Recent content by castor

I don't think so, because I've been trying to access it for about a week now.

Is there something wrong with that page? I can't seem to access it now.

It's a part of the Hertzsprung-Russell classification or the Morgan-Keenan of stellar bodies, depending on their heat output from what I understood. Depending on their surface temperatures, stars are labelled O, B, A, F, G, K, and M in the decreasing order. Therefore, the hottest stars are...

If ## tan(a) = -1##, it means that ## sin(a) = - cos(a) ## Since the domain of ## tan(x) ## is between ## -\frac{\pi}{2} ## to ## \frac{\pi}{2} ##, ## a = -\frac{\pi}{4} ##, or -45 degrees.

What about research? Is it possible for a graduate (here in my country, it means bachelor's) engineer without any prior research in physics to do a PhD in experimental/observational Physics?

Don't take that literally. Crashed, soft landing, it doesn't really matter. We really thought Venus might hold some form of life before the Venera probes dispelled that notion.

Not to mention, any intelligent life that may have developed over there wouldn't have much incentive to beam anything towards the Earth. Remember, the distance of 1400 ly works both ways. If any hypothetical life sent out signals 1400 years back, they would have done so following data they...

Right, thanks for clearing that up! :)

The same can be said for the x function; x" = - acceleration, isn't it? ## x = A\cos (\omega t + \phi) ## ## x' = - A\omega\sin (\omega t + \phi) ## ## x'' = - A\omega^2\cos (\omega t + \phi) ## ## x'' = - \omega^2 (A\cos (\omega t + \phi)) ## ## x'' = - \omega^2 x ## No, the only thing I'm...

Why is it that ## y = A\sin (\omega t + \phi) ## whereas ## x = A\cos (\omega t + \phi) ##? Why is it that the y function is a sine wave, whereas the x function a cosine wave? I'm sorry if this question sounds ridiculous.