Jacques

Because he is blind ! That the principel of relativity. The hard part in relativity is to leave the notion of absolute space behind us. No reason to have an absolute space. But here we have a prefered frame: the frame of the light source. When the source emit the photons, they have the momentum of the electrons of the laser in the ship. Is it a way we can rationalize the surprising solution of relativity to this problem ?

What I understand is that velocity have no meaning by itself. Only relative velocity have a meaning. What is the relative velocity betwen the two spaceships ? 0. So no correction needed. If we sented a bullet instead of a laser pulse, intuitively we know that the bullet already have the same velocity as the spaceship and we wont add an angle to catchup the other spaceship. From the star point of view it is like the light emitted by the spaceship already have this velocity toward the other galaxie or that if there is a medium to transmit the light, the medium goes at the same speed as the spaceship. Just some thaught...

OK So using any frame to calculate the pointing direction of the laser will give the same result ?

Why ? Is the spaceship frame more valid than the star frame or any other star frame ?

The captain of the spaceship knows he is moving at 1000 km/sec relative to the last star of the galaxy. To aim his laser he have two choices: use the star reference frame or use his ship reference frame. They are both valid reference frame. How will he decide which frame to use ???

No offence Calbiterol. NeonBlack is right my native language is french, so forgive me if I do some gramatical errors. ( you can tell me so I will improve my english) So simple and logical! can't be correct... In french we say: Pourquoi faire simple quand on peux faire compliqué. Why do it simple when we can do it complicated. Thanks for your answers. Also the implications of the abondance of H2 are very big . If you read other articles on that site, specialy the one about the non-Doppler redshift... No more BigBang necessary.

How does that observer be able to conclude that ?

OK I see they don't have any speed relative to each other. But from our point of view the laser won't hit ???

The spaceships are at rest with respect to each other. But they will need to point the laser where the other spaceship will be in 6 seconds remembering that they see the spaceship where he was 6 seconds ago.

I am asking who is Paul Marmet because on the internet anybody can claim that he is a doctor or anything. I had a quick look at the University of Ottawa site and he is an auxiliary professor. An other side of my question about Paul Marmet is how does the scientific community consider him ? How does his ideas accepted ? Also it is said: "The halo culture that has grown up around the dark matter problem might never have arisen if the ISO results (large quantity of H2) had been known earlier." Maybe dark matter theory is just an accident.

Hi I found that webpage http://www.newtonphysics.on.ca/hydrogen/index.html It tells that molecular hydrogene (H2) is very hard to detect and that there maybe enought undected H2 to explain the rotations curves of galaxies. I find it very attractive theory but I would like to have your opinion on that Who is Paul Marmet ? Thanks in advance for your inputs.

Number of atoms time the atomic mass of the element. The downward force is not a mesure of mass. It's a mesure of force. The same mass on the moon will exert a different force on a scale.

So the particule in accelerator does't increase mass ? Why is it harder and harder to accelerate ? The definition of mass I am used to is a quantity of matter.

So it is not right to say that mass increase with velocity ?

Let have 10kg of gold and take a train. Because of the velocity, relativity tell me that I now have a little bit more gold ! Now I throw it at the same velocity as the train toward the back, to my friend who is beside the track. Again because of the velocity relative to me the mass is increased again... If I do that many times I will endup with a lot of gold Isn't that illogic ?

What I am telling is that he is never both. Probability of being both 0% I am not expert in QM but I have the feeling that QM is all about probabilities and that the expert speak about superposition when they don`t know the state of a particule.

The fact that we don`t know if the cat is alive or dead, does not imply that he is both. Simply we don`t know. We can tell that the probability of being dead is 50% and 50% alive. That is just a probability... Maybe I am wrong but I think that the successes of quantum physic is mostly a succes of applying probability to physic problem.

My initial idea was: At the speed of light time freeze. Photon move at the speed of light. Each photon have frequency. n/t ??? Solution: An other time dimension is needed, not affected by time dilatation. How can the frequency be stored in a photon without Eigentime (0) ? Maybe it doesn't need to be stored when Eigentime is 0 Ah! ah! Still need to transmit from point A to point B. Maybe we must forget to speak of photon in terms of frequency but speak of it in term of energy that doesn't have a time conotation..

My brother told me to visualize the photon like a packet of energy, some kind vibrating point moving at the speed of light. Is it a better analogy ? It is a vibration that doesn`t disperse like the spherical model of electro-magnetics waves . I think that model can be used to calculate the collective behavior of photonssss. I am trying to understand expressions like "the wave function colapse" something like this... Thanks for your answers

Photon are considered a wave in some case like interference and as a particule in other case like the photo-electric effect. I imagine a wave of light leaving from a distant star like a sphere expanding in all directions. When that wave hit a photo detector or a CCD the behavior of that wave is like a particule. Does it mean that all the energy spread out on the sphere having many lights years of diameter is instanly concentrated on one pixel of my CCD ??? Is my image of a wave bad ??? Thanks

Yes it knows when you look at it because it interact with the matter of the detector (eyes, polarizer, photographic plate , CCD... ) I like when you say "when it has No frequency, it`s called a Magnet "

My intuition tells me that when light travel it doesn't vibrate, only when you mesure it that you see a vibration..

The definition of frequency I learn at school is number of cycle per unit of time. Can you explain me or direct me to some reading about the definition of frequency as a unit of coordinate time ? Also I don't understand the Eigentime word... Thanks

Do you know about relativity ? Time dilatation ?

Hi I have a little question that is bugging me: If time freeze at the speed of light, how is it possible for light to have a frequency other than 0 ?