Is this orbit possible?

[cicatrix]

Am I right thinking that this kind of orbit is impossible to achieve:

[andrewas]

Yes, that one's impossible. The primary is at one focus of the ellipse, not at the center.

[UmbralRaptor]

It's somewhat infamous for being perfectly possible, provided gravity scales with 1/r instead of 1/r².

[Nibb31]

You can only have one periapsis and one apoapsis. Your orbit has two of each, which is impossible.

[Bill Phil]

No...

Which is good. Having orbits like that would just be, confusing.

[PB666]

It's somewhat infamous for being perfectly possible, provided gravity scales with 1/r instead of 1/r².

It is possible if there is Bosian mass at one of the F , and the object at C is half composed of negative energy. lol, lets start this discussion again. Then the orbit would only have one periapsis and one apoapsis. IOW if it is possible for a warp field to exist, it is also possible for this orbit to exist.

Also you can rotate the plane of a circular orbit by 80' and look at it from an angle, it may not be possible, but it would sure look possible.

[Frida Space]

Generally speaking, orbits are ellipses with the parent body in either of the two foci, not at the center (unless it's a perfectly circular orbit, but then again a circle is just an ellipse with e = 0)

Edited March 13, 2015 by Frida Space

[Bill Phil]

Generally speaking, orbits are ellipses with the parent body in either of the two focuses, not at the center (unless it's a perfectly circular orbit, but then again a circle is just an ellipse with e = 0)

Sir, it's foci.

[RainDreamer]

Can it be possible due to some other outside factors like extra bodies around it though? Probably won't be stable, but, is it?

[KSK]

It is possible if there is Bosian mass at one of the F , and the object at C is half composed of negative energy. lol, lets start this discussion again. Then the orbit would only have one periapsis and one apoapsis. IOW if it is possible for a warp field to exist, it is also possible for this orbit to exist.

Also you can rotate the plane of a circular orbit by 80' and look at it from an angle, it may not be possible, but it would sure look possible.

Low quality troll. 3/10 - would not read again.

Is it some strange compulsion that you have to go wildly, pointlessly and unhelpfully off-topic on every Science forum thread that you post in?

[Beowolf]

Low quality troll. 3/10 - would not read again.

Is it some strange compulsion that you have to go wildly, pointlessly and unhelpfully off-topic on every Science forum thread that you post in?

I disagree. What you call pointless I call "learning something new".

[Frida Space]

Sir, it's foci.

I'm sorry, i'm not English (I know it's a latin word, I actually know Latin really well, but I didn't think English kept the Latin plural termination)

[ZetaX]

I disagree. What you call pointless I call "learning something new".

How is an unfounded post mostly composed of technobabble "learning something new"¿ For example, why is having "Bosian mass" (bosonic?) relevant, why not any other normal type of mass¿ What does it even mean for a planet to be composed of negative energy¿ And the post also claims that there then is only one apoapsis, so it surely cannot be that orbit anyway.

[K^2]

It's somewhat infamous for being perfectly possible, provided gravity scales with 1/r instead of 1/r².

You are mistaken. The gravity must scale as r instead of 1/r² to produce an ellipse centered at the body. 1/r produces completely different orbits, most of which are not closed.

[Jovus]

The gravity must scale as r instead of 1/r² to produce an ellipse centered at the body. 1/r produces completely different orbits, most of which are not closed.

Which doesn't make it an impossible shape in real life. If we replace the word 'gravity' with 'force', and then construct a system where an object is, say, on the end of a spring, this is a perfectly possible 'orbit'.

Newton wasn't being silly when he developed the Principia. (Unless you ask him; he says he was.)

[Bill Phil]

I'm sorry, i'm not English (I know it's a latin word, I actually know Latin really well, but I didn't think English kept the Latin plural termination)

English is weird. I often think that Kindergarten English sometimes makes more sense.

Yes, the plural of focus is foci, we keep Latin words for some reason.

[ZetaX]

English is weird. I often think that Kindergarten English sometimes makes more sense.

Yes, the plural of focus is foci, we keep Latin words for some reason.

AFAIK, "focuses" is also fine.

[lajoswinkler]

I'm sorry, i'm not English (I know it's a latin word, I actually know Latin really well, but I didn't think English kept the Latin plural termination)

English is weird. I often think that Kindergarten English sometimes makes more sense.

Yes, the plural of focus is foci, we keep Latin words for some reason.

No, focuses is fine enough. Viruses, cactuses.

[PB666]

Low quality troll. 3/10 - would not read again.

Is it some strange compulsion that you have to go wildly, pointlessly and unhelpfully off-topic on every Science forum thread that you post in?

That gave me such a good laugh . . . . . . . . I take it you've had your lemon juice this morning.

Heaven forbid we git a little wild on a topic discussing a physical impossibility.

[UmbralRaptor]

You are mistaken. The gravity must scale as r instead of 1/r² to produce an ellipse centered at the body. 1/r produces completely different orbits, most of which are not closed.

Doh. So this sort of ellipse should show up if one abused a hooke's law problem enough?

[YNM]

I don't know was bosian a troll or not. But bosons... Ah, not the thread.

Could be possible depends on the forces. But for gravity, you can't - the energy conservation would be quite weird. Other possibility are creating a hole right through Earth's poles - your trajectory will actually be a degenerate ellipse. Or other orbits passing through the middle of a circular ring or cylinder.

Something which might holds true is that a parabolic orbit doesn't need to have it's focus on the parent body. I haven't updated anything about that through.

[Jovus]

Doh. So this sort of ellipse should show up if one abused a hooke's law problem enough?

Yes. That's the easiest example.

[ZetaX]

Something which might holds true is that a parabolic orbit doesn't need to have it's focus on the parent body. I haven't updated anything about that through.

No, it should also be restricted to the focus. The same goes for hyperbolas.

But truly parabolic orbits (e=1) should, like circles (e=0), not exist.

[Kerbart]

You could do a circular orbit and then look at it from an angle.

Does that help?

[WestAir]

You could do a circular orbit and then look at it from an angle.

Does that help?

Sure. It would just go really really fast at D and really really slow at C.