# Jacques

Senior Members

562

1. ## Distance and space expansion

Let use te balloon analogy Take 2 points 5cm appart. Trace a line every cm on the surface. Inflate the ballon. If I use the line traced on the surface the distance will be 5cm. But for someone outside of the surface world the ruler didn`t expand and he will mesure more than 5cm. Since we are in the universe our ruler will also expand. When we use the redshift, the wavelength of light is our ruler, so our ruler is expanding...
2. ## Distance and space expansion

I was under the impression that space expansion was meaning that the units of space was expanding. If the amount of space in between increase them galaxies have proper motion...
3. ## Distance and space expansion

Hi, I have a question: I read many place that space expansion is not proper motion. That faraway galaxies doesn't move but are caried by space expansion. So if today a galaxy is mesured to be 1G lightyears away, in 1 millions years that galaxy will still be 1G lightyears a way because she have no proper motion. If I go back in time, the same will be true. No need for a bigbang... where am I wrong in my reasonning ? Thanks
4. ## infinitiies in relativity

That is true. If we use regular math. But, if 1/infinity = 0/1 and 5/infinity= 0/5 then infinity * 0/1 = 1 and infinity * 0/5 = 5 Some kind of "rational numbers" that flip spacetime dimension. Numerator becomming a denominator and visversa. May be wath I just wrote here is pure scrap, I am not a mathematitian , but I know that some math can cope with infinity (projective geometry projective space) and I thaught that it might be useful for physic.
5. ## infinitiies in relativity

Hi General and special relativity have some problem with some infinit solution. I was thinking (I am prety sure some else thaught of that) why not use some mathematic that admit infinity as a solution ? I am specialy thinking of projective geometry. Maybe by admitting infinit solution we are not stuck there, and can go further in our understanding of black hole. Can we extend Lorentz transform to work at c ?
6. ## vacuum Einstein equation

Thanks for your answers The universe is expanding, so the solution to Einstein equation must give an expanding universe... I did some other reading and saw the scale factor a(t). Is it the space expansion ?
7. ## vacuum Einstein equation

Hi I have a general understanding of general relativity, but when it comes to equation, I have a very vague idea of the math involved and cannot answer by myself some questions. 1- Does Einsten equation include the space-time expension ? 2- Does the vacuum Einstein equation give an expanding space-time or a static space-time ? Thanks wiki Einstein equation
8. ## Why does mass curve space-time?

Because mass eat spacetime all around it
9. ## Dimension and blackhole

between3and26characterslon that is it! Thanks for the link In relation with that paper where the author discuss of 3D time, that the 2 extra time dimension are compact (some kind of loop) maybe inside a black hole the space dimension turn into compact dimension and the time dimension turn into an open dimension ...
10. ## Unified String (u21s19) Theory predicts characteristics of New Worlds

Hi In french God is Dieu can you give me your 7_4 on that ?
11. ## Multiple dimensions of time

It look serious, but can someone who knows quantum theory can take a look and tell me if it make sense http://arxiv.org/PS_cache/quant-ph/pdf/0510/0510010v1.pdf Thanks
12. ## Dimension and blackhole

From the point of view of an external observer far from a blackhole, spacetime look like streached. I readed that the time dimension is dilated and at the event horizon it is infinetly dilated. I concluded that the spaces dimensions must be infinitely contracted to conserve the canstancy of the speed of light. Am i correct ? Also I readed that the time dimension become spacelike passed the event horizon so the spaces dimension should become timelike and there are 3 spaces dimensions so there are timelike dimension pass the event horizon. What do you think about that reasonning? I also found that paper that speak of 3D time http://arxiv.org/PS_cache/quant-ph/pdf/0510/0510010v1.pdf
13. ## Hot fusion puzzle

No do you think I am stupid. Plasma get cooler when it expand, for what ever reason. Here the reason in stellar core, is that the pressure in the core is greater than the gravitationnal pressure and the core pressure is increased because of an increase in temperature caused by fussion reaction. It is a dynamic process that goes to an equilibrum
14. ## Hot fusion puzzle

Do you think that the plasma getting colder than before the heating ? Let me explain The plasma is at temperature T The plasma is heated: the plasma is now at T + x The plasma expand: the plasma is now at T + x - y Usually x >= y Hope it help
15. ## You have received \$100,000,000,000.

