The pregalactic hydrogen has structures of all sizes which are the precursors of galaxies, and there are up to 1000 of these structures at different distances along every line of sight. A radio telescope can separate these because structures at different distances give signals at different observed wavelengths. Metcalf and White show that gravitational distortion of these structures would allow a radio telescope to produce high-resolution images of the cosmic mass distribution which are more than ten times sharper than the best that can be made using galaxy distortions. An object similar in mass to our own Milky Way could be detected all the way back to the time when the Universe was only 5% its present age. Such high-resolution imaging requires a extremely large telescope array, densely covering a region about 100 km across. This is 100 times the size planned for densely covered central part of LOFAR, and about 20 times bigger than densely covered core of the Square Kilometre Array (SKA) the biggest such facility currently under discussion. Such a giant telescope could map the entire gravitating mass distribution of the Universe, providing the ultimate comparison map for images produced by other telescopes which highlight only the tiny fraction of the mass which emits radiation they can detect.
Well, du-uh.
2 posted on 12/14/2006 2:26:10 PM PST by Maceman
(This is America. Why must we press "1" for English?)