The path a body takes while moving through space under the influence of the gravitational forces of other bodies

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41 views

Can an atoms energy levels be changed by changing the de Broglie wavelength of electrons?

So an electron can only orbit a nucleus where its wavelength makes a standing wave, leading to discrete energy levels in atoms. But the de Broglie wavelength of an electron = h/mv. So the wavelength ...
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1answer
57 views

Is it possible to determine the velocity of electron in its orbit?

I read here that the orbital speed of an electron around a proton can be calculated as: $$\frac{m_ev^2}{r} = F_G+F_E$$ where $F_E$ is the proton-electron electromagnetic force, $F_G$ is the ...
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1answer
41 views

Can 4 colinear planets exist?

Imagine 4 planets, A has moon a and B has moon b. A and B are binary planets. Is it possible that a and b and A + B all have same the period, so that the 4 planets are colinear?
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1answer
33 views

Does the mass change for a body with eccentric orbit?

I am a student with a programming and electronics background attempting to recap on orbital mechanics. I would appreciate anyone with a physics specialisation helping me understand where my ignorance ...
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2answers
28 views

Difference between circular motion and rotational motion

Are rotational motion and circular motion different or the same? If different then when can we say that a body is in circular motion, and when it's in rotational motion? I find several answers where ...
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0answers
18 views

Eccentricity of planetary orbits: What information is contained?

I'm having a little trouble understanding what makes a planetary orbit explicitly elliptical. Is it simply that the initial velocity was different from the circular orbit case for a given starting ...
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0answers
28 views

Can a roller coaster accelerate solely due to its weight on the top of a vertical loop?

If it were a string connected to an spinning object, I would have a second thought, because for string there doesn't exist any normal force. But for roller coaster placed on a rail, the rail acts as ...
4
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1answer
54 views

How “large” is a Lagrange point?

When placing an object at a L-point, the natural assumption, as with all things gravity, is that you needn't place it in an exact spot to achieve a stable configuration. How much room do you have to ...
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2answers
51 views

Guidelines for $n$-body problem inital conditions

I'm trying to solve a 5-body problem (for the sake of the argument it can be any given $n$) numerically, yet every initial condition I choose seems to eventually drive the bodies apart to infinity or ...
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1answer
36 views

Rocket thrust over time [closed]

I have calculated the thrust of a rocket, and it's burn time for an orbital manoeuvre. I need to know how much force is applied on the rocket every half-second. How would I go about doing this? ...
0
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1answer
41 views

Orbital Velocity and Tangential Velocity

The tangential velocity of an object is directly proportional to the radius of the circular motion. How come orbital velocity is inversely proportional to the radius?
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1answer
56 views

Which ellipse does the Earth's semi-major axis refer to?

In Wikipedia the semimajor axis of the earth is reported to nine digits of accuracy (nearest kilometer), and the eccentricity to eight. But to which ellipse exactly does that apply? Sun-at-the-focus? ...
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1answer
95 views

Why doesn't the moon crash into the Earth?

I was searching about 'why do not moon crash to earth due to its gravity?'Then by reading physics stake exchange existing questions I came to know that its the sideways motion of the moon that keeps ...
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1answer
30 views

Advent of our solar system

When the solar system was born why did Sun not consume all the planets by its immense gravity, as the planets were all gases, so it would have been very easy?
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1answer
82 views

Acceleration orthogonal to movement direction

I've been told that acceleration orthogonal to an objects movement direction doesn't require energy. Thus when a satellite goes around the earth, the change in direction caused by gravity doesn't use ...
2
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3answers
94 views

Solving the two body problem numerically

I'm trying to solve the two body problem numerically, setting up $G$, $m1$ and $m2$ to be equal to 1. then I located each mass on positions -5 and 5 respectively along the $x$ axis and gave them both ...
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0answers
44 views

Planetary alignment of the gas giants?

There is this nice and new applet of the orbits of the planets around the sun: Solar System Orrery You can click and drag any planet and watch their relative orbits evolve in time. I was curious ...
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3answers
156 views

Infinite acceleration

Let's say we have two planets at a stand still within reasonable distance of each other. They will accelerate towards each other and subsequently collide. If instead we give them a sufficient (but ...
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2answers
42 views

How can contact binaries persist?

