Gliese 832c: Is A Potentially Habitable Super-Earth Discovered Only 16 Light-Years From Earth

Researchers find proteins that might restore damaged sound-detecting cells in the ear

Using genetic tools in mice, researchers at Johns Hopkins Medicine say they have identified a pair of proteins that precisely control when sound-detecting cells, known as hair cells, are born in the mammalian inner ear. The proteins, described in a report published June 12 in eLife, may hold a key to future therapies to restore hearing in people with irreversible deafness.

“Scientists in our field have long been looking for the molecular signals that trigger the formation of the hair cells that sense and transmit sound,” says Angelika Doetzlhofer, Ph.D., associate professor of neuroscience at the Johns Hopkins University School of Medicine. “These hair cells are a major player in hearing loss, and knowing more about how they develop will help us figure out ways to replace hair cells that are damaged.”

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Behold NGC 6357, “cathedral to massive stars.” Credit: NASA, ESA and Jesús Maíz Apellániz (IAA, Spain). (NASA/APOD)

Colourised footage of Benjamin, the last know Tasmanian Tiger (Thylacine).

Benjamin died on September 7th, 1936 in Hobart zoo. It is believed that he died out of neglect, as he was locked out of his shelter and was exposed to the searing hot sun and freezing cold night of Tasmania.

The Thylacine was one of the last large marsupials left on Australia (the other being the Kangaroo) after a great extinction event occurred around 40 thousand years ago. This extinction event, caused mainly by the arrival of humans, wiped out 90% of Australia’s terrestrial vertebrates, including the famous Megafauna.

The Thylacine was around 15-30kg (33-66lbs), were carnivorous, and had numerous similarities to other species like dogs, despite not being related and purely by chance, in a phenomenon known as convergent evolution (just like the ability to fly of bats and birds, despite following different evolutionary paths). Not only that, they could open their jaws up to 120 degrees, could hop around on two legs like a kangaroo, and both males and females had pouches.

Lastly in a cruel twist, the Tasmanian government decided to protect the Thylacine - just 59 days before the last one died, in a very notable case case of “Too little too late”. To date, many biologists believe that there are still Thylacine roaming the wild plains of Australia. 

Three galaxies at once

Rising majestically above the telescopes of ESO’s La Silla Observatory in Chile we see the Milky Way accompanied by its two dwarf neighbour galaxies, the Large and Small Magellanic Clouds.

Credit: ESO/A. Santerne

Can you explain in a simple (???) way gravitational waves? please? do you know any books about it?

Sure!

According to Einstein’s General Theory of Relativity, what we think of as "empty space” isn’t nothing. Instead, space is more like a fabric that can be stretched, squashed, bent and shaped, and all matter and energy cause space to bend around them. The more mass or energy something has, the greater the bending of space around it it causes, a bit like heavier and lighter balls on a rubber sheet:

(Source - Note that this picture is a 2D analogy, and space is actually 3D! The bending of space isn’t something we can easily visualise, so we have to use analogies like the “balls on a rubber sheet” analogy - as long as we recognise their shortcomings!)

Let’s imagine the Sun is a bowling ball dropped onto a rubber sheet, creating a huge dent in space. And now let’s roll a marble - Earth - onto that sheet too. IF the marble is rolling too slowly, it will fall into the dent and roll around a few times, spiralling in and eventually colliding with the ball. If the marble is rolling too quickly, its path will be bent, but it will escape. If it’s rolling at a certain speed, however, the marble will roll around the bowling ball and go into orbit around it. (Here’s another shortcoming of the rubber sheet analogy - real rubber sheets have friction, so the marble would eventually slow down and roll in towards the bowling ball. Space, however, has no friction, so the Earth can stay in orbit around the Sun for a long time.) In other words, this bending of space is what we refer to as gravity!

