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Astrophysics

- The branch of astronomy that deals with the physics of the universe.
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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
Jenab6
45 67,789
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
Drakkith
20 45,201
Hey everybody, I'm doing my International Baccalaureate extended essay (2500 to 4000 words) in Astrophysics, which...
Feb4-09 05:34 AM
Vanadium 50
1 3,986
im struggeling with the notion of experiencing angular momentum in a spinning space station. to me it would seem that...
Jul28-10 10:41 PM
Deuterium2H
15 3,985
Off course we should not take too seriously what we read in Sci Fi books. I've just been to lazy to do any research...
Dec11-07 08:37 AM
Astronuc
22 3,980
Hi, i'm studying my astronomy course at the moment and i have question about the r- and s-process. As I understand it,...
May29-05 09:13 PM
Nereid
3 3,979
How did the planets acquire their spin?
Mar18-11 08:41 AM
Ken G
30 3,974
Either the Big Bang began in a small, restricted area/volume/domain/node/etc or the universe sprang into existence...
Jun13-11 05:26 AM
Cosmo Novice
5 3,974
If the earth suddenly disappeared. and the moon started to travel in a straight line instead of its orbit of earth,...
Mar25-08 04:08 PM
russ_watters
14 3,960
Does the gravity constant change slightly over time due to the expansion of the universe? What would be the...
Dec13-04 10:59 AM
J20gU3
3 3,957
Okay, it may be a dumb question, I am probably missing something obvious... Let's consider the Sun. There is only,...
Apr6-11 04:21 AM
twofish-quant
15 3,956
Why is the spectrum of sunligt similar to that of a blackbody?
Jun25-04 11:06 PM
Tyger
4 3,952
Hello everyone, Its good to FINALLY be back! :biggrin: I was wondering why the path of the planets in our solar...
Aug12-05 08:15 PM
kjknohw
25 3,952
I have no clue if this has been done before, even though I Searched... But I'm 17 and want to learn about...
Apr24-07 07:31 PM
Red Anvil
15 3,946
I once read our solar system resides close the edge of our galaxy and that it has an up and down orbit that swings it...
Apr15-11 11:57 PM
D H
24 3,943
I have been wondering, in films, we can often see small ships flying faster than giant ones. Top speed is clearly...
Feb8-12 10:34 AM
Ryan_m_b
20 3,943
<Hmm. I just realized that this post would be better suited for the "Celestial Mechanics" forum. Would you mind moving...
Dec16-04 07:08 AM
BobG
22 3,942
precession of perihelion for Mercury (arc s/century) 5025".6 Coordinate 531".4 ...
Dec16-05 03:34 PM
RandallB
15 3,936
Could somebody give me a quick demo of how to convert from one system to another. I have a homework to do and none...
Oct24-05 02:11 PM
tony873004
1 3,923
Is our angular momentum altering our gravitational attraction to the earth so that if the rotation of the Earth was...
Aug12-04 05:34 PM
BobG
8 3,915
Hi, I'm wondering why the Sun's luminosity has increased over time. I have learned that every star in the main...
Nov14-08 09:40 AM
Arch2008
11 3,913
i.e something happening out of nothing or was there no birth at all and all that exists today existed since forever?
Nov22-10 04:29 PM
PhysDrew
23 3,911
I would like to model a cooling sphere, losing heat at the boundary through radiation. Is there a book that can help...
Jul19-07 03:26 AM
Helios
2 3,909
Hello everyone ! :smile: I am new here, so before to post my question, I'll just introduce myself shortly. I'm a...
Dec5-08 10:07 AM
Abbas Sherif
3 3,901
I'm trying to understand the Hill Sphere formula. (Yes, I've already been to Wikipedia.) I notice that it doesn't...
Nov18-07 02:40 AM
pervect
7 3,893
How do you think our universe will end like? I think it would be the Big crunch! One evidence is that the amount of...
Mar30-06 03:49 AM
AlphaNumeric
1 3,889
It is my understanding that when an electron drops to a lower orbital that 2 photons of light are produced. The moving...
Sep9-11 02:28 PM
Drakkith
12 3,882
All rocky planetoids are born as balls of molten magma, and take millions of years to cool, crust over, & solidify. ...
Dec16-08 10:26 PM
cristo
13 3,876
could anyone explain p-process in nucleosynthesis for me? i didnt find any suitable site.
Mar1-07 10:28 PM
Astronuc
1 3,875
Is the spectrum of reflected light of a planet the same as the spectrum of the star near it but just less in...
Feb21-08 10:00 AM
mgb_phys
3 3,875
Assuming that black holes do in fact evaporate via Hawking Radiation, how can an infalling observer ever get inside...
Jun11-12 03:04 PM
PAllen
37 3,875
I have read somewhere that you need to have zero mass to be able to travel at the speed of light; is this true? Also,...
May11-08 10:08 AM
MeJennifer
5 3,869
http://www.science27.com/forum/g2.jpg http://www.science27.com/forum/g1.jpg At radius 1: Acceleration Due to...
Dec27-09 02:28 AM
kjohnson
18 3,859
Hello. Has anyone ever heard of a spiral tracer? and what characteristics they have?? any good link on the topic...
Jul21-06 04:38 AM
SpaceTiger
1 3,856
I know about the blue shift of all the galaxies that we see, but does that really prove that galaxies are expanding,...
Jan27-07 05:28 PM
cdm1a23
14 3,848
After reading in Longair's Galaxy Formation through the derivation of the virial theorem in the context of a dynamical...
Oct10-08 08:53 AM
Arch2008
10 3,847
Hello, Can you please tell where radio waves originate from? Thanks, Glynis
Apr22-07 01:57 PM
HallsofIvy
1 3,844
I don't know what happened, but it seems that all the "hot" research is in fields like astrobiology, cosmology,...
Aug21-11 06:16 PM
Astronuc
13 3,843
http://www.physorg.com/news/2011-08-dark-illusion-quantum-vacuum.html "His ideas (like those in the previous paper)...
Sep8-11 11:58 AM
moejoe15
15 3,843
I think this is an aproriate forum to ask this, I'm curious to the effect a planets gravity field has on a rocket...
Dec12-06 06:13 AM
SpaceTiger
3 3,836
can someone explain to me in simple language why does not Moon fall on the Earth? I dont understand it why? ...
Jul3-07 06:58 AM
russ_watters
15 3,835
So just a thought that popped into my head, and I wanted other peoples opinion on it. What if a fundamental law in...
Mar21-10 03:43 AM
Vanadium 50
25 3,826

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