This answer discusses contact binaries, which I did not even know existed. I can understand how they could exist for a short time (maybe) as gravitational waves carry off energy that causes the stars' ...
2
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1answer
38 views

What kind of orbit would be needed to map the surface of a nonrotating planet?

I am not a mathematician and it may even take me weeks to understand the math involved but I have an odd question on orbital mechanics that I hope will be worth the experts' time. I am a hobbyist ...
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2answers
114 views

How long will it take before the orbit of the earth is 365 days exactly?

I understand that the number of days per year has changed throughout the history of the Earth. Apparently there were once over 400 days per trip around the sun. How long will it take approximately ...
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0answers
23 views

Calculating initial velocity to achieve orbital motion using verlet integration

I'm attempting to build a simple computer programme which models bodies orbiting other bodies. I've implemented a Verlet integrator (https://en.wikipedia.org/wiki/Verlet_integration) and I can ...
8
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2answers
2k views

Why we don't see time dilation in stars orbiting black hole?

We have images of stars orbiting black holes or black holes destroying near stars, but why do we see the stars moving normally? I mean, if time dilation does exist, shouldn't we see that stars slow ...
3
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1answer
52 views

Can stable non-circular orbits exist in 2 or 3 dimensional hyperbolic space

I know that stable non-circular orbits in euclidean space exist only in 3 spatial dimensions but what about if the spatial dimensions are hyperbolic instead? Are there any stable non-circular orbits ...
3
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1answer
165 views

How does the Pluto-Charon orbital 'dance' affect Pluto's elliptical orbit around the Sun?

Like many Scientists (and people in general), I have been watching the New Horizons mission results with great interest. One aspect in particular caught my attention - the Pluto-Charon orbital ...
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2answers
31 views

Earth “satellite” breadcrumb: Have we ever placed an object orbiting our Sun and the Sun only?

Have we ever placed an object orbiting our Sun and the Sun only? like a breadcrumb of our orbit... I was reading about VLA for satellites and wouldn't this breadcrumb be a viable solution to create a ...
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1answer
32 views

What velocity do I need to get the moons orbit perfectly aligned with the earths center [closed]

I have a simulation for universal gravity with two objects. How can I calculate the velocity or instantaneous force I would need to apply to object 2 (the moon) to get it to orbit so that the origin ...
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0answers
26 views

Central Force Scattering in Goldstein

On page 108 in Goldstein 3rd edition in the paragraph after equation (3.94) he says that $\psi$` can be obtained from the orbit equation (3.36) using the limits as $r_0=\infty$ $r=r_m$ which the ...
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1answer
74 views

How do spacecraft gain kinetic energy by passing near planets? [duplicate]

When a a spacecraft like Voyager travels close to Jupiter, it somehow gains kinetic energy. I'm not sure how this energy isn't simply lost again as it moves away from Jupiter. I'm also hoping this ...
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3answers
123 views

General Relativity 2-Body Closed Form

Is there a closed form solution in general relativity to the 2-body orbit problem?
4
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4answers
134 views

Calculating how fast a mass needs to travel in order to launch itself from a hill

Today I was driving on a hill side and on the opposite lane this very careless gentleman was traveling at a very high speed on a large truck that I surely thought his truck would of lifted off the ...
2
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1answer
99 views

Black Hole surface area at Schwarzschild radius is half?

I have been interested in black holes for some time, and am still trying to wrap my head around some of their more obscure properties. Now I know that the Schwarzschild radius is $r= ...
0
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1answer
55 views

Drag in low earth orbit

So I'm looking at the following problem; Arrow type configuration in orbit. Each end of the arrow has a mass and a cross sectional area (we can assume the head and tail are connected by a ...
0
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1answer
32 views

Can a Space tether be made from AmSteel (Samson Rope’s Dynameen)?

AmSteel is a high strength poly-ethylene fiber. Its strength passes that of stainless 316/8 and is considerably less mass per foot. A 4 inch piece could support a length of 160 miles if the ...
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1answer
34 views

If we were to observe a cluster of planets from a star's magnetic north, which direction would they appear to orbit? Clockwise or counter clockwise?

