MAP Satellite Launch

PineGreen writes: "Tomorrow, MAP Satellite is to be launched. MAP is the first space mission to measure Cosmic Microwave Background (CMB) fluctuations after the famous COBE who was first to detect fluctuations in the CMB. It is supposed to do the job with an unprecedented accuracy. There were several successful balloon experiments (Boomerang, Maxima) and interferometer experiments (VSA, DASI, CBI), some of which still haven't published their data. But of course, we are all waiting for the big European Planck mission in 2007. Measuring CMB fluctuations can tell us a lot about the universe in which we live, its constituents and its geometrical properties."

Comments

abbreviations

[jfinke]

I wonder if it is possible to use any more abbreviations in that story....

Re:Big Bang or just a fizzle?

[jafuser]

Ok, I am not an astrophysicist, but I did just get the highest score in my astronomy class (by a margin of 10% even) :)

The general temperature of the cosmic background radiation is evidence of the big bang. I think it was something close to 2.7 degrees Kelvin. This temperature is a minimal black body temperature which exists everywhere in the universe, no matter which direction we look. Apparently the uniformity of this tells us that as the universe is expanding, that the temperature will go down. So someone looked at this and figured out that if you play the expansion in reverse, that as the universe was smaller, this background temperature would have to be higher, eventually focusing on the big bang.

When we use very sensitive equipment and draw an image from measurements of this black body radiation, we at first can see an effect caused by doppler shift becuase our planet is moving through space. Space seems hotter in the direction we are going, and cooler in the direction we are coming from.

Finally, if we adjust for this doppler effect, and look at the temperature at even much higher accuracies (something like millionths of degrees) we start to see a nonuniform image of random warmer and cooler spots across space.

One major significance of this is that if we measure the average distance between the cooler and warmer spots, we can compare this to a mathematical model which will tell us the curvature of space itself (on a very large scale) . If they match a mathematical model of flat space, then space is probably flat. If the patterns are larger or smaller than the flat model then space is probably curved, either hyberbollically or spherically.

Of course, a non-flat space has some interesting consequences. The angles of a triangle don't add up to 180 degrees, and parallel lines will not stay equidistant (they may merge or converge) as they due in euclidian geometry.

This satellite will provide a higher resolution image than COBE.

I just woke up so I probably left out something important or really said something stupid...

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