Astronomy

[YesNo]

I suppose there might be some reference to the skies in Ovid's Metamorphoses, mal4mac, but I can't remember any in particular at the moment.

I just finished checking on the positions of Jupiter, Venus and Mars and it looks like Venus and Mars are in a line next to each other. One of the things I've noticed about watching these planets is that their movements are not subtle.

[Dreamwoven]

It seems our own galaxy, the Milky Way, has a mysterious Great Dark Lane of dust around it. The link is from Space.com. its origins are unknown, but this is potentially an important discovery.

[YesNo]

I wonder how much this dust removes the need for dark matter.

The crescent moon and Venus were amazing this morning.

Here's a picture:



I took this with my camera without a tripod. Notice the phases of the Moon. I think you can also see the phase of Venus. It isn't pointed in the same direction as the Moon which makes me think it doesn't have to, but then I wonder why not? Mars is very faint just above Venus and Jupiter is at the top. It looks better in real life.

[Dreamwoven]

Interesting that you got the picture of the phases of both Moon and Venus in the same shot.

[Dreamwoven]

This from space.com: http://www.space.com/20930-dark-matter.html on Dark Matter is very peculiar. It tries to say what Dark Matter is. Yet it left me confused. Perhaps we don't really know what it is.

[YesNo]

Dark matter is an interesting mystery. This is how I see it based on your link.

Our current laws of gravitation require there to be more matter in the universe than our measurements have accounted for so far. There are three explanations for the discrepancy:

1) Our current laws of gravitation are incorrect.

2) Our measurements of the amount of ordinary, "baryonic" matter are incorrect.

3) There is a new kind of "non-baryonic" matter out there that we can't measure or even detect.

It seems to me that 1 and 2 or some combination of them are more likely, but apparently many scientists favor 3. It seems to me more likely that there exist alien life forms out there that we have not found than that there exists another form of matter, but who knows?

[Dreamwoven]

Yes, it is all very confusing.

[Dreamwoven]

Eric, a recently discovered trans-Neptunian dwarf planet,dubbed Eris, has been discovered. See http://www.space.com/28379-eris-dwarf-planet.html. Its in the kuiper belt and takes some 550 years to make one orbit of the sun. Read about it on the website. Published in January 2015, I must have missed it!

[YesNo]

It is amazing how much we don't know. In the "dwarf planet" link in the link you cite I hear there may be 200 dwarf planets out there. We know of only a handful of them. http://www.space.com/15216-dwarf-pla...tem-sdcmp.html

I also ran into a link saying that black holes can't exist: http://phys.org/news/2014-09-black-holes.html For some reason, I thought these had been observed already.

[tailor STATELY]

I thought the conventional theory was that there are observable black holes in the center of all spiral galaxies (including the Milky Way and Andromeda), and that crazy-fast velocity stars have been observed orbiting them ?

Ta ! (short for tarradiddle),
tailor STATELY

[Dreamwoven]

Yes, tailor STATELY, it is the dominant theory, as you say.

I've just read the two links in YesNo's post, and neither of the two theories are any more than that - theories. I've been particularly suspicious of one single big bang theory, it assumes there is only 1 universe and that it is finite:

"Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened, or whether it is unique."

Read more at YesNo's second link: http://phys.org/news/2014-09-black-holes.html#jCp

[tailor STATELY]

I ♥ fizz9, but it makes my brane hurt.

Ta ! (short for tarradiddle),
tailor STATELY

[Dreamwoven]

Yes, tailor STATELY, it is the dominant theory, as you say.

I've just read the two links in YesNo's post, and neither of the two theories are any more than that - theories. I've been particularly suspicious of one single big bang theory, it assumes there is only 1 universe and that it is finite:

"Many physicists and astronomers believe that our universe originated from a singularity that began expanding with the Big Bang. However, if singularities do not exist, then physicists have to rethink their ideas of the Big Bang and whether it ever happened, or whether it is unique."

Read more at YesNo's second link: http://phys.org/news/2014-09-black-holes.html#jCp

The last para in the link is as follows:

"Physicists have been trying to merge these two theories – Einstein's theory of gravity and quantum mechanics – for decades, but this scenario brings these two theories together, into harmony," said Mersini-Houghton. "And that's a big deal."

Read more at: http://phys.org/news/2014-09-black-holes.html#jCp

[tailor STATELY]

Yes I read the article 3 - 4 times. "But for now, Mersini-Houghton says the mathematics are conclusive." - sounds a little dubious. Hope they're right in a way; if not just to push forward from there.

Ta ! (short for tarradiddle),
tailor STATELY

[YesNo]

A lot of it sounds dubious to me as well, but I thought black holes were as established as, say, exoplanets which can be spotted as they make a transit across their suns. It makes me wonder just what the evidence is for black holes.