Interesting websites ( OPEN SUBJECTS)

Discussions in the vein that would most interest those looking for the "meat and potatoes" of Townsend Brown's scientific work.

Re: Interesting websites ( OPEN SUBJECTS)

Postby G-Man » Tue Nov 14, 2017 9:34 pm

I suspect it may be less than five hundred years...
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Re: Interesting websites ( OPEN SUBJECTS)

Postby ecker2011 » Tue Nov 21, 2017 1:00 pm

ESO observations show first interstellar asteroid is like nothing seen before

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This artist's impression shows the first interstellar asteroid: `Oumuamua. This unique object was discovered on Oct. 19, 2017 by the Pan-STARRS 1 telescope in Hawai`i. Subsequent observations from ESO's Very Large Telescope in Chile and other observatories around the world show that it was travelling through space for millions of years before its chance encounter with our star system. `Oumuamua seems to be a dark red highly-elongated metallic or rocky object, about 400 metres long, and is unlike anything normally found in the Solar System. Credit: ESO/M. Kornmesser

For the first time ever astronomers have studied an asteroid that has entered the Solar System from interstellar space. Observations from ESO's Very Large Telescope in Chile and other observatories around the world show that this unique object was traveling through space for millions of years before its chance encounter with our star system. It appears to be a dark, reddish, highly-elongated rocky or high-metal-content object. The new results appear in the journal Nature on 20 November 2017.

On Oct. 19, 2017, the Pan-STARRS 1 telescope in Hawai'i picked up a faint point of light moving across the sky. It initially looked like a typical fast-moving small asteroid, but additional observations over the next couple of days allowed its orbit to be computed fairly accurately. The orbit calculations revealed beyond any doubt that this body did not originate from inside the Solar System, like all other asteroids or comets ever observed, but instead had come from interstellar space. Although originally classified as a comet, observations from ESO and elsewhere revealed no signs of cometary activity after it passed closest to the Sun in September 2017. The object was reclassified as an interstellar asteroid and named 1I/2017 U1 ('Oumuamua).

"We had to act quickly," explains team member Olivier Hainaut from ESO in Garching, Germany. "'Oumuamua had already passed its closest point to the Sun and was heading back into interstellar space."
ESO's Very Large Telescope was immediately called into action to measure the object's orbit, brightness and colour more accurately than smaller telescopes could achieve. Speed was vital as 'Oumuamua was rapidly fading as it headed away from the Sun and past the Earth's orbit, on its way out of the Solar System. There were more surprises to come.

Combining the images from the FORS instrument on the VLT using four different filters with those of other large telescopes, the team of astronomers led by Karen Meech (Institute for Astronomy, Hawai`i, USA) found that 'Oumuamua varies dramatically in brightness by a factor of ten as it spins on its axis every 7.3 hours.

Karen Meech explains the significance: "This unusually large variation in brightness means that the object is highly elongated: about ten times as long as it is wide, with a complex, convoluted shape. We also found that it has a dark red colour, similar to objects in the outer Solar System, and confirmed that it is completely inert, without the faintest hint of dust around it."

These properties suggest that `Oumuamua is dense, possibly rocky or with high metal content, lacks significant amounts of water or ice, and that its surface is now dark and reddened due to the effects of irradiation from cosmic rays over millions of years. It is estimated to be at least 400 metres long.

Preliminary orbital calculations suggested that the object had come from the approximate direction of the bright star Vega, in the northern constellation of Lyra. However, even travelling at a breakneck speed of about 95 000 kilometres/hour, it took so long for the interstellar object to make the journey to our Solar System that Vega was not near that position when the asteroid was there about 300 000 years ago. 'Oumuamua may well have been wandering through the Milky Way, unattached to any star system, for hundreds of millions of years before its chance encounter with the Solar System.

Astronomers estimate that an interstellar asteroid similar to 'Oumuamua passes through the inner Solar System about once per year, but they are faint and hard to spot so have been missed until now. It is only recently that survey telescopes, such as Pan-STARRS, are powerful enough to have a chance to discover them.

