Celestia Forums

I've had some experience with Lua (v5), and it works great though it is still in beta.

/Alexis

Alexis> Actually, all light from stars would be infinitely redshifted in the light-speed limit!
Grant> I think you might be wrong, there.

You're right, I misplaced a gamma Thanks for correcting me.

/Alexis

Redfish wrote:So your explanation tells me that by looking forward i could see my own ass while flying at near lightspeed?

No... not unless you separated from your ass at near lightspeed. It's the relative speed that matters, you know. Relativity theory

(sorry for this off-topic post)

/Alexis

At lightspeed you would "see" all the stars condensed into an infinitely blueshifted dimensionless point dead ahead. Actually, all light from stars would be infinitely redshifted in the light-speed limit! This is due to the relativistic Doppler-shift that includes time-dilation. See the entry What ...

I think Don refers to the web page provided by Bruno above, which states that this eclipsing planet candidate has been ruled out as being a planet ("disproven"). In fact, most of the 40 planet candidates found in this way have turned out to be binary stars, but not OGLE-TR-56 b, so the web page is i...

Actually, the star is "only" 5000 ly away, and should be within grasp for Celestia. Although I don't know if there's much sense in adding it, being that far from the main stellar database (and its visual magnitude, as seen from Earth, is merely V=16.6!). Read all about the discovery, as told by the ...

Image Eye shows DDS as well as 20 other image file formats. There's a 30 day limit for the demo, the program itself is $25 to register. Image Eye is developed by a friend of mine who put a lot of effort into the program, and I can highly recommend it for windows users.

/Alexis

PS Velikovski's ideas were much more crazy than this

The hot Jupiters are thought to be produced by planet migration due to planet-disk interaction, not planet-planet interaction. There is a group at our institution doing massive parallel simulations of this very problem (on twenty connected Athlon 1800+ CPUs!). For a readable recent review on planet ...

This is interesting. So the "edge" to the data (apart, that is, from the artefactual 5000 pc sphere) is determined by the fact that there are vanishingly few stars bright enough to allow Hipparcos to detect their parallax at such extreme distances? Well, yes and no. The average parallax error of th...

Thanks for your input, selden and anonymous! It seems indeed as a large fraction of the Hipparcos database contains radial velocities after all. Now you only have to come up with an efficient "culling scheme" to display them efficiently. Remember, that a radius of interest doesn't help much since yo...

When I researched this some years ago, I found that only a few thousand stars have measured radial velocities. That's about as many stars as can be seen with an unaided eye a clear dark night, and the measured stars are not necessarily the brightest ones. The early ones (of spectral class O,B,A etc)...

I take it you're on a tight time schedule, but we can discuss AutoMag further when you come back from England. Let d(m) be the stellar space angle density d (e.g. "stars per square arc second") as a function of limiting magnitude m , and let m(d) be its inverse (it exists because d(m) is monotonous)...

From a users point of view, I would tend to agree with Chris's point here. It feels more natural if switching on AutoMag would keep the limiting magnitude in the current field of view, and then change it according to your scheme when the fov changes. Similarly, when AutoMag is switched off it should...

Whoa! I think your discussion has run a little wild here ;-) There is absolutely no way you can expect Celestia to make detailed emulations of gravitational interactions between galactic stars. As pointed out, you simply need too much computer power to that at any reasonable fps (remember, Celestia ...

If the AutoMag is active, the [,] keys that adjust the limiting magnitude in case of the "fixed mag" scheme, are blocked, of course. Since I'm fond of discussing AutoMag with you ;-) : I think it would be useful to leave the [,] keys enabled but let them adjust the relative magnitude limit instead....

Thanks! Next time you need a stubborn besserwisser, you know where to find him I always enjoy learning new things, and the work you refered to (like Clark's) took into depth things I've casually thought about. So, I thank you for taking the time to argue with me...

/Alexis

Your "jokes" about my (1 minute lasting) typo: "since I /am/ a child" and "herr Dr. Clark" (note he is british) fit in well and are neither particularly intelligent nor amusing... In contrast to your's, examplified in an earlier post in this thread? :lol: Well, I'm sorry you don't share my sense of...

Mathematical induction proofs and blindly extrapolating arguments to infinity (like your "counter argument" above) are not at all the issue in this discussion. Often, driving matters to extremes helps clarify the logic. (Yes, I do observe the sky with telescopes since I am a child). Not only childr...

"A star image is actually a diffraction disk, but it is so small that, if faint, the disk is a point to the eye at any reasonable magnification at all" :!: This is misleading! Only very small telescopes (D < 5cm) do generally produce diffraction limited images of stars. A typical good site has a se...