The Sidereal Day is 4 minutes shorter than the Mean Solar Day, because the rotation of the Earth on its axis, and the orbiting of the Earth around the Sun, are both counterclockwise, as viewed from above (or north of) the Ecliptic Plane. See planetary retrograde motion for an example of the opposite situation.
The reason that the Solar Day varies around the Mean Solar Day is that the Earth moves at different speeds through its orbit around the Sun. This is in keeping with Kepler's Second Law of Planetary Motion.
Please note that the Mean Solar Day changes over a long period of time, due to the slowing of the rotation of the Earth due to tidal forces exerted on the Earth primarily by the Moon. For example, the Mean Solar Day was about 23 hours about 250 million years ago.
To answer the question what is 77800000 in scientific notation let’s recall how to convert 77800000 to scientific notation as detailed on our home page.
When you split the number 77800000 into a coefficient and a power of 10 you do get 77800000 in exponential form, but there is an indefinite number of possibilities.
As you probably want 77800000 in normalized scientific notation, the coefficient or significand of 77800000 in scientific notation must be in the interval [1,10[.
As there are many ways to express 77800000 in scientific notation, in this post we mean 77800000 in normalized scientific notation, unless stated otherwise. Therefore:
77800000 in scientific notation = 7.78 × 107.
