Why the Lorentz factor?

[swansont]

43 minutes ago, michel123456 said:

We are observing the sun vanishing behind the horizon at sunset. Reality is different. Or we have a different definition of what "reality" is.

Wut? The sun is not really beyond the horizon after sunset? 

[michel123456]

24 minutes ago, swansont said:

Wut? The sun is not really beyond the horizon after sunset? 

That is all relative.

1 hour ago, Strange said:

Just to clarify this. I think it is more accurate to say that, according to GR, the geometry of space-time curves. But geometry is just a mathematical abstraction that we have invented. 

And the geometry really is curved (we invented it in the first place and if we want to say it is curved, we can).

For an alien A1 somewhere in the universe, you are now traveling at close to c velocity. For another alien A2, you are traveling at 1/2 c. For me, you are not traveling at all. Does that mean that you are curving the geometry substantially for A1, less for A2, and not at all for me, all at the same time? Or do you believe that aliens A1, A2, and me are observing different sides of the same thing?

[Strange]

43 minutes ago, michel123456 said:

For an alien A1 somewhere in the universe, you are now traveling at close to c velocity. For another alien A2, you are traveling at 1/2 c. For me, you are not traveling at all. Does that mean that you are curving the geometry substantially for A1, less for A2, and not at all for me, all at the same time?

Geometry is a set of measurements (or, better, the mathematics of how those measurements are related). It is a mathematical abstraction, a tool. So different observers of the same thing will apply different geometry to their measurements.

It is an effect of the observer, not the observed. Or, at least, the relationship between the observer and the observed.

[swansont]

1 hour ago, michel123456 said:

That is all relative.

What observer will see that there is still a line-of-sight between the person in darkness on earth and the sun?

Being in light vs. darkness is not a relative event.

[michel123456]

3 hours ago, swansont said:

What observer will see that there is still a line-of-sight between the person in darkness on earth and the sun?

Being in light vs. darkness is not a relative event.

Another observer at another point. If you are on the east coast of the US, I am observing sunset 7 hours before you do because I am in east Europe. So for me when it is sunset, it is not for you. So yes, being in light & being in darkness is relative. It depends on position & time.

Even an observer at your place but at another altitude will observe things differently than you do.

[Endy0816]

40 minutes ago, michel123456 said:

Another observer at another point. If you are on the east coast of the US, I am observing sunset 7 hours before you do because I am in east Europe. So for me when it is sunset, it is not for you. So yes, being in light & being in darkness is relative. It depends on position & time.

Even an observer at your place but at another altitude will observe things differently than you do.

That is only the planet's shadow.

If both clocks are set the same initially, both remain synchronized.

 

When relativity is noticeably in play, the clocks will disagree(at points) on how much time has passed.

Edited April 4, 2018 by Endy0816

[swansont]

1 hour ago, michel123456 said:

Another observer at another point. If you are on the east coast of the US, I am observing sunset 7 hours before you do because I am in east Europe. So for me when it is sunset, it is not for you.

But we both agree that you are in darkness and I am in light.

1 hour ago, michel123456 said:

So yes, being in light & being in darkness is relative. It depends on position & time.

That's not what relative means in a physics context. We have to be making the same measurement. Not two different measurements.

1 hour ago, michel123456 said:

Even an observer at your place but at another altitude will observe things differently than you do.

 Again, these are distinct measurements.

[MaximThibodeau]

11 hours ago, michel123456 said:

Maybe you skip the fact that time changes also. The ticking rate of a clock on the moving object changes as observed from the stationary observer.

Again, you are right:

Im working actually, on a detailed answer...

[beecee]

11 hours ago, michel123456 said:

Maybe you skip the fact that time changes also. The ticking rate of a clock on the moving object changes as observed from the stationary observer.

The peculiar thing is that many people (scientists included) firmly believe that a moving object has the power to bend Space & Time around it. I am convinced that it is not the case. The only thing that do happen is that the observers are observing an observation. Space & Time do not bend, they are observed (and measured) as being bend.

My interpretation, rightly or wrongly is that we model what we see, and trust that the model/theory actually aligns as close as possible with that reality, if any realty  at all exists. 

The model tells me that space is real...it tells me that time is real....it tells me that spacetime is real: It tells me that this spacetime is warped/curved/twisted in the presence of mass, and which we observe/feel as gravity. It obviously lacks physicality but is that really what determines what is real or what isn't? I don't believe so. 

 

[MaximThibodeau]

I worked all day to understand the actual Physics correctly, Im to this:

From Wikipedia and terms arranged

I continue my work on it, c = light speed; v = the speed in earth referential; a = acceleration in earth ref.; t = the clock in the spacecraft

 

without the terms arranged

t = time in earth referential

where t = time in earth speed; a = 9.8 m/s² 

 

https://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration

So time will be contracted, kind of, so we will need to continue our acceleration of 9.8 m/s², the fact of speed limitation is corrected by the time dilatation. Im to it now...

https://www.ibiblio.org/ebooks/Einstein/Einstein_Relativity.pdf

Quote

p.67: The four-dimensional mode of consideration of the “world” is natural on the theory of relativity, since according to this theory time is robbed of its independence. This is shown by the fourth equation of the Lorentz transformation:  FOUR–DIMENSIONAL  SPACE Moreover, according to this equation the time difference ∆t' of two events with respect to K' does not in general vanish, even when the time difference ∆t of the same events with reference to K vanishes. Pure “space-distance” of two events with respect to K results in “time-distance” of the same events with respect to K'. But the discovery of Minkowski, which was of importance for the formal development of the theory of relativity, does not lie here. It is to be found rather in the fact of his recognition that the four-dimensional space-time continuum of the theory of relativity, in its most essential formal properties, shows a pronounced relationship to the three- dimensional continuum of Euclidean geometrical space.1 In order to give due prominence to this relationship, however, we must replace the usual time co-ordinate t by an imaginary magnitude ct⋅− 1 proportional to it.

This is for linking his theory to https://en.wikipedia.org/wiki/Minkowski_space#Minkowski_metric

Minkowski that was use to arrange terms.

On ‎2018‎-‎04‎-‎01 at 12:47 PM, MaximThibodeau said:

So it will be more affordable to cut the engine around 0.8 ?

No, we will use this energy to warp space.

 

On ‎2018‎-‎04‎-‎01 at 12:47 PM, MaximThibodeau said:

Are thermodynamic laws, wrong ?

The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. The law of conservation of energy states that the total energy of an isolated system is constant; energy can be transformed from one form to another, but can be neither created nor destroyed. The first law is often formulated

Will my space craft overheat to explosion ?

No, They are right under this assumption,

But my spacecraft may still explode, but not for that

Edited April 5, 2018 by MaximThibodeau

[Strange]

I don't know if you have seen it but this brilliant video was posted in another thread. It might help you makes sense of all this: