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brush

(57,498 posts)
Wed Feb 8, 2023, 08:36 PM Feb 2023

DU 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?

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rickford66

(5,666 posts)
4. For one thing his equations for gravity.
Wed Feb 8, 2023, 09:29 PM
Feb 2023

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.

Jim__

(14,456 posts)
5. Newton's cannonball
Wed Feb 8, 2023, 09:30 PM
Feb 2023

There are diagrams at the site. From wikipedia



...

In this experiment from his book (pp. 5–8),[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.

...

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.

...

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.

...

usonian

(13,809 posts)
6. This is a bit geeky, but it tries to explain circular motion as a consequence of Newton's laws.
Wed Feb 8, 2023, 09:37 PM
Feb 2023
Uniform Circular Motion

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)
7. Thank you. I just get curious at times how things work...
Wed Feb 8, 2023, 09:43 PM
Feb 2023

and usually someone on DU has answers.

usonian

(13,809 posts)
10. So did I at an early age. That's why I majored in physics.
Wed Feb 8, 2023, 09:50 PM
Feb 2023

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!

usonian

(13,809 posts)
13. No, I graduated about a year early, because I started first grade at the tail end of the cutoff.
Thu Feb 9, 2023, 12:55 AM
Feb 2023

Eveyone else was up to a year older.
No biggie.

slightlv

(4,325 posts)
11. Wow...
Wed Feb 8, 2023, 11:04 PM
Feb 2023

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)
14. I used to watch the Cosmos shows (now you can watch the videos) by Carl Sagan
Thu Feb 9, 2023, 01:17 AM
Feb 2023

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.

intrepidity

(7,892 posts)
16. I put your question to ChatGPT, fwiw...
Thu Feb 9, 2023, 12:14 PM
Feb 2023

Revolving or rotating energy has been an integral part of the universe since the dawn of time. It is the basis of the fundamental laws of motion, such as inertia, centripetal force and centrifugal force. These laws describe how objects move and interact with one another in their environment. It is also the basis of the conservation of angular momentum, which is the sum of the angular momentum of each object in the system.

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.

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