Starship Asterisk*

I don't understand the test. We have made measurements of the gravitational constant to as fine a degree as our instrumentation currently makes possible (which is not very good compared with most other measurements of universal constants), and it has shown no variation with position, mass, or dista...

Sound plausible? It would not qualify as "plausible" until someone could propose a way the idea could be tested. It would not offer a better explanation of current theory until some of those tests were performed and failed to disprove the idea. Well, it could be tested by making a random ...

I have wondered about gravity and dark matter and dark energy for some time now, and have (I think) come up with a somewhat crazy explanation. Actually, I think I heard a similar explanation on a science program. Could gravity be from the strong nuclear forces acting on 'our' universe from an infini...

Chris Peterson wrote:This remains one of my least favorite APODs ever. It is horribly processed, producing a result that looks absolutely nothing like a total solar eclipse. The human eye would never see anything like this.

I agree.

RJN wrote:Great discussion!

This APOD's text has been updated....

Yes this has been a good discussion.
I was wondering if anyone else has problems displaying the gif in the June 16th, 1995 APOD (the one in your profile pic)? Maybe you could update the gif to animate correctly, if it needs it?

As an addition to my previous comment, I would add that evaporation from ice crystals (sublimation) could also be a source of charge separation, though most of the ice crystals in an Active storm may not be sublimating, but growing.

As a photographer of lightning, I have to say that today's APOD is awesome! I have often wondered how lightning is born - more to the point - how the charges are separated in the clouds. So I have formulated a hypothesis of how that could happen. The charge separation starts with rapidly rising air ...

Photons, gravitons and all other real particles with trajectories into the event horizon never return and augment the mass of the black hole. Virtual particles with trajectories into the event horizon also never return but they reduce the mass of the black hole. Yes, but If a small black hole orbit...

I'm guessing gravity waves can not escape black holes, since supposedly nothing can. But what happens to gravity waves inside, say, a super-massive black hole that are being created by an orbiting smaller black hole? If gravity waves can not escape the large black hole, then the smaller black hole'...

Awesome detector! I'm guessing gravity waves can not escape black holes, since supposedly nothing can. But what happens to gravity waves inside, say, a super-massive black hole that are being created by an orbiting smaller black hole? If gravity waves can not escape the large black hole, then the sm...

It's cool how Horseshoe Bend echos Barnard's Loop.
But that brings up a question... Isn't Barnard's Loop more of a horseshoe? Or is it a full circle (or sphere) that is partially obscured?

Tardigrades can endure a lot of extreme conditions, but can they survive a photo-shoot of the close-up variety? I guess it would be ironic if getting their electron micrograph for their visa to visit the Martian moon Phobos killed them instead of the trip itself.

I'm sure others have noticed the black rectangles near the two moons... but what are they? Was Jupiter too bright compared to the moons to get them all in one exposure?

So, the telescope, "is optimized for the infrared exploration..." Does this mean that it will be able to take visible light images? If not, why not? It seems kind-of a waste to make such a good telescope that only sees in such a narrow wavelength.

I'm quite sure that Daphnis would still make the waves if it were not in an eccentric orbit relative to the edges Keeler Gap, though the waves would look different somehow. Also, it's interesting how the waves look much brighter than the relatively undisturbed rings. I would guess that it's due to t...

This is a similar photo to the one posted on Jan 21st of this year, though this one gives more detail of the waves. I am temped to call these waves gravity waves, like cloud waves are gravity waves, but are they? Aren't these 'waves' just kind of an allusion? They are just the combined orbits of rin...

OK, back to the X on the moon.
Does anyone think it looks like the "X" in SpaceX?

I was on a pier in Tampa Bay when a storm moved in. I came prepared with my camera, but was not really prepared for how close the lightning would be. A particularly close bolt landed about 500 feet away, and the instant it flashed, I heard a 'snap' sound like a static discharge. I got a photo of it ...

At first I thought that the cone in the thick dust was from a star shooting through the dust cloud. But I see that there is another cone opposite it, so the cones must be from a star near the tips of the cones. But it got me thinking. Years ago on this comment site, I noted that clouds of dust in fr...

Glenriven wrote:The only thing that comes to mind, is how easily we are manipulated by the media.

That is true, whether the manipulation comes from the usual media, or talk radio, Drudge, etc.

If the bright spots are not photo artifacts, I suppose they could be areas where out-gassing water vapor is condensing into ice (frost). Most of the spots are near crevasses or shadowed areas (colder areas where out-gassing is more likely), so that seems to support the idea. And maybe the two spots ...

What are those many white spots? Ditto! What are those super bright spots? Are the similar the the bright material on Ceres? I'm no expert, but some of them could be caused by charged particles from the sun, and/or bad pixels in the sensor. Note that there is one in the 'sky' to the far left, and a...

Thanks Chris. I wasn't sure if the nebula was held "up" by the light pressure or 'solar wind' of the stars of the Milky Way.

The description says that the Nebula is "drifting above the plane of our Milky Way galaxy." But wouldn't it be orbiting the Milky Way like our solar system is? In other words, wouldn't it move "up" and "down" through the plane of the galaxy?

I wonder how much material the rings contain... If they were rolled into a solid ball, how big would it be?