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HELPFUL DESCRIPTIONS. a : semimajor axis For elliptical orbits, the semimajor axis is half the length of the...
May2-10 02:49 PM
45 67,846
To help me in understanding this procedure, I read the fifth chapter of THE DETERMINATION OF ORBITS by A. D. Dubyago,...
Apr22-12 12:10 PM
20 45,251
Hello Folks, I have an interesting question (I think)... how far back in the history of universe would you have to...
Oct21-12 08:05 AM
38 6,843
I heard that light speed is attainable for a space craft from Jupiter's magnetic field and by Lorentz force. in this...
Nov9-12 01:43 PM
4 1,402
Hey folks, A couple of weeks ago I took a photo of the moon, not sure if you will be able to see this in the image,...
Nov5-12 05:20 PM
13 1,718
From an early age I thought that scientists knew what gravity is, the actual thing and not just the effect it has on...
Nov4-12 09:20 PM
21 4,333
For a ground-based Cherenkov radiation detection, what are the theoretical/practical constraints on the gamma-ray...
Oct5-12 09:15 AM
8 1,747
Hi all Looking for some assistance if possible. Astrophysics is not my field--so please be gentle with me, as I...
Oct19-12 07:38 AM
4 1,462
I know the title sounds stupid, but I have a serious question. If you look at the simulations for the massive...
Oct19-12 10:10 AM
4 1,180
Hello, I have a 20 minutes presentation about Vogt-Russell theorem and to discuss how to model stellar structures....
Oct18-12 05:01 PM
George Jones
2 1,274
Hello everyone, I come here with a question. I'm not a physicist, so this might be a stupid question. But...
Oct20-12 05:14 AM
1 921
Hope you enjoy the following, From, ...
Nov3-12 11:37 PM
5 1,417
I have a thought whilst in the shower this morning, it is usually said that shock waves only take part in star...
Oct31-12 05:51 PM
3 822
The escape velocity on Planet X is the speed the rocket needs in order to never fall back down again in a universe in...
Oct31-12 10:37 PM
6 1,056
I've been reading about Hubble Space Telescope and the concept of momentum dumping done by the magnetic torque rods. I...
Nov9-12 03:43 PM
2 2,713
Hello all, this is my first post. My question is, do any theories exist about time relativity based on distance from...
Nov11-12 10:17 AM
6 1,316
If dark energy repels things at the speed of light, does that mean if light energy is produced near it, it would repel...
Nov11-12 09:32 PM
2 1,213
how can black holes bend time if time bending is impossible ?
Nov11-12 05:15 PM
3 1,552
We can determine what kind of elements exist in different planets by observing electromagnetic waves from planets'...
Dec3-13 03:43 PM
16 2,817
The speed of light in a vacuum is the universal constant c. The speed of light in a medium is something less than c;...
Apr24-13 09:15 AM
7 1,062
I understand that massive spinning objects drag spacetime along with their rotation, and that the inner region is...
Jan30-14 04:51 AM
28 2,795
As far as avoiding a killer asteroid in the future, I have what I consider to be a simple solution. Japan has already...
Dec10-13 04:10 PM
35 3,524
How does the Oberth Effect work, and why? Why would acceleration applied at one point in an orbit be different from...
Dec8-13 08:54 AM
3 1,316
Hey I'm trying to find out the maximum velocity that ISON had, should I use Newtonian physics or general relativity...
Dec5-13 09:32 AM
24 2,074
Hi, I'm basically wondering why there is any residual angular momentum in the universe left over from the big bang...
Dec1-13 10:45 AM
1 924
Do we have any evidence that either: 1. There exist stellar black holes which orbit supermassive black holes in...
Dec1-13 05:27 PM
3 899
What are the odds that there is a different event horizon for dark matter?
Dec1-13 10:09 PM
1 782
Given: According to my reference (An Introduction to Modern Astrophysics), I should start with this equation: r =...
Dec2-13 09:20 AM
0 841
I asked a question recently about orbiting black holes. Thanks for the answers. So if I'm correct in my thinking,...
Dec15-13 12:48 PM
7 1,205
Do you have to "stick to the left of your orbit" or "give way to the unmanned vessel"?
Dec10-13 02:19 AM
3 970
Hi, I try to solve excercises from the book Stellar Atmospheres by Mihallas. I'm stuck on this one: By use of...
Dec8-13 05:09 PM
0 850
People are saying that Kepler 22b looks like it may harbour life. How could we ever know? I was just wandering, but...
Dec10-13 06:34 PM
2 883
Assuming that an object in orbit has no means of propulsion (dead satellites, NEOs, etc.) and it remains aloft long...
Dec14-13 09:12 PM
2 917
Plasma-fire Unlike a (normal) fire, a plasma-fire combusts at excess 10 billion Kelvins (in general terms, 3.8...
Dec17-13 09:31 PM
9 962
Sorry, strange question, but let's do a thought experiment: if a train was moving at near light speed and hit a slow...
Dec22-13 02:43 PM
9 986
I was wondering at what temperature would Titan's atmospheric particles reach escape velocity? Since Titan lacks the...
Dec19-13 07:39 PM
1 905
In the big crunch scenario, matter would clump together faster and faster, could a blob of this matter form a black...
Dec28-13 06:06 PM
5 1,581
Could you please clarify for me how much each of these contribute to the red shifting of light from distant objects? ...
Dec22-13 11:33 PM
2 907
meteorites that are not large enough to reach the ground vaporize in the atmosphere (as do large portions of the ones...
Dec29-13 01:03 PM
1 693
Since we can observe gravitational lensing and conclude that mass can affect the path of EM radiation it seems logical...
Dec29-13 01:22 PM
Jonathan Scott
1 788
Hello, all. I'm trying to find an equation to determine a star's absolute magnitude in order to populate a table of...
Jan16-14 09:26 AM
1 597
Hi, I joined this forum because I love learning new things about our universe and I often have questions like...
Jan15-14 07:02 PM
5 693

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