"We are continuing to observe this unique object," concludes Olivier Hainaut, "and we hope to more accurately pin down where it came from and where it is going next on its tour of the galaxy. And now that we have found the first interstellar rock, we are getting ready for the next ones!"

(See Videos also)

https://phys.org/news/2017-11-eso-inter ... eroid.html
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Re: Interesting websites ( OPEN SUBJECTS)

Postby G-Man » Tue Nov 21, 2017 2:51 pm

Saw this on BBC News just now. I'm thinking they came for a closer look but decided to keep going... :lol:
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Re: Interesting websites ( OPEN SUBJECTS)

Postby ecker2011 » Tue Nov 21, 2017 3:55 pm

Think about the book by Arthur C Clarke, rendezvous with Rama.

https://en.wikipedia.org/wiki/Rendezvous_with_Rama
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Re: Interesting websites ( OPEN SUBJECTS)

Postby ecker2011 » Fri Nov 24, 2017 1:06 pm

Something to think about.

What is Space? The 300-Year-Old Philosophical Battle Still Rages Today
By Emily Thomas, Durham University

This article was originally published at The Conversation. The publication contributed the article to Space.com's Expert Voices: Op-Ed & Insights.

Mountains. Whales. The distant stars. All these things exist in space, and so do we. Our bodies take up a certain amount of space. When we walk to work, we are moving through space. But what is space? Is it even an actual, physical entity? In 1717, a battle was waged over this question. Exactly 300 years later, it continues.

You might think physicists have "solved" the problem of space. The likes of mathematician Hermann Minkowski and physicist Albert Einstein taught us to conceive space and time as a unified continuum, helping us to understand how very large and very little things such as individual atoms move. Nonetheless, we haven't solved the question of what space is. If you sucked all the matter out of the universe, would space be left behind?

Twenty-first century physics is arguably compatible with two very different accounts of space: "relationism" and "absolutism." Both these views owe their popularity to Caroline of Ansbach (1683-1737), a German-born Queen of Great Britain, who stuck her oar into the philosophical currents swirling around her.

Caroline was a keen philosopher, and in the early 18th century she schemed to pit the leading philosophies of her period against each other. On the continent, philosophers were stuck in "rationalism," spinning world theories from armchairs. Meanwhile, British philosophers were developing science-inspired "empiricism" – theories built on observations. They were worshipping scientists such as Robert Boyle and Isaac Newton.

Caroline asked two philosophers to exchange letters. One was the German philosopher Gottfried Leibniz, rationalist par excellence. The other was the English philosopher Samuel Clarke, a close friend of Newton. The two men agreed, and their exchange was published in 1717 as A Collection of Papers. The dull title doesn't sound like much, but these papers were revolutionary. And one of their central issues was the nature of space.

Everything or nothing?

Is there space between the stars? The relationist Leibniz argued that space is the spatial relations between things. Australia is "south of" Singapore. The tree is "three meters left of" the bush. Sean Spicer is "behind" the bush. That means space would not exist independently of the things it connects. For Leibniz, if nothing existed, there couldn't be any spatial relations. If our universe were destroyed, space would not exist.

In contrast, the absolutist Clarke argued that space is a sort of substance that is everywhere. Space is a giant container, containing all the things in the universe: stars, planets, us. Space allows us to make sense of how things move from one place to another, of how our entire material universe could move through space. What's more, Clarke argued that space is divine: space is God's presence in the world. In a way, space is God. For Clarke, if our universe were destroyed, space would be left behind. Just as you can't delete God, you can't delete space.

The Leibniz-Clarke letters exploded early 18th century thought. Thinkers like Newton, who were already involved in the debate, were dragged deeper in. Newton argued that space was more than the relations between material objects. He argued it was an absolute entity, that everything moves in relation to it. This led to the distinction between "relative" and "absolute" motion. The Earth moves relative to other material things, such as the sun, but it also moves absolutely – with regard to space.

