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Everything posted by Mordred
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You have otherwise I would have corrected it. The paper shows both conserved and not conserved metrics.. The author in this case supports the latter case. Keep in mind there are different views on the subject. Also note the FLRW metric hasn't particularly incorporated the Higgs field as the Higgs needs further study. ( in particular the Mexican hat potential) technical name metastability.
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Yes via pressure waves
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Impacts can change Earths orbit though in extremely small amounts depending on size of impact. This in turn changes the orbital velocity. Theoretically outgassing in a particular direction could also do the same. Again the amount of change would be immeasurable. Quite frankly the physics that can change a meteor momentum and orbit apply to any mass. It's just a matter of scale
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It's not an easy topic to cover on a forum due to the number of calculations involved. This arxiv may help. "Does the Universe obey the conservation of energy law" http://www.google.ca/url?sa=t&source=web&cd=3&rct=j&q=energy%20conservation%20in%20the%20universe&ved=0ahUKEwj7rruO3Y_LAhVP92MKHacUAzwQFgggMAI&url=http%3A%2F%2Farxiv.org%2Fpdf%2F0810.1629&usg=AFQjCNFEE3r8ue80KsHouYnJnhcePF7lqA
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Geodesics, free fall and the equivalence principle - for dummies.
Mordred replied to Robittybob1's topic in Relativity
Here try these gifs http://casa.colorado.edu/~ajsh/sr/wheel.html http://www.physics.nyu.edu/~ts2/Animation/special_relativity.html# The math above on a graph would look like this gif on the last link Space-Time Diagrams of Events in Primed and Unprimed Frames Showing Grid -
An asteroid passing by can change the rotational speed of the planet via conservation of angular momentum. Doesn't even need to interact with the atmosphere. Usually though the effect is too small to be measurable.
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All forms of energy can in effect attribute to spacetime curvature via the stress energy/momentum tensor.
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Good catch I did miss that aspect, long work day and just flew home. Should have just used the term mediates charge but doesn't carry charge itself.
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I don't see a single scientific concept in the post.
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Electromagnet,Maxwell's demon and entropy distortion
Mordred replied to ABV's topic in Classical Physics
The same degrees of freedom still exist. What your describing is the changes within the electromagnetic degrees of freedom. Not the number of degrees of freedom. -
No how QED handles fields is based upon the gauge boson (exchange particle for electromagnetic force). This is the photon, but the photon itself has no charge itself it merely exchanges the charge from one charged particle to another. An electromagnetic field is comprised of a virtual (off shell ) photon at every point in space, first you set a baseline value for that field (zero or non zero). Then introduce your influence (charged particles). The photon being the mediator boson transfers the charge from one particle to the other on that field. But in itself the photon causes no direct influence upon the field ( other than its role as the mediator boson)
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Geodesics, free fall and the equivalence principle - for dummies.
Mordred replied to Robittybob1's topic in Relativity
To expand on Swansorts reply, there is no hard and fast cross over point. Every equation in physics is a reasonable approximation. For every day applications on Earth Newtons laws are of a high enough degree of accuracy that we don't need GR nor SR. Until you get closer to Mercury Keplers laws are accurate to match observational evidence. While GR is more accurate, Newtonian math works fine. For example do you need to know the rate of time at your head is different than at your feet when you won't notice the effect over a thousand years? GR and SR doesn't ignore Newtonian physics such as centrifugal acceleration. Rather it modifies the observer coordinate changes. an oversimplified way of thinking of this is Newton assumed time was a constant. SR doesn't. Without time dilation effects spacetime is just space as time isn't used as a vector coordinate. This is what is termed Euclidean coordinates (geometrically it's equivalent to Cartesian coordinates, visualize a flat map.) When you add the time component as not being constant but light being constant to all observers. The geometry of the coordinates of the map must change, (length contraction). The map becomes curved like a globe (polar coordinates). For the Euclidean to polar coordinate rules Google Lorentz transformations. If you use a Lorentz factor calculator and play with the numbers, you can a better feel for when you may wish to use GR or Newton. ( This is what I did when I first started learning GR) Now the reason I asked you to start this thread, from a previous thread you asked a question on geodesics and acceleration. Geodesics are specifically falling objects or objects in freefall. Think of it this way if your a rocket or object that generates its own acceleration you can choose whatever path you want. However a freefall object must follow the spacetime curvature geodesic. I find myself posting these metrics repeatedly, but if one can follow them the important transformation rules from Euclidean to polar coordinates are detailed. (Newtonian to spacetime curvature Lorentz transformation. First two postulates. 1) the results of movement in different frames must be identical 2) light travels by a constant speed c in a vacuum in all frames. Consider 2 linear axes x (moving with constant velocity and [latex]\acute{x}[/latex] (at rest) with x moving in constant velocity v in the positive [latex]\acute{x}[/latex] direction. Time increments measured as a coordinate as dt and [latex]d\acute{t}[/latex] using two identical clocks. Neither [latex]dt,d\acute{t}[/latex] or [latex]dx,d\acute{x}[/latex] are invariant. They do not obey postulate 1. A linear transformation between primed and unprimed coordinates above in space time ds between two events is [latex]ds^2=c^2t^2=c^2dt-dx^2=c^2\acute{t}^2-d\acute{x}^2[/latex] Invoking speed of light postulate 2. [latex]d\acute{x}=\gamma(dx-vdt), cd\acute{t}=\gamma cdt-\frac{dx}{c}[/latex] Where [latex]\gamma=\frac{1}{\sqrt{1-(\frac{v}{c})^2}}[/latex] Time dilation dt=proper time ds=line element since [latex]d\acute{t}^2=dt^2[/latex] is invariant. an observer at rest records consecutive clock ticks seperated by space time interval [latex]dt=d\acute{t}[/latex] she receives clock ticks from the x direction separated by the time interval dt and the space interval dx=vdt. [latex]dt=d\acute{t}^2=\sqrt{dt^2-\frac{dx^2}{c^2}}=\sqrt{1-(\frac{v}{c})^2}dt[/latex] so the two inertial coordinate systems are related by the lorentz transformation [latex]dt=\frac{d\acute{t}}{\sqrt{1-(\frac{v}{c})^2}}=\gamma d\acute{t}[/latex] So the time interval dt is longer than interval [latex]d\acute{t}[/latex] transformation rules. Here is relativity of simultaneaty coordinate transformation in Lorentz. [latex]\acute{t}=\frac{t-vx/c^2}{\sqrt{1-v^2/c^2}}[/latex] [latex]\acute{x}=\frac{x-vt}{\sqrt{1-v^2/c^2}}[/latex] [latex]\acute{y}=y[/latex] [latex]\acute{z}=z[/latex] -
