Talk:Gravitational lens: Difference between revisions
imported>Jori Liesenborgs No edit summary |
imported>Fredrik Johansson No edit summary |
||
| Line 2: | Line 2: | ||
Just finished an initial version (with home-made images :-) ) which should contain most of the basic information. Feel free to comment... | Just finished an initial version (with home-made images :-) ) which should contain most of the basic information. Feel free to comment... | ||
--[[User:Jori Liesenborgs|Jori]] 15:26, 26 February 2007 (CST) | --[[User:Jori Liesenborgs|Jori]] 15:26, 26 February 2007 (CST) | ||
A few thoughts: | |||
:''Albert Einstein published a new expression, differing only by a factor of two from the Newtonian result'' | |||
I wouldn't call a factor of two an "only". The difference is enormous compared to, say, the Lorentz factor for objects moving at classical speeds. In fact, isn't the huge difference the point of the section? Had the factor been, say, 1.01, Einstein's theory would not have been verified (at that time). Are there actually instances in which the Newtonian value is useful? The article could be a bit more explicit about whether the Eddington measurement did or did not render the classical approximation useless. With the "only" in there, I get the impression that it didn't. | |||
:''d is the impact parameter of the light ray'' | |||
I have no idea what an impact parameter is. A short definition wouldn't hurt. | |||
Also, in the "thin lens approximation" section, there are a few undefined variables. The text should be comprehensible without looking at the image. | |||
Instead of "Note that the distances are", I'd write "The distances are", since I don't see how one could note this (without prior knowledge) from the information given in the preceding text. | |||
[[User:Fredrik Johansson|Fredrik Johansson]] 15:37, 8 March 2007 (CST) | |||
Revision as of 15:37, 8 March 2007
Initial version
Just finished an initial version (with home-made images :-) ) which should contain most of the basic information. Feel free to comment... --Jori 15:26, 26 February 2007 (CST)
A few thoughts:
- Albert Einstein published a new expression, differing only by a factor of two from the Newtonian result
I wouldn't call a factor of two an "only". The difference is enormous compared to, say, the Lorentz factor for objects moving at classical speeds. In fact, isn't the huge difference the point of the section? Had the factor been, say, 1.01, Einstein's theory would not have been verified (at that time). Are there actually instances in which the Newtonian value is useful? The article could be a bit more explicit about whether the Eddington measurement did or did not render the classical approximation useless. With the "only" in there, I get the impression that it didn't.
- d is the impact parameter of the light ray
I have no idea what an impact parameter is. A short definition wouldn't hurt.
Also, in the "thin lens approximation" section, there are a few undefined variables. The text should be comprehensible without looking at the image.
Instead of "Note that the distances are", I'd write "The distances are", since I don't see how one could note this (without prior knowledge) from the information given in the preceding text.
Fredrik Johansson 15:37, 8 March 2007 (CST)