Mordred

Roflmao

Thank you for the accolade I do my best to post solid articles and resources usable by anyone without misleading them from the textbook concordance teachings on that site. I rarely use video references as they typically tend to mislead and miss inform due to over symplification. However I can post a free to use entry math level textbook on relavity. The author has given me permission to add a reference link to my site. Currently building a second page of reference links. Anyways the author is also an experienced forum member on another forum so his book is also geared to common misconceptions in relativity. It's also why he sticks to the basic Minkowskii math forms. Download is free http://www.lightandmatter.com/sr/ I'm surprised I didn't think of this example of photons vs conservation of energy and momentum before but one of the better examples of its applications is to look at Compton scattering. As Compton scattering is a direct application of photon interactions and the two conservation laws. Here is a link to a quick low math level coverage. http://khuntersscience.blogspot.ca/2012/07/using-energy-and-momentum-conservation.html?m=1 it's a good example of how momentum is imparted onto other particles

Sorry mate I've been studying cosmology since Allen Guthrie first proposed false vacuum . Back when the arguments of Universe geometry was still unknown and the words Higgs dark energy and dark matter was met with scorn. This was also before WMAP which determined the universe geometry question. LCDM is a result of WMAP data. Prior to WMAP they were still debating hot or warm or cold dark matter and quintessence and MOND over LCDM. So your understanding of the importance of the WMAP is in error. As far as photons and conservation of momentum is conserved. We have supplied enough data to show that it is. It's up to the OP to prove that it isn't. In any process conservation of momentum is conserved. If you like I could show you an article where virtual particle production affects the angular momentum of a blackhole. Yes in the form of virtual photons. See my signature look for the black hole accretion disk article. I would post it but you have more important articles to study. That article is highly technical. Also over 900 pages.

Your understanding of relativity is in error. The fact that a photon has no perspective does not mean that the photon has no time or distance. The photon has no valid frame of reference. There has been numerous posts explaining that in the relativity forum. So let's leave that for that forum. The WMAP data strongly supports LCDM model which is the big bang with cold dark matter and the cosmological constant. However the big bang model does not attempt to predict how the universe began. It states nothing prior to 10^-43 seconds. It's only premise is that from that point forward it began with a hot dense state. It does not attempt to state how the universe began as the physics and mathematics reaches a nonsensical state prior to that point in time. As to the photon. A photon does not gain or lose momentum. It's momentum c is invarient. It's speed is always c. It can gain or lose energy but not momentum. If it had any other momentum other than c. Then it isn't a photon. I fail to see why you have such difficulty with photons exerting a force. Everyone posted numerous examples of everyday numerous and practical applications as well as tests that photons exert a force due to its momentum. Any time a force is exerted an equal and opposite force is also in effect. Newtons laws tells you that. Experiments showing that a photon can exert a force has been tested numerous times it's been around in our understanding since Maxwell. We have had plenty of time to disprove it. Instead of discounting the answers you were given. (Particularly since several of the repliers hold various physics degrees). Perhaps you should take the time to study the data provided. You might find your understanding is misguided and learn from it. What is truly amusing is the fact that the photon is the electromagnetic FORCE carrier. It is the boson responsible for transferring the electromagnetic FORCE from one particle to another. Anything that can exert a force can also exert a pressure. PS the electromagnetic FORCE includes heat.

As others have mentioned photons exert a force as photons have momentum. There is a couple other areas where this is considered and applied. http://en.m.wikipedia.org/wiki/Radiation_pressure when we launch probes and satellites at different planets they calculate the radiation pressure due to the sun emitting various spectrums of light. See link above. In cosmology radiation including photons has an equation of state that correlates its energy density to its pressure influence. Google equations of state (cosmology) http://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology) Photons can and do exert a force. Just as the others have been telling you. See the equations on that page under ultra relativistic matter note it includes radiation.

Pretty bright light..ouch that's hot Lol

The thanks is enough

Ah I see well the balloon analogy itself is meant to merely model a 2d representation of how galaxies seperate. Nothing more than that. There is a few details left out in that thread. Mainly that per m^3 the energy density of the cosmological constant is extremely weak. Roughly [latex]6.0 *10^{-10}[/latex] joules per cubic meter. This weak energy density per cubic meter is easily overpowered by local gravity as well as the strong force

Have you looked at the balloon analogy? Take a balloon draw some dots on it. Then inflate it. Don't concern yourself with what is inside or outside the balloon. Were only concerned with how the dots move. Notice how they seperate with evenly from each other with no change in angle between any of the dots. How galaxies move from each other works the same way as those dots.

