The February talk was on astronomy, titled "The Big Bang ... Star Dust ... and the Pale Blue Dot. This is a brief summary of the talk, click on this link for a more detailed exposition.
In 1927 Edwin Hubble announced that the universe was expanding. Astronomers debated the cause of this strange phenomenon for nearly 40 years until in the mid-1960s the issue was resolved - we are living in the aftermath of a massive cosmic explosion that was named the Big Bang. The Big Bang occurred 13.8 billion years ago.
A lot of energy came out of the Big Bang, and you might expect all of the elements that make up the universe did as well, but this was not so. The only elements produced by the Big Bang were Hydrogen, Helium and a little bit of Lithium.
So where did all of the other elements come from - ie Oxygen, Nitrogen, Carbon and the like. The answer is from stars!
We are all ...
The energy that the sun produces and which makes life possible on our planet comes from converting hydrogen to helium in the core of the sun.
Large stars produce many more elements which are eventually expelled into the universe when the star dies in a massive explosion.
So the oxygen you are breathing and most of the elements that make up your body came from stars.
About 4.5 billion years ago a large gas cloud collapsed to form our solar system. The Earth is very unusual as life developed on it, which in the space of 3.5 billion years led to us.
Humanity was a restless species and eventually explored all of the planet and then looked around for more challenges. And so the Apollo program to explore the moon was born. The first Apollo mission to orbit the moon was Apollo 8. Its main objectives were to test out the equipment and plans made by Nasa and scout possible landing zones. But it actually became well known for a photograph which became so famous that it was given a name "Earthrise".
Although we knew that the Earth orbited the sun, seeing out beautiful planet rising above the barren plains of the Moon, surrounded by dark and hostile space started many people thinking more carefully about ways to care for our home.
Nine years later Nasa launched the Voyager space probes to investigate the outer solar system. When Voyager 1 had completed its mission Nasa turned the spaceship around and took a photo of Earth. This became known as the "Pale Blue Dot".
The video below shows the photo and provides a moving commentary, by Carl Sagan, on its significance.
The Big Bang
In 1927 Edwin Hubble announced that the universe was expanding. Astronomers debated the cause of this strange phenomenon for nearly 40 years until in the mid-1960s the issue was resolved - we are living in the aftermath of a massive cosmic explosion that was named the Big Bang. The Big Bang occurred 13.8 billion years ago.
A lot of energy came out of the Big Bang, and you might expect all of the elements that make up the universe did as well, but this was not so. The only elements produced by the Big Bang were Hydrogen, Helium and a little bit of Lithium.
So where did all of the other elements come from - ie Oxygen, Nitrogen, Carbon and the like. The answer is from stars!
We are all ...
... Star Dust ...
The energy that the sun produces and which makes life possible on our planet comes from converting hydrogen to helium in the core of the sun.
Large stars produce many more elements which are eventually expelled into the universe when the star dies in a massive explosion.
So the oxygen you are breathing and most of the elements that make up your body came from stars.
... the Pale Blue Dot
About 4.5 billion years ago a large gas cloud collapsed to form our solar system. The Earth is very unusual as life developed on it, which in the space of 3.5 billion years led to us.
Humanity was a restless species and eventually explored all of the planet and then looked around for more challenges. And so the Apollo program to explore the moon was born. The first Apollo mission to orbit the moon was Apollo 8. Its main objectives were to test out the equipment and plans made by Nasa and scout possible landing zones. But it actually became well known for a photograph which became so famous that it was given a name "Earthrise".
Although we knew that the Earth orbited the sun, seeing out beautiful planet rising above the barren plains of the Moon, surrounded by dark and hostile space started many people thinking more carefully about ways to care for our home.
Nine years later Nasa launched the Voyager space probes to investigate the outer solar system. When Voyager 1 had completed its mission Nasa turned the spaceship around and took a photo of Earth. This became known as the "Pale Blue Dot".
The video below shows the photo and provides a moving commentary, by Carl Sagan, on its significance.
No comments:
Post a Comment