Thursday, March 27, 2008
Universe is 13.73 Billion Years Old
The latest on the "age of the unoverse" thread of this blog is news from NASA that it's been estimated to be 13.73 billion years old, see WMAP Reveals Neutrinos, End of Dark Ages, First Second of Universe
"NASA released this week five years of data collected by the Wilkinson Microwave Anisotropy Probe (WMAP) that refines our understanding of the universe and its development. ... WMAP measures a remnant of the early universe - its oldest light. The conditions of the early times are imprinted on this light. It is the result of what happened earlier, and a backlight for the later development of the universe. This light lost energy as the universe expanded over 13.7 billion years, so WMAP now sees the light as microwaves. By making accurate measurements of microwave patterns, WMAP has answered many longstanding questions about the universe's age, composition and development.
Microwave light seen by WMAP from when the universe was only 380,000 years old, shows that, at the time, neutrinos made up 10% of the universe, atoms 12%, dark matter 63%, photons 15%, and dark energy was negligible. In contrast, estimates from WMAP data show the current universe consists of 4.6% percent atoms, 23% dark matter, 72% dark energy and less than 1 percent neutrinos.WMAP cosmic microwave fluctuations over the full sky with 5-years of data. Colors [in the image] represent the tiny temperature fluctuations of the remnant glow from the infant universe: red regions are warmer and blue are cooler."
Labels: Age, Cosmology, Universe
Monday, March 10, 2008
Scientific American tells all?
I've been reading articles from Scientific American for fifty years or more, and still enjoy it tremendously. While there are many other extremely worthwhile scientific journals, I'm a creature of habit and this one is good enough for me!
Relative to the "Basic Questions" theme of this blog, I would heartily recommend that you read various online Scientific American articles. The following two articles in particular are very cogent summaries of several aspects of cosmology that I've mentioned in earlier posts, and they're well worth a read:
Relative to the "Basic Questions" theme of this blog, I would heartily recommend that you read various online Scientific American articles. The following two articles in particular are very cogent summaries of several aspects of cosmology that I've mentioned in earlier posts, and they're well worth a read:
- Misconceptions about the Big Bang - Baffled by the expansion of the universe? You're not alone. Even astronomers frequently get it wrong. ... Expansion is a beguilingly simple idea, but what exactly does it mean to say the universe is expanding? What does it expand into? Is Earth expanding, too? To add to the befuddlement, the expansion of the universe now seems to be accelerating, a process with truly mind-stretching consequences. ... The universe does not seem to have an edge or a center or an outside, so how can it expand?
- The Universe's Invisible Hand - Dark energy does more than hurry along the expansion of the universe. It also has a stranglehold on the shape and spacing of galaxies. ... Scientists are just starting the long process of figuring out what dark energy is and what its implications are. One realization has already sunk in: although dark energy betrayed its existence through its effect on the universe as a whole, it may also shape the evolution of the universe's inhabitants--stars, galaxies, galaxy clusters. Astronomers may have been staring at its handiwork for decades without realizing it.
Labels: Cosmology, Science, Scientific American
Monday, June 04, 2007
Big -- Mandelbrot Universe
Watch this fractal unfolding, and listen to it too. (It reminds me a bit of scenes near the end of 2001 A Space Odyssey.)
There are more Mandelbrot/fractal animations on the same YouTube page. If you want to get a rigid mathematical explanation of Mandelbrot's accomplishments , be sure to listen to the following one as it unfolds:
A Mandelbrot the size of the known universe"An extremely deep dive into the Mandelbrot zoom. If the final frame were the size of your screen, the full set would be larger than the known universe."
There are more Mandelbrot/fractal animations on the same YouTube page. If you want to get a rigid mathematical explanation of Mandelbrot's accomplishments , be sure to listen to the following one as it unfolds:
Mandelbrot Set Zoom
Labels: Universe
Sunday, May 13, 2007
Is the Universe Finite, or Not?
