[AntonioLao]

What does it means to be truly Lorentz invariant? All modern physical theories seem to require this validity. These theories include the most advanced and mathematically extended quantum field theories (QTFs).

See more about this invariance at

http://scienceworld.wolfram.com/phys...Invariant.html

http://mathworld.wolfram.com/LorentzTransformation.html

[Guille]

From the simple names of the Lorenz things, I get that if something is an invariant even through a "transformation" process (either empirical or mathematical or philosophical) it means that it is completely fundamental, and that it is one of the basic things of the universe.

[AntonioLao]

The Lorentz invariance seems to imply the absoluteness of the speed of light. And the constancy of this speed implies that the spacetime interval is always zero.

[Guille]

antonio,

What is the space-time interval?

[AntonioLao]

the interval is defined at the following website

http://scienceworld.wolfram.com/phys...eInterval.html

[Guille]

I see....

Do you know what is exactly that is used in theories that mantain invariant through a Lorenz transformation? (I'm starting to get what Lorenz things are about.....)

[AntonioLao]

Originally Posted by GUILLE Do you know what is exactly that is used in theories that mantain invariant through a Lorenz transformation?

Velocity dependence. This is the key requirement for Lorentz invariance.

[dleviwing]

Antonio;
Post #3 you use the absoluteness of the speed of light as and example of Lorentz invariance. If I may suggest that you state it such to clarify that it is the "measurement" of the speed of light in a vacuum that is invariant by definition.
To often students and others interpret the speed of light to be a fixed constant.
The defined method for measuring the speed of light in a vacuum will away render the same value regardless of the frame of reference and thus the measurement is invariant.
The sites you suggested are excellent but may be a little heavy for some of our younger members that have not yet entered this phase of academics.
Thanks;
Dave

[AntonioLao]

Originally Posted by dleviwing The sites you suggested are excellent but may be a little heavy for some of our younger members that have not yet entered this phase of academics.

Even I have trouble with the sites. I just gave them in order to let anyone knows the facts involve to get through the understanding of something as complicated as Lorentz invariance. The truth is I am still learning tensor analysis on my own and knowing that it is needed to fully comprehend special relativity and general relativity.