I have a question, and it's been a topic of great discussion amongst my peers. If we look at galaxies or clusters of planets around stars, they appear to be moving both clockwise and counter ...
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1answer
64 views

What is the velocity of Sun due to Earth alone?

If Earth and Sun were in a isolated system, will the Earth's motion around Sun will be similar? What will be Sun's and Earth's velocity when Earth is at its aphelion? Please note that it's not a ...
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0answers
31 views

Anomalous orbit of pluto [duplicate]

Can anyone explain, why, like unlike all planets, Pluto does not have a regular orbit? Why does it have an orbit that meets the orbit of Neptune? Why does it never collides with Neptune? Is it ...
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0answers
41 views

Hyper/parabolic kepler orbits and “mean anomaly”

In an elliptical kepler orbit there is an easy recipe to describe the motion/position of a satellite at time $t$. One just follows the following steps - an important detail for me is that the ...
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0answers
33 views

Bertrand's Theorem: Perturbative Methods Leading to $1/r^3$ Solution

My professor and I have been working on a proof of Bertrand's Theorem using perturbative methods. We have arrived at a solution yielding 1/r^3, which we had presumed to be an incorrect result. While ...
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2answers
113 views

Does an orbiting body accelerate?

Wikipedia says that : "Transverse acceleration (perpendicular to velocity) causes change in direction. If it is constant in magnitude and changing in direction with the velocity, we get a ...
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2answers
83 views

What is the binding energy in General Relativity?

In general relativity, the potential energy is given by $$V(r)=\frac{h^{2}}{2r^{2}}\left(1-\frac{2M}{r}\right)-\frac{M}{r}.$$ Solving $V^{\prime}(r)=0$, there are two points where circular orbits ...
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1answer
24 views

Rendezvous Orbits [closed]

If I have two orbits, Orbit 1 and Orbit 2, and the spacecraft with Orbit 2 is trying to dock with the spacecraft in Orbit 1, but does not have a stable orbit (it will crash into Earth) how will this ...
2
votes
1answer
38 views

Planetary hohmann transfer epoch [closed]

For an exam I was asked to derive the follow equations for epoch departure $t_1$ and epoch arrival $t_2$. (planet 1 has a smaller orbit, eccentricity/inclination can be assumed 0) $$t_1 = t_0 + ...
7
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2answers
1k views

Do we know what event caused the Sun and Solar System to form?

Some stellar formation theories suggest that stars are formed by shock waves from trigger events such as supernovae. This excerpt from Star Formation basically gives the background to my question: ...
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0answers
43 views

Gravity between Moon and Earth [duplicate]

It's known that the greater the mass the stronger its gravitational force. Hence, Sun's gravity is definitely stronger than Earth's. So the question arises that why does the Moon orbit around the ...
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2answers
40 views

Falling into the sun, a thought experiment for trying to understand reference frames

If someone were transported out into empty space, idk like hundred of thousands of miles straight "up," would they fall into the sun? It would depend on their velocity right? If they were moving at an ...
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1answer
103 views

Calculate orbital changes after acceleration

With the vis-viva equation I can calculate the orbital speed at any position on the ellipse. I want to calculate the opposite way. Assume a satellite with an apogee of 600km and a perigee of 400km is ...
1
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1answer
28 views

How may one calculate the escape velocity of a binary system at a given radius from the COM?

Apologies if this is a bit general, even some pointers in the right direction would be great (reading material etc.) Given an object of mass $m_3$ travelling outward at speed $v$ from the centre of ...
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0answers
40 views

Why does planetary spin affect the stability of orbits?

Reading about the Hill Sphere I notice that "the region of stability for retrograde orbits at a large distance from the primary, is larger than the region for prograde orbits at a large distance from ...
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2answers
61 views

Deriving the velocity for circular orbital motion

I'm trying to derive the (circular) orbital velocity for a given height from the center of mass of a body, like Earth. First I used the equation of the circle $x^2 + y^2 = r^2$ to get $y = \pm ...