[Tim_Lou]

ive recently viewed a show on the tv saying that there is something called "dark energy" causing the universe to expand faster and faster.
something like anti-gravity...
what are the possibility of this energy?

if gravity is simply a time curve, would it be possible that this dark energy is also a "curve"???

edit: i found a web page describing dark energy:
http://universe.gsfc.nasa.gov/science/darkenergy.html


so, a vacume is full of rejecting energy???

[BlameTheEx]

Tim

That link doesn't work. The page is there, but you accidentally added a break to the end of it. I have to confess I made the same mistake in one of my posts.

"Dark Energy" is certainly respectable at the moment, but I have some slight doubts. It seemed essential to salvage the Big Bang theory when the universes expansion was shown not to follow the script (the expansion appears to be speeding up). However I am not sure it can be called an explanation, more a matter of giving a name to our ignorance.

Personally, it feels like a fudge. As long as no convincing explanation comes up for Dark Energy, I reckon there is as good a case for rethinking the whole explanation for the observed expansion. While I am sure to be in a minority group here, I am perhaps not alone in my doubts:

"This starts to look incredibly ugly and complicated," says Mario Livio of the Space Telescope Science Institute. "I even wonder if we are we asking right questions."

That is from a rather good article on Dark Energy here:
http://www.space.com/scienceastronomy/generalscience/darkenergy_folo_010410.html

[Bo]

The main idea behind Dark energy (which has nothing to do with dark matter!) is the following.
After the big bang the universe expanded fast ('inflation', see my post somehere in the cosmology section) but this expension was counteracted by the gravitational pull of all the matter. So the fast expension should be slowed down. Measurements in 1998 or so provided proof on the other hand that the universe was accelarating. This means that there is some force pushing the universe apart.
Since the strong and weak forces only are effective on very short scales, the electromagnetic force is in avarage zero (the universe has no total charge) and the gravitational force (as we know it) only attracts, there has to be something else. This has been dubbed dark energy.
What can it be? (i'll be a bit short, i have to leave in 4 minutes...)
- Einsteins laws permit gravity also to be repulsive. It could be that on very large scales gravity works also in a repulsive way.
- The vacuum could have certain properties that 'effectively' works as a pushing force.
- Gravity could 'leak away' to extra dimensions. Also this gives effectively gravity a small pushing part.
- the compactification of string theory (going from 10 to 4 dimensions) gives rise to fields that effectively work as a pushing force.
- None of the above

[Freethinker]

Originally posted by: BlameTheEx
That link doesn't work. The page is there, but you accidentally added a break to the end of it. I have to confess I made the same mistake in one of my posts.

I think it is the site's parser that does that.

"Dark Energy" is certainly respectable at the moment, but I have some slight doubts. It seemed essential to salvage the Big Bang theory when the universes expansion was shown not to follow the script (the expansion appears to be speeding up).

I love your continual attempt to pretend the Scientific community has a problem in or with the BB. It is so cute! So totally erroneous, but cute!

There is nothing about an increase in the expansion rate that bothers the BB in the least. Since the BB was first developed out of extensive evaulation of gathered facts, one of the next questions was whether it was going to continue to expand or ultimately stop expanding and start contracting.

We found that it's expansion was accelerating.

OK.

It's accelerating.

Show us why that is so harmful to the theory of the BB that it required being "salvaged".

However I am not sure it can be called an explanation, more a matter of giving a name to our ignorance.

You hit this one on the head! We discovered that the expansion rate was increasing. We needed to discuss and set up propositions for that new knowledge. New knowledge ALWAYS leads to more ignorance. We learn that we din;t know something and now we need to learn more, and more, and more.

The feeble mind would grasp at ignorance with fear and based on superstition "give it a name" GOD!

The intellectuall approach is to avoid such stop gap (god of the gaps) filling nosnesne and research factual answer.

Personally, it feels like a fudge.

Ah so now you can FEEL dark energy? Incredible.

As long as no convincing explanation comes up for Dark Energy, I reckon there is as good a case for rethinking the whole explanation for the observed expansion. While I am sure to be in a minority group here, I am perhaps not alone in my doubts:

I asked once already above. I doubted that you would actually give any factual answers as you never do on other discussions, but I will state the question again here.

Show us why that is so harmful to the theory of the BB that it required being "salvaged".

"This starts to look incredibly ugly and complicated," says Mario Livio of the Space Telescope Science Institute. "I even wonder if we are we asking right questions."

And I love how you take the singular quote that shows concern while the vast majority were shown as it being a "New ocean of discovery".

And it was an old story you drug up from when the discovery first hit.

How typically disingenuous of you.

[Tormod]

Originally posted by: BlameTheEx
That link doesn't work. The page is there, but you accidentally added a break to the end of it. I have to confess I made the same mistake in one of my posts.

It's a pain - the parser occasionally adds a BR tag after the link and I have no way to fix it except report it to the forum software developers.

[Freethinker]

Originally posted by: Bo
The main idea behind Dark energy (which has nothing to do with dark matter!) is the following.
....
- None of the above

And that is the beauty of the Scientific approach to knowledge. We are not forced to find ways to fit ridgid theological revelations into factual discoveries. At any point that it would be shown most benefitial, we can throw it all out and start over. But in general we have found our basic foundation of physics to be reasonably accurate and we are merely learning greater detail.

[Bo]

hmm read today some things on the ekpyrotic scenario (don't know exaclty anymore what it was; i dont have my stuff here at home... it was also called 'the big clash'). The main idea was that if you smash 2 universes together; in the middle a new one comes to existence, which wouldn't need inflation of space or dark energy, but still have the desired properties.
I think this is qualified as 'none of the above'

ps i hope to know more on this subject soon so i'll might inform you

Bo

[Tim_Lou]

this dark energy sounds like the 2nd law of thermodynamics....

[BlameTheEx]

Freethinker

Edit you post to cut out the abuse and I will reply.

[Uncle Martin]

Blame,
I see in FT's post some sarcasm and dark humor,... but no abuse. We accept and deal with your "style" of posting,... I think it only fair that you try to do the same. IMHO