And our days will continue to lengthen
Download 13.69 Kb.
|
atg-worksheet-presentperfect-20210908, PLAN ANIVERSARIO XIV
|
In physics, gravity (from Latin gravitas 'weight') is a fundamental interaction which causes mutual attraction between all things that have mass. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a result, it has no significant influence at the level of subatomic particles. However, gravity is the most significant interaction between objects at the macroscopic scale, and it determines the motion of planets, stars, galaxies, and even light. On Earth, gravity gives weight to physical objects, and the Moon's gravity is responsible for sublunar tides in the oceans (the corresponding antipodal tide is caused by the inertia of the Earth and Moon orbiting one another). Gravity also has many important biological functions, helping to guide the growth of plants through the process of gravitropism and influencing the circulation of fluids in multicellular organisms. While our days are 24 hours long (23 hours and 56 minutes to be precise), those of Jupiter , the fastest rotating planet, are 10 hours long. Interestingly, Earth's days used to be shorter than that , but ever since it has liquid oceans and a moon, its rotation has been slowing down due to tidal friction. That is to say that for long, very, very long periods of time the days have been getting longer. About 4.5 billion years ago, it took Earth only 6 hours to complete its rotation. And our days will continue to lengthen. There are three other planets with days shorter than Earth: Saturn : about 11 hours Neptune : about 16 hours Uranus : about 17 hours. The planet that rotates the slowest and has the longest day is Venus . It takes 243 Earth days to comple… Gravity, that force that acts between all objects, is what keeps all the planets moving around the Sun. The length of the year depends on how far away the planet is from our star: the further away it is, not only does it travel further, but it travels slower. Therefore, the difference is enormous. It takes Earth about 365 days to complete the journey ; to Mercury -the closest to the Sun-, 88 days. One year on Neptune , the most distant, is the equivalent of almost 165 our years. In other words, an Earth year is as long as 4.1 Mercury years and just 0.004 Neptunian years Venus is one of Earth's closest neighbors and its years are a bit shorter: it takes 225 days to travel around the Sun. Mars is further from the Sun than Earth and it takes almost two years -1.88- to complete its orbit. The year of the longest planet in the Solar System, Jupiter , lasts 11.86 our years. Ringed Saturn's orbit around the Sun takes almost 30 times longer than Earth's: 29.46 years. And finally, Uranus , which is so far away that it travels 84 our years to complete a single year of its own. Download 13.69 Kb. Share with your friends:
|