[zenlogo]

Two interesting stories for science fans – they discovered a giant void in space - a one billion light-year hole devoid of dust, stars, galaxies or even dark matter:

DailyTech - Gaping Hole Found in Universe

And speaking of dark matter, some scientists in Italy think they found some under a mountain!:

Italian researchers claim they are first to have found dark matter | Science | The Guardian

[Sigga]

Thanks, Zen.

I love this stuff.

Regarding the dark matter piece, I'm not really convinced that dark matter exists (as many scientists aren't). It is a very convenient theory, though.

Also, if dark matter doesn't interact with 'our' matter, how can we possibly detect it? There's a similar experiment that's been going on in the UK for over a decade (I think). It has yet to detect anything.

If this stuff is so abundant, and can be detected, I think we would have detected it a long time ago.

Interesting, nonetheless.

[Claire ex-ax]

That's the great thing about science; the more we learn the greater our understanding. Old theories may fall but at least we can build new ones with the new information we gather.

The most exciting phrase to hear in science, the one that heralds new
discoveries, is not 'Eureka!' (I found it!) but 'That's funny ...' Isaac Asimov

[zenlogo]

Yes Sigga; dark matter is another term for "we really don't know what this is so lets give it a name so it looks like we do". They do know they can't see it and they do know that things they can see like galaxies are gravitationally affected by 'something' there.

Claire we will always have some sort of explanation, valid or not. What I find interesting about cosmology and quantum mechanics is that today's explanations are far more amazing than any science-fiction.

[Sigga]

Some scientists are thinking that they got it wrong all along; there is no dark matter or energy, our understanding of gravity needs to be revised.

The idea is that gravity works differently at different scales - at the human scale and the cosmic scale. It might be that we need to rejigger the equations instead of looking for more matter.

Some extra bits here:
Gravity theory dispenses with dark matter - space - 25 January 2006 - New Scientist Space

But still no widely-accepted theory of everything! I wonder what such a theory would make possible...

[zenlogo]

Sigga, thanx for the link - i did not know this other idea. Sounds valid. That would explain why we can't see dark matter - it ain't there!

Have you read any of Hawking's stuff on blackholes - there's another kettle of fish.

[Sigga]

Well, I read A brief history of time.

I understood the three first pages and then...

It was interesting, but it's mind-bending stuff.

I think part of the problem with understanding string theory, black holes, gravity waves, multiple universes, infinity, 9 dimensions, etc. is that the physicists start from observations and postulate mathematical theories to explain them. We have no idea of the underpinnings and just get presented with 'the universe is composed of giant strings in multiple dimensions, and matter is actually the vibrations on the strings', or something.

All these loony theories (all but one of them are, by definition) must have a reasonable basis, but we don't see it. Sadly, I don't think my mind is equipped to deal with the maths.