"You are talking about people...who thought that there is a tree at the centre of the universe that draws water from the water of various worlds...they didn't know much about the laws of physics or how the universe works, at all."
If you examine the legend carefully, you will find an extraordinary number of parallels between Yggdrasil and the supermassive black holes that are found at the centre of many galaxies. Yggdrasil was an incomprehensible size, similar to the infinite density and enormous size of supermassive black holes. The darkness that permeated the insides of the tree is clearly paralleled in the ability of black holes to absorb light.
As to drawing water from various worlds, this is clearly a metaphorical device to explain the existence of quasars, i.e. supermassive black holes that devour stars in their accretion disks, spewing out vast quantities of light. The liquidisation of these entire "worlds" (if you will), to sustain the black hole and produce new light is clearly reflected in the water that the tree draws to maintain life.
Obviously we cannot expect the Norse people to get everything absolutely correct, hence the metaphors, but we can also easily forgive them for their discrepancies (e.g. between the centre of the universe and the centre of the galaxy) as merely teaching aids. How easily could you explain complex cosmological principles to the layman today without being innaccurate, let alone explain to a bloodthirsty viking.
You may dismiss them as myths from thousands of years ago, but I find it particularly remarkable that they were able to make these observations thousands of years before any of the knowledge and instruments of modern cosmology. It seems they knew more about the universe than even we did 100 years ago. How's that for science?
Who knows what else we could learn from them?