In Newton’s view of gravity, Earth would naturally follow a straight line through space, but its path would be bent towards the Sun by a mysterious pulling force. That force holds the planets in orbit around the Sun and pulls apples to Earth, but Newton couldn’t explain why - a mysterious influence that spread out through space, called the gravitational field, somehow caused bodies to attract one another. Einstein explained that massive objects curve the space around them. Earth would also naturally follow a straight line through space, but the space itself is curved, forcing Earth to follow a curved path - it’s a bit like trying to walk in a straight line along a hill. Try as you might, your path will have to bend to follow the contours of the landscape. According to Einstein, gravity isn’t really a “force” as such but an effect of this bending of space. Matter and energy tell space how to bend; space tells matter and energy how to move. That’s all gravity is. The gravitational field isn’t some mysterious entity in space - the gravitational field is the space itself! Here’s a nice little video to help you visualise all this:

(I’m oversimplifying a little, btw, saying that gravity is the bending of “space.” In Einstein’s theory, the three dimensions of space are unified with time into one four-dimensional fabric, the space-time continuum. So gravity isn’t just the bending of space, but the warping of time too - you can’t change one without changing the other! Gravity actually slows time down, so you would age slightly faster in space than you do at Earth’s surface. The difference is incredibly tiny, but measurable - time passes more quickly for the GPS satellites than it does for us here on Earth, and what the clock of a GPS satellite would measure as “one day” is about 38 microseconds shorter than what we measure as “one day.” That doesn’t sound like a big difference, but engineers have to take it into account when designing GPS systems - if they didn’t account for this, your GPS location would drift by as much as 10 kilometres per day! So this isn’t just some abstract theory - this is a real effect that’s already important for technology you probably use every day.)

General Relativity has now been through many, many tests and has passed every one with flying colours, and all of its predictions had been verified by the beginning of 2016 except one - gravitational waves.

What would happen if we could somehow destroy the Sun? Newton believed that there was a mysterious gravitational connection between the Sun and Earth, holding Earth in its orbit, that would instantly be broken if the Sun was destroyed. Earth would instantly fly out of its orbit in a straight line. Einstein, however, didn’t like this - his Special Theory of Relativity (which he put out 10 years before the General Theory) says that no information could ever travel faster than light. It takes about 8 minutes for the Sun’s light to reach us, so how could Earth fly out of its orbit instantly? That would let us know the Sun had been destroyed 8 minutes before the light from the Sun’s destruction reached us. Einstein wasn’t comfortable with this.

Thankfully, General Relativity resolves the paradox - if you got rid of the Sun, Earth would still stay in its orbit for a while, because the space-time around the Sun would still be curved. Meanwhile, at the place where the Sun was, space-time would spring back to its original flat state, and that would ripple through the surrounding space-time as everything adjusted back to where it was. That ripple - a gravitational wave - would spread out through space at the speed of light, so the space around Earth would stay curved and Earth would remain in its orbit until the same time the light from the Sun’s destruction passed us - at which point the gravitational wave would ripple through the space around Earth and restore it back to its original flat state, and Earth would finally leave its orbit.

Of course, in reality, stars don’t just disappear. But the gravitational environment does change. Stars move around, and the fabric of space-time also moves with them. Stars explode. Black holes and neutron stars form, putting huge dents in space-time, and sometimes they collide. All these events are a bit like changing the environment in a still pond - stars and planets gently orbiting are like ducks gently gliding through the pond, creating gentle ripples as they disturb its surface - and black hole collisions are more like throwing a rock into the pond and sending out massive waves. Almost everything in our universe produces gravitational waves, but most of the time, they’re too tiny to detect. (That’s why I said in real space the Earth can orbit the Sun for “a long time,” and not “forever.” Earth is constantly sending out very faint gravitational waves as it rolls around the Sun and moves through the fabric of space-time. Those waves are too small to detect, but they very, very slowly sap Earth’s energy and cause it to very, very slowly spiral in to the Sun. In reality, that would take unimaginable trillions upon trillions of years, and Earth will probably be destroyed by the dying Sun long before that! Even if Earth manages to survive that, it’s more likely to be pulled out of orbit by an incredibly rare passing star or knocked out by unpredictable gravitational tugs from the other planets or something before it spirals into the Sun. Orbits are stable for a very, very, very, very long time.) More intense sources of gravity than our puny Earth and Sun, however - things like neutron stars and black holes - can generate detectable gravitational waves.