Local isotropic length transformation - hypothesis
Mordred replied to caracal's topic in Speculations
While it's good your looking at the math I'm not confident your looking at the history of how these formulas came into effect. some of the changes you've made I can't see working out to observational evidence but that's tricky to determine due to the incomplete sections. Seems to me your modifying equations without studying the physics behind them. For example earlier this thread I posted a couple of links on recent tests of the gravitational constant. Which fine tuned the value to an extremely high degree. I need to ask how much do you understand on relativity which the FLRW metric derives from ? The reason I ask is there is some concerns I have that the equations you posted will alter the light paths from a near critically flat universe to one that I can't even describe as being homogeneous and isotropic. (Despite the fact your using equations that require a homogeneous and isotropic distribution) -
Not quite, geodesics are for free fall. The subject for more detail is the equivalence principle https://en.m.wikipedia.org/wiki/Equivalence_principle If you want I recommend a new thread and I'll help you out with it if you need. Though it will have to wait till I land lol. (Not supposed to have cell phones going on flights hehe)
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I'm going to reward a +1 to that response. Time dilation is a tricky subject to accept.
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not bad you have the concept. A better terminology would be the acceleration is an acceleration of the seperation distance, not the rate of expansion per Mpc. the universe will expand without DE, just to be clear the DE is needed to expalin why the rate between galaxies or Observable universe radius isnt slowing down. we can measure a relative velocity faster than c above the Hubble horizon which is c* age of the universe. Yuo already know recesive velocity is only an apparent but not real velocity. well done. +1
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What dates are accepted for the age of the Sun?
Mordred replied to Robittybob1's topic in Astronomy and Cosmology
actually I gave you the formulas to understand DDE, including the steps. That was the discussion on redshift conversions. Every step you need to calculate DDE (Newtonian sense) from Luminosity is covered in this thread. On PR the only step missing is Mie scattering. As far as the hydrodynamic and magnetosphere I'm still working on a way to properly cover those and simplify at the same time. Granted I'm assuming you know angular momentum, vs orbits of you don't I'd advise a different thread. I can't teach all the physics involved. That's an unreasonable expectation. I can provide direction. -
What dates are accepted for the age of the Sun?
Mordred replied to Robittybob1's topic in Astronomy and Cosmology
Not in argument with this reply but its handy for me to note in order to dig up the right metrics to show you... by the way option B is more agreed upon currently afiak. So this is one model for seperation to address eventually. At one time it as felt the density increased right up to the protostar. However later views and research now support magnetosphere seperation. How early this occurs will take some research. The other factor is heat convection. -
Star formation questions (split from age of sun)
Mordred replied to David Levy's topic in Astronomy and Cosmology
Were talking of nebula in the sense of plasma within a galaxy, for example the Orion Nebula is only 1.35 light years from Earth. I is a star forming region. "The Orion Nebula is an example of a stellar nursery where new stars are being born. Observations of the nebula have revealed approximately 700 stars in various stages of formation within the nebula." https://en.wikipedia.org/wiki/Orion_Nebula that should answer your questions. Stars can and do form in any nebula with sufficient density provided some mechanism causes over densities to form. A common occurance is nearby supernova shockwaves. -
What dates are accepted for the age of the Sun?
Mordred replied to Robittybob1's topic in Astronomy and Cosmology
Okay well the excel sheet is handy to get the feeling for the numbers. It doesn't particularly lead to understanding what those numbers mean. Nevertheless, as a lot of your posts are directly related to T Taurie stage. I would like to know what view you have on the accretion disk itself. A) the accretion disk increases in density right up to the protostar? B) or are you looking at a seperation via magnetosphere accretion theory.? The reason I ask this is for the luminosity functions. Now I assume your aware the inner accretion disk has a higher angular velocity than the outer disk. Also the mass density and temperature will follow a gradient. Ie no open regions. (Unless you count case b.) So taking that into consideration "How would you apply DDE ?" As Luminosity has a mass to luminosity relation https://en.m.wikipedia.org/wiki/Mass%E2%80%93luminosity_relation It also has luminosity to wavelength relations that depend upon its spectral index. If the mass density follows a curve then the luminosity will as well (assuming same spectral index) If you think about this how can you apply the Poynting vector or DDE metrics without determining the nebula dynamics? -
What dates are accepted for the age of the Sun?
Mordred replied to Robittybob1's topic in Astronomy and Cosmology
When asked what your goal was your response was Now how to you plan to accomplish this without understanding the metrics involved describing the accretion disk? here is a list of some of the formulas involved. https://astro.uni-bonn.de/~astolte/StarFormation/Lecture2012_PMS.pdf how many of these do you understand?