Astronomy, cosmology and space thread

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Re: The WOW Science Thread

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"Einstein's most incredible prediction may be proven right on February 11 — or a wild rumor debunked

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An illustration of two black holes colliding.

Gravitational waves may have been detected for the first time, but we won't know for sure until February 11, 2016 — when scientists will either confirm or dispel the rumors, sources close to the matter tell Tech Insider.

Detection of gravitational waves would be unprecedented. Whoever finds them is also likely to pick up a Nobel prize, since the phenomenon would confirm one of the last pieces of Albert Einstein's famous 1915 theory of general relativity.

Confirming they exist would tell us we're still on the right track to understanding how the universe works. Failing to find them after all these years might suggest we need to revisit our best explanation for gravity, or rethink our most sensitive experiments, or that we simply haven't looked long enough.

"Gravitational waves are ripples in the fabric of space-time, predicted by Einstein 100 years ago," Szabi Marka, a physicist at Columbia University, told Tech Insider. "They can be created during the birth and collision of black holes, and can reach us from distant galaxies."

Black holes are the densest, most gravitationally powerful objects in existence — so a rare yet violent collision of two should trigger a burst of gravitational waves that we could detect here on Earth.

Colliding neutron stars and huge exploding stars, called supernovas, are thought to generate detectable gravitational waves, too.

However, any sort of signal has eluded the planet's brightest minds and the most advanced experiments for decades.

Until now — maybe.

A 'major' event? ..."

http://www.techinsider.io/gravitational ... -11-2016-2
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Re: Astronomy, cosmology and space thread

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Scientists discover hidden galaxies behind the Milky Way
Hundreds of hidden nearby galaxies have been studied for the first time, shedding light on a mysterious gravitational anomaly dubbed the Great Attractor.

Despite being just 250 million light-years from Earth — very close in astronomical terms — the new galaxies had been hidden from view until now by our Milky Way Galaxy.

Using CSIRO’s Parkes radio telescope equipped with an innovative receiver, an international team of scientists was able to see through the stars and dust of the Milky Way into a previously unexplored region of space.

The discovery may help to explain the Great Attractor region, which appears to be drawing the Milky Way and hundreds of thousands of other galaxies towards it with a gravitational force equivalent to a million billion Suns.

http://www.astronomy.com/news/2016/02/s ... -milky-way
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Re: Astronomy, cosmology and space thread

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"Say "Hello" to the Spaceship That Will Bring Humans to Mars

NASA — It sent men and women to the moon, it safely carried them back to Earth and now it has its sights on its most ambitious target yet: Mars.

But for NASA to make its most giant leap yet toward the final frontier, agency astronauts are going to require an updated rocket unlike anything it has previously produced.

Here's what that might look like.

Enter the Space Launch System, NASA's new megarocket that's all but straight out of Star Wars. "NASA's Space Launch System (SLS) will be the most powerful rocket in history for deep-space missions, including to an asteroid and ultimately to Mars," the agency said on its website. "The Space Launch System has the capability to launch payloads such as telescopes, rovers and planetary probes on dedicated science missions."

The rocket is built to a scale never before seen in NASA. Though it is slightly smaller than the Cold War-era Saturn 5, it still comes in at 323 feet — taller than the Statue of Liberty. The SLS is also expected to produce 13% more thrust at the time of launch than previous rockets and more essentially will be able to carry 70 tons of cargo, compared to only 22 tons for NASA's traditional space shuttle.

It's all spelled out in this nifty NASA infographic.

Image
Source: NASA

On a NASA Flickr account, more specific details about the SLS were released and were included among 253 arresting images and photographs. For example, the booster, known as QM-1, weighs 1.6 million pounds; all its contents will burn in just two minutes. That breaks down to 5.5 tons of propellant expelled every second — in layman's terms, that's a lot of blow.