Others joined the party later, like Immanuel Kant. He believed space is just a concept humans use to make sense of the world, rather than a real entity. It wasn't just philosophers and physicists who had views on space either. All sorts of people had their say, from stocking makers to tenant farmers. One especially unlikely discussion of space turns up in Thomas Amory's 1755 Memoirs: Containing the Lives of Several Ladies of Great Britain.

The problem with God

People were especially edgy about Clarke's view that space is God. Does that mean we're moving through God all the time? God doesn't just see everything, he is everywhere? They also became worried about Big Things. As a whale takes up more space than a holy man, is a whale holier? As mountains are so large, are they like God?

The 20th century philosopher Bertrand Russell once argued we shouldn't worship mere size. "Sir Isaac Newton was very much smaller than a hippopotamus, but we do not on that account value him less than the larger beast," he wrote. Some 18th century thinkers would have disagreed – they were worried they should be worshipping a hippopotamus over Newton.

Today, the concept of God is disappearing from the debate. Yet some contemporary philosophers, such as Tim Maudlin and Graham Nerlich think that current theories in physics do support Clarke's view (minus the religious parts). Spacetime is one big container, and all of us move around in it.

Other philosophers, such as Kenneth Manders and Julian Barbour, think our best physics is compatible with both views, and there are other reasons to believe Leibniz's theory was right. If the physics really is compatible with absolutism or relationism, then perhaps we should prefer relationism as the simpler theory? After all, why posit a giant entity that acts like a container if we don't have to?

As a historian of space and time, I'm fascinated by how the debate has evolved, how something that started 300 years ago has unfurled and grown. Clearly, though the Leibniz-Clarke papers are not well known outside of philosophy, the debate they started continues. Caroline of Ansbach has a lot to answer for.

Emily Thomas, Assistant Professor of Philosophy, Durham University

This article was originally published on The Conversation. Read the original article. Follow all of the Expert Voices issues and debates — and become part of the discussion — on Facebook, Twitter and Google +. The views expressed are those of the author and do not necessarily reflect the views of the publisher. This version of the article was originally published on Space.com.

https://www.space.com/38791-what-is-spa ... rages.html
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Re: Interesting websites ( OPEN SUBJECTS)

Postby ecker2011 » Thu Dec 14, 2017 5:15 pm

Dark energy survey offers new view of dark matter halos, physicists report
by Ali Sundermier

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This artist’s impression shows the Milky Way galaxy. The blue halo of material surrounding the galaxy indicates the expected distribution of the mysterious dark matter, which was first introduced by astronomers to explain the rotation properties of the galaxy and is now also an essential ingredient in current theories of the formation and evolution of galaxies. Credit: ESO/L. Calçada

Dark matter, a mysterious form of matter that makes up about 80 percent of the mass of the universe, has evaded detection for decades. Although it doesn't interact with light, scientists believe it's there because of its influence on galaxies and galaxy clusters.

It extends far beyond the reach of the furthest stars in galaxies, forming what scientists call a dark matter halo. While stars within the galaxy rotate in a neat, organized disk, these dark matter particles are like a swarm of bees, moving chaotically in random directions, which keeps them puffed up to balance the inward pull of gravity.

Previous research led by postdoctoral fellow Eric Baxter; Bhuvnesh Jain, Walter H. and Leonore C. Annenberg Professor in the Natural Sciences in the Department of Physics and Astronomy in Penn's School of Arts and Sciences; and Chihway Chang of the University of Chicago provided evidence that dark matter halos around galaxy clusters have an edge due to the "splashback effect."

"You have this big dark matter halo that surrounds every galaxy cluster," Baxter said, "and it's been accreting matter gravitationally over its entire history. As that matter gets pulled in, it goes faster and faster. When it finally falls into the halo, it turns around and starts to orbit. That turnaround is what people have started calling splashback, because stuff is splashing back in some sense."