I've just come across a few interesting items in my quest to understand "life and the universe" and would like to share them with you:
- On A Finite Universe With No Beginning Or End (a PDF document) - by Peter Lynds of New Zealand, with the following abstract:
"Based on the conjecture that rather than the second law of thermodynamics inevitably be breached as matter approaches a big crunch or a black hole singularity, the order of events should reverse, a model of the universe that resolves a number of longstanding problems and paradoxes in cosmology is presented. A universe that has no beginning (and no need for one), no ending, but yet is finite, is without singularities, precludes time travel, in which events are neither determined by initial or final conditions, and problems such as why the universe has a low entropy past, or conditions at the big bang appear to be so "special," require no causal explanation, is the result. This model also has some profound philosophical implications."
If the above paper is too much for you, then from Science a Go Go there's a pair of articles that might make it more digestible: The Universe As Magic Roundabout: Part I plus The Universe As Magic Roundabout: Part II
Here's an earlier paper by Peter Lynds (also a PDF document):
Time and Classical and Quantum Mechanics: Indeterminacy vs. Discontinuity - For another view, this time about multiple universes, there's Towards observable signatures of other bubble universes (another PDF document) with the following abstract:
"We evaluate the possibility of observable effects arising from collisions between vacuum bubbles in a universe undergoing false-vacuum eternal inflation. Contrary to conventional wisdom, “typical” observers inside a bubble should have access to a large number of collision events. We calculate the expected number and angular size distribution of such collisions on an observer’s “sky”, finding that for typical observers the distribution is anisotropic and includes many bubbles, each of which will affect the majority of the observer’s sky. After a qualitative discussion of the physics involved in collisions between arbitrary bubbles, we evaluate the implications of our results, and outline possible observable effects. In an optimistic sense, then, the present paper constitutes a first step in an assessment of the effects of other bubble universes on the cosmic microwave background and other observables."
Labels: Universe
Sunday, April 01, 2007
Light Speed (and Other Puzzling Data)
Doing a bit of Web searching discover more views and answers to some of my basic questions, I came across the following interesting presentations by by Barry Setterfield (over at YouTube):
- Light Speed and Other Puzzling Data - Part 1 of 6
- Light Speed and Other Puzzling Data - Part 2 of 6
- Light Speed and Other Puzzling Data - Part 3 of 6
- Light Speed and Other Puzzling Data - Part 4 of 6
- Light Speed and Other Puzzling Data - Part 5 of 6
- Light Speed and Other Puzzling Data - Part 6 of 6
Wednesday, March 07, 2007
How big is BIG?
This morning I was looking at the Web site of the Sloan Digital Sky Survey
Fascinating stuff! SDSS is systematically mapping the entire sky, determining the positions, brightnesses and distances of celestial objects, to give a three-dimensional picture of the universe through a volume one hundred times larger than that explored to date.
They are obviously asking some basic questions. And getting answers, too. one question that really tickles my fancy is described in the article How big is big? Probing the conditions of the universe on the largest scales
Back in May 2006 researchers at SDSS announced the first measurements of galactic structures more than a billion light years across. Now that's getting to be sizable, isn't it!
Fascinating stuff! SDSS is systematically mapping the entire sky, determining the positions, brightnesses and distances of celestial objects, to give a three-dimensional picture of the universe through a volume one hundred times larger than that explored to date.
They are obviously asking some basic questions. And getting answers, too. one question that really tickles my fancy is described in the article How big is big? Probing the conditions of the universe on the largest scales
Back in May 2006 researchers at SDSS announced the first measurements of galactic structures more than a billion light years across. Now that's getting to be sizable, isn't it!
Thursday, February 01, 2007
Dark energy - the pressure exerted by empty space!
I would never have thought it, and even after reading it cannot begin to properly understand or appreciate this:
Read more in the following Dr Dobb's article: Quantum Mechanical Theory Behind 'Dark Energy'?
... dark energy is the pressure exerted by empty space. From a quantum mechanical perspective, empty space is unstable. According to statistics, photons and subatomic particles pop into the vacuum of space in a way that shows that "empty" is only an approximation: Space actually comprises a statistical soup of particles and antiparticles that are in a constant state of creation. Today scientists can demonstrate this by pumping the gases out of any empty chamber. After every atom has been pumped out, particles begin to percolate into existence in a process called vacuum fluctuation. ...
... unless the vacuum itself exerts the negative pressure observed, then the universe must otherwise be composed of as much as 70 percent dark energy.
Read more in the following Dr Dobb's article: Quantum Mechanical Theory Behind 'Dark Energy'?
