Recent content by borvis

Homework Statement Light with two wavelengths (510.0 nm and 525.6 nm) is spread by a diffraction grating. On a screen 4 meters behind the grating we observe that the diffrence between the two second order maximum is 1 cm. What is the grating constant (d) ?Homework Equations I think i only need...

Can we really say that a black hole is a singularity? Is there any theory that says that a black hole can't have a circumference/volume?

You can use: \omega^{2}=2\alpha s , where s=2\pi r * 3 (3 times the circumference) and 500 rev/min=4770 rad/sec

And this means because of Hubbles law, v=Hr, you can say that a \propto r? Since the expansion factor is proportional to the speed that objects move from each other in space?

Thanks!

I have a simple question: What does it mean that the universe is mass-dominated or radiation-dominated? I can't find the answer anywhere on the internet. But i kind of think that it means that the energy-density of the universe is either dominated by the energy from mass or radiation. Is this...