been hypothesized that a habitable time zone exists for the creation of Earth-like systems. For two billion years after the Big Bang, carbon, oxygen, phosphorous, potassium, sodium, iron, copper, as well as uranium were not present in the universe. These elements are required (among a few others) for organic life. Only after this time period were supernovae explosions able to produce heavy elements up to uranium. Stars forming now have fewer radioisotopes than the sun did when it formed 4.6 billion years ago. If a planet were to form around a star with fewer amounts of these isotopes, the planet’s core would not have enough radioactive heat to drive plate tectonics. Also, galaxies 30-40% older than ours seem to have more instances of being irregularly shaped, and therefore not able to contain an Earth-like system. To expand the habitable zone to a broader category, consider the entire universe. Statistically the universe is either too cold or too hot, too dense or too vacuous, too dark or too bright, or contain too little heavy elements to support Earth-like planets. However, even though time and statistics my prove otherwise, I adamantly disagree that these findings lead to Earth being totally unique and the entire universe being devoid of intelligent life. The vast, almost incomprehensible size of the universe leads me to believe that the information that we know at this time is astronomically smaller than what we don’t know about its properties. For example, in 1961 there was a now renown conference held at the National Radio Astronomy Observatory in Green Bank, West Virginia, to discuss the question of a 'search for extraterrestrial life' (SETI). That gathering brought together a worldwide array of prominent astronomers and exobiologists. The conference set out with the intention of attempting to quantify, by theoretical means, the number of technically advanced extraterrestrial intelligence civilizations within the Milk...