Our first indirect evidence of gravitational waves came in 1984, when the American astronomers Russel A. Hulse and Joseph A. Taylor discovered a binary neutron star system - two intense sources of gravity orbiting each other very rapidly. As they orbited each other, they sent out huge gravitational ripples - a bit like stirring up that duck pond with two oars whirling round and round - and lost energy by a detectable amount. Hulse and Taylor found that their orbital period slowed down by about 75 milliseconds per year - short, but detectable! That slowing exactly matched the predictions of gravitational wave theory and got its discoverers the Nobel Prize for Physics in 1993.

(Source)

But gravitational waves weren’t directly observed until 2015 (and confirmed until this year) by a detector named LIGO (the Laser Interferometer Gravitational wave Observatory). All LIGO is is basically two beams of laser light travelling between two pairs of mirrors oriented at right angles to each other, like this, so you can measure how space-time is stretched in one direction and squashed in the other by a passing gravitational wave by recording how long it takes the light to travel from one mirror to the other*:

(Source for both images: http://phys.org/news/2016-02-ligo.html)

LIGO’s two “arms” (the two beams of light) are each 4 kilometres long, and a gravitational wave passing through the detector stretches or squashes each of the “arms” by a ridiculously small amount - the ones LIGO actually found stretched and about 1/10,000th the width of a proton. As you can imagine, the LIGO physicists had to account for many, many different effects that shook the detector too. But gravitational waves distort the two beams in a predictable way that would make that distortion stand out from ordinary passing trucks or distant earthquakes, and by February 11th, 2016, the LIGO physicists were confident enough that they really had detected a faint ripple in space-time passing through their detector. The signal was consistent with a gravitational wave from two black holes in orbit around each other, spiralling in to one another.

(Source)

This is exciting for two reasons:1) It confirms the last outstanding prediction of General Relativity, and2) It opens up a whole new field of astronomy! Every so often astronomy is revolutionised by the discovery of new things we can look at from space. Originally all we could detect was the visible light that we could see with our eyes and telescopes. But soon we learned to build radio telescopes, and that opened up a whole new world to us - we could see phenomena that were invisible in ordinary light. With space telescopes we could see the sky in gamma rays, x-rays, ultraviolet and infra-red light as well. Now we could see the explosions of distant stars halfway across the observable Universe, look at clouds of gas and dust too cool to shine in visible light, and peer through other dark clouds to see stars forming inside. We also found particles we could see coming from space, too - neutrinos from the Sun and from supernovae, and cosmic rays. These opened up other windows on the Universe. And now we have gravitational waves - yet another new way of “seeing.” Gravitational wave astronomy will let us study some of the most puzzling events in the Universe, like colliding neutron stars, or black holes falling into other black holes - events we’ve never been able to see before. 

So I hope that helps, Anon! 

As for books, the problem is gravitational waves were detected so recently I don’t know of any books that have come out since then on the subject, so everything will be out of date. However, the basic physics has stayed the same since Einstein first predicted them, so any good popular book on general relativity (Spacewarps by John Gribbin, The Fabric of the Cosmos by Brian Greene and Travelling At the Speed of Thought: Einstein and the Quest for Gravitational Waves by Daniel Kennefick are good examples) should give you some good insight - just replace phrases like “if we detect gravitational waves” with “when we detected gravitational waves!”

(*Yes, yes, I know LIGO isn’t actually measuring the time taken for light to travel down each “arm,” but the interference of the laser beams. Still, that interference allows us to infer the travel time for the light, so I’m simplifying.)

Photographing the Milky Way Over Greece

Alexandros Maragos is an Athens based filmmaker and photographer best known for his landscape photography, astrophotography and timelapse imagery. In his own words:

The Milky Way is the name of the spiral galaxy in which our solar system is located. It is our home in space. The Earth orbits the Sun in the Solar System, and the Solar System is embedded within this vast galaxy of stars. In the northern hemisphere, the Milky Way is visible in the southern half of the sky. This makes Greece one of the best places in the world to see and photograph the galaxy because of the country’s geographic location in Southern Europe at the crossroads of Europe, Asia, and Africa. 

