DESCRIPTION:
Since Earth completes one revolution around the sun in 1 year, it would make sense
to think that after the completion of year, Earth would be exactly at the same spot
where it was at the beginning of the year, wouldn't it? But is it actually true?
TRANSCRIPT:
Earth takes 365 days to complete one revolution around the Sun which means that it traces
the entire length of its orbit in that time. So, does this mean that during its never-ending journey
around the Sun earth comes back to the exact same spot on your birthday every year?
That's pretty special if you think about it right. Earth is very punctual in its habits.
Our planet takes 24 hours to rotate once on its axis, and 365 days to complete one revolution
around the central star of our solar system, the Sun, only. It's not exactly 365 days.
It's a tad bit more than that the exact time taken by Earth's travel around the Sun one time comes
out to be three hundred and sixty five point two four to one eight nine one days which is generally rounded off to 365.25 or 365 days and six hours.
Thus, in one year earth takes 365 days and six hours to complete one revolution around the Sun.
If earth were to take precisely 365 days to complete one revolution then theoretically it could be
said that the planet is at exactly the same spot in its orbit each year on your birthday; however,
since it takes an additional six hours to complete a full circle around the Sun. It's impossible for
the planet to be at the same spot every year on your birthday or on any other date whatsoever.
Those extra six hours really complicate things.
They can't just be ignored as doing that would miss calibrate our calendars to such an extent that
they eventually wouldn't work in sync with the seasons, and by extension plenty
of other things based on seasons would cease to line up properly. That's why, simply
neglecting those extra six hours is just not an option.
They must be accounted for somehow if you're wondering that's why leap years are a thing you
see the calendar that we use all over the world. Today, the Gregorian calendar only shows 365 days
in a year and not the surplus six hours as a result, the extra six hours will accumulate each
year and after every four years. Those extra six hours total 24 hours or in other words a full day
this extra day is called a leap day and the year in which the day is added to the month of February is called a leap year. However, February twenty-ninth is not an extra day in our lives. It's simply a
mathematical trick we play to make sure our calendars remain in sync wit Earth's movement
which ultimately makes our lives easier.
However, even if Earth took exactly 365 days to complete one revolution around the Sun.
It still wouldn't be at the exact same spot in space, as it was a year ago. Remember that
our entire solar system including the Sun Earth and all the other celestial bodies it contains is
moving as a single entity around the central black hole of the Milky Way. The whole solar system
is also moving very fast with an average velocity of eight hundred and twenty eight thousand
kilometers per hour yet even at that incredible speed.
It still takes our solar system roughly 230 million years to complete a single revolution around the Milky Way. So, Earth does not come to the same spot in space on your birthday every year rather it continues
to hurtle through space at an extreme speed. Never truly occupying the same location twice while simultaneously circling our beloved sun.
QUESTIONS:
1. How long does Earth take to complete one revolution around the sun?
2. Do you think Earth comes back to the same spot every year on any given
day, say, your birthday? Why to you think so?
3. If the Sun disappeared completely, what would happen to the
Earth and the rest of our solar system?