Lol my post got split up by the other relevant comments guess we have some active members on this thread

By the way higher density is a requirement of a smaller universe in the past than it is today. This conforms to the thermodynamic laws. Google the term "ideal gas laws in Cosmology". If you wish further detail outside the material I provided. The links contain everything stated on this thread. Take the time to learn it. "I don't understand it" therefore don't accept it is plain wrong. Read the material and post specific questions on it. Include the article and page we can easily step you through it if you truly want to learn. It would be a pleasure. After all that is the only reason why I visit forums. To help others learn. I never ask questions. Why is simply due to buying and studying over 40 textbooks. As well as spending 15 years of self study. I come here to help others only... so please feel free to show us a willingness to learn. I would be more than happy to help with that proven willingness

If you want to understand it then take the time to read the material provided. The first section of links is no math or little math needed. In all honesty most of the material provided is entry cosmology level.

Well I'm glad to see the cosmic inventory included in your links. It's rather extensive and detailed. Judging by your calcs and what I recall its in the right range. For an approximation Though I am still unclear what you are presenting that is new.

As Strange mentioned the FLRW metric is an exact solution to the Eintein field equations. However showing how is a rather complex matter. The best article is a 995 page technical article. Unfortunately advanced. Outside of textbooks and the other articles on my free non profit website it is the best I can offer. The problem is this particular text requires a good understanding of math and differential geometry. Some of the other articles on my site less so however this is the one that answers specifically the GR to FLRW relation. It will take time to study I would recommend the FAQ Strange posted as well as working downward the links in my Sig prior to reading this link if you cannot afford a textbook. http://www.blau.itp.unibe.ch/newlecturesGR.pdf If you have a strong interest the best intro textbook I ever read out of 27 of them is Barbers Rydens "Introductory to Cosmology" followed by "Modern Cosmology" by Scott Dodelson to simplify the math Roads to Reality by Sir Roger Penrose. (This is a non specific model math breakdown at high school level text) This last part needs addressing as it is vital. First off we have to cover a few aspects. 1 expansion is homogeneous and isotropic. (No preferred location or direction. In other words uniform) Now the FLRW metric also includes the ideal gas laws. Treat every energy density contributor as a gas with a pressure contribution according to its equation of state (cosmology) Link added at the end. Now as expansion is uniform pressure exerts An equal uniform force upon those galaxies in all directions equally. So the galaxies themselves experience no greater force in a particular direction. Therefore they themselves gain no intertia or kinetic energy. Instead the cosmological constant aka dark energy can only affect the regions between galaxies or gravitationally bound objects. Sounds counter intuitive but it helps to think of energy density as pressure and the universe as an ideal gas. ,(this is how the FLRW metric is designed with GR added.) As stated start with the link Strange posted earlier. The tutorial on that site is excellent. Then read downward the links on my site. The articles were chosen to teach textbook cosmology for those that cannot buy textbooks http://en.m.wikipedia.org/wiki/Equation_of_state_(cosmology) Forgot to add one key concept to understand is that no galaxy gains inertia due to expansion. Instead the volume of space between galaxies simply increased so GR is not violated. Also as mentioned recessive velocity required a huge distance measurement between observer and object measured to show a distance dependant recessive velocity in excess of c. (Past Hubbled sphere)

[latex]{\small\begin{array}{|c|c|c|c|c|c|}\hline R_{0} (Gly) & R_{\infty} (Gly) & S_{eq} & H_{0} & \Omega_\Lambda & \Omega_m\\ \hline 14.4&17.3&3400&67.9&0.693&0.307\\ \hline \end{array}}[/tex] [tex]{\small\begin{array}{|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|r|} \hline a=1/S&S&T (Gy)&R (Gly)&D_{now} (Gly)&D_{then}(Gly)&D_{hor}(Gly)&V_{now} (c)&V_{then} (c) \\ \hline 0.001&1090.000&0.0004&0.0006&45.332&0.042&0.057&3.15&66.18\\ \hline 0.003&339.773&0.0025&0.0040&44.184&0.130&0.179&3.07&32.87\\ \hline 0.009&105.913&0.0153&0.0235&42.012&0.397&0.552&2.92&16.90\\ \hline 0.030&33.015&0.0902&0.1363&38.052&1.153&1.652&2.64&8.45\\ \hline 0.097&10.291&0.5223&0.7851&30.918&3.004&4.606&2.15&3.83\\ \hline 0.312&3.208&2.9777&4.3736&18.248&5.688&10.827&1.27&1.30\\ \hline 1.000&1.000&13.7872&14.3999&0.000&0.000&16.472&0.00&0.00\\ \hline 3.208&0.312&32.8849&17.1849&11.118&35.666&17.225&0.77&2.08\\ \hline 7.580&0.132&47.7251&17.2911&14.219&107.786&17.291&0.99&6.23\\ \hline 17.911&0.056&62.5981&17.2993&15.536&278.256&17.299&1.08&16.08\\ \hline 42.321&0.024&77.4737&17.2998&16.093&681.061&17.300&1.12&39.37\\ \hline 100.000&0.010&92.3494&17.2999&16.328&1632.838&17.300&1.13&94.38\\ \hline \end{array}}[/latex] See if this works here Nope guess not tried posting the cosmocalc in my Sig... works on other forums just not this one

