Jacques

Severian you are telling me that In relativity space and time are the same thing ???

Same as herpguy from an other source... MORNING COMET: A new comet is emerging in the morning sky: Comet Pojmanski has been brightening since its discovery in January and can now be found just east of Venus before sunrise: sky map. It looks like a slightly fuzzy blue star of magnitude 5; binoculars reveal a small tail. A good morning to look is Monday, Feb. 27th, when the comet glides by the double star Algedi. http://spaceweather.com/

Time what I don't have to read these post

Who are "we" . Are you part of a group ? I don't see proof I just see claims

Thanks again for your answer and time ! Still not confortable with that, but I must live with it if I want to go deeper in my learning of SR.

Thanks for your answers. But doesn't we lost something ? For example it make speed a pure number without units. s=space t=time speed=s/t or in relativity speed= s/s

So the distance between two tic-tac of my clock is 300,000 km ! For me it's 0 km distance and 1 second apart. I understand that using ct make space-time symetric, but don't we lost the distintion between space and time ?

What is the difference between momentum and energy ?

Yes I know I should have said, interact very little with matter. Thanks for all your answers !

Why think time as a distance ?

Sorry but your definition of speed of time doesn't make sense to me. It's like saying the speed of space. Does it make sense to you ? For me time is one aspect of motion, the other aspect is space. To have motion you need time and space.

Does the speed of neutrinos have been mesured ? Does it mean that a neutrinos can exist at rest ? From what I readed, Hydrogen, chloride and gallium are used in detectors. Does these elements have some special property that increase the chance of a neutrino to interact with ?

Oups Sorry I misreaded

Look post #3 from 5416

I thaught that a mass traveling at the speed of light would have infinite energy ???

Doesn't that violate relativity ?

OK thanks for your answer. I was wondering about that because forgetting that some parameter in an equation have unit of time may lead to something completely erronous. It is important to carry the unit in the equations specialy if you use normalized unit. For example taking the speed of ligth to be 1, it's easy to forget that it is a speed. Thanks again

Tell me if I am right but neutrino were invented to account for some energy that does showup in nuclear fusion: conting the mass and energy before the fusion and the mass and energy after, there was a discrepancy. So the neutrino was born. Neutrino carry energy. Does neutrino have momentum ? Does netrino have spin ? I know they don't have electric charge and I suppose that they don't have magnetic charge because they would interact with matter. There is some evidence that they have mass. So they must have momentum ... If they have mass they are not moving at the speed of light. Also the detectors all around the world detect a so small number of events out of false event caused by natural radioactivity cosmic-ray etc... How much confidence can we put in these mesurement. Can we say we are 100% sure that these mesurement are from neutrino events or must we say that there is a good probability... These particle fascinate me and I would like to know more about them. Thanks

Relativity use ct for the time dimension . Why ? Why not use simply t for the forth dimension ? I understand that ct bring te dimension of time to a dimension of space. But why do we need to do that ? Thanks for your answer

????speed = space / time What does mean "speed of time" ???

With the Rydberg equation we can calculate spectrum line of hydrogen. Is there a simple equation like that for Helium and other elements ? Does the Rydberg equation cover all hydrogene spectrum line ? Thanks

Maybe electron/positron creation from gamma rays ?

Jupiter is at 5.2 Astronomical Unit from the sun. The AU is the distance from earth to the sun. Light follow inverse square law so the sun intensity is 5.2^2 or 27 time fainther than on earth. Longer exposure and sensitive electronics for sure. An astronaut I think will see prety the samething. Our eyes can adapt to this reduced luminosity. Maybe color won't be as bright because our color receptor are less sensitive.

Yes that would be appreciated ! Thanks

Then can we tell that the unit for E is 1/t , or E is the inverse of time ? I don't follow I thaught that the charge units are coulombs ??And I know about inch and cm, you can convert from one to the other by multiplying by 2.5, but inch and cm are the same kind of units thay are units of lenght. I convert apple to apple. The conversion from time to space with ct, for me, look like converting apple to bananas.