PDA

View Full Version : Discussion: Black Holes Might Obscure ...



Fraser
2005-Mar-10, 08:28 PM
SUMMARY: Astrophysicists from Penn State University are concerned that the light bending effects of gravity around black holes might be so severe that early times in the Universe might be impossible to study. Gravitational lenses, where the gravity of one galaxy serves to focus the light from a more distant galaxy, have been used to study deeper into space than would normally be possible. But in the close vicinity of black holes, light is bent in unpredictable ways, completely obscuring the direction of the source.

View full article (http://www.universetoday.com/am/publish/black_holes_obscure_time.html)

What do you think about this story? Post your comments below.

greenone
2005-Mar-12, 05:57 PM
this article seems a little vague as to the implications of "negative refraction". are positive and negative refraction analogous to cis and trans (right and left handed) molecules?

antoniseb
2005-Mar-12, 08:07 PM
I find it hard to imagine that there are enough black holes in the early universe to have a profound effect. I imagine that the actual paper tells more, and that the Penn State press release couldn't possibly do it justice.

vet
2005-Mar-13, 01:40 AM
i wonder if the Penn state study is taking into consideration the shown link between gravity and positive entropy? the 'extreme' ability of black hole gravity just seems to make matters worse, unless some math whiz may counter it, filter this known effect via calculation. otherwise, the problem remains---one may even postulate the problem as 'thermodynamic-disorder', which applies to information, as well as 'living systems'.

The Near-Sighted Astronomer
2005-Mar-14, 07:56 PM
Hi All,

Frankly we will never see the Big Bang event anyway since it is obscured by the opacity of the early hyperinflationary epoch (0-380,000 years after the Big Event). So the article's thesis is already precluded by that fact. But I did like the notion of seeing space as possessing a variable refractive index - this falls nicely into my own pet theory of spacetime as a "stressor" field where em wavefronts induce "hot potato" moments propagating expansively to eliminate photonic disruption.

Ah well, we shall see what we shall see. But right now we could really use some good "synthetic thinkers" who could start to pull together all the bizarre phenomena of the Cosmos and give it to us straight...

Cheers,

jeff

vet
2005-Mar-14, 11:08 PM
as history has shown, the 'emperor's new clothes' phenomena often shows up 'down the line' in science. i'm not yet ready to embrace inflationary models---kind of reminds me of applying duct-tape, after the facts don't fit. sure won't be the 1st time---it's regrettable AI is not up and running---that would enhance problem solving, if for no other reason than lessening the human tendency for 'personal-agenda'. that's been a big problem---

Darwinism is a perfect example---only possible, as a major evolutionary engine, if it were a smooth homogonous process---which the fossil record never supported---and there must be No instance of 'environmentally-interactive acquired characteristics'---now shown---but look at how long it's taking for even
'educated' people to 'snap-out-of' it. evolution, as even mr. darwin stated, could, and apparently does proceed as living systems actively change their hereditary structure with respect to environment---as the great sci-fi writer Alfred Bester pointed out---it's not 'survival of the fittest', rather 'arrival of the fittest'.

doubters only have to do a bit of surfing---enjoy---

eburacum45
2005-Mar-15, 01:20 AM
Because the first stars that formed in the early universe were either large or giant there will have been a lot of black holes in the early universe.

It seems likely that there were no small stars in the first generation after the Big Bang, simply because there are no red dwarfs surviving from that era. Red dwarfs have a lifetime longer than the age of the universe, but there are no red dwarfs without metal lines- a primordial red dwarf would be almost completely made of hydrogen and helium even after all this time, as they don't fuse hot enough to produce metals.
Yet none seem to exist.

So the early universe would quickly fill up with black holes; today they would be much further apart, because of the expansion of the universe; but in the very early days of star formation, they would be close together, and could disturb light propagation noticably.
It might be the case that our view of the early universe would be like looking through ripple glass.

Guest
2005-Mar-15, 12:10 PM
Originally posted by vet22@Mar 13 2005, 01:40 AM
i wonder if the Penn state study is taking into consideration the shown link between gravity and positive entropy? the 'extreme' ability of black hole gravity just seems to make matters worse, unless some math whiz may counter it, filter this known effect via calculation. otherwise, the problem remains---one may even postulate the problem as 'thermodynamic-disorder', which applies to information, as well as 'living systems'.
...as well as 'living systems', :P such as turtles on top of each others