Dark Energy

[oex]

Hi Guys,

Yet another crazy question on a topic I know very little about but I was wondering....

I have read about dark energy/matter that it must exist because otherwise gravity doesnt work, the edges of the universe are expanding (aparently because of this misterious dark energy we cant see or prove exists....

All I wondered was could this just be like a lense effect where the curvature of space (because of gravity) made the universe appear to fly apart.... Maybe like a bumpy 3D plane where the real distance is still influenced only by gravity (ie the plane gets deeper troughs) but the distance between points along the plane expands....

I guess this would be a 4th (5th) dimensional effect?

I really dont understand this well but maybe someone will post information that will help me to understand better

http://www.bbc.co.uk/news/science-environment-18503703

[dedndave]

i'm with you, Peter
there might be some un-accounted-for numbers that have been left out of the calculations
something we don't know about or understand
i am more comfortable with things i can hold in my hand - lol

[FORTRANS]

Hi,

   Dark matter is required to explain the anomalous rotation
rates of galaxies, the clustering of galaxies, some hot gas
structures, and some gravitationally bent light.  Without
some sort of matter these do not make sense.  Since we
(they) cannot see the required matter, they call it dark
matter.

   In the late 90's two independent groups of astronomers
found that the universe's expansion rate was growing
rather than slowing.  That led to dark energy.  (Give or
take.)

   Expansion into a negatively curved space would look like
a faster than expected expansion.  (I think it would anyway.)
but they have a bunch of reasons to believe the universe
is uncurved or flat.  Some of this is from analysis of the
cosmic microwave background.  And some of it is from
study of expected products from nucleosynthesis from
the big bang.  And so forth.

   Unfortunately, figuring this out is non-trivial.  Fortunately,
it dosen't have an effect on you or me.  And it's fun stuff.

Cheers,

Steve N.

[Zen]

PETER !!!
I was wondering when you'd show up,...good to see you again,... (baltoro, here...)
Weird,...I was reading a book just recently about the Dark Matter/ Dark Energy "problem"
"The 4 % Universe: Dark Matter, Dark Enery, and the Race to Discover the Rest of Reality", author: Richard Panek, 2011
Here is a review of the book: Exploring the Dark Universe, American Scientist
However, I would NOT recommend this book. Although it is well-written, and depicts the evolution of the thinking of the astrophysicists and astronomers that have published on the subject in research journals,...it really isn't very skeptical of the science. There is NO rigorous or empirical analysis of the subject. It leaves you even more confused about just what Dark Matter actually is than when you started the book.
FORTRANS...above...describes the situation in condensed form.
Much of the development of the logic is based on the values for Omega, the Density Parameter and Lambda, the Cosmological Constant.
The Big Bang Theory gave birth to cosmology as a science,...but, it is almost completely hypothetical,...and, the existence of Dark Matter to explain certain observed anomalies is very controversial.
...I get the distinct impression that cosmologists use the term "Dark Matter" to designate that which they do not adequately understand,...

[dedndave]

gosh, let me think....
1) how much mass does a "typical" black hole have
2) how many black holes are out there that we don't know about
3) what is beyond our visible/detectable range with current technology

[FORTRANS]

Hi Dave,

   Stellar mass black holes (BH) are supposed to be 4 - 22
times the mass of the son.  Larger BH go from hundreds to
billions of solar masses.

   Given that there is three times as much dark matter
than regular matter, that would be a troublesome number
of black holes.  You would not be in a safe neighborhood
any more.

   The fact we cannot see it or detect it in other ways means
it is beyond our current technology.  Unless the LHC gets to
find some.  Or one of the other experiments that are trying
to detect dark matter pan out.  No verifiable results so far.
A couple of contested claims have been made though.

Cheers,

Steve

[Daydreamer]

so what comes next?
experts on dark matter/dark energy gets titled Sith? :lol:

[MichaelW]

This dark energy/matter stuff seems to me to be too close to the “black magic” that people used to explain things they didn’t understand in medieval times.

[hutch--]

There is really a simple explanation for postulating dark matter, not everything in the universe glows in the dark.

[Daydreamer]

This dark energy/matter stuff seems to me to be too close to the “black magic” that people used to explain things they didn’t understand in medieval times.

but that turns out correct that all physic laws etc was invisible energy and gravity,magnetic,radioactivity etc are still is unseen forces for ordinary joe without instruments to reveal for example gammarays, radiotransmitter etc

[dedndave]

that's right - we don't even fully understand the easy stuff yet   :P

[hutch--]

Actually black holes sound like a ton of fun in open space, if we ever get the technology to travel really long distances, one of the risks is trying to drive through a black hole if you fail to detect it. General drift is you go in and you don't come out. (Splot ! )

[npnw]

Do you go splot???? or do you go to another dimension?  Where the speed of light constant or matter to energy ratio constant is changed?

Are Black Holes uptakes to a faster than light travel? Thus warp drive theory? Heinlein had some interested SciFi ideas on things.

http://en.wikipedia.org/wiki/Quark%E2%80%93gluon_plasma

With is type of energy we may be able to develop faster than light travel. Of course that is if we don't develop a black hole first  :t

There is a slight risk.

Also good article http://news.bbc.co.uk/2/hi/science/nature/4462209.stm

black hole article http://news.bbc.co.uk/2/hi/science/nature/4357613.stm

[hutch--]

Einstein frame of reference comes into play here, from an external fixed viewpoint it going SPLOT (albeit silently), if you are on the object going into the hole you may experience time at a different rate to the external fixed point. I seriously doubt you come out the other side into a new dimension unless you are committed to the viewpoint that you end up in heaven. 

[npnw]

http://arxiv.org/pdf/nucl-ex/0410020v1.pdf

Could be hutch.  They think this is the state of the universe before particles were formed. The first 400,000 years I think? 

If I cross over Hutch and can get back I'll stop bye. Should make the commute time to Australia .... well faster than light :)

Who knows if Heaven isn't another dimension. Would explain the loss of our body here and a new body there. Because of the change from one place to another. Yet maybe the soul or pattern of energy would be transferred to that new body.  Sounds like religion, but may actually be supported in science. 

Remember your article on the bacteria with the electrostatic drive? There is an article about this too... somewhere.