The Universe in three dimensions

The non amateur stuff. Hawking, black holes, that sort of thing

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brian livesey
Posts: 5436
Joined: Mon Jan 09, 2006 11:05 am
Location: Lancashire

The Universe in three dimensions

Post by brian livesey »

The largest-to-date three dimensional map of the Universe, capturing more than a million galaxies, has been produced by a team led by British astronomers. The map has made it possible for astronomers to make the most precise measurements yet of the mysterious "dark energy" that is thought to be responsible for the accelerating universe.
In today's "i", Dr. Rita Tojeiro of the University of Fife, the co-leader of the international team, said: "By measuring the positions of 1.2 million galaxies over one quarter of the sky, we mapped the three-dimensional structure of the universe over a volume of 650 cubic billion light years. Using this map, we were able to make some of the crispest measurements yet of how dark energy is driving the expansion of the universe."
The "i" article said, 'Hundreds of scientists from the Sloan Digital Sky Survey III project collaborated to make the map. A system called the Baryon Oscillation Spectroscopic Survey ( Boss ) was used to measure the expansion rate of the cosmos by looking at density "pressure waves" travelling through the universe. These are viewed as if they are sound waves, to produce an "acoustic" imprint.
By studying the cosmic microwave background - the afterglow of the Big Bang that gave birth to the universe - the scientists were able to see how the pressure waves had helped to shape the cosmos over time. "We see a dramatic connection between the sound wave imprints in the cosmic microwave background 400,000 years after the Big Bang to the clustering of galaxies 7 to 12 billion years later," Dr. Tojeiro added.
The map also reveals the distinctive signature to the movement of galaxies towards regions of the universe containing more matter, due to the attractive force of gravity. A series of papers detailing the research has been submitted to the journal Monthly Notices of the Royal Astronomical Society.'
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Re: The Universe in three dimensions

Post by Cliff »

Dear Brian
I seem to vaguely recall that towards the end of the 19th century, someone thought that some aspects of science (physics I think ?) was at that time fully understood.
Now in the field of cosmology -which I think is part (astro)physics new discoveries & ideas seem to come up every week. I find it rather confusing although I think its only because of our obsessions with computers, the cmb and mobile phones. Personally I'm still struggling with mobile phones. I think I'll forget about the cmb until the 22nd century by which time I hope I'll know how to use a mobile phone.
Best wishes from Cliff
PS How do you make crispy measurements of something you think probably exists.
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