Posts by tony873004

by tony873004
20.07.2008, 22:08
Forum: Physics and Astronomy
Topic: How to find Lagrange points???
Replies: 8
Views: 5830

Re: How to find Lagrange points???

I made a javascript calculator to find the Lagrange points:
http://orbitsimulator.com/formulas/Lagr ... inder.html
by tony873004
23.10.2007, 00:24
Forum: Physics and Astronomy
Topic: Earth's water: where did it come from?
Replies: 26
Views: 9611

Re: Earth's water: where did it come from?

I believe the problem with comets is that the water has the wrong isoptotes: too much heavy water. Asteroids would be more likely.
by tony873004
25.07.2007, 17:56
Forum: Physics and Astronomy
Topic: Basic Black Hole Question
Replies: 12
Views: 6498

Re: Basic Black Hole Question

There is also a black hole in every dryer...... :lol: What confuses me about black holes is that 1) nothing can escape the gravity well, and yet 2) Black holes produce xrays which stream away from the event horizon. Now how are the xrays able to do this one? Nothing can escape after crossing the ev...
by tony873004
22.07.2007, 05:11
Forum: Physics and Astronomy
Topic: Gravity Simulation
Replies: 3
Views: 4025

Re: Gravity Simulation

...although he hasn't been very vocal lately... I guess I should post more often :) ...My question is, does anyone know of this program? Is it good and accurate (relative to, say, other freeware)?... It's actually quite good for testing the stability of orbits, in my biased opinion :lol: . You woul...
by tony873004
22.04.2007, 22:28
Forum: Physics and Astronomy
Topic: Could an earth-sized planet have 2 moons?
Replies: 10
Views: 6948

Re: Could an earth-sized planet have 2 moons?

The biggest problem with a natural moon interior to the Moon's orbit is that it is theorized that the Moon was formed just outside Earth's Roche Limit, and spiraled out to its current position. So it would have swept this region clear. It's possible that the Earth had more than one moon billions of ...
by tony873004
27.08.2006, 05:55
Forum: Physics and Astronomy
Topic: A new 4 planet system
Replies: 12
Views: 6356

Re: A new 4 planet system

In table 1 of the journal paper, does anyone know what K and lambda[sub]0[/sub] are? My guess is that K is the observed velocity of the star at time T. And since the star's velocity will be sinusoidally oscillating between 0 and its maximum value, lambda[sub]0[/sub] is the planet's position in the o...
by tony873004
19.06.2006, 16:39
Forum: Physics and Astronomy
Topic: Geosynchronous orbital drop duration and velocity
Replies: 13
Views: 6564

Re: Geosynchronous orbital drop duration and velocity

lol. I didn't even see your post when I posted my sim numbers. How do you integrate the drop?
by tony873004
19.06.2006, 06:18
Forum: Physics and Astronomy
Topic: Geosynchronous orbital drop duration and velocity
Replies: 13
Views: 6564

Re: Geosynchronous orbital drop duration and velocity

This problem either requires calculus or an n-body simulation. Using n-body with Gravity Simulator: Ignoring atmosphere, it would take it 4 hours 7 minutes, 53 seconds to fall from geosychronous orbit, assuming that its orbital velocity was zero. It would be travelling 10.3 km/s as it hit the ground.
by tony873004
24.05.2006, 17:37
Forum: Physics and Astronomy
Topic: An astronomy related quiz - just for fun
Replies: 18
Views: 7589

Re: An astronomy related quiz - just for fun

my guesses (font color = background color) highlight to see.
{

1. Alberito?
2. Saturn
3. White dwarf
4. pulsars
5. organic molecules
6. ejected stars
7. acretion disk of a neutron stars
8. other universes


}
by tony873004
11.02.2006, 20:20
Forum: Physics and Astronomy
Topic: L4/L5 "Halo" orbits
Replies: 5
Views: 4053

Re: L4/L5 "Halo" orbits

Orbits around L4 and L5 points aren't really orbits at all. The object's only true orbit is around the parent body (Earth in your example). The "orbit" around L4 or L5 is simply a matter of perspective. Look at the bottom 2 images on this page http://www.orbitsimulator.com/gravity/tutorials/rotating...
by tony873004
11.02.2006, 08:19
Forum: Physics and Astronomy
Topic: L4/L5 "Halo" orbits
Replies: 5
Views: 4053

