michel123456

Could you please explain your statement, It is not clear to me.

If A moves relative to B, the length, mass and time in A are true as observed from A. Mass, time and length of B are true as observed from B.

O.K. There is a "nice" FOR in which measured mass is minimal, in which length is maximal and in which time is minimal relatively with all other FORs around the Universe. If you hear a crash it means reality won against observation. If you hear no crash it means the meter stick passed without touching the posts. In this case, only the meter stick was moving, only the meter stick was contracting, the posts were not contracting ,the observer on the meter stick was wrong. Do you have another alternative?

You are free to make the experiment.

My position is not against Relativity, it goes about the interpretation.of Relativity.

1.So, there exist a "nice" FOR that smart scientists can use to easily measure the longest dimension of an object. In no other FOR can such a length be observed. 2. It is the same FOR in which smart scientists measure the rest mass ("invariant mass") of an object. 3. Does this FOR also have some "nice" particularity about time? Question: Is there a FOR for which an observed time interval is less than a time interval as measured in the FOR of the object? (I mean, instead of time dilation, time contraction)

So you are measuring from a distance a length contracted meter stick traveling at vertiginous velocity. And you know better than an observer upon the meter stick that observes for himself no contraction at all. The observer on the meter stick believes it is you and your posts that are traveling at .99c. And he observes that you are contracting. Both things cannot "happen" "simoultaneously", they are mutually exclusive. As I said before, IMHO iy is all about observation (which is not exclusive) not about anything really contracting.

I don\t want to discard Relativity. There is a misunderstanding. The part I do not accept from your statements is when you say that Relativity describes accurately what is really happening. I remain on my statements that Relativity describes accurately what we are observing and measuring. Sure there is a link between measurement and what is really happening. But nobody says (or should say) that what we measure is what is happening. It is a supposition, not an axiom. I am not a solipsist. That is correct: never trust your instruments. Science works on a vicious circle: observation -measurement -Theory- confirmation through observation & measurement. It is true that if you insert a doubt about the coincidence between reality & measurement, the actual scientific method is in trouble. There must be some other method though. Mathematics for example are always helpful, geometry and all that stuff. Logic. And also exporation, new technologies, etc. The world doesn't stop at philosophy.

Is there a FOR for which the observed length of an object is more than the length measured in the FOR of the object?

I say that measurement can be an illusion. I say that when different FOR make different measurements of the same thing, then the measurements are illusions*, even if you have a scientific Theory that link all the measurements and explain how one FOR measures this and the other FOR measures that. * not sure if the word "illusion" is correct. Paramorphosis maybe?

I agree on all except the conclusion. If you say that perspective is NOT an illusion, then IMHO you are wrong. Perspective is a geometrical deformation caused by the way we observe things. I call that an illusion. IOW the world is not the way we look at it. The edges of a road do not reach each other at the horizon. THE SAME goes for Relativity. We observe (and measure) a whole bunch of "deformations" that DO NOT happen. It is all about observation and measurement. The real state of affairs is that we are measuring things. The conclusion is different. Your conclusion is that things described by Relativity do happen, I understand that, because there are an infinity of FOR, an infinity of situations do happen and that is insanity IMHO. My conclusion is that observers have no influence on what is happening, that there is only one thing happening, and that Relaivity describes accurately how that one thing is observed in each FOR.

Is there a FOR for which the observed lenght of an object is less than the lenght measured in the FOR of the object?

That's the question. Swansont doesn't seem to say that. And that is not so simple. If it was simply a question of a scale factor, why not. But Relativity states that objects deform diferently along the direction of movement. The objects are deformed. And they are deformed not because some force is acting upon them. No. They are deformed because somewhere somebody is observing. I am on planet Earth and I observe my planet round (roughly) You are on planet X and you observe planet Earth elongated. If we are both right, then there are 2 realities. There is a round Earth and there is an elongated Earth. This is not science, this is bad interpretation. What is your problem to interpret Relativity as a deformation caused by observation? Why does it have to be more profound? Why does it have to describe what is really happening?

Call that stubborness, but I disagree. Your statement implies that there is no "one Reality" with a big R, but as many realities as there are observers. To me, this is insane. Observers do not change reality.

I guess so. Other FOR will measure my own mass as different. Simply, because observers in other FOR know the Theory, they will not call this mass "Mass" but otherwise. It would be a non sequitur if you could show me a FOR where my own mass is measured null (for example). I expected that. What should I do then?

I understand that the laws of physics do not change and that all observers in all FOR must agree on the laws of physics. I understand that the difference between the measurements made by all observers in all FOR can be transformed from one FOR to another through Relativity. But IMHO there is a very special case that happens when the observer and the observed object are in the same FOR. To me, it is a preffered FOR because it differs from all the others. Now If I understand correctly, I have to prove that it is simpler to measure my own mass (or the mass of the Earth) than the mass of a flying airplane or the mass of Jupiter. Does that correspond to the definition?

Mercator

When you have a minimum value in graph, doesn't that point differ from all other values? I would agree if there was a way for some observer to measure a mass less than the rest mass. A situation where rest mass of a random object can be measured by some observer in a range going from zero to infinite. It is not the case. What we observe is a range going from rest mass to infinite. So IMHO rest mass is a very special value and the FOR in which you measure rest mass a very special FOR.

No. from the fact that there is only one value for the rest mass. And that this value is a minimum. All other observers from different FOR will measure (correctly) another value for this mass. And call this value "relativistic". Which will always be more than the initial value. Never less.

Yes. The material will produce heat.

Yes for the bold part But We are saying the same thing and make different conclusions.

Do you have a link please?

With heat I presume.

Would it be possible to perform an experiment in void where a broken solid material can be put together? And release energy? (since the material would have less energy).That would be cool. Like ice?

Is rest mass a "true information"?