It's consensus that the very similar apparent sizes of the Moon and the Sun as seen from Earth is a coincidence (as already answered in this site). This provides us with almost exact total solar
I want to know how much lux the sun emits on a bright day - I don't mean when one stares directly at the sun, but rather when one walks casually outside when the sun is shinning brightly. Now the
1) The sun seems brighter (more dazzling) if there is more scattering in the atmosphere. The sun would actually look very small to us in the sky if there were no atmosphere (it's the same angular size as the moon) and most of the brightness seen in the direction of the sun is from small deflection rayleigh scattering.
The Sun's energy comes primarily from fusion of light elements in its core. It is estimated that a very small fraction of mass of the Sun (~$10^{-12}$ times the abundance of hydrogen) is uranium (b...
The Sun appears white at noon because the sunlight reaching the observer maintains its full spectral composition, meaning that all visible wavelengths arrive in nearly equal proportions.
If this is the case, then when we read things like what time sun sets and rises on websites, books, calendars, other official times, et al… does that mean when we see for example ‘sun set at 18:35’ is the time denoting the actual sun set taking into account of the mirage or what is visible to us.
The sun will last, at its current brightness for 9 billion more years. How long until the sun gets burned down to the point where it cannot sustain life on Earth anymore? Updated: I am more concer...
The sun's spectrum is very complex, and indeed there are a lot of "lines"—both light and dark (emission and absorption)—amidst a sea of what looks to be continuous frequencies.
The crescent of the moon is almost straight up/down because the Sun is horizontal with us, and therefore also horizontal with an imagined observer standing on top of the Moon from our perspective. The lunar terminator of the moon need not point towards the Sun as it is only the edge of the lit-up moon.
Here is the measured radiation from the sun It is fitted with a black body curve, at the top of the atmosphere (yellow) and even though it is evident that there are deviations from the theoretical black body, it is still a good approximation. Generally all bodies radiating are approximated with a black body spectrum. If it fits well, that means that it also absorbs the same type of spectrum ...