As a filmmaker and photographer I feel very fortunate to live here. Every time I want to shoot the night sky, all I do is to pick a new spot on the map and just go there and take the shot. Greece is a heaven for astrophotography. Whether you choose a mountain, a beach, a peninsula or any of the 6,000 islands, the Milky Way is always visible in the southern sky.

To see more of his work visit his website or follow him on Facebook, Twitter, or Instagram.

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is there anything you can tell us to expand on the space time ripples found in simulated black hole collisions?

Hi!

In one of my other responses I explained the whole concept of space time, here’s how i explained that:

A way that you can picture the bending of space time is this:

Picture two chairs, the backs facing each other. Then tape one end of a blanket to one of the chair backs and the other end of the blanket to the other chair back. What you have now should like this:

Now, if you were to place a tennis ball somewhere on the light blue blanket (top blanket), that blanket would no longer be flat, there would be a bend or a curve in it. Let’s say you put a basketball on the top blanket instead of a tennis ball. Since the basketball is bigger, the bend/curve that it makes will be a lot bigger than the tennis ball’s because the basketball has more mass.

So that blue blanket at the top of the chairs represents space time. If there were to be two large objects, let’s say basketballs, that were to “collide” (representing two black holes). Since they’re so large, they’d create these ripples in the blanket that can be observed.

Another easier way to think about it is like dropping a pebble into a lake. The bigger the pebble, the stronger and more frequent the ripples are. So since black holes are very massive, they create larger ripples compared to something smaller!

Astronomers haven’t been able to directly observe these ripples in space time, they were theorized by Einstein, however there’s an announcement being made all over the world today about data obtained from the Laser Interferometer Gravitational-Wave Observatory (LIGO)!

Here is a link talking a bit about that press conference!

I hope that helped to clarify everything! If not, feel free to ask again and I’ll try my best to clarify!

UPDATE: HERE are the findings of the conference, they’ve detected them for the first time!

Strap in for a Tour of the Milky Way

The night sky isn’t flat. If you traveled deep into this part of the sky at the speed of the radio waves leaving this tower, here are some places you could reach.

Jupiter: Travel time – 35 minutes, 49 seconds.

The closest object in this view is the planet Jupiter, brilliant now in the evening sky…and gorgeous when seen up close by our Juno spacecraft. Distance on the night this picture was taken: 400 million miles (644 million kilometers). 

Saturn: Travel time – one hour and 15 minutes.

The next closest is Saturn, another bright “star” in this summer’s sky. On the right, one of the Cassini spacecraft’s last looks. Distance: 843 million miles (1.3 billion kilometers).

Pluto: Light-speed travel time from the radio tower – four hours, 33 minutes.

It’s not visible to the unaided eye, but Pluto is currently found roughly in this direction. Our New Horizons space mission was the first to show us what it looks like. Distance: more than 3 billion miles.

F-type star, HD 1698330: Light-speed travel time from the radio tower – 123 years.

Within this patch of sky, there’s an F-type star called HD 169830. At this speed, it would take you 123 years to get there. We now know it has at least two planets (one of which is imagined here) — just two of more than 4,000 we’ve found…so far.

The Lagoon Nebula: Light-speed travel time from the radio tower – 4,000 years.

If you look closely, you’ll see a fuzzy patch of light and color here. If you look *really* closely, as our Hubble Space Telescope did, you’ll see the Lagoon Nebula, churning with stellar winds from newborn stars.

Black hole, Sagittarius A*: Light-speed travel time from the radio tower – 26,000 years.

In 26,000 years, after passing millions of stars, you could reach the center of our galaxy. Hidden there behind clouds of dust is a massive black hole. It’s hidden, that is, unless you use our Chandra X-ray Observatory which captured the x-ray flare seen here.

The next time you’re under a deep, dark sky, don’t forget to look up…and wonder what else might be out there.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Festo’s Bionic Flying Fox, as an example of Bio-mimