Check out these images of the earth’s gravitational field taken by a couple of satellites from the GRACE project:
This information will let scientists get a better idea of the earth’s internal structure, in turn helping them to model things like weather patterns and geographic change more accurately. Plus, it looks awesome.
(Via)
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There’s no context for this picture. It would be nice if I knew what the colors mean, and all that.
interesting, but I agree with the first comment.
Maybe you need to go to the GRACE site for more in depth explanation. <a href=”http://www.csr.utexas.edu/grace/gallery/gravity/03_07_GRACE2.jpg”
Hey guys, thanks for the comments. Larsalan is right – you get get more information from the GRACE website. I’ll update the post when I get chance to explain it a bit more
My first thought was, how do you measure gravity? Maybe you see how much force is needed to escape it? The GRACE mission has twin-satellites flying in formation – maybe they look for differences in the amount of force each has to exert to stay where it is?
But the bottom line seems to be that the results “infer” (their word) the denser lumpy bits in the the overall soup. So presumably the standard reference is that density equals attraction equals gravity.
Satellites don’t stay in a perfect orbit, because the earth is not a uniform sphere. They can however find their position in relation to fixed points on the earth. By measuring the satellites’ slight tendency to veer towards or away from predicted orbit (as if earth was a perfect sphere) this “lumpiness” can be mapped. Do note that the 3D models are very exaggerated.
gravity can also be measured by a ground-based machine. they showed it on mythbusters one time, and if i can remember correctly, they fired a laser into a vacuum chamber, and measured how long it took (since if there was more gravity, it would fall faster due to relativity) to get to the other side. it was extremely accurate, and the myth was busted.
What is going on in Indonesia? Any why is India wicked light? (I might have them backward, I dont know if the red is heavy, just assuming)
What’s amazing is we don’t even understand gravity. or light.
The best way to deliver this type of data might be with a rotating ball effect. SS
-sigh- Reading these comments has been frustrating. A moment’s observation of the models shows a clear correlation between the color (ranging from blue to hot-pink) and diameter of the sphere. Blue-colored areas don’t “stick out” as much as the hot-pink areas. So that answers THAT question. To the poster who claimed that this has ANYTHING to do with “lumpiness”, actual topography, or the fact that the models are “exaggerated” is just plain wrong. This is NOT a depiction of physical shape, it is a map of where gravity is the strongest (Indonesia) versus the weakest (India). This occurs because of high concentrations of mass (‘mascons”) which do not necessarily “stick out” as mountains. Put another way, the earth isn’t made up of uniformly dense material. Some of it is fluffy, some of it is packed hard. The hard-packed stuff has a higher gravity field than the fluffier stuff. The model, then, is how the earth would have to be shaped IF a) you wanted the gravitational field to stay the same as it is now and b) the earth was made up of the same uniform material throughout. Does that clear it up?
Oh, I nearly forgot. To those wondering why those two areas are so different, here’s the theory scientists have. The big Sumatran earthquake in Dec 2004 in the Indian Ocean has left a “scar” in the gravity field. I observe that the “ring” along Indonesia corresponds with the famous “ring of fire” we all learned about in Grade 3/4, and presume this would have something to do with molten rock constantly being deposited and packed down in the same place over and over again (creating a mascon and therefore a gravity field anomoly).
So red means evil, right?
Rght over Japan… tsunami and earthquake problem?