There is a very short time to 29 February . Before we came to February 29, now called the Day, we wanted to share the science behind this Now Day.
February 29 was added to the calendar, taking into account the Earth's rotation around itself and the rotation around the Sun. February 29, if it weren't really on our calendar, we wouldn't have a calendar based on Earth's movements. So Now Day is one of the important pillars of our calendar . Let's look at the eight scientific facts behind Day 29 February.
The Earth's movement has two basic parts: it revolves around itself and the Sun revolves around it. Typically, we think of the Earth turning around itself as 24 hours, and the rotation around the Sun as 365 days.
Since these two movements of the world take place together, they cannot actually be considered separately. If the Earth rotated around itself, remaining in the exact same position, a 360 ° turn would equal a full day, that is 24 hours. However, the 24 hour turn time is not really equal to a 360 ° turn. The world revolves around itself in 23 hours, 56 minutes and 4 seconds .
However, as the Earth revolves around itself, it must rotate one more time so that the Sun revolves around it, so that it can be relatively the same. Therefore, one day is on average 24 hours.
Have you noticed that the sun rises at the earliest and the sunset does not occur on the summer solstice, and that the sun rises at the latest and does not fit the winter solstice of the earliest sunset? This is because the Earth orbits the Sun in an elliptical orbit . In other words, the Earth performs its fastest movement at the point where it is closest to the Sun (perihelion), and the slowest movement at the point where it is the farthest from the Sun (aphelion).
When you combine the Earth's movements at the moments closest and farthest to the sun with the fact that it does not match the equinoxes, you will find that some days are shorter than 24 hours and some other days are slightly longer than 24 hours.
In fact, the 24-hour day is an average of the days of an entire year. However, the Earth will never complete its rotation around itself in exactly 24 hours .
In Astronomy, the Earth's return to its starting point while rotating around the Sun is considered a complete tour . Astronomy is also called this full tour star year. To sum up, a full round of Earth around the Sun is called a star year.
However, a star year is not equal to a calendar year. As the earth revolves around the Sun, it also continues to revolve around itself. However, the Earth's axis also progresses over time. So a world based on the previous year when the tour finished astronomical position , may be slightly different than the sun. There is a difference of approximately 20 minutes between a star year and a calendar year.
To put it in full disbelief, a calendar year is actually 365,242188931 days. This is not an exact number. Every year here was hesaplans as 365 days per century, starting one month longer time out would come.
If we put the Leap Day in the calendar every four years, the years would be 365.25 days on average . Although this is not exactly correct, it is a number close to a full year. A Leap Day was put in the Julian Calendar, which was used until the 16th century. However, since a calculation in the Gregorian Calendar was not included in this calendar, more days began to appear in the Julian Calendar.
Italy, Poland, Spain and Portugal; This is why he ignores between 5 and 14 October 1582 . Other countries skipped these days later. For this reason, Isaac Newton's birthday was set as December 25 in the UK, while it was recorded as January 4 in other countries.
A perfect solution was found to compensate for the mismatch caused by the combined action of the Earth in calendars. One day was added to each year that can be divided by 4. But when the days that can be divided by 100 and can not be divided into 400 are not added anymore, the problem of excess days has been solved.
According to this calculation, 2004, 2008, 2012, 2016 and 2020; they are now years since they can be directly divided into 4. The year 2000 is now a year, but 1900 is not a year, though it can be divided into 4. Because the year 1900 is not divided into 400 .
If everything on Earth was fixed, the calendar we are using now would be a perfect calendar . However, whenever an earthquake occurs, the rotational speed of the Earth accelerates a bit. However, this increased speed is tolerated due to the gravitational effect of the Sun and Moon on Earth.
This deceleration effect is known as tidal braking and affects 12 microseconds per year . This number can be seen as a negligible number. But over time it becomes a huge number. According to calculations, 620 million years ago, one day of the Earth was a little shorter than 22 hours . When the world first formed, it was only 6 to 8 hours a day.
The extraordinary effect of tide braking will become more and more important over a thousand years. We are currently adding one second every 18 months to eliminate this effect. However, the days continue to grow. Therefore, 4 million years later , it will be necessary to add times equal to a calendar year .
At this point, we will have to make changes to the calendars. As one of the approaches, the number of days can be reduced or days can be eliminated as it will be completely unnecessary .
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