Wonders Of The Universe
by Chita C. Heap
This information was taken from the advertisement feature of The Times Newspaper in the United Kingdom during my recent visit. In this issue Professor Brian Cox reveals how the most fundamental scientific principles and laws explain not only the incredible story of the Universe, but the story of us all.
How Will Planet Earth End?
Inconceivable but true- One of the most bizarre truths to have emerged from science is that we know more about the eventual fate of our Earth, and indeed the entire Universe, countless trillions of years hence, than about what the weather will do next.
As far as our planet is concerned, for instance, we know that it is doomed. Happily, the end is not exactly nigh; astronomers and physicists have calculated that our star, the sun, will start to run out of its hydrogen fuel in four or five billion years. After that it will swell into a grotesque parody of its current form, engulfing the planets Mercury and Venus as they swell into a bloated giant more than 200 million miles across. The Earth will be a seething hell hole, oceans of water replaced by seas of liquid rock.
But life on Earth will be over long before that. In just a billion years or less, the Sun will have become significantly hotter, causing oceans to heat up and eventually boil away. The end of the story of life on Earth will start at the Equator and finish at the poles, the last hardy microbes perhaps surviving for hundreds of millions of years after the last plants and animals have died out.
But the Universe itself will carry on. Stars will continue to be born and die, perhaps for trillion years or more. In the meantime, dramatic events will overtake our galaxy, the Milky Way, at about the same time the Sun swells into a Red Giant.
Astronomers operating the Hubble Space Telescope calculated that the Milky Way will collide with its nearest galactic neighbor, the Andromeda Galaxy, in about four billion years. Currently, the two giant galaxies are racing towards each other at 250,000 mph, a velocity that will quadruple as the galaxies fall into a gravitational embrace. Despite the enormity of the collision, it is quite possible that not a single star in either galaxy will hit another. This is because space is almost unimaginably empty.
But it is the largest scales and in the most distant future, of hundreds of billions of years hence, that things to get seriously weird. Cosmologists have known since the 1920’s that the Universe as whole is getting bigger. Local collisions aside (such as the Milky Way-Andromeda impact), most galaxies in the Universe are rushing apart, and have been doing so since the Big bang 13.7 billion years ago.
We can measure this expansion very precisely and give it the phenomenon and who posthumously gave his name to the space telescope. For every million light years one travels, farther-away objects are travelling a further 25 km a second or so faster away from you.
Time is perhaps the most mysterious property of our Universe. We still have no real idea of what time is and why it flows in the direction it does. Is it possible to travel backwards in time? In theory yes, but whether this will ever be practical no one knows, nor do they know what would happen if you caused one of the famous time-travel paradoxes, such as going back and shooting your parents before you were conceived (how then would you exist to do the shooting).
The more we learn about the Universe the weirder it seems. Many cosmologists, including the Astronomer Royal, Martin Rees, now believe that the magnificent assemblage of galaxies that we see is but a tiny mote on a much larger and grander entity called the Multiverse. The more we learn about the cosmos, the more we are forced to agree with the observation of the great scientist J.B. Haldane, who said that the Universe is “not only queerer than we CAN suppose.”
Did You Know?
A) That ancient fossils suggest that life arose on Earth just a few hundred million years after its formation, 4.6 billion years ago. The fact that life was able to get a hold so quickly on what would then have been a hostile world suggests, say astrobiologists, that life should be everywhere.
B) Another possible Earth twin is Gilese 667Cc, a planet about 42 light years away that orbits a long-lived Red Dwarf star. This is a “super earth” about 3.9 times the mass of our world but a little larger. It receives about 90% of the sunlight that we do, meaning surface temperature should be similar to ours. It orbits its tiny sun so closely that a year only lasts seven Earth Days.
C) Based on observations from Earth based telescopes and space observatories, it is thought that around one in 50 of all the stars in our galaxy, the Milky Way, have earthlike planets orbiting them in the Habitable Zone. This would mean there are about two billion Earth twins in our galaxy alone and several tens of millions in the observable Universe. /MP