I need somebody knowledgeable in physics

[Coelho]

glad to see a cool pot smokin physics teacher :jointsmile:

My students liked it a lot! They knew i did smoke (well i only teached while high...) and i even invited some of them to toke with me... but they declined... i think they became afraid when i said i would give them the strongest hash oil... sometimes i think they were only posers, not stoners...

Woohoo for classical physics then! But are you telling me then, Coelho, that if I push the end of the bar the other end won't move for something like a million years?

Exactly.

And if so, how can you have the first (lets say) 100 lightyears of bar bent, and the rest of it still strait because the waves haven't reached it yet? Wouldn't this have to result in the iron bar bending a good deal at the mere push of my finger, or breaking altogether?

Well... you could not push one end of the bar all the distance that you wished at once... remember that a bar that long would have an enormous mass, and so an enormous inertia. If you were pushing it, you only could push it VERY slowly... so, the wave of compression created by your push would be microscopical (as it actually is in hard materials like iron and so).