We all know to compress objects into smaller volumes, you would need to apply pressure to them. The required pressure depends on how strong the material is and which form is it (gas, liquid, solid). I have a 10 cm3 block of steel in my room. I am always wondering how much pressure it would take t...

When we talk about, lets say, the Lorentz group, we define the action of the Lorentz transformation $\varLambda$ on \begin{alignat}{1} x^{\mu} & \in\mathbb{R}^{1,3},\\ x^{\mu} & \rightarrow x'^{\mu}=\varLambda^{\mu}{}_{\nu}x^{\nu},\\ \varLambda^{T}g\varLambda & =g \end{alignat} and we can show th...

I have 1 main and 1 sub question, please dont remove my post for this i just want to clear this up its been bugging me, thanks. Fundamentally, I don't understand 2 things, and if anyone could clear this up I would really appreciate it; at what point does an emission line spectrum become continuou...