why is there 24 hrs in a day?

Answer 1

There are twenty-four hours in a single day, as that is the duration required for the Earth to complete an entire revolution on its axis. There are 365 days in a year; however, the Earth requires 365.25 days to revolve around the sun, which justifies the event of periodic leap years.

Answer 2

That is a good question which is difficult to answer with real certainty. Some will say that there are 24 "hours" in an entire day (and night) because it requires that much time for a star to transit the meridian (a line drawn in the sky from directly North to direct South.) Nevertheless, why "24" hours?...rather than the entire day and night being divided into a time equation where an "hour" is actually 120 minutes rather than 60? This must be relative to the circumfrance of the Earth which is approximately 24,000 miles. It requires the Earth upon it's axis to turn a full 1,000 miles (at the Equator) for every hour of time. Exactly how the Ancients figured this out is unknown to me (never researched it), but it is nevertheless accurate.

Answer 3

day

The sidereal day is the time required for the Earth to rotate once relative to the background of the stars—i.e., the time between two observed passages of a star over the same meridian of longitude. The apparent solar day is the time between two successive transits of the Sun over the same meridian. Because the orbital motion of the Earth makes the Sun seem to move slightly eastward each day relative to the stars, the solar day is about four minutes longer than the sidereal day; i.e., the mean solar day is 24 hours 3 minutes 56.555 seconds of mean sidereal time; more usually the sidereal day is expressed in terms of solar time, being 23 hours 56 minutes 4 seconds of mean solar time long. The mean solar day is the average value of the solar day, which changes slightly in length during the year as Earth's speed in its orbit varies.

The solar day is the fundamental unit of time in both astronomical practice and civil life. It begins at midnight and runs through 24 hours, until the next midnight.

hour

in timekeeping, 3,600 seconds, now defined in terms of radiation emitted from atoms of the element cesium under specified conditions. The hour was formerly defined as the 24th part of a mean solar day—i.e., of the average period of rotation of the Earth relative to the Sun. The hour of sidereal time, 1/24 of the Earth's rotation period relative to the stars, was about 10 seconds shorter than the hour of mean solar time.

In even earlier systems of timekeeping, an hour was 1/12 of a period of daylight or darkness—hence, variable in length with seasonal changes in the length of day and night. The custom of dividing the cycle of day and night into 24 periods seems to have originated with the ancient Egyptians.

Answer 4

Erm... because the earth takes 24 hours to turn one time?

Answer 5

Because that is approximately how long it takes the Earth to revolve once about its axis.

Answer 6

That's life

Answer 7

that's the approximate time (not exact) it takes the earth to turn on its axis once.

Answer 8

Because if it were different - I'd have to buy a new clock

Answer 9

ur so kind. wasting ur points so we can get 2. ty =D

Answer 10

that is just a waste of points. what a stupid question