SLS's first launch, set for 2018, won't be a mission to Mars just yet, but rather will concern itself with data-gathering expeditions involving what Florida Today described as "13 roughly shoe box-sized CubeSats," that are expected to "hitch deep space rides near the moon." The shoe box bots are expected to mine moon data on everything from space radiation to lunar ice spots. The agency even issued an open call to ordinary Americans called the Cube Quest Challenge to submit ideas for what deep space phenomena is worthy of exploration.

Image
"
https://news.yahoo.com/hello-spaceship- ... .html?nf=1
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Re: Astronomy, cosmology and space thread

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Astronomers have finally found evidence of gravitational waves
After 100 years of theory and decades of experiments, astronomers have detected gravitational waves directly for the first time. The announcement, made Thursday by the Laser Interferometer Gravitational-Wave Observatory (LIGO) and accompanied by a paper in Physical Review Letters, describes a powerful signal that ultimately began with the merger of two black holes located 1.3 billion light-years away.

The finding not only confirms yet another aspect of Albert Einstein’s theory of gravity, known as general relativity, but it also opens another avenue for researchers to observe and study the universe.

“Ladies and gentlemen, we have detected gravitational waves. We did it!,” said LIGO scientific spokesman David Reitze at the announcement Thursday. Before crashing together, the black holes were 36 and 29 times the Sun's mass. Afterward, the new combined black hole has only 62 solar masses, with the colossal difference — 5,000 supernovas' worth of energy — radiated away as gravitational waves.

Gravitational waves are literally distortions in space-time, ripples in the fabric of the universe. Gravity is the weakest of the four fundamental forces, so only the most extreme events — black holes colliding, neutron stars twirling, a supernova erupting — would produce detectable waves. LIGO’s twin detectors, in Louisiana and Washington state, use lasers to watch for these tiny stretches and squeezes of space-time.

http://astronomy.com/bonus/gravity
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Re: Astronomy, cosmology and space thread

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What's more astounding, is that gravitational waves were predicted by Albert Einstein 100 years ago - a genius doesn't even begin to describe his intellect.
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Re: Astronomy, cosmology and space thread

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Dannie Boy wrote:What's more astounding, is that gravitational waves were predicted by Albert Einstein 100 years ago - a genius doesn't even begin to describe his intellect.
Absolutely - couldn't agree more :bow:
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"Einstein Would Be Beaming": Scientists React to Gravitational Waves

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This is just amazing news! IT'S OFFICIAL: GRAVITATIONAL WAVES HAVE BEEN FOUND!!
THEY WERE PRODUCED BY TWO MERGING BLACK HOLES. "Einstein Would Be Beaming": Scientists React to Gravitational Waves.

http://www.popsci.com/its-official-ligo ... ts&src=syn
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Re: "Einstein Would Be Beaming": Scientists React to Gravitational Waves

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Siani wrote:This is just amazing news! IT'S OFFICIAL: GRAVITATIONAL WAVES HAVE BEEN FOUND!!
THEY WERE PRODUCED BY TWO MERGING BLACK HOLES. "Einstein Would Be Beaming": Scientists React to Gravitational Waves.

http://www.popsci.com/its-official-ligo ... ts&src=syn
Sinai, sometimes it's a good idea to check the previous page before you post, this news had been posted already| :cheers:
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Re: Astronomy, cosmology and space thread

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:oops: , I normally do, sorry I missed this one. My apologies.
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Re: Astronomy, cosmology and space thread

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First detection of super-Earth atmosphere
For the first time, astronomers have analyzed the atmosphere of an exoplanet in the class known as super-Earths. Using data gathered with the Hubble Space Telescope and new analysis techniques, the exoplanet 55 Cancri e is revealed to have a dry atmosphere without any indications of water vapor. The results indicate that the atmosphere consists mainly of hydrogen and helium.