Re: L4/L5 "Halo" orbits

I don't think that animation gets it right. The long axis on the white ovals should always align as close as possible with the Moon's orbit, and never go perpendicular to it. They're known as tadpole orbits. Tadpole orbits with enough energy to make it beyond the Moon's L1 point would be know as hor...
by tony873004
03.02.2006, 08:49
Forum: Physics and Astronomy
Topic: Stable Perpendicular Orbits
Replies: 14
Views: 8380

Re: Stable Perpendicular Orbits

Might want to explain what the "Kozai Mechanism" is... I've never heard of it and I've done some orbital dynamics in my time... If you Google or Yahoo it, my website is first :) . There's an explanation that attempts to sum it up in laymans' terms, and a few diagrams. But you'll probably want to re...
by tony873004
03.02.2006, 08:47
Forum: Physics and Astronomy
Topic: Stable Perpendicular Orbits
Replies: 14
Views: 8380

Re: Stable Perpendicular Orbits

Just a thought... I overlooked where you said you wanted to hide from all the planets. You could orbit the Sun interior to Mercury. It's a futuristic space station, so shading themselves from the Sun wouldn't be difficult. Your spacestation would be lost in the solar glare as viewed from every plane...
by tony873004
03.02.2006, 08:37
Forum: Physics and Astronomy
Topic: Stable Perpendicular Orbits
Replies: 14
Views: 8380

Re: Stable Perpendicular Orbits

Chuft-Captain has suggested some good hiding points. Earth's L3 and the Moon's L2 aren't stable, but only minor correction burns can keep you there indefinately. Of course you're not invisible to an interplanetary spacecraft designed to look for you. Christophe is right. Even a polar orbit has to cr...
by tony873004
24.01.2006, 07:45
Forum: Physics and Astronomy
Topic: Total Solar Eclipse Visible in USA
Replies: 1
Views: 2088

Re: Total Solar Eclipse Visible in USA

Only 11 years to wait! And for me, a short drive to Oregon. But 2045 will be the biggie. I only have to drive 2 hours north. I'll be 81 then.
by tony873004
05.11.2005, 10:49
Forum: Physics and Astronomy
Topic: Mars Center of Gravity not at Center of Shape
Replies: 29
Views: 11885

Re: Mars Center of Gravity not at Center of Shape

That's very cool!

Why should they point to the geographic center? Local "down" is going to be towards center of mass.

It's amazing what you can expose by severely exaggerating a system.
by tony873004
08.10.2005, 10:41
Forum: Physics and Astronomy
Topic: Do you think Pluto is a Captured asteroid or a planet?
Replies: 17
Views: 7280

Re: Do you think Pluto is a Captured asteroid or a planet?

Here's a link to a page I wrote about the possibility of Sedna being captured into Solar orbit. http://www.orbitsimulator.com/gravity/articles/sedna.html It is theorized that captures would have occured early in the Sun's life when it was still part of a star cluster. The encounter speed between the...
by tony873004
20.09.2005, 07:26
Forum: Physics and Astronomy
Topic: Death of our Earth
Replies: 26
Views: 7554

Re: Death of our Earth

I've heard a figure of more like 1-2 inches a year. The Moon would have to approach about 1,500,000 km from Earth before Earth lost its grip. This is known as the Hill Sphere. But like Dollan said, the further it ventures, the slower it receeds. Earth's rotation would tidally lock to the Moon orbita...
by tony873004
23.08.2005, 03:38
Forum: Physics and Astronomy
Topic: Cometary orbits
Replies: 18
Views: 6496

Re: Cometary orbits

i wanted to know this... when i used auto save... the data txt file that was created... was too complicated to comprehend... is there any way to make it more readable??? I agree it looks a bit cryptic, but it's meant to be imported into a spreadsheet program where you can add titles, etc. If you us...
by tony873004
21.08.2005, 04:37
Forum: Physics and Astronomy
Topic: Tide-Locked Planets and Moons
Replies: 12
Views: 4530

Re: Tide-Locked Planets and Moons

Except that its slowly orbiting away from the Earth? d.m.f. Yes, but this is in reference to the hypothetical situation that the Moon all of a sudden found itself outside Earth's Hill Sphere. The Moon is slowly spiraling away from the Earth. As a consequence, the Earth's rotation is slowing down. T...

Go to advanced search