2017 January 14

Yowah Koroit Boulder Opal | #Geology #GeologyPage #Opal #Mineral

83.10Ct Natural Australian Queensland Yowah Koroit Boulder Opal

Dimensions (mm): 37.5 x 18.3 x 12mm

Locality: Queensland, Australia

Photo Copyright © opalauctions

Geology Page www.geologypage.com

page 590 of “Science and literature in the Middle Ages and the Renaissance” (1878)

Pulsars: How The First ‘False Alien’ Signal Opened Up A New World In Astronomy

“In 1967, a radio source emitting regular, 0.04-second long pulses every 1.3373 seconds was found for the first time using a scintillation array. After the “noise” explanation was ruled out, the next thing people turned towards were intelligent extraterrestrials. There was no natural mechanism in existence that would have explained it at that time, so turning to aliens was logical, if ultimately incorrect.”

Observations that surprise us, of a phenomenon we weren’t expecting and don’t have an explanation for, are some of the most exciting things we can encounter in astronomy. In 1967, regularly pulsing radio sources, discovered without any expectation, provided exactly that. It wasn’t noise; it was definitely a robust, repeatable observation; so what was it? While our imaginations might have run to aliens initially, further developments quickly showed that this was a ball of rapidly rotating neutrons, more massive than even the Sun but only a few kilometers in diameter. These pulsars, as they’re now know, are ubiquitous and come about from the corpses of core-collapse supernova. Could this be a harbinger of what we can expect from the ‘alien megastructure’ controversy?

Come find out how the first ‘false alien’ signal from astronomy opened up a whole new field of science for us to investigate!

Celestial nomad takes centre stage

In this new ESO image, nightfall raises the curtain on a theatrical display taking place in the cloudless skies over La Silla.

In a scene humming with activity, the major players captured here are Comet Lovejoy, glowing green in the centre of the image; the Pleiades above and to the right; and the California Nebula, providing some contrast in the form of a red arc of gas directly to the right of Lovejoy.

A meteor adds its own streak of light to the scene, seeming to plunge into the hazy pool of green light collecting along the horizon.

The telescopes of La Silla provide an audience for this celestial performance, and a thin shroud of low altitude cloud clings to the plain below the observatory streaked by the Panamericana Highway.

Comet Lovejoy’s long tail is being pushed away from the comet by the solar wind. Carbon compounds that have been excited by ultraviolet radiation from the Sun give it its striking green hue.

This is the first time the comet has passed through the inner Solar System and ignited so spectacularly in over 11 000 years. Its highly elliptical orbit about the Sun — adjusted slightly due to meddling planets — means that it will not grace our skies for another 8000 years once it has rounded the Sun and begun its lonely voyage back into the cold outer regions of the Solar System.

Image credit: P. Horálek/ESO

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The eight planets of our solar system image credits: [x]

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A giant predatory lizard swam in Antarctic seas near the end of the dinosaur age http://www.geologypage.com/2016/11/giant-predatory-lizard-swam-antarctic-seas-near-end-dinosaur-age.html

Dun Aengus - prehistoric fort at the edge of an 100 meter high cliff. The first construction goes back to 1100 BC; around 500 BC, the triple wall defenses were probably built along the western side of fort. Ireland

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Space station flyover of Gulf of Aden and Horn of Africa

European Space Agency astronaut Samantha Cristoforetti took this photograph from the International Space Station and posted it to social media on Jan. 30, 2015. Cristoforetti wrote, “A spectacular flyover of the Gulf of Aden and the Horn of Africa. #HelloEarth”

Image credit: NASA/ESA/Samantha Cristoforetti

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This shows a valid method for computing square roots without using a calculator, and can be used to solve this question. This document was written by Prof. Jeff Forshaw