A profile of US astrophysicist Neil deGrasse Tyson, who is to host a follow up of Carl Sagan’s iconic TV show “Cosmos: A Personal Voyage”.
Tyson first saw the Milky Way when he was nine, projected across the ceiling of New York’s Hayden Planetarium. He thought it was a hoax. From the roof of the Skyview Apartments in the Bronx, where he grew up, he could only see a few bright stars. When Tyson turned eleven, a friend loaned him a pair of 7×35 binoculars. They weren’t powerful enough to reveal the Milky Way in the Bronx sky. But they did let him make out the craters on the moon. That was enough to convince him that the sky was worth looking at.
It’s a very chaotic universe we live in but a number of events of – literally – cosmic scale, taking place over billions of years, have ultimately resulted in our presence here on Earth.
From the ructions of the early cosmos to the growing pains of our planet and life’s daring evolutionary leaps, not everything about how we got here seems obvious, or even likely. Perhaps in other corners of the cosmos other sentient beings are also pondering the implausibility of their origins. Perhaps that very implausibility means we are alone with such questions.
I’ve heard, for as long as I can remember, that we live in a expanding universe, but have you ever wondered where all this expansion is going?
So what is the universe really expanding into? Nothing. There is no cosmic storage locker just waiting to be filled up with stuff.
The Big Picture’s Hubble Space Telescope imagery Advent Calendar for 2009.
Bookmark and check for a new photo daily through December.
A (stunning) photo set comparing events in our history with happenings across the universe.
Starting with nearby stars, Benson moves through the Milky Way, to distant galaxies, and finally to the edge of the known universe. As we go deeper into the past, his lyrical essays explore what was happening on Earth when light left these celestial objects: the rise of plant life, the fall of the Roman Empire, the birth of Homo sapiens.
Ok, the universe is not expanding as quickly as we thought it was… this isn’t because the universe itself has stopped expanding, or has even slowed down its growth, rather it’s time that is slowing down (it may even come to a complete halt one day), thus creating the impression that outward expansion of the cosmos seems to be faster than it really is.
If time has been slowing down, and clocks are now running more slowly than they did long ago, it would appear from our perspective as if things have been speeding up. Looking back over billions of years, galaxies would seem to be travelling away from each other faster and faster at various intervals since the Big Bang.
Our galaxy, the Milky Way, is destined to “merge” with our giant neighbour, Andromeda, in about five billion years.
Currently both galaxies are approaching each other at speeds of 120 kilometres (km) per second, and “Milkomeda” is one name that has been dubbed for the combined entity.
Before the collision occurs though both galaxies will fly past each other twice, occurrences that could possibly result in the Sun, and its family of planets, being drawn into the Andromeda system.
There is also a remote 3% chance that the Sun will jump ship and defect to the Andromeda galaxy during the second close passage. “In the night sky, we would then see the Milky Way from a distance,” says Loeb.
Just to put the distances into some perspective, moving at a rate of 120 km per second means covering about 3.8 billion km per year. The planet Neptune is some 4.46 billion km from the Sun, so we are talking about some very, very, vast amounts of space here.
Biggest Black Hole in Universe Discovered – and it’s BIG
It threatens to gobble up all of creation, but rest easy, at least the behaviour of the largest known black hole, and that of a (slightly) smaller orbiting companion, are consistent with the observations Albert Einstein made in his theory of General Relativity.
Whatever gave birth to this monster can be real proud. The biggest black hole in the universe weighs in with a respectable mass of 18 billion Suns, and is about the size of an entire galaxy. Just like in the Arnold Schwarzenegger and Danny Devito flick â€œTwinsâ€, the massive black hole has a puny twin hovering nearby. By observing the orbit of the smaller black hole, astronomers are able to test Einstein’s theory of general relativity with stronger gravitational fields than ever before.