17-02-2007 TV static (Article 73)

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Simon Kenny
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Location: Shannon, Co. Clare, Ireland

17-02-2007 TV static (Article 73)

Post by Simon Kenny » Wed Feb 04, 2009 10:42 am

TV static (Article 73)

You know the scene - you settle down to watch the telly, press the zapper and- nothing, only black and white dots and a loud hissing noise. Next time you see this happen, look again, because what you see and hear has inspired a huge growth in our knowledge of the universe in the past 40 years- how it began, how it grew and how it might end. This irritating TV static is the birth-cry of our universe, some 13.7 billion years ago!

In 1963, Arno Penzias and Robert Wilson built a microwave receiver in New Jersey to study radiation from the Milky Way galaxy. Everywhere they pointed the antenna they were bothered by low-level static interfering with their work. They discovered it came from beyond our galaxy, from everywhere in space and was very smooth in texture, so smooth that the variations were less than 1/10,000th of the signal’s strength.

Back in the 1960s there were two main theories about the origin on the universe. The first was that it didn’t begin at all: the Steady State theory. The second was the ‘Big Bang’ theory: that the universe began with an explosion at some distant time in the past. Supporters of the Big Bang model predicted that this explosion would have released massive amounts of energy, which should now be detected as microwave radiation coming from all parts of space. Penzias and Wilson had accidentally discovered in this annoying background hiss the fingerprint of creation: powerful evidence that the universe did indeed begin in a ‘Big Bang’.

Then a puzzle arose. The Cosmic Background Radiation (CBR) as it became known, is very smooth, which means that in the early universe, all the matter and energy was very evenly distributed. Nowadays, the universe looks anything but smooth: the matter and energy of the cosmos are formed into complex galaxy clusters and super-clusters with vast tracts of emptiness in between. Why, if the universe started off so smoothly, did it get so granular in structure as it evolved over time? This question needed answering before the Big Bang theory was accepted.

To solve the riddle, NASA launched the COBE space telescope in late 1989. It carried sensitive detectors to examine the smoothness of the CBR. In 1992 the answer came: the radiation did have very small but detectable variations in intensity. Scientists now had the answer to why the matter of the universe is so clustered: the clusters originated in the very small variations in the density of the primordial matter and energy just after the creation of the universe. So the Big Bang is now accepted as the most likely cause of the universe.

So the next time you see that annoying soup of dots on your TV screen and that hiss in the speakers, stop and think: you are witnessing the birth pangs of our universe nearly 14 billion years ago! Clear skies!

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