The international team, led by scientists from University College London (UCL), took observations of the nearby exoplanet 55 Cancri e, a super-Earth with a mass of eight Earth-masses. It is located in the planetary system of 55 Cancri, a star about 40 light-years from Earth.

http://www.astronomy.com/news/2016/02/f ... atmosphere
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Re: Astronomy, cosmology and space thread

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"The Hubble Space Telescope just snapped photos of the biggest black hole we've ever observed

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A new photograph of galaxy NGC 4889 may look peaceful from such a great distance, but it’s actually home to one of the biggest black holes that astronomers have ever identified. The Hubble Space Telescope allowed scientists to capture photos of the galaxy, located in the Coma Cluster about 300 million light-years away. The supermassive black hole hidden away in NGC 4889 breaks all kinds of records, even though it is currently classified as dormant.

So how big is it, exactly? Well, according to our best estimates, the supermassive black hole is roughly 21 billion times the size of the Sun, and its event horizon (an area so dense and powerful that light can’t escape its gravity) measures 130 billion kilometers in diameter. That’s about 15 times the diameter of Neptune’s orbit around the Sun, according to scientists at the Hubble Space Telescope. At one point, the black hole was fueling itself on a process called hot accretion. Space stuff like gases, dust, and galactic debris fell towards the black hole and created an accretion disk. Then that spinning disk of space junk, accelerated by the strong gravitational pull of the largest known black hole, emitted huge jets of energy out into the galaxy.

Related: Scientists just saw light coming from around a black hole for the first time

During that active period, NGC 4889 would have classified as a quasar (quasi-stellar radio source) thanks to the black hole’s emissions of up to a thousand times more energy than our Milky Way galaxy. But the black hole is now in dormant mode because there isn’t any more sustenance stored in the orbiting accretion disk. “The accretion disk sustained the supermassive black hole’s appetite until the nearby supply of galactic material was exhausted. Now, napping quietly as it waits for its next celestial snack, the supermassive black hole is dormant”, says the Hubble Space Telescope website.

Of course, the announcement posted with new photos of the NGC 4889 galaxy is quick to point out that the pictures don’t exactly capture the likeness of the supermassive black hole. It is impossible to observe a black hole directly, but scientists have been able to identify the implied presence of a black hole by analyzing the way celestial objects interact with some invisible force. For this particular black hole in the NGC 4889 galaxy, scientists used instruments on the Keck II Observatory and the Gemini North Telescope to measure the velocity of stars moving around the center point of the galaxy. The stars’ specific velocities re what allowed scientists to calculate the incredible size of NGC 4889’s black hole."

https://www.yahoo.com/tech/astronomers- ... 00237.html
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Re: The WOW Science Thread

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"NASA Recorded the Sun Every Day for a Year and the Result Is Stunning"

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Description and video:

https://news.yahoo.com/nasa-recorded-su ... .html?nf=1
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Re: The WOW Science Thread

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"If You Fall Into a Black Hole, There's Only One Way to Survive

If your starship ran into a black hole, it wouldn’t just drop into the void like the Titanic sunk into the North Atlantic.

Instead, you’d be caught in the black hole’s ferocious gravitational pull and slip toward its center of infinite density.

Gravity would yank on the closest part of you and your ship until you became “spaghettified” and turned into paper-thin strands of matter. Eventually, your spaghetti self would slip over the event horizon (also known as the black hole’s point of no return), everything would go black and you’d be lost forever.

If Stephen Hawking’s theory is right, then tiny little bits of you might escape from the black hole over time in the form of radiation, but otherwise you’d be toast.

Image

But if you do ever find yourself near a black hole, there may be a shred of good news — that is, if it’s spinning rather than stationary. New research published in the journal Physical Review D suggests that you might be able to survive the inside of a spinning black hole.

A team of researchers figured this out by creating the first-ever computer model of a quickly spinning black hole, called a Kerr black hole.

“It has often been assumed that objects approaching a black hole are crushed by the increasing gravity," Lior Burko, a physicist who worked on the research, said in a press release. "However, we found that while gravitational forces increase and become infinite, they do so fast enough that their interaction allows physical objects to stay intact as they move toward the center of the black hole.”

So if your black hole is spinning fast enough, you might just live to tell the tale.

