Starship Asterisk*

Dear Sputnick: Gah! :oops: Now I remember reading something here that revealed that you were an adult. Sometimes my memory short-circuits too. Thanks for brushing off my false assumption so well. Regarding learning math, the Internet offers lots of good material at the high school level (and far bey...

Yep, math! The name "logarithmic spiral" comes from the relation between the radius r and angle θ (polar coordinates) of a point on the spiral. If c and w are constants, then r = c * e^(w * θ), or θ = (1/w) * ln (r / c) ...there's the logarithm. Yet another place where the spiral crops up ...

Hi Phil, The text (implicitly) refers to the angular radius of the circle. If you point an imaginary line at the Sun and a second line at the halo's rim, they'll intersect at an angle of 22 degrees. In other words, the halo rim is 22 degrees from the Sun. Along the same lines (HEY-OHH), the horizon ...

Hello and welcome, Lewis (Animation)! 1) I've seen a few images where the galaxy spiral arms of our Milky Way show up in the image. A recent example was from May 3 ( http://antwrp.gsfc.nasa.gov/apod/ap080503.html ). In these images, for some reason the arch fills the sky as if it is a rainbow. i wou...

A light-year is 9.5 x 10^9 km. So the volume of a 1 light-year sphere is 4.5 x 10^29 cubic kilometers. Caution! A light-year is 9.46 trillion kilometers: 1 ly = 9.46 x 10^12 km, and a sphere of radius 1 ly encloses a volume of 3.5 x 10^39 km^3. A 25-solar mass sphere would have a mean density of 1....

Godspeed, ACC.

http://apod.nasa.gov/apod/ap080217.html WAhat causes the filaments in a nova like this? Orin More of that "fur" again. Synchrotron radiation means magnetic field lines. http://fuse.pha.jhu.edu/~wpb/hstcrab/hstcrab.html <<Although this is a complicated region of filaments, you can see a nu...

Feeling eloquent today? ;) Both spiral galaxies and hurricanes form "logarithmic spirals," as do many other natural structures. At any point in a log spiral, the tangent line of an arm makes a constant angle with the radial line passing through the tangent point. Do any readers have insigh...

Thickening of the atmosphere is probably the best explanation. So you are saying that in this train of particles the caboose is catching up with the engine. That does not add up. That analogy doesn't capture what I meant. Here's my admittedly naive reasoning: assume that atmospheric density falls e...

this does not make a whole lot of sense Sure it does! Read it again (carefully this time), or tell the proton therapy people at the Paul Scherrer Institut and at TRIUMF and elsewhere who save cancer patients' lives that the Bragg peak does not make a whole lot of sense . That being said, the Bragg ...

Speculation: could the brightening at the bottom of the green rays be a manifestation of the Bragg peak? The interaction cross-section of nuclei passing through matter increases with decreasing kinetic energy.

EDIT: happy new year and happy perihelion day!

I hate to butt into this exchange between you and Chris Peterson, but please don't go pinning humanity's failures on science funding. Sure, we've got more problems right here on Earth than we know how to begin to solve: disease, environmental problems, starvation, wars, corrupt governments that lead...

Dr. Skeptic wrote:There needs to be a finite number of Planck's Lengths for math to be a valid measuring tool.

Kind of like how there needs to be a finite number of integers for math to be a valid measur... oh, wait.

Hey nycpaull, To identify the objects making the trails, one could just look at a single ordinary photograph. The star trail APOD http://antwrp.gsfc.nasa.gov/apod/ap071208.html was produced from multiple short exposures (over a single night), so any one of those would show identifiable stars. Taking...

Hi kovil & everyone, A project similar to the one you propose has actually been in polar orbit around the Sun since 1990: Ulysses ( wiki article ), by NASA/ESA. My search results have turned up observations of the Sun's magnetic rather than electric field by Ulysses, probably because, as Chris m...

"Infinity" is certainly not a particular number and can't be thrown into equations like that; you get obvious contradictions like

Dr. Skeptic wrote: 1/infinity = 100B/infinity

implying 1 = 100B.

orin stepanek wrote: Think it will get that bright? Nice song though!
Orin

I hope it gets that bright! More likely it will eventually make its way to conjunction and get lost behind the Sun.

That's pretty awesome that you received Moon mission signals. Sputnik was a little before my time... It's a powerful example of how political interest and scientific advancement influence each other.

uh huh, , , :roll: explain Hyperion then, , FOCLMAO :P Amazing. In one sentence (featuring more than enough commas), you've managed to refute current generally accepted theories of crater formation and open readers' eyes to the now-obvious true origin of craters. Seriously, I shouldn't feed the tro...

bystander is of course right; I wasn't sure what craterchains was trying to insinuate in his post.

FieryIce wrote:

"UFO" in the software name was meant to be tongue-in-cheek

Y'ah think?

Pete wrote:I'm pretty sure...

FieryIce, you avoided bystander's question. Also, what's your alternative explanation to high kinetic impacts?

Well understood, maybe, but as you so mordantly pointed out, never actually observed :) Here's a 2002 APOD composite of what an eclipse might look like from the Moon: http://apod.nasa.gov/apod/ap070302.html For a computer-generated video of an eclipse of the Sun by the Earth seen from the Moon, chec...

Giant Space Cow? http://apod.nasa.gov/apod/ap070829.html Very cool footage. The phenomenon looks like the upside down version of what I'd imagine a cosmic ray air shower to look like. The gigantic jet shape is also reminiscent of particle jets and showers common in high-energy physics: Annotated ATL...

The view was nice from Vancouver; we also got to see an Iridium flare and the Pleiades through binocs Did you end up seeing the eclipse from the East? And wouldn't a smoked glass filter be used only for this kind of eclipse?

There's nothing fake about the image... Maybe they used red light to make a wicked picture, or maybe they used it because red light intereferes least with night vision.