Orbit
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If you have an Android device there is a game called Orbit that you should be able to get from the google play store for free. It's a simple game and all you need to do is get satellites into orbit around a planet - it's not easy and quite addictive(so beware...).
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
Linky?
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My dilemma today is why do things orbit other things - moons, planets, satellites, that sort of thing. If something in orbit around the earth gets too close it falls to the ground/burns up etc. Too far away and the thing will just keep going under its own momentum and disappear into space. So, there must be an exact distance where these two opposing concepts balance themselves out and things orbit happily. But for that to work, everything would have to be exact, which it isn't. Maybe orbits are just transitory things which happen for a bit but they're the only things we can see. If everything just drifted all over the place in space there wouldn't really be any structure. What's going on?
Regards, Rob Philpott.
What I find mind blowing is the "window" for a rocket launch to orbit. I know the physics, I know the mathematics, but still it does not seem right. Too many Star Wars movies I guess. :)
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My dilemma today is why do things orbit other things - moons, planets, satellites, that sort of thing. If something in orbit around the earth gets too close it falls to the ground/burns up etc. Too far away and the thing will just keep going under its own momentum and disappear into space. So, there must be an exact distance where these two opposing concepts balance themselves out and things orbit happily. But for that to work, everything would have to be exact, which it isn't. Maybe orbits are just transitory things which happen for a bit but they're the only things we can see. If everything just drifted all over the place in space there wouldn't really be any structure. What's going on?
Regards, Rob Philpott.
One thing orbits another because it's curious and doesn't want to get to close but by the time it realizes it sucks it's to late?
VS2010/Atmel Studio 6.1 ToDo Manager Extension
It's not the destination, it's the journey. -
As explained elsewhere, the dissolution of the orbit would occur over such a time frame that other factors would be greater. qv by the time the moon has moved sufficiently far from the earth for the gravitation to be negligible, the sun would be a brown dwarf.
Mark_Wallace wrote:
If a constant force is used to overcome friction, there's no acceleration
If we are talking Maths here that that is irrelevant, and even in the real universe it would be such a small amount as to be safely ignored. When you consider how long the universe has been around, the friction of matter in the otherwise vacuum of space doesn't amount to a hill of beans. I would be more concerned with the effects of relativity rather than the tiny perceived friction of particles. Also, there is no such thing as a vacuum, as a vacuum would not contain energy or gravity or time, and it has to have somewhere to 'be'. This level of conceptual physics is probably beyond most people here, and I certainly do not understand the concept of non-spacetime volumes within a multi-dimensional universe. It is entirely probably that we do not live in a Minkowski universe, it is just that assuming we do makes the maths easier.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
Dalek Dave wrote:
I certainly do not understand the concept of non-spacetime volumes within a multi-dimensional universe.
Then you need to enter better search strings into Google.
I wanna be a eunuchs developer! Pass me a bread knife!
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One thing orbits another because it's curious and doesn't want to get to close but by the time it realizes it sucks it's to late?
VS2010/Atmel Studio 6.1 ToDo Manager Extension
It's not the destination, it's the journey.Ah, that explains the Justin Bieber fan club.
I was brought up to respect my elders. I don't respect many people nowadays.
CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier -
Mark_Wallace wrote:
It's called whatever I bloody well decide to call it, especially in the context of a discussion board, where such frippery is not relevant.
Google again, you'll find that there are several ways of describing/naming it.+5 purely on that! I raise a :java: in your direction
Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch
So that's how the coffee got onto my nice white shirt! I knew I hadn't dribbled.
I wanna be a eunuchs developer! Pass me a bread knife!
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Ah, that explains the Justin Bieber fan club.
I was brought up to respect my elders. I don't respect many people nowadays.
CodeStash - Online Snippet Management | My blog | MoXAML PowerToys | Mole 2010 - debugging made easier:laugh: Yeah they ought to call it the Bieber effect?
VS2010/Atmel Studio 6.1 ToDo Manager Extension
It's not the destination, it's the journey. -
My dilemma today is why do things orbit other things - moons, planets, satellites, that sort of thing. If something in orbit around the earth gets too close it falls to the ground/burns up etc. Too far away and the thing will just keep going under its own momentum and disappear into space. So, there must be an exact distance where these two opposing concepts balance themselves out and things orbit happily. But for that to work, everything would have to be exact, which it isn't. Maybe orbits are just transitory things which happen for a bit but they're the only things we can see. If everything just drifted all over the place in space there wouldn't really be any structure. What's going on?
Regards, Rob Philpott.
Rob Philpott wrote:
What's going on?
Seeing noone has mentioned this (I think). http://en.wikipedia.org/wiki/N-body_problem[^]
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Linky?
“That which can be asserted without evidence, can be dismissed without evidence.”
