Last updated on August 31, 2019
The universe is the whole of Existence- all of space, matter, energy, and time. The Universe is so vast as to be unimaginable. but we do know that it is steadily expanding following it’s beginning 13.8 billion years ago in an explosive event called Big Bang.
THE SHAPE OF SPACE
The three dimensions of space are “bent” by the force of gravity from the matter in the Universe into a fourth dimension that we can’t see.
This is hard to visualize, so scientists use the metaphor of a two-dimensional rubber sheet to explain the Idea. The mass of the Universe could bend this rubber sheet in one of the three ways, depending on how densely packed with matter the Universe is.
THE SCALE OF SHAPE
The universe is so vast that we cannot appreciate its size without making leaps of scale. When dealing with the vast distances in space, kilometers aren’t big enough. Instead, astronomers use the speed of light as a yardstick. Light is so fast it can travel around Earth 7.5 times in a second.
IS THERE, ANYBODY, OUT THERE?
One of the biggest questions in science is whether life is unique to Earth or has arisen on other worlds. And if life has appeared elsewhere, could intelligent beings have set up projects to watch and listen for signals from extraterrestrials, and messages have been sent to the stars to inform any aliens out there of our existence.
In 1974 Scientists used the giant Arecibo radio telescope in Puerto Rico to broadcast a radio message towards the star cluster M13. The message contains symbols, our base ten counting system, the DNA molecule, and the solar system. More a publicity stunt than a serious attempt to contact aliens, the broadcast will take 25,000 years to reach M13, and the reply will take 25,000 years to return.