Quote:
Originally Posted by erick
Looking at today's APOD
http://antwrp.gsfc.nasa.gov/apod/ap080614.html
I found myself wondering on the relative proportions of clockwise and anticlockwise spiral galaxies that we observe from our vantage point on earth. Logically I would expect equal numbers? A bit of internet searching turned up:-
Referring to the GalaxyZoo project, a poster said:- "A recent and ongoing study shows that the direction of the arms in spiral galaxies is uniformly distributed in 'all' directions. That is, no regions have been found with concentrations of clockwise or anti-clockwise rotating galaxies. A previous smaller study seemed to indicate that there was such a 'preference'. The larger study seemed to confirm that at first, but when presented with mirrored images, the 'preference' stayed the same. So it seems it was human error: a human viewer would have a preference in seeing a certain rotation when the image wasn't very clear. Careful analysis of the classification of regular and mirrored images shows no preference in either rotation."
So 50:50. Is that what you understand it to be? |
Yeah, 50:50. As I understand it, if it
wasn't a 50:50 ratio, it would appear as though the universe had a preference for one specific direction. However, that contradicts some of the big understandings of cosmology (if I recall correctly, on large scales the universe is supposed to be relatively homogeneous).
Hence, there was some interest in the initial GalaxyZoo study as it appeared to be showing that there
was a preference. Big trouble. But upon further thought, it turned out to be merely the way our human brain interprets images of spirals. To test this, they flipped the GalaxyZoo images - if there really was a preference then the other direction would start getting more hits, but if it was just human interpretation then the same results would be gathered. As I understand, the same results were obtained - it was just a human brain thing.
That's my understanding of it all. I may have gotten some details wrong though. Someone with more info will hopefully be along soon.