― Christopher Hitchens
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Pete O'Hanlon wrote:
You're correct in thinking that there's a sweet spot, and also that orbits are transitory
Er...I think not. There are millions of possible orbits, billions, trillions... There is no 'Sweet spot', so long as the orbiting body has a tangential velocity between the upper and lower ranges then it will orbit. If the 'sweet spot' existed then orbits would be rare rather than exceedingly commonplace. As for the transitory nature, well, yes, I suppose the Universe will end one day. In a two satellite system the harmonics are such that eventually one of the orbiting bodies will crash into the planet (this is inevitable owing to gravitational harmonics), one of the bodies slows the other, causing it to fall in, and 'steals' that angular momentum for itself, thus speeding up and moving outward. Once the collision takes place the system reverts to a stable single orbit system. In the Earth Moon system for example, the moon is racing away at the rate of several centimetres a year, but it will be BILLIONS of years before this becomes a problem. In fact the sun will have shrunk to a brown dwarf which will be rather more problematic than the prospect of losing a moon.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
Off topic, you have mentioned in the past you are doing an OU Biology degree, I seem to remember you saying you did Physics at Uni, you are an EX Royal Engineer, what the elephant are you doing as an Accountant? It's just from some of things you say it appears that Accountantcy is a waste of your talents:confused:
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Off topic, you have mentioned in the past you are doing an OU Biology degree, I seem to remember you saying you did Physics at Uni, you are an EX Royal Engineer, what the elephant are you doing as an Accountant? It's just from some of things you say it appears that Accountantcy is a waste of your talents:confused:
glennPattonWork wrote:
what the elephant are you doing as an Accountant?
Too stupid to do much else that pays as well and lets me get away with doing very little actual work. EDIT: It was a poor degree, I only got a Desmond. I am hoping for a Geoff this time round.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
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glennPattonWork wrote:
what the elephant are you doing as an Accountant?
Too stupid to do much else that pays as well and lets me get away with doing very little actual work. EDIT: It was a poor degree, I only got a Desmond. I am hoping for a Geoff this time round.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
Me, I got a third Bronze Swimming Cert. strangle after my first job no one been interested other than "oh good you have a degree"
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No. (Get some brain plasters ready). The Moon orbits the earth. It does so because the Earth is pulling it gravitationally. The Moon would carry on in a straight line if it were not for this pull so it is therefore ACCELERATING toward the Earth. However, because it is now travelling slightly faster, the orbit diameter increases. Therefore, and this is where non-physicists have a conniption fit, it is constantly moving away from the Earth as it constantly accelerates toward it. The reason it does not crash into the Earth is because the tangential velocity is greater than the terminal gravitational velocity. Remember that virtually no orbits are circular, so be mindful of Kepler's Laws of Motion. The nearer something is, the fast it has to orbit to avoid collision, which is why the inner planets orbit much quicker than the outer ones. And in an elliptical orbit, the orbiting body moves much more quickly as it passes the major loci than at other times.
Rob Philpott wrote:
So, there must be an exact distance where these two opposing concepts balance themselves out and things orbit happily.
No, all things in the universe are gravitationally attracted to all other things, and the laws of orbital mechanics show there are a vast array of areas of orbital possibility. Think about how relatively small our galaxy is, and how far away it is from all the other galaxies. They are all (with the exception of Andromeda) flying away from us at great speed. And yet, our 'Local Group' is orbiting a centre of gravity that is itself being pulled, along with the rest of our cluster, toward The Great Attractor.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
Dalek Dave wrote:
The nearer something is, the fast it has to orbit to avoid collision, which is why the inner planets orbit much quicker than the outer ones.
Nope. The outer planets are just lazy and figure they are so far away no one will notice them taking their sweet time about it.
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My dilemma today is why do things orbit other things - moons, planets, satellites, that sort of thing. If something in orbit around the earth gets too close it falls to the ground/burns up etc. Too far away and the thing will just keep going under its own momentum and disappear into space. So, there must be an exact distance where these two opposing concepts balance themselves out and things orbit happily. But for that to work, everything would have to be exact, which it isn't. Maybe orbits are just transitory things which happen for a bit but they're the only things we can see. If everything just drifted all over the place in space there wouldn't really be any structure. What's going on?
Regards, Rob Philpott.
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I see what you say. Obviously the Gravity would be a constant force, I was referring to the force applied to impart a vector other than toward the other body. Try working out the orbits of a three body system. Seriously difficult (and chaotic) and, sadly well beyond my limited ability.
--------------------------------- I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave CCC Link[^]
Dalek Dave wrote:
Try working out the orbits of a three body system. Seriously difficult (and chaotic) and, sadly well beyond my limited ability.
Good luck trying to figure out the three-body problem:
Wikipedia:
In 1887, mathematicians Ernst Bruns and Henri Poincaré showed that there is no general analytical solution for the three-body problem. The motion of three bodies is generally non-repeating, except in special cases.