Some final things about inflation.....!!!! As I explained earlier that the curvature of the universe depends on its density. So, if we somehow can the curvature of the universe at a particular point in the space, we can estimate its density. At this point, Id like to explain the CMB radiation or COSMIC MICROWAVE BACKGROUND RADIATION. In a nut shell CMB is actually the remnant of the radiation, liberated at the time of the Big Bang. It has been travelling ever since the beginning alonwith the universe. Your radio catches it, your television antenna catches it, you listen or see this signal everyday as the noise or waves in between the TV channels or radio stations. Now, having understood CMB, imagine two planes, being struck by light waves at different angles as in the illustration below. Depending upon the angle, each of them will absorb and reflect the radiation differently, making the temperature change different from each other. SO, it goes like this, 1) If we can measure the temperature difference between different patches in the sky, we can estimate the angle between them i.e. the angle at which the CMB is heating each patch. 2) AND if we can, measure this angle, we can find the curvature of the universe at that point in the sky. 3) AND if we can find the curvature, we can estimate the density of the universe. THIS VERY LOGIC IS BEING USED BY THE RECENTLY LAUNCHED SPACE PROBE WMAP(Wilkinson Microwave Anisotropy Probe). NOW...... QUESTION ARISES WHY CANT WE FIND THE DENSITY SIMPLY BY MASS DIVIDED BY VOLUME FORMULA? ANSWER IS 1) We dont know the volume or the mass of the universe. 2) If we use the observable universe only, its volume and its mass only, still there is error because there is a lot of dark matter, far more than matter itself.
Posted on: Sun, 05 Oct 2014 06:40:24 +0000