Science
Related: About this forumDU scientists/astronomers: Would someone pls expound on how...
revolving/rotating energy seems to be a prevalent building block of the universe (another post here just discussed that a dwarf planet in the trans-Neptune region has a ring).
And also what theory was understood by Russian scientist/other scientists in knowing that Sputnik would revolve around the earth when it was launched way back then?
rickford66
(5,666 posts)brush
(57,498 posts)rickford66
(5,666 posts)Any HS physics student could solve the equations for a satellite. FYI the Moon is a satellite and it was well known since Newton's time how a satellite revolves around the Earth.
brush
(57,498 posts)Jim__
(14,456 posts)There are diagrams at the site. From wikipedia
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In this experiment from his book (pp. 58),[2] Newton visualizes a stone (you could also use a cannonball) being projected on top of a very high mountain. If there were no forces of gravitation or air resistance, the body should follow a straight line away from Earth, in the direction that it was projected. If a gravitational force acts on the projectile, it will follow a different path depending on its initial velocity. If the speed is low, it will simply fall back on Earth. (A and B) for example horizontal speed of 0 to 7,000 m/s for Earth.
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If the speed is the orbital speed at that altitude, it will go on circling around the Earth along a fixed circular orbit, just like the Moon. (C) for example horizontal speed of at approximately 7,300 m/s for Earth.
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If the speed is higher than the orbital velocity, but not high enough to leave Earth altogether (lower than the escape velocity), it will continue revolving around Earth along an elliptical orbit. (D) for example horizontal speed of 7,300 to approximately 10,000 m/s for Earth.
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sorcrow
(511 posts)usonian
(13,809 posts)The point is that the same laws apply to satellites, CD's, atoms ...
An object in circular motion is falling towards the object that's attracting it, and at the same time, being pushed away from it by the energy it was propelled with. The only way to balance this is to rotate. (It it wasn't propelled, it would just fall, like the proverbial apple from a tree.
Most stuff in the universe rotates. We are right now rotating around the sun, and the sun is rotating around the center of the galaxy and so on.
brush
(57,498 posts)and usually someone on DU has answers.
usonian
(13,809 posts)But other stuff paid real money. Physics is a great foundation for anything scientific. I also took stuff apart, much to the consternation of parents and uncles and aunts. Most of it went back together ok.
Stay curious!
brush
(57,498 posts)graduated from college.
usonian
(13,809 posts)Eveyone else was up to a year older.
No biggie.
I never thought about Earth and the Sun revolving around the center of the Universe. Do I feel dumb, or what?! (LOL) And I LOVE Astronomy! Physics is truly interesting, as well... but most of it goes way over my head.
usonian
(13,809 posts)So long ago I forgot, but they are probably good explainers.
I seriously used to enjoy simple physics and astronomy books. They got me going.
Like 1,2,3, Infinity by George Gamow (very dated, but so am I)
Cheers.
slightlv
(4,325 posts)LOL. I find myself more and more like that everyday!
intrepidity
(7,892 posts)On a larger scale, revolving or rotating energy can be seen in the orbits of the planets around the Sun, in the rotation of galaxies, and in the ring systems of some of the outermost objects in the Solar System. The recent discovery of a ring system around a trans-Neptune object is a great example of how revolving energy can manifest itself in the universe.
The idea that revolving or rotating energy could be used to propel a spacecraft was understood by the Russian scientist Konstantin Tsiolkovsky in the late 19th century. He proposed that a spacecraft could be launched into a circular orbit around Earth by spinning it on its axis. This concept was later adopted by the Soviet Union when they launched the first artificial satellite, Sputnik, in 1957. Sputnik was spun on its axis as it was launched, allowing it to enter a stable orbit around Earth. This demonstrated the potential of revolving or rotating energy in space travel and exploration.
brush
(57,498 posts)to learn.