Same here I would also take the time to study why a model states what it does before discounting it.

That is not what you are measuring. When we look further back in time we see a higher density. We see the thermodynamic laws that form the basis of big bang nucleosynthesis. We see the predicted quantities of elements in particular hydrogen and lithium. We see different stars type 1a that can only form as a result of a higher density. We see the CMB which is a prediction of the big bang model. We see a higher number of quasars which is a result of a higher energy density in the past. We see the redshift of the light from those objects. We SEE plenty of evidence that supports an expanding universe. You choose to ignore all of that evidence. You fail to take the time to study the tools that will teach you why we know the universe is expanding. Google Hubble for example. Remember he observed and measured galaxies moving away from each other. If you refuse to look at the info provided then believe whatever unicorns suit your fancy

It's amazing though I and others post numerous articles including peer reviews. My signature also contains free peer reviewed textbooks. As well as provides An expansion and redshift calculator. Yet you choose to ignore this wealth of information . The LCDM (hot big bang model with cold dark matter and the cosmological constant.). Is a model that is continously being tested by observations. That data set and model gets tested with every observation made every single day that provides new data. As mentioned there is also redshift. I already provided an article explaining in simple terms what that means. Please take the time to read the links I provided. Especially the one titled. "What we have learned from Observational evidence" http://arxiv.org/abs/1304.4446

You also aren't considering that the CMB is measured accurately. At 3000 Kelvin in the past. Then consider how the ideal gas laws work. A higher density means a higher temperature.

Think of it this way the further we look the more dense the universe becomes. Thus the universe also becomes hotter. Ie the CMB at 3000 Kelvin. Galaxies included. Remember baryonic matter is only a small contributor to the energy budget of the universe. The term recessive velocity and its superluminal measurement is very misleading. We're stuck with it but it's far more misleading than what it is worth. The term accelerating expansion is a result of recessive velocity. It is based on geometry. Take that 10 cm ruler. Let's apply simple numbers. Say there is a galaxy at each centimeter dividend. Now increase the distance between each galaxy by 1mm (10% the total volume) So second two has a total volume of 11 cm to start now add 10% for new total of 12.1 cm. Then add 10 % of that the next second and so forth. See how it has an accelerating exponential expansion. However per 1" divident the change remains 1mm per second per inch. Or 10% of each centimeter. Hope this helps. Keep in mind the space between each of the original coordinates all change equally in every direction. Ie if you did the same thing with two rulers to represent 2d or 3 rulers to represent ,3d with no change of angles between any of the galaxies or rulers Notice the rate of change remains 10% per volume. This is the same as Hubbles constant 70 km/sec/Mpc. However the rate of change in the recessive velocity will be accelerating. By 10% of the total volume between any two galaxies of the previous second.

You could add up the energy budget to check your numbers http://arxiv.org/pdf/astro-ph/0406095v2.pdf

Have a good sleep hopefully you can explain how your bubble model can possibly explain wave particle duality. Just a side note I found a handy animation on it. http://m.youtube.com/watch?v=Xmq_FJd1oUQ Might come in handy on the forum at some point Granted these types of simulations are numerous

Your welcome really makes you think

Lol this topic is beginning to remind me of whether or not virtual particles are real or not. The discussion on another forum went on and on for over 100 pages. No agreement was ever reached. Just a side note ( It was entertaining though as it involved roughly a dozen professors in the discussion)coincidentally also in a quantum mechanics forum

How could your spacetime bubbles show the wave particle duality is the other question. It could certainly be pointlike. How would it show the wave function. Particularly since the photon is defined as having only electromagnetic interactions.