Astronomy and Cosmology

[Dotini]

http://www.eso.org/public/news/eso1217/
The most accurate study so far of the motions of stars in the Milky Way has found no evidence for dark matter in a large volume around the Sun. According to widely accepted theories, the solar neighbourhood was expected to be filled with dark matter, a mysterious invisible substance that can only be detected indirectly by the gravitational force it exerts. But a new study by a team of astronomers in Chile has found that these theories just do not fit the observational facts. This may mean that attempts to directly detect dark matter particles on Earth are unlikely to be successful.

“Despite the new results, the Milky Way certainly rotates much faster than the visible matter alone can account for. So, if dark matter is not present where we expected it, a new solution for the missing mass problem must be found. Our results contradict the currently accepted models. The mystery of dark matter has just become even more mysterious.

Respectfully submitted,
Steve

 

[Dotini]

It seems another wheel has fallen off the dark matter wagon.

http://www.ras.org.uk/news-and-pres...ways-companions-spell-trouble-for-dark-matter

http://arxiv.org/abs/1204.5176

http://www.youtube.com/watch?v=nUwxv-WGfHM <--Very peculiar (anisotropic) motion of vast, polar structure (disc) rotating in step with the Milky Way.

http://www.scilogs.eu/en/blog/the-d...ing-in-many-places-a-crisis-of-modern-physics
Here, in the personal blog of Marcel Pawlowski one can find serious doubts as to the validity of General Relativity and Newtonian gravity at the scale of galaxies and larger. This is a shaking of the very foundation of modern physics!

Respectfully submited,
Steve

 

[Emptyone]

Could be MOND be slightly further to be being a viable alternative to the Lambda-CDM theory now. Every time I see it mentioned in either papers or online, it is normally discredited in favour of dark matter. However it does explain rotation curves if galaxies very well, which after all, is what dark matter was invented for. Maybe if everyone wasn't so keen to stick to Newton there might be more research into possible alternatives to continual dark matter pushing.

 

[Dotini]

Could be MOND be slightly further to be being a viable alternative to the Lambda-CDM theory now.

Yes. Pavel Kroupa is highly enthused over MOND.
http://www.scilogs.eu/en/blog/the-d...1-03-21/question-c.ii-mond-works-far-too-well

Respectfully,
Steve

 

[Emptyone]

Yes. Pavel Kroupa is highly enthused over MOND.
http://www.scilogs.eu/en/blog/the-d...1-03-21/question-c.ii-mond-works-far-too-well

Respectfully,
Steve

Indeed he is, he positively enthuses in that article that MOND is a better solution to our gravity problems than L-CDM. It's interesting to note the way general relativity is designed specifically for our galaxy, whilst MOND is designed for the universe. The article is certainly persuasive, and it might be worth invoking Occam's razor at this point, and in that case MOND makes more sense. Another issue is the lack of a fundamental theory describing the true nature of gravity as a force. As always in cosmology, only more data will suffice.

 

[photonrider]

Annular Eclipse soon. Members in Japan, China and the U.S. should be able to view this.

 

[Sly Guy]

Also, in Hawaii, the Transit of Venus is soon.

 

[PeterJB]

June 6th. Visible for about 45 minutes after sunrise in Europe.

 

[photonrider]

Members in Hawaii should wake up soon and get that #14 welder's glass out.
While the VENUS TRANSIT takes place on the 6th in the Eastern Hemisphere, it happens a day before that (5th) in N. America, but of course afterwards.

This event won't happen again till December 2117. Even if you're from Mars, try to see it; it's a once-in-a-lifetime opportunity.

Cheers,
Harry.

 

[Sly Guy]

I'll have a view from a prime location today

 

[CodeRedR51]

Good web stream.

http://sunearthday.nasa.gov/webcasts/mtwilson/

 

[Emptyone]

Voyager is almost out of the Solar System!

 

[Beeblebrox237]

Voyager is almost out of the Solar System!

I heard about that! It will be very exciting to see what information it sends us after it leaves. I personally would love to see a second set of voyager missions more focused on exploring the area outside of our solar system and interstellar space. With our current technology we could easily send something very quick that would last longer than the Voyager probes, which are expected to run out of energy in 10-15 years.

 

[CodeRedR51]

How long will we be able to communicate with it though?

 

[Emptyone]

Wikipedia says that the power from the nuclear power should be enough to support some systems until 2025, which is another 40AU or so. Plenty enough to tell if it gets to interstellar space hopefully.

 

[PeterJB]

Technically it doesn't leave the solar system until it's left the Sun's hill sphere, which is still about a lightyear away. But at this point it's passed the Kuiper belt and the scattered disc, so their isn't much left out there apart from CBR and the occasional comet from the Oort Cloud.

 

[VspecZR1GT2RS89]

Voyager is almost out of the Solar System!

Amazing! I can't believe that this is finally happening . I wonder how much time can it take for Voyager to leave the Solar System. I just hope we can be in contact with it though.

 

[photonrider]

Never thought we'd see the last of Voyager . . . hupefully not too soon.

In other news: Atlas 5 takes off with a classified payload.

 

[Dotini]

Mysterious and elusive portals connect connect the suns magnetosphere with that of Earth.

http://www.youtube.com/watch?feature=player_embedded&v=y3_vW5yrNek#t=233s

Respectfully submitted,
Steve

 

[photonrider]

The Perseids Saturday night/ Sunday Morning. Don't miss it. Great balls of fire!

 

[Touring Mars]

Except for viewers in Scotland

 

[Dennisch]

I was out fishing, and I already saw a lot of them, couple of big ones too!

 

[photonrider]

Hipster.




Oh! Are you talking about the fish?

We saw some big ones, too (shower meteors, not fish); I swear one passed right before my nose. Funny how close they seem sometimes. Not as good as the year before last - which had a ZHR of about 60 - 80 for us. While there was no moon this year to spoil the fun, there was some cloud and the light pollution from our viewpoint (we were on a seven-story building rooftop) interfered with what could have been a better show. On tomorrow, too, and plenty of viewing parties all around the town, including the Science center that's a block away from me - so maybe another skyfall tomorrow.

Except for viewers in Scotland

You have Andy Murray. He's meteor enough.

 

[Dennisch]

Clickie.

Check it out, it's like Google space, with a lot of current NASA missions.

Very cool.

 

[kikie]

Reviving this thread.

Any of you Americans seen this IRL on December 26, 2013?

 

[Touring Mars]

My cousin in Oregon saw a bright meteor/fireball on Boxing Day... looks pretty epic.

 

[kikie]

Just read that 26% of the Americans still believe that the sun revolves around the earth.

 

[Touring Mars]

And 34% of Europeans...

 

[kikie]

Really?

But in our defence, in Europe the sun does revolve aroud the world.

 

[kikie]

http://news.nationalgeographic.com/...rnate-universe-multiverse-einstein-wormholes/