math]T^{00}[/math] is the mass density in the rest frame. The other diagonal terms describe the flux {pressure} [math]diag T^{xx},T^{yy},T^{zz}[/math] for simplicity. T^00 being the mass density entry. (Trying to keep the above as simple as possible lol). There is quite a bit of math involved to fill in the entries which I won't go into.
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Incorrect photons has two measurable polarities in its transverse wavefunction.
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I don't, I pointed out a different examination that employs proper acceleration. One that the Bells spaceship paradox has been worked out in. The ships and string are just added descriptives. You will find that your redshift relations can be shown through the same transformations.
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If you placed an accelerometer front and rear of the same spacecraft in linear acceleration the acceleration would be the same. So at each time segment the instantaneous velocity must also be the same between the two points. If you placed an accelerometer front and rear of the same spacecraft in linear acceleration the acceleration would be the same. So at each time segment the instantaneous velocity must also be the same between the two points. Albeit a slight delay rear to front assuming rear end thrust. This scenario reminds me of Bells spaceship paradox but in this case the craft is held together my electrostatic forces. In Bells paradox it's two spaceships with a string between them. (The string will break). However depending on the observer relativity of simultaneity will be involved. However you will need a reference frame as in the lab frame there is no seperation but in the MCIF frame there is. (Momentary commoving inertial frame.) In essence to break it down the answer will depend on if your in the lab frame or in the MCIF frame. In the lab frame there is no seperation between points a and b and the acceleration is simultaneous and of equal value. In the MCIF frame you will have a seperation between points A and B due to different accelerations. Anyways here is a link that discusses the effects of proper acceleration. The formulas in this article can be applied to this thought experiment. https://arxiv.org/abs/physics/0601179
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Sure why don't you. Start with the standard Lorentz transforms. Then use instantaneous velocity for acceleration. Or if you prefer a commoving inertial frame. As Marcus mentioned the field front and back of spacecraft will be approximately uniform. PS don't forget length contraction as well as time dilation.
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Well for one thing there are no rigid rods in relativity. Markus reply is accurate.