ANSWERS: 2
  • No, it is not true that the hours of 'darkness' and 'daylight' are equal, but that is because you used those words. It is true that at sea level (and actually at sea, so no land forms distort the real horizon) on the Equator there are 12 hours between 'sunrise' and 'sunset' and then another 12 hours between that 'sunset' and the next 'sunrise.' ('Course if your 'at sea' you aren't in a country, so let's go wade in the surf on the Galapagos Islands, which are part of Equador, and ya can't get much equatorial than that). Notice the quotes, there are different but relatively precise definitions for 'sunrise' and also for 'sunset,' depending on who is doing the defining and for what purpose. Darkness and daylight have less precise, even subjective definitions. 'Night' and 'day' are a little more precise but still not as precise as 'sunset.' Most people use 'sunrise' in the observational sense, that is sunrise is when we see the sun first come over the horizon, but the atmosphere refracts, or bends, the light from the sun. We actually see the sun before it really is above the horizon, the amount of refraction, and the time between seeing the sun and its actual rising can vary with atmospheric conditions, dust, water vapor, even barometric pressure, and other factors. (That direct 'subjective' eyeball measurement [as well as of lunar risings] is used by religious observers for determining when various religious rites should be performed. Because of the atmospheric conditions, different observers can get different results. [ I think there was some controversy over Ramadan this year because of that.]) Astronomers, navigators, and others use a more specific definition for 'sunset'; usually the precise time that the top of the sun's actual disc, and not just the refracted light, reaches the horizon. That time is determined with mathematical formulae, actual measurement and observation with various specialized instruments designed to counter act the refraction. Often the observations and measurements are made at the time when the *center* of the disc crosses the horizon because it is easier to determine. " Now! Mark! No, no, its still getting bigger, Now! Nope not yet ... Mark! nope.. Mark! Nope Mark! Now it's getting smaller, go back to the last mark." Then they calculate backwards to figure out when it really rose. Sunset is measured the same way. when the rim of the sun actually leaves the horizon. Some scientists actually use the midpoint as 'sunrise.' The actual time between 'refracted sunrise' and actual mathematical sunrise is usually less than five minutes, the same for sunset. So Equatorial or 'day' can be 10 minutes longer than 'night.' That 10 minutes doesn't take into account 'dawn' or 'twilight,' that is when the sky is lit, 'daylight,' but the sun's disc hasn't reached the horizon even refractedly, or has already dropped below it, but there is not yet true 'darkness upon the face of the deep'; which can be quite a while depending on atmospheric and climatic conditions. But what's 10 minutes? All other things being equatorial, er..equal, day and night are unequivocally equal at the Equator.
  • What the previous answer states is true, but for most people I think a simplified answer is more explanatory. If you live on the equator, you basically will get 12 hour cycles between daylight and darkness. The sun will not pass directly over your head at noon on every day. On most days the noon time sun will either be north of south of directly overhead. Only on the two days of equinox will the sun pass directly overhead at noon. Of course the days right before and after those two days of equinox the human perception of the sun being directly overhead will be undistinguishable. I hope this helps.

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