3, "COSMIC ALCHEMY"|
UK Air Date (BBC 2): September 14th at 7.45pm, US Airdate (PBS): October 27th at 9pm
In the beginning the Universe started as a single point. Yet from this tiny beginning came all the matter than we can see around us today. How could pure energy become matter? Over the past century a series of discoveries have shed light on our understanding of matter.
The medieval alchemists unknowingly were already studying the transformation of matter. They believed in the Greek idea of four basic substances, earth, air, fire and water. By rearranging these substances they hoped to make gold. Although they were a long way from achieving their goal many of their practices were taken on by the modern scientists in the study of chemistry in their quest to understand the nature of matter.
By the late 1800's scientists no longer believed in the four elements, but that there were about 65 elements. Mendeleev was the first to lay out the basic pattern that connected all the elements by their atomic weight. He created the Periodic Table. From this he aroused great interest in the last element in the table uranium.
The Curies' studied the rays that Becquerel had shown were coming off the uranium. They wanted to find out how radiation was emitted from various substances. They discovered two new elements, most importantly - radium the most radioactive element known.
Ernest Rutherford took the study of radioactivity another step further finding that the radioactive elements were not just decaying but actually regrouping to become a different element releasing vast amounts of energy in the process. This was a major step towards dispelling the idea of the atom as the fundemental building block of all matter.
With the developments in particle physics Rutherford used the radioactive elements to make a new discovery. He proved that the atom was not fundemental by firing particles at a target at great speed and splitting the atom.
At the same time Albert Einstein was publishing his theory of special relativity which would include the famous equation E=Mc2. This suggested a basic relationship between energy and matter, confirming Rutherford's discovery. If matter could create energy could the reverse happen.
Paul Dirac took Einstein's equation and found something extraordinary. If the equations were to work something else had to be created when energy transformed into matter. Carl Anderson was to confirm this with his discovery of anti-matter with his cloud chamber.
Today modern particle accelerators can create anti-matter and matter and produce extraordinary images of creation. These particle collisions can give us greater detail and give us the possible story of how the universe was a long time ago. By an extraordinary twist of nature more matter is created out of these collisions and because of this asymmetry we and everything we know can exist.
From a white hot big bang to planets and people is an extraordinary journey. We may not understand why the big bang exploded but we have a picture of how matter evolved after that which is supported by observation and experiment. It may be difficult to believe that all the matter in the universe came from just energy, but that is the way the universe seems to be.