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The Size Of Our World. Resizenowmap.jpg (JPEG Image, 715×514 pixels) Build a Solar System Model. Free Astronomy Books. This is the updated list of astronomy books available for free download or online reading.

Free Astronomy Books

These books andpapers cover all the areas of astrophysics, cosmology, galactic and extragalactic astronomy, solar and stellarphysics, celestial mechanics, planetary science, astrobiology, as well as some popular works. The books aremade available free of charge to the reader by their authors or publishers. Here is a categorized directory ofastronomy books. This page is updated daily. Errors in the "The Big Bang Never Happened" Top | Criticism | Alternative | Miscellaneous | Bottom Eric Lerner starts his book "The Big Bang Never Happened" (hereafter BBNH) with the "errors" that he thinks invalidate the Big Bang.

Errors in the "The Big Bang Never Happened"

These are Are these criticisms correct? No, and they were known to be incorrect in 1991 when Lerner wrote his book. Let us look at the superclusters first. Lerner gives the example of filaments or sheets 150 million light years apart in Figure 1.1, and then asserts that material would have to travel 270 million light years to make the structure. Furthermore, velocities relative to the Hubble flow naturally decrease with time, so the 1000 km/sec velocity was larger in the past. For example, the neutrinos in the hot dark matter model are just coasting, or "free streaming". V = H*D*Omega0.6 Using Lerner's value of 1000 km/sec, and a distance of 75 million light years, and Ho = 50 km/sec/Mpc, we find perfect agreement as long as Omega is close to 1.

So where was the "crisis"? Is there dark matter? Our place in the cosmos. Universcale. ASTR 1230, Whittle [Fall 2009]. Lecture Notes. Last modified September 2008 by rwo Text copyright © 1998-2008 Robert W. O'Connell. All rights reserved. Opening fisheye lens picture of comet Hale-Bopp and night sky from Ujue, Spain, April 1997, copyright © J. C. What Happened Before the Big Bang? The New Philosophy of Cosmology - Ross Andersen - Technology. What existed before the big bang?

What Happened Before the Big Bang? The New Philosophy of Cosmology - Ross Andersen - Technology

What is the nature of time? Is our universe one of many? On the big questions science cannot (yet?) Answer, a new crop of philosophers are trying to provide answers. Last May, Stephen Hawking gave a talk at Google's Zeitgeist Conference in which he declared philosophy to be dead. In December, a group of professors from America's top philosophy departments, including Rutgers,* Columbia, Yale, and NYU, set out to establish the philosophy of cosmology as a new field of study within the philosophy of physics.

One of the founding members of the American group, Tim Maudlin, was recently hired by New York University, the top ranked philosophy department in the English-speaking world. Yesterday I spoke with Maudlin by phone about cosmology, multiple universes, the nature of time, the odds of extraterrestrial life, and why Stephen Hawking is wrong about philosophy. Maudlin: So, I guess I would divide that into two classes. And what's driving the renaissance? Cdfs_ill_ionlabel.jpg (JPEG Image, 1800×792 pixels) - Scaled (79%) How Big Are Solar Flares? Pie.jpg (JPEG Image, 612×792 pixels) - Scaled (82%)

Earth-class Planets Line Up. In this space wallpaper, this chart compares the first Earth-size planets found around a sun-like star to planets in our own solar system, Earth and Venus.

Earth-class Planets Line Up

NASA's Kepler mission discovered the new found planets, called Kepler-20e and Kepler-20f. Kepler-20e is slightly smaller than Venus with a radius .87 times that of Earth. Kepler-20f is a bit larger than Earth at 1.03 times the radius of Earth. Venus is very similar in size to Earth, with a radius of .95 times that our planet. Prior to this discovery, the smallest known planet orbiting a sun-like star was Kepler-10b with a radius of 1.42 that of Earth, which translates to 2.9 times the volume. Both Kepler-20e and Kepler-20f circle in close to their star, called Kepler-20, with orbital periods of 6.1 and 19.6 days, respectively. There are three other larger, likely gaseous planets also know to circle the same star, known as Kepler-20b, Kepler-20c and Kepler-20d.

Credit: NASA/Ames/Caltech. We are listening. NRAO Very Large Array. The Nine Planets Solar System Tour. Lunar Eclipses for Beginners. 2004 Lunar Eclipse SequenceThe total lunar eclipse of 2004 Oct 28 was widely visible from the USA.This sequence of images captures the eclipse from start (right) to finish (left).

Lunar Eclipses for Beginners

(click to see more images) (c) Copyright 2007 by Fred Espenak Introduction What is an eclipse of the Moon? What causes eclipses and why? The Moon is a cold, rocky body about 2,160 miles (3,476 km) in diameter. New Moon > New Crescent > First Quarter > Waxing Gibbous> Full Moon > Waning Gibbous > Last Quarter > Old Crescent > New Moon (again) Phases of the Moon. The phase known as New Moon can not actually be seen because the illuminated side of the Moon is then pointed away from Earth. To many of us, Full Moon is the phase of love and romance.When the Moon is Full, it rises at sunset and is visible all night long. Geometry of the Sun, Earth and Moon During an Eclipse of the MoonEarth's two shadows are the penumbra and the umbra. Types of Lunar Eclipses Astronomers recognize three basic types of lunar eclipses: 1. 2.

HST. ISS COMPUTER OUTAGE COULD DELAY MONDAY'S SPACEX ROCKET LAUNCH - A computer outage at the International Space Station may require a spacewalk by astronauts and threatens to delay next week's launch of a commercial supply ship for NASA.

HST

NASA said Friday night that a backup computer on the outside of the orbiting lab is not responding to commands. The main computer, called an MDM or multiplexer-demultiplexer, is working fine, and the six-man crew is in no danger, officials said. But these computers control some robotic functions that would be needed for the upcoming supply run by SpaceX, one of two U.S. companies contracted by NASA to keep the space station well stocked. More (Source: Bay News 9 - Apr 12) NEXT ANTARES LAUNCH FROM WALLOPS COULD BE DELAYED - Orbital Science Corp.' HUSH-HUSH PAYLOAD RIDES ATLAS 5 ROCKET INTO ORBIT - Setting sail at mid-day on a marathon trip to orbit, an Atlas 5 rocket launched a classified spacecraft for the National Reconnaissance Office on Thursday. Video. Video. Physics 20b: Introduction to Cosmology - Spring 2010 - Download free content from UC Irvine. Description Overview of modern scientific cosmology, including discussion of stars, the Milky Way galaxy, black holes, dark matter, the big bang, and evidence for our current understanding of the universe.

Physics 20b: Introduction to Cosmology - Spring 2010 - Download free content from UC Irvine

Customer Reviews Great content, but audio is seriously lacking by AngryFanOfBirds Great content and the professor is very good at giving real-world analogies which are easy to comprehend. ...More amazing by RRO3 This man is amazing. Fantastic… But need a mic by VernontheIII This is a wonderful podcast. Mysteries of Deep Space - History of the Universe Timeline. Radio telescopes capture best-ever snapshot of black hole jets. An international team, including NASA-funded researchers, using radio telescopes located throughout the Southern Hemisphere has produced the most detailed image of particle jets erupting from a supermassive black hole in a nearby galaxy.

Radio telescopes capture best-ever snapshot of black hole jets

"These jets arise as infalling matter approaches the black hole, but we don't yet know the details of how they form and maintain themselves," said Cornelia Mueller, the study's lead author and a doctoral student at the University of Erlangen-Nuremberg in Germany. The new image shows a region less than 4.2 light-years across -- less than the distance between our sun and the nearest star. Radio-emitting features as small as 15 light-days can be seen, making this the highest-resolution view of galactic jets ever made. The study will appear in the June issue of Astronomy and Astrophysics and is available online. Mueller and her team targeted Centaurus A (Cen A), a nearby galaxy with a supermassive black hole weighing 55 million times the sun's mass. Universe-history-wmap.jpg (JPEG Image, 496×358 pixels) Radio_broadcasts.jpg (JPEG Image, 2795×2795 pixels)

The Carl Sagan Portal. Space Adventures. Powers of Ten. Based on the film by Charles and Ray Eames. An Eames Office Website. NASA Science. The Scale of the Universe. Your Age on Other Worlds. Looking at the numbers above, you'll immediately notice that you are different ages on the different planets.

Your Age on Other Worlds

This brings up the question of how we define the time intervals we measure. What is a day? What is a year? The earth is in motion. Actually, several different motions all at once. The top-like rotation of the earth on its axis is how we define the day. The revolution of the earth around the sun is how we define the year. We all learn in grade school that the planets move at differing rates around the sun. Why the huge differences in periods? Kepler briefly worked with the great Danish observational astronomer, Tycho Brahe. Here you see a planet in a very elliptical orbit. Kepler's third law is the one that interests us the most. Let's just solve for the period by taking the square root of both sides: Note that as the distance of the planet from the sun is increased, the period, or time to make one orbit, will get longer. The Gravity Of The Situation Your Weight On Other Worlds.

