When you sit down to hear Stephen Hawking, the questions you face cannot be small. “There is nothing bigger or older than the universe. The questions I would like to talk about are: one, where did we come from? How did the universe come into being? Are we alone in the universe? Is there alien life out there? What is the future of the human race? Up until the 1920s, everyone thought the universe was essentially static and unchanging in time. Then it was discovered that the universe was expanding. Distant galaxies were moving away from us. This meant they must have been closer together in the past. If we extrapolate back, we find we must have all been on top of each other about 15 billion years ago. This was the Big Bang, the beginning of the universe.”
Hawking goes on to add, “The Universe can spontaneously create itself out of nothing…” He explains this statement by saying that we distinguished between space and time but, “…under extreme conditions, general relativity and quantum theory allow time to behave like another dimension of space. This removes the distinction between time and space, and means the laws of evolution can also determine the initial state. Moreover, we can calculate a probability that the universe was created in different states. These predictions are in excellent agreement with observations by the WMAP satellite of the cosmic microwave background, which is an imprint of the very early universe. We think we have solved the mystery of creation.” Hawking takes a dig at our lives and thinking by saying, “Maybe we should patent the universe and charge everyone royalties for their existence.”
It is mind boggling as he says that one cannot rule out other life in space. “…are we alone, or is there other life in the universe? We believe that life arose spontaneously on the Earth, so it must be possible for life to appear on other suitable planets, of which there seem to be a large number in the galaxy. But we don’t know how life first appeared. We have two pieces of observational evidence on the probability of life appearing. The first is that we have fossils of algae from 3.5 billion years ago. The Earth was formed 4.6 billion years ago and was probably too hot for about the first half billion years. So life appeared on Earth within half a billion years of it being possible, which is short compared to the 10-billion-year lifetime of a planet of Earth type. This suggests that a probability of life appearing is reasonably high. If it was very low, one would have expected it to take most of the ten billion years available.”
Giving meat to our imagination, Hawking has a cautionary tone based on recent evidences, “On the other hand, we don’t seem to have been visited by aliens. This probably indicates that there are no alien civilizations at our stage of development within a radius of a few hundred light years….” Even then the limits are given. Beyond the few hundred light years, we may still be able to find a living being? But this at least gives us monopoly over quite a distance. What then does our future hold?
“If we are the only intelligent beings in the galaxy, we should make sure we survive and continue. But we are entering an increasingly dangerous period of our history. Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill. But our genetic code still carries the selfish and aggressive instincts that were of survival advantage in the past. It will be difficult enough to avoid disaster in the next hundred years, let alone the next thousand or million. Our only chance of long-term survival is not to remain lurking on planet Earth, but to spread out into space. That is why I am in favour of manned –– or should I say, personed –– space flight.”
Take flight, readers with your imagination!
sudhmamahi@gmail.com
