Pages

Sunday, January 31, 2016

Petra (Jordan), all you've heard is wrong. The true ancient history of P...


Tuesday, December 15, 2015

Catch Comet Catalina Before It’s Gone Forever

Comet Catalina

http://www.slate.com/blogs/bad_astronomy/2015/12/15/comet_catalina_is_your_christmas_star_for_2015.html?ref=yfp

If you get up early enough over the next few weeks—a couple of hours before sunrise should do it—and look east, you’ll see the brilliant beacon of the planet Venus. Fairly close to it in the sky, but not so obvious is a visitor to these parts; one that is just passing through. Literally.
The visitor is the comet C/2013 US10 (Catalina); most people are just calling it Comet Catalina (the official name has a bit more complicated nomenclature). There are a couple of very cool things about this comet you should know about, but before I get to that part let me tell you how to see it.

Sunday, December 13, 2015

What Is a Human? Long-Standing Debate Surrounds Our Family Tree

What Is a Human? Long-Standing Debate Surrounds Our Family Tree

http://news.yahoo.com/human-long-standing-debate-surrounds-family-tree-195750519.html

Several ancient human species and relatives have been unearthed in bits and pieces over the years, including one with an orange-size brain, another dubbed the "hobbit" for its miniature size and a flat-faced hominin with a huge brow ridge.
Although these finds have opened more windows into the evolutionary landscape in which today's humans arose, some researchers are not convinced such discoveries belong alongsideHomo sapiens.
The controversy — whether the human family tree had few or many branches — is part of a long-standing debate between the so-called lumpers and splitters. [Infographic: Human Origins – How Hominids Evolved]

What Will Happen When Gene Editing Is as Easy as Cut-and-Paste?

What Will Happen When Gene Editing Is as Easy as Cut-and-Paste?

http://news.yahoo.com/what-will-happen-when-gene-1319326469775414.html

The other day, I found myself looking at a startling photo of my wife standing in the kitchen. The counter came up, exactly, to her waist, which was not itself so strange — I guess it’s sort of the point of counters — except for the fact that I occasionally stand there, too, and know that it also comes up to my waist, when I am actually ten inches taller. Of course, I’ve known for a while that my legs are preposterously short — for instance, it’s the way I explain to myself that while I can run a few seven-minute miles, the crazy hamster-wheel effort of churning that fast turns my sneakers into sweat sponges. When I went to find a pair of sneakers that could help, the salesman laughed — they don’t make shoes to help people like me, he said. But what if they made legs that did? What if gaining a few inches below the waist could be as simple as using colored contact lenses? And what if we could interpret that phrase — Gain a few inches below the waist — any way we wanted? While we’re at it, what if we could change our real eye color that easily too?
Perhaps you’ve heard of CRISPR — an enthralling bacteria-based gene-therapy technique that is spelled like a Silicon Valley joke, pronounced like the vegetable-drawer contraption in your aunt’s refrigerator, and promises, in fact, to so completely change the nature of our relationship to our own genes that Michael Specter’s recent account of it, in The New Yorker, was called “Humans 2.0.” They weren’t being all that hyperbolic: CRISPR is a way of dispatching a probe into a cell to seek out and modify a particular stretch of genetic code about a million times more efficiently, and much more cost-effectively, than has ever been possible before. It is often described as a genetic cut-and-paste tool: Using it, you can easily select any segment of DNA and replace or delete it. Which means that anything that’s genetic is editable, and since everything is genetic, at least partially, a whole lot of stuff might just be possible, from eradicating cystic fibrosis to (theoretically, anyway) gene-therapy sex changes. They’re already CRISPR-izing pigs to more easily grow human organs inside them for transplant. And, to fight malaria, unleashing an air force of reprogrammed mosquitoes.

Saturday, December 12, 2015

Want to feel really small? Meet UY Scuti, the largest star in the universe

UY_Scuti_zoomed_in,_Rutherford_Observatory,_07_September_2014

http://finance.yahoo.com/news/everything-know-uy-scuti-largest-201544542.html

Looking up at the sky inspires deep moments of introspection and curiosity. It’s easy to feel small under a starry night sky, but in order to begin to grasp just how small we truly are, we must know what our relative size is compared to the larger celestial bodies of the Galaxy — and what makes a better point of comparison than a star? Enter UY Scuti, a bright red supergiant variable star that resides within the Scutum constellation and is currently believed to be the largest star in the Milky Way galaxy.
German astronomers originally discovered UY Scuti at the Bonn Observatory in 1860, but it wasn’t until astronomers observed UY Scuti through the Very Large Telescope in Chile’s Atacama Desert in 2012 that the star’s true size became well documented. Following this discovery, UY Scuti was officially named the largest known star in the galaxy, surpassing previous record holders such as Betelgeuse, VY Canis Majoris, and NML Cygni.
While there are stars that are brighter and denser than UY Scuti, it has the largest overall size of any star currently known, with a radius of 1,708 ± 192 R☉. That figure amounts to somewhere between 1,054,378,000 and 1,321,450,000 miles in sizewhich is about 1,700 times larger than our Sun’s radius and 21 billion times the volume. Wrapping one’s head around such number can be difficult, so let’s break this down a bit. For more click on link.

Electron "Lifespan" is at Least 5 Quintillion Times the Age of the Universe

Electron "Lifespan" is at Least 5 Quintillion Times the Age of the Universe

http://gizmodo.com/electron-lifespan-is-at-least-5-quintillion-times-the-1747606990

Basic physics suggests that electrons are essentially immortal. A fascinating experiment recently failed to overthrow this fundamental assumption. But the effort has produced a revised minimum lifespan for electrons: 60,000 yottayears, which is — get this — about five-quintillion times the current age of the Universe.

That’s a Yotta Years

An electron is the lightest subatomic particle that carries a negative electric charge. It has no known components, which is why it’s considered to be a basic building block of the universe, or an elementary particle. For more visit link.