![]() There are two days during the year when both night and day are roughly 12 hours long.ĭespite the word equinox coming from the Latin words for 'equal' and 'night', those two days do not fall on the equinoxes. There are only three factors that matter in balancing eggs: the stability of the surface you are using, the 'bumpiness' of the eggs being balanced, and the steadiness of your hands. For something as small as an egg, their effect is so weak that it can be considered negligible. However, the tides only occur due to the cumulative effect of these objects pulling on immense bodies of liquid. The Moon's gravity is the next strongest influence, followed by the Sun, and they are the reasons for our ocean tides. Secondly, Earth's gravity completely overwhelms any other gravitational forces experienced here on the planet's surface. Visit our Complete Guide to Fall 2021 for an in depth look at the Fall Forecast, tips to plan for it and much more! RELATED VIDEO: THE SCIENCE BEHIND SCIENCE HOAXES For example, in 2023, the equinoxes will be on March 20 and September 23, and in 2024, they'll occur on March 19 and September 22. Right now, in 2021, we are in the part of this cycle were we will mostly see the equinoxes happen on March 20 and September 22. Other times, the March equinox will fall on the 20th, year after year for decades, while the September equinox drifts back and forth between the 21st and 22nd, or the 22nd and 23rd. Sometimes the March equinox will flip back and forth between the 20th and 21st, or the 19th and the 20th, on a year to year basis, while the September equinox consistently occurs on the 22nd. These dates shift, though, moving forward and backward on the calendar by a day or so, on a cycle that lasts for more than a century. In the northern hemisphere, the vernal equinox typically occurs on the 20th of March, and the autumnal equinox usually happens on the 22nd of September. Due to the fact that our orbit around the Sun doesn't always take exactly the same amount of time, year-to-year, and also due to the way we tick off our calendar, the timing of the equinoxes changes. Those two brief moments don't always happen at the same time and day every year, though. WATCH BELOW: This animation shows Earth's tilt throughout the year, which gives rise to our changing seasons. ![]() The bottom right panel shows the angle at the point where the stick figure is standing, at roughly 44 degrees North latitude. The panels on the right show how this affects the angle of the sunlight falling on Earth. Each hemisphere ends up pointed most towards the Sun during its summer solstice and pointed furthest away from the Sun at its winter solstice. It's this change in angle that is ultimately responsible for the changing of the seasons.Īs the video below shows, as Earth travels around the Sun, the angle of the planet's axis stays the same. Perhaps the most directly noticeable effect, which can be tracked on a day-to-day basis, is how high the Sun reaches in our sky throughout the year. While we don't feel the tilt itself, we see its effects. It's this consistent tilt, along with our world's motion around the Sun, that are the reasons for our seasons. Earth's tilt remains the same all year long, with the planet's axis always pointing out of the North Pole towards a star named Polaris. ![]() The planet does not 'wobble' back and forth by 23.4 degrees during the year, though. As the Earth traces its elliptical path around the Sun every year, the axis it rotates around each day is tilted with respect to that path, by roughly 23.4 degrees. When you look at it from afar, though, our entire world is slightly off-kilter. Standing here on Earth's surface, nothing may seem particularly out of the ordinary. September 22nd is the Autumnal Equinox for 2021, the fall season's start for the northern hemisphere. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |