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View Full Version : Black holes bend light the wrong way


wolram
Feb24-05, 11:14 AM
http://www.nature.com/news/2005/050214/full/050214-5.html
Something called negative refraction.

RoboSapien
Feb26-05, 08:43 AM
I read it but I am an amature, can U explain it in 100 words please.

DaveC426913
Feb26-05, 10:46 AM
It doesn't really explain what happens, it merely comments on the effect: under very specific circumstances rotating black holes can bend light away from themselves, instead of towards themselves.

They then go on to suggest that this is messing up all our previous observations.



But personally, I think they've got the scientific method backwards, at least the way the article is laid out.


"...researchers showed that certain artificial materials bend light in the opposite direction..."

"...prompted a flurry of research ... understanding and developing negative refracting materials..."

"...demonstrated that negative refraction could occur in a vacuum ... identified something that meets these requirements: a rotating black hole..."

They've encountered the phenomenon in materials, they look for other places where the phenomenon mgiht happen. It could happen here, so it must.


And is further weakened by its usefullness:

"some researchers question how much influence the effect will have in practice. ... in doubt as to the astronomical relevance ... the effect will be limited to small regions of space, as it can only occur in regions where the gravitational field is extremely strong.

wolram
Feb26-05, 12:31 PM
I have googled the net but i can not find anything related to
negative refraction, maybe i am not looking in the right places
but the author of this paper is not very forthcoming.

turbo
Feb26-05, 12:52 PM
I have googled the net but i can not find anything related to
negative refraction, maybe i am not looking in the right places
but the author of this paper is not very forthcoming.One way to search for recent papers is to use citebase search - here:

http://citebase.eprints.org/cgi-bin/search

I keep that bookmarked in my browser. Just punch in the author(s) name and have the search sorted by date. That yielded this paper:

http://citebase.eprints.org/cgi-bin/citations?id=oai%3AarXiv%2Eorg%3Aastro%2Dph%2F0501 522

You can also search by title, keyword, etc, and sort the results in all kinds of useful ways.

wolram
Feb26-05, 02:16 PM
Thanks for the tip Turbo
Im not sure if this anomaly has any relevance, even if it exists,
being confined to the event horizon of a rotating BH, it may screw
up some observations if anything.

RoboSapien
Feb27-05, 06:59 AM
Are there any images that show what is the right way and what is the wrong way Please ?