I would invest massively in High-altitude winds: The greatest source of concentrated energy on Earth. It will bring cheap energy, enought to produce hydrogen for cars reduce global warming and make some money. With that money build desalination plan where needed. No more war for petroleum, and people having lot of water to farm there needs. Some education so that the new energy infrastucture be runned by local people. I was thinking of the jet stream and kite is one of my hobbies and thaugth that if we can put a wind turbine on a kite that fly at that altitude we will have a constant powerfull wind. I google and found that the idea is already developped
16. ## neutino and neutron decay

Thanks very interesting Would be difficult to move such appartus. May be it would be simplier to move the neutrino source to do the tests.
17. ## neutino and neutron decay

How the half life of neutron is mesured ?
18. ## neutino and neutron decay

A way to test would be to mesure the half-life of neutron beside an intense neutrino or antineutrino source, like a nuclear reactor. If there is a difference make others mesurements with different neutrini intensity and extrapolate for background neutrino intensity. I don't know how the half life of neutron is mesured...
19. ## neutino and neutron decay

The half life of free neutron is 15 minutes. I was wondering if it is possible that the decay of neutron is the result of neutrinos collision. Some neutrino detector use chlorine that transform into argon or gallium that transform to germanium and both reaction imply that a neutron is transformed into a proton. Neutrinos are all around so there is a chance that a neutron can be hit by a neutrino. Just a thought. What do you think of it?
20. ## The reason behind "moving magnetic field creates electric current"

A transformer is basically like your two coils around the iron bar. Transformer work with alternative current, that mean that the magnetic field produced by the primary is changing (high- low -high -low...) wich cause an alternating current in the secondary. The ratio of the peak voltage depend on the ratio of the number of turns. Battery produce direct current, and what I think you are trying to do with you capacitor is to produce an alternating current. That is possible if you add and active device like a transitor to cycle the capacitor from charging to discharging.
21. ## Neutronium

Ok let estimate the work needed to extract the mass of one neutron from the surface using F=G*m1*m2/r^2 G is gravitational constant m1 is mass of neutron star = 2 solar mass = 4*10^30 kg m2 is mass of a neutron = 1.67*10^-27 kg r is radius of neutron star = 5000 m F=1.8*10^-14 Newton Using Arthur Clark simplified calculation for the energy given to a payload's mass when lifted from the ground up out of the gravity well ( http://home.earthlink.net/~jedcline/workenergy.html ) W=F*r 9*10^-11 Joule Transforming Joule to electron volt 9*10^-11 / 1.6*10^-19=562 500 000 or 562.5 MeV That give more than half the mass of the neutron The energy release by the beta decay is very small compared to what would be needed to extract neutronium. Are you sure that gravity is the weakess of the four fondamentals forces ?
22. ## Shadows in the water

Yes! I would need something to replace the sun. Maybe a flashlight.
23. ## Shadows in the water

I found that on a search on soliton and after I read that I did the experiment in my swimming pool ! So when I read you I knew it was it. I no longer have a swimming pool but I would like to see the experiment with some dye to vizualise the string joining the 2 vortex.
24. ## Neutronium

I was thinking about how we would takeout that neutronium from the star. How much energy would it take to extract the mass of an iron atom from the surface ? Would it be the same energy that the original atoms emited during there life into the star and during the supernova explosion ? Also it would be a gradual process: you need time to climb out the gravity well. Then not all neutrons will get a chance to decay at the same time. Heavy isotopes may form ...
25. ## FTL explosion

Light echo ! Interesting illusion! Back on the FTL explosion topic. First: relativity prohibit anything having mass to be accelerated to c. photon have no mass and are created travelling at c. Would it be possible that a process exist that create particle travelling at 2c or at something else FTL? We don't know much about these extreme conditions 10^11 to 10^12 kelvin and extreme pressure...
×