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NGC 5905 & 5908 (APOD 29 Sep 2006)
Posted: Fri Sep 29, 2006 2:36 pm
by orin stepanek
http://antwrp.gsfc.nasa.gov/apod/ap060929.html
The writeup says NGC 5908 looks like the Sombrero galaxy. I guess it does some; but upon enlarging it looks like NGC 5908 may have better defined spirals than the Sombrero. These galaxies are both symmetrical and very beautiful. I wonder if they are attracting each other like the Andromeda and the Milky Way.
Orin
The picture of the day 09-29-06
Posted: Fri Sep 29, 2006 2:47 pm
by Lawrence J. Carmalt Sr.
After viewing the picture of the day and noticing the spiral shape of the galaxy, I thought there is a similarity to the spiral galaxy and the way water flows in a drain here on earth. Using this Idea, it is probable that we can determine the, so to speak, position that galaxy within the universe or the universes shape.
Is it just possible that these galaxies are affected by the entire universe's magnetic field, just as water in a drain is affected by its location on earth, Clockwise in the Northern hemesphere, counter-clockwise in the Southern hemesphere, and in no particular direction at the equater?
In any case the pictures I have viewed today are awesome, too say the least.
Posted: Fri Sep 29, 2006 3:41 pm
by Qev
Actually, the direction water spirals down the drain in your sink is not significantly affected by your location on the planet. While the coriolis effect does exist, it only plays a noticable role in much larger systems, like hurricanes.
The direction a galaxy spirals depends pretty much solely on what side of the galaxy you happen to be viewing it from. There aren't really any preferred directions in the Universe, at least as far as I'm aware.
Reply to post of Lawrence Carmalt
Posted: Fri Sep 29, 2006 4:39 pm
by Lawrence J. Carmalt Sr.
Actually if you are looking at a hurricane from above the direction of the wind is different then if you are looking from below, so you are right as far as that is concerned. The effects of gravity do affect the rotation of water on earth but the direction the water rotates depends upon where you are watching it and if you are looking from above or below. Check it out the next time you flush the toilet. :>}
I also did an experiment when I worked at Lockheed with fellow workers and found that most people when told to spin around do so in the direction water rotates if looked upon from above. This was not a scientific experiment but when they were asked to spin around the direction was usually as I have said, The human body is more than 70% water.
P.S. I didn't take into consideration right or left handed people. I'm sure that played a part. Try it on some of your friends, and let me know.
Thanks
Posted: Fri Sep 29, 2006 4:53 pm
by BMAONE23
You can actually feel the same effect by spinning in you office chair (if it happens to be able to spin). I personally feel thet it feels better (easier) to spin in one direction vs the other. As I live in the Northern Hemisphere, I think clockwise is easier. Caounetclockwise tends to make my head swim sooner and to a greater effect.
Posted: Fri Sep 29, 2006 7:07 pm
by iamlucky13
Try watching the water drain from your sink after doing the dishes. I was slightly disturbed the first time I did this to find it draining the wrong way, but in another sink, it drained counterclockwise, as I was told to expect. I very seriously doubt Coriolis effect is responsible for everyday effects that form on scales less than at least quite a few yards, probably miles.
For example, I have a round sink 2' in diameter with the southern rim at exactly 45 degrees latitude. The distance to the earth's axis, assuming 4000 miles radius at the equator, is 4000 cos(45deg) = 2828.42712 miles. My angular velocity is therefore 740.48049 mph. The latitude of the northern edge of the sink is 45.0000077 degrees, so its radius is 2828.42674 miles. Thus its velocity is 740.48039 mph.
The difference in the angular velocity between the southern and northern edges of the sink? 0.0001 mph or 4/100 of a millimeter per second. That's hardly any effect compared to, say, pouring water into the sink, which visibly causes swirls moving several inches per second.
Right handedness probably a much bigger effect. I prefer to spin counterclockwise (same direction as cyclones in the north) in my chair, but I also prefer to corner left when driving hard, I turn left to stop when skiing, I'm better at left turns on switchbacks when mountain biking, and I usually slide tackle with my left leg down (right leg forward) in soccer. I've got a hunch these are all related effects.
Anyway, in relation to the original question, the direction a galaxy spins, or in fact a galaxy cluster, or a solar system, or a planet, would be dependent on the initial disturbances that led to the formation of those bodies. I would be inclined to say that there should be a trickle down effect from large features to small features related to Coriolis effect, but the thought of trying to model the interactions make my head spin.
Posted: Fri Sep 29, 2006 8:21 pm
by Wadsworth
Here ya go