Jacques

Hi The high redshift supernovao survey came out with a supprising result: the expansion of the universe is accelerating. The first explaination proposed is that there should be an unknowed force that drive that acceleration, and cosmologist called it drak energy. I have an other explaination using only relativity. Let me exposed the principles and observations on withch I base my reasonning. 1- Time slowing down in a gravity well. This is experimentally verified by many method. One of it involve and radiation emiter situated above a detector: the radiation is blue shifted. 2- The large scale structure of the universe is like a foam: a web of galaxies and galaxy cluster with large buble of empty space. 3- These buble increase with time due to the expansion 4- The expansion of the universe happen mainly in these bubble Now from there I can deduced : The gravity potential in these bubble is smaller than in our galaxy, so time in these bubble seen from our galaxy is faster. When the universe was younger, these buble where smaller, so the gravity potential in these buble was bigger than today. I dont know if you make the link now ??? OK the acceleration of the expansion of the universe is an observational illusion. Has we go deeper and deeper in our gravitationnal well (galaxies condensing into a web) we observe the expansion of the universe happening in the bubble going faster. I hope I made my idea clear enough and don't hesitate to ask for clarifications. What do you think of that ? Is there some expert that can do the calculation to see if it can account for the mesured acceleration ? Thanks

Hi all I just had a thought that might explain the rotation curve of galaxies. It maybe wrong, I don't know but here it is: The stars at the edge of spiral galaxies are going to fast to be kept in orbit only by the gravity of the visible matter. The main explaination is that there exist some unseen matter who was called dark matter. My thought was: At these distances from the center of the galaxies the gravitationnal acceleration is very very small, so we don't need a big "force" to keep the stars on track around the center. Intergalactic space is almost empty of matter. Almost, a few atom per cubic meter or kilometer I don't remember, but it is not empty. And I think that these few atom are very energetic. Is it possible that this "intergalactic gas" exert a sufficient pression on galaxies to keep them from flying apart ? I don't know the data and how this "pression" can be calculated, but I think someone may have figured it out... Thanks

It is a postulate of relativity, it is the concept on witch relativity is build. You can imagine a theory with a universal reference, but it won't be relativity.

OK That answer my questionning Thanks

Is there any evidence that it is true or is it deduced from the Big Bang theory ? If we suppose that the redshift depend on the recession speed, does it create any contradiction with logic or observation ?

What I mean is Doppler redshift is caused by the motion of the source away from the observer, and the Cosmological redshift if caused by space expanding. I read that distant galaxies doesn't move, it is space that expand. Why ? Why do we say that the galaxies doesn't move. Is there something special in the redshift ? Thanks

Thanks all for your answers. Can we say that a neutron star is a macroscopic QM object ? Isn't it QM that keep electron from falling on the proton of the nucleus ?

Thanks Martin So the neutron star are not completly made out of neutron. With time as the neutron star cool down, all neutron will lose there kinetic energy and nothing will replace it except for the microwave background radiation. I guess that it would take a lot of time to dissipate that heat since the radiative surface is so small compare to the mass... I can conclude that the neutron are not toutching each other if they can move.

Matter in a neutron star is made only of neutron packed together. There is no space between the neutrons so they can not move. Temperature is the mesure of the kinetic energy of the particle that constitute matter. Then if the neutron can not move the temperature of a neutron star should be 0 K Does that make sense or am I missing something ? Thanks in advence for your answers and comments

I just thought of something time slow when gravity increase. In the early universe maybe the gravity was high enought to stop time. Just a thinking...

Why ? I don't see how it can help... I don't understand the purpose of your work. Why convert everything into seconds... 100 seconds of mass + 3 second of volt = 103 seconds ... Completely useless.

You need the time the acceleration from 0 m/s to 8m/s took place. From there you will be able to calculate the acceleration and use F=ma to find the force

Do you plan to change earth orbits???

If one end of the long wire is already connected, the potential will arrive at the other end after 1.1hr like Klaynos calculated. During all the years it took to streatch the wire on earth orbit the potential was there so when he connect the wire, the bulb will be illuminated instantaneously.

You have a quadratic equation [math]d=at^2/2 + vt[/math] [math]0=at^2/2 + vt -d[/math] remember the good old solution [math]-b +- \sqrt (b^2 -4ac) / 2a[/math] Just plug the good value in that Quadratic equation solver and you will get the time the acceleration took place and from there I am sure you can get it

Dho I didn't thought of it... lol

How about attaching the chain to the south pole. You wont need the rail system

Distance formula you used is for initial velocity = 0... but the initial velocity is 19 m.s-1 d=(at^2)/2 + vt

You understand me correctly. I am not that good also in physic that is why I asked, but you make a good question about how the virtual photons are exchanged. I don't really understand how the electric force is mediated with the virtual photons. I know the analogy using two persons on ice, pitching eachother a ball... That easy to imagine for the repulsive force but it is an other story triing to have an analogy for the attractive force. Before you brought that point, I took a look at the equations for the relativistic doppler shift and for the relative mass increase, and I remarked that both use the same gamma factor...

Hi all Relativity tell us that we cannot accelerate something up to c. The closer we get to c the more energy is needed to get the same acceleration. An explaination I often readed is that a part of the energy is converted to relativist mass and having more mass to accelerate need more energy. An experimental proof often cited is the case of particle in accelerator. I don't know if there are other experimental proof... The basic principle used in particle accelerator is to used an electric field to "push" the particle. How the electric field push on the particle is by mean of virtual photon exchange. My question is do we need the relative mass increase to explain that we need more energy to get the same acceleration? I have an other explaination: The closer the particle speed get to c the more redshifted the virtual photon getting to the particle and redshift mean less energy delivered to the particle. In short, it is an eneergy transfer problem and has nothing to do with increase in relative mass. Thanks in advance for your answers:confused:

Thank you all for your answers.

Right. You need a capacitor with the inductor to have a band-pass filter ans some feedback loop to get an oscillator. Depending how it is connected, you have a hightpass or a lowpass filter. For very highht frequency, the capacitance of the connecting wire may act as the capacitor.

An explaination I readed is that , part of the energy is transformed in "relative mass" and having more mass make it harder to accelerate. I think that the only experimental data on that come from particle accelerator where particle never reach c, no matter how much energy you add.

Thanks for your answer

Or is SR a special case of GR where acceleration is equal to zero ?