Explore Nature» Air Resources Division-Natural Lightscapes. The darker the sky, the more stars can be seen.

Explore Nature» Air Resources Division-Natural Lightscapes

The following simulated images depict how the constellation Orion appears under various sky conditions. Images are courtesy of GLOBE at Night. How good is your sky at home? Limiting Magnitude=2. This is typical of an urban sky. Limiting Magnitude=4. Limiting Magnitude=6. Limiting Magnitude=7. Ensign Software - ESPL: Dances of the Planets. The planets in the heavens move in exquisite orbital patterns, dancing to the Music of the Cosmos. There is more mathematical and geometric harmony than we realize. The idea for this article is from a book Larry Pesavento shared with me. The book, 'A Little Book of Coincidence' by John Martineau, illustrates the orbital patterns and several of their geometrical relationships. .

Take the orbits of any two planets and draw a line between the two planet positions every few days. Because the inner planet orbits faster than the outer planet, interesting patterns evolve. Earth: 8 years * 365.256 days/year = 2,922.05 days Venus: 13 years * 224.701 days/year = 2,921.11 days (ie. 99.9%) Watching the Earth-Venus dance for eight years creates this beautiful five-petal flower with the Sun at the center. (5 is another Fibonacci number.) Another intriguing fact is the ratio between the Earth's outer orbit and Venus's inner orbit is given by a square. Article by Howard Arrington. PH1600- Introductory Astronomy - Download free content from Michigan Technological University. New estimate for alien Earths: 2 billion in our galaxy alone. Roughly one out of every 37 to one out of every 70 sunlike stars in the sky might harbor an alien Earth, a new study reveals. These findings hint that billions of Earthlike planets might exist in our galaxy, researchers added.

These new calculations are based in data from the Kepler space telescope, which in February wowed the globe by revealing more than 1,200 possible alien worlds, including 68 potentially Earth-size planets. The spacecraft does so by looking for the dimming that occurs when a world transits or moves in front of a star. Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., focused on roughly Earth-size planets within the habitable zones of their stars — that is, orbits where liquid water can exist on the surfaces of those worlds. [The Strangest Alien Planets] "This means there are a lot of Earth analogs out there — two billion in the Milky Way galaxy," researcher Joseph Catanzarite, an astronomer at NASA's Jet Propulsion Laboratory, told SPACE.com. First man in space. Daylight Hours Explorer. Shows the hours of daylight received during the year for an observer at a given latitude.

This is an important factor contributing to the seasons. Running this animation on your computer... right-click to download daylighthoursexplorer.swf and daylighthoursexplorer.html to the same directory open the html file in a browser to run the animation Linking to this animation... copy and paste the code below into your webpage or blog: Putting this animation on your website... upload daylighthoursexplorer.swf to the same directory as your webpage copy and paste the following code into your webpage:

Carl Sagan will now remind you what we get by going to space. What Are The Odds? What are the odds? What are the odds that you exist, as you, today? Author Ali Binazir attemps to quantify the probability that you came about and exist as you today, and reveals that the odds of you existing are almost zero. LET'S START SMALL What is the probability of your dad meeting your mom? Though the world was smaller 20 years ago, your dad could have met almost 200 million of its women (go dad!)

But over 25 years, he probably met around 10,000 women. BUT WE KNOW HOW TRICKY LOVE CAN BE. So far, the combines odds of you being here are: 1 in 40,000,000 That is about the size of the population of California. NOW THINGS ARE GOING TO GET PRETTY INTERESTING Why? What are the odds that the 1 egg... BUT WE'RE JUST GETTING STARTED Because your existence here, now, and on planet earth presupposes another supremely unlikely and utterly undeniable chain of events.

What are the odds that you lineage remained unbroken for the length of human existence? How large is that number? (Weeeee!) Gravity Probe B - Special & General Relativity Questions and Answers. Distances from the Sun. LIVE REAL TIME SATELLITE AND SPACE SHUTTLE TRACKING AND PREDICTIONS. Video Courses on Academic Earth. Brian Greene on string theory. Patricia Burchat sheds light on dark matter.