Image

What’s more, the researchers say, this lends some small credence to the science-fiction idea that black holes could act as a portal or wormhole for interstellar travel. ..."

https://news.yahoo.com/fall-black-hole- ... .html?nf=1
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Re: Astronomy, cosmology and space thread

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"A 5-dimensional black hole could break the laws of physics as we know them

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If you thought regular black holes were about as weird and mysterious as space gets, think again, because for the first time, physicists have successfully simulated what would happen to black holes in a five-dimensional world, and the way they behave could threaten our fundamental understanding of how the Universe works.

The simulation has suggested that if our Universe is made up of five or more dimensions — something that scientists have struggled to confirm or disprove — Einstein's general theory of relativity, the foundation of modern physics, would be wrong.

In other words, five-dimensional black holes would contain gravity so intense, the laws of physics as we know them would fall apart.

There's a lot to wrap your head around here, so let's start with the black holes themselves.

In a five-dimensional universe, physicists have hypothesized that black holes are more like very thin rings rather than holes, and as they evolve, they can give rise to a series of 'bulges' that become thinner and thinner over time, and eventually break off to form mini black holes elsewhere.

These ring-shaped black holes (or 'black rings') were first proposed in 2002, but until now, no one's been able to successfully simulate their evolution. This has been made possible thanks to the COSMOS supercomputer at the University of Cambridge in the UK — the largest shared-memory computer in Europe that can perform 38.6 trillion calculations per second.

University of Cambridge

The problem with five-dimensional black holes is that they're thought to consist of 'ultragravity rings', where gravity is so intense, it gives rise to a state known as naked singularity. Naked singularity is an event so strange, no one really knows what would occur, except that the laws of general relativity would no longer apply.

Einstein’s general theory of relativity is based on how we think gravity governs the behavior of the Universe. We know that matter in the Universe warps the surrounding fabric of space-time, and this warping effect is what we refer to as gravity. Since it was first proposed 100 years ago, general relativity has passed every test — everything we observe in the Universe follows its stipulations, but singularity can pose some problems.

In a four-dimensional universe (where the fourth dimension is time), singularity is thought to be the point of a black hole where gravity is at its most intense — the center — and this is surrounded by the event horizon at the black hole's edge.

"As long as singularities stay hidden behind an event horizon, they do not cause trouble and general relativity holds — the 'cosmic censorship conjecture' says that this is always the case," says theoretical physicist Markus Kunesch from the University of Cambridge. "As long as the cosmic censorship conjecture is valid, we can safely predict the future outside of black holes."

But what if singularity could exist outside a black hole's event horizon? When Physicists have hypothesized that in five or more dimensions, if an object that has collapsed to an infinite density — singularity — is not bound by an event horizon, it becomes naked singularity, and things would get so crazy in and around that object, we'd need to completely rethink our understanding of how physics works. The whole thing just makes me really nervous.

"If naked singularities exist, general relativity breaks down," said one of the team, Saran Tunyasuvunakool. "And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power — it could no longer be considered as a standalone theory to explain the Universe."

If our Universe only has four dimensions, everything is cool, and ring-shaped black holes and naked singularity are not a thing. But physicists have proposed that our Universe could be made up of as many as 11 dimensions. The problem is that because humans can only perceive three, the only way we can possibly confirm the existence of more dimensions is through high-energy experiments such as the Large Hadron Collider.

Kunesch and his team say they've just about hit the limits of what their supercomputer can simulate, but would like to figure out what it is about four-dimensional universes that make naked singularity impossible, and general relativity correct. "If cosmic censorship doesn't hold in higher dimensions, then maybe we need to look at what's so special about a four-dimensional universe that means it does hold," says Tunyasuvunakool. "

http://www.businessinsider.com/a-five-d ... ity-2016-2
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Re: Astronomy, cosmology and space thread

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Pesky leap year upset the equinox this year. Missed it yesterday!

http://www.timeanddate.com/calendar/march-equinox.html
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