As the matter "splashes back," it slows down. Because this effect is happening in many different directions, it leads to a buildup of matter right at the edge of the halo and a steep fall-off in the amount of matter right outside of that position.

In their initial study, the researchers used data from the Sloan Digital Sky Survey to investigate the distribution of galaxies around clusters. In a follow up study using data from the first year of the Dark Energy Survey, the researchers used a different method called gravitational lensing, which takes advantage of a phenomenon in which light coming toward an observer bends as matter exerts gravitational force on it. By looking at the slight stretching of objects behind galaxies, the researchers can directly measure the mass profile, how mass is distributed within the galaxy.

"There are many different applications of lensing," Jain said, "but this is one where something went from being undetectable to detectable, so it's particularly exciting."

In a paper to be published in the Astrophysical Journal, the researchers showed that this method produced an understanding of the dark matter halos that is broadly consistent with what they saw using the light of the cluster galaxies in their first study.

"We were pursuing this question of whether dark matter halos have a sharp boundary," Jain said. "The gold standard for establishing this is to look directly at the mass through gravitational lensing, which hasn't been done before now. With the latest compilation of DES data we see a picture very similar to what we saw in the distribution of galaxies."

Measuring gravitational lensing is a lot harder than simply measuring the distribution of galaxies, Jain said.

"We can see galaxies easily, we just take a picture of them," he said, "but with gravitational lensing we have to take pictures of many more faint, background galaxies and measure how those are distorted in tiny ways. It's a challenging measurement."

This leaves more room for error in the measurements, causing them to be less precise. However, the findings were only based on the first year of observations of the Dark Energy Survey. By the end of the survey, there will be four additional years of data for the researchers to analyze. This will allow them to make more precise measurements, directly probing the matter in galaxies and galaxy clusters using gravitational lensing. Tests of dark matter will then be possible, since any new physical interactions between dark matter particles could shift the location of splashback.

"We can look forward to a clearer picture of mysterious dark matter halos," Jain said.

https://phys.org/news/2017-12-dark-ener ... halos.html
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Re: Interesting websites ( OPEN SUBJECTS)

Postby ecker2011 » Sat Dec 16, 2017 6:55 pm

Pentagon acknowledges program to investigate UFO encounters: report
BY MAX GREENWOOD

The Pentagon has acknowledged for the first time the existence of a program charged with investigating unidentified flying objects.

According to a New York Times report, the $22 million advanced Aerospace Threat Identification Program began in 2007 and was funded primarily at the request of former Sen. Harry Reid (D-Nev.), who has long had an interest in the topic.

The Pentagon told the Times that the program ended in 2012. Its supporters say it is still in existence, but that the Defense Department has stopped funding it.

Most of the money went to a Nevada-based research firm and government contractor, Bigelow Aerospace, run by Robert Bigelow, a billionaire businessman and a friend of Reid.

The program was headed up by Luis Elizondo, a military intelligence officer, who resigned earlier this year. In his resignation letter to Defense Secretary James Mattis, Elizondo questioned why the Pentagon was not "spending more time and effort on this issue," the Times reported.

Elizondo told the Times that he kept working on the project out of his Pentagon office until his resignation, along with officials from the Navy and the CIA, despite the lack of funding.

The program, which began as part of the Defense Intelligence Agency, produced documents detailing sightings of mysterious aircraft and collected videos and audio recordings of alleged encounters with UFOs, according to the Times. The program publicly released a video apparently showing an encounter between a Navy F/A-18 Super Hornet and an unknown object.

Reid told the Times that he did not have any regrets about getting the program started, saying that he was proud of the effort.

"I’m not embarrassed or ashamed or sorry I got this thing going,” he said. “I think it’s one of the good things I did in my congressional service. I’ve done something that no one has done before.”

http://thehill.com/policy/defense/36525 ... ssion=true

Glowing Auras and ‘Black Money’: The Pentagon’s Mysterious U.F.O. Program

https://www.nytimes.com/2017/12/16/us/p ... -reid.html
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