for Hal - Precise Age of the Universe Revealed

[Biggles of 266]

This photo released by NASA shows a full-sky map of the oldest light in the universe. Colors indicate warmer red and cooler blue spots. NASA called the image the best ¿baby picture¿ of the Universe ever taken. The new cosmic portrait, capturing the afterglow of the Big Bang was captured by scientists using NASA s Wilkinson Microwave Anisotropy Probe WMAP during a sweeping 12-month observation of the entire sky. One of the biggest surprises revealed in the data is that the first generation of stars to shine in the Universe first ignited only 200 million years after the Big Bang, much earlier than many scientists had expected. In addition, the new portrait precisely pegs the age of the Universe at 13.7 billion years old, with a remarkably small one percent margin of error. Photo: AFP



Scientists using a robotic NASA probe have determined the precise age of the universe - 13.7 billion years - and figured out when stars began to shine.

NASA researchers say astronomers have been closing in on these numbers for decades, but a spacecraft now about 1.6 million kilometres from Earth was able to look back to nearly the dawn of time to find the answers.

Announcing findings of the so-called WMAP mission, scientists say stars started shining 200 million years after the Big Bang.

WMAP - short for Wilkinson Microwave Anisotopy Probe - has looked back in time to just 380,000 years after the Big Bang explosion that many astronomers believe gave birth to the universe.

 

[amk714]

Interesting news! Thanks, Biggles. 🙂

 

[Haltickling]

Thanks, Biggles, that's really interesting. I saw a TV report on the WMAP mission only a few days ago, but they didn't mention all that info about the first stars, only the new estimated age of the universe. 😎

 

[omega]

Thanks, Biggles, that's really interesting. I saw a TV report on the WMAP mission only a few days ago, but they didn't mention all that info about the first stars, only the new estimated age of the universe. 😎

For my own information: What was the former estimated age of the universe?

 

[RichardAuc]

I have a question, also

That's a good question. I have a question, also.

If the estimated age of the universe is 13.7 billion years, and the estimated age of earth is 4.5 billion years, where did the earth come from when the universe was 9.2 billion years old?

 

[THE THREAD]

The heavier elements that make up the earth were synthesized in the cores of first stars and in the resulting supernova explosions of some of those stars. It is like the Moby song "We are all made of Stars.". So the earth came from those first stars.

 

[Haltickling]

A few answers...

Omega, sorry, I must have missed your question. The last estimate I know of dated the universe back to 9-10 billion years. Now that we have found new, more exact methods, it’s over 13 billion. I won’t exclude that with even more sophisticated tools, we might have to revise that again.

Richard, I’ll try to give you a more elaborate explanation for the time between the Big Bang and the ‘appearance’ of the Earth: The early universe developed only the most simple of atoms, hydrogen (1 proton, 1 electron). As the distribution of mass in the universe was not uniform (due to the chaos of the big explosion), more and more mass particles were attracted to each other by gravity, until there was a huge ball of hydrogen. When this ball became big enough, the pressure under the increasing gravity initiated an atomic chain reaction. Hydrogen atoms were transformed into helium, radiating off energy. That was the first sun. This process took already several billion years.

The same thing happened in many dense spots in the universe. But there was no heavy matter to form planets yet. Our sun, for example, seems to be a second generation star. Its predecessor ran out of hydrogen, now it burned helium into lithium, and so on. The last stage before the collapse is carbon. Then the star collapsed under its own weight, as no more energy produced pressure from within. The outer spheres of hot gas get blown out in space.

The next stage depends on the size of the original star. One possibility is that the increasing pressure re-ignites the core, the heat increases to several hundred million degrees because of the pressure. The result: the star explodes. But in the extremely hot center, it baked even heavier elements than it could burn. Iron and Silicium for example, the main ingredients of planets. In this explosion, these heavy elements get blown out into space.

If the clouds of debris were big enough, a new star could form itself, and planets revolving around it. Sun and planets are formed in the same process, so our sun should also be about 4.5 to 5 billion years old. Second generation stars are usually a bit more stabile than the rather short-lived first ones. Our own sun will have burnt off all its hydrogen in about 5 billion years. Most probably, the human race as we know it will be long extinct by then.

This birthing of stars can be observed everywhere in space, as well as the violent deaths of stars in Novae and Supernovae. It’s a constant process. And as everything we see around us originates from the debris of an exploded star, we literally consist of stardust…

 

[THE THREAD]

It's like I said "We are all made of stars." just like the Moby song.