It's sciencey!

[mmcirvin]

1. Backlit Saturn.
2. Ununoctium, the noble gas after radon.
3. This Wikipedia featured picture showing Lorentz transformations in action is really clever.

Comments

[bottlroktt.livejournal.com]

i can't wait till 2 is renamed Freedomium...

[ronebofh.livejournal.com]

Why are they eager to discover element 120 and not element 119?

[mmcirvin.livejournal.com]

Not sure. I was thinking it might have something to do with the theorized Island of Stability, but that's not right.

[mmcirvin.livejournal.com]

...oh, right: I think the even-proton-numbered nuclei are stabler for reasons involving the Pauli exclusion principle and filled shells.

[mmcirvin.livejournal.com]

...uh, that should be filled orbitals. Just as with electrons in atoms, you get paired identical particles of opposite spin.

[partiallyclips.livejournal.com]

That's simply one of the most amazing photographs I have ever seen. I'd love a framed copy.

I'm not sure I understand

[vardissakheli.livejournal.com]

the geometry of what we're seeing! It looks like the viewpoint is above the rings with the sun below, so at the top the sunward side disappears behind the planet, and at the bottom the other side disappears into its shadow. So then what are we seeing where we look through the darkened rings at the planet? Is that an inverted image of the sunward side of the rings viewed through the planet as a giant lens?

Re: I'm not sure I understand

[mmcirvin.livejournal.com]

(Oops, I linked to the APOD front page--a permalink to the picture we're talking about is here (http://antwrp.gsfc.nasa.gov/apod/ap061016.html).)

The sun is directly behind the planet. Everything we're seeing is forward-scattered light. We can't see through the planet but we can see through the rings in some places. The viewpoint is above the rings, and the part of the rings right in front of the planet is further darkened by Saturn's shadow on the rings, which is why there's such a pronounced boundary at the limb of Saturn.

Re: I'm not sure I understand

[mmcirvin.livejournal.com]

...Also, the rings are lighting up the planet's clouds, which is the reason for that soft illumination over Saturn's disc.

but look at the discontinuities

[vardissakheli.livejournal.com]

Between the lower half of the planet and the bright part of the rings, there's a dark gap, which would be the shadow of the planet, right? And the outer edges of the image of rings we see across the lower half of the planet don't line up with the bright rings next to it at all. It seems like it's got to be either a reflection (which doesn't make sense when what's reflected is in shadow) or a refracted image seen through the lens of the planet (which also seems a little impossible).

EXCEPT! now I see that all the lines in the middle of the rings DO line up. The outer edge just seems to fade into oblivion in the more diffuse light. But I'm still baffled by what I thought was an image of the inner edge, the uppermost section of the bright band across the middle of the planet.

Re: but look at the discontinuities

[mmcirvin.livejournal.com]

But I'm still baffled by what I thought was an image of the inner edge, the uppermost section of the bright band across the middle of the planet.

I think that's a combination of the rings, and the ring-light illuminating the surface of the planet itself. The relatively sharp dark line across the equator is there because the rings block most of the light reflected off them when seen edge on, so the clouds along the equator get less ring-light.