About 1,800,000 results
Open links in new tab
  1. astronomy - How big a coincidence is the Sun and Moon having …

    May 3, 2020 · 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 …

  2. How much lux does the Sun emit? - Physics Stack Exchange

    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

  3. How is distance between sun and earth calculated?

    Apr 27, 2015 · Do you want to know both how the Earth-sun distance is measured and how the speed of light is measured? Those are completely different things. As I asked before, separate …

  4. Nuclear fission in the Sun - Physics Stack Exchange

    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 …

  5. What is the simplest way to prove that Earth orbits the Sun?

    Apr 17, 2015 · Assume you're talking to someone ignorant of the basic facts of astronomy. How would you prove to them that Earth orbits the Sun? Similarly, how would you prove to them …

  6. What is actually meant by 'sun set' and 'sun rise' times, when …

    Feb 15, 2017 · 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 …

  7. Why does the sun make me feel warm? - Physics Stack Exchange

    Aug 27, 2015 · The sun outputs about 1300 watts per square meter (W/m²) in space near the earth, which gets reduced to around 650 W/m² in the middle of the day after going through the …

  8. Why does the Sun rotate? - Physics Stack Exchange

    Apr 28, 2020 · The Sun was certainly much faster rotating in the past. When it was 100 million years old it likely had a rotation period somewhere between 0.5 and 5 days (observed in solar …

  9. sun - Why is sunlight spectrum continuous? - Physics Stack …

    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.

  10. Why is the solar noon time different every day?

    0 A solar noon is defined when the Sun is at the zenith (directly above). Since the Earth revolves round the Sun, the point that is directly above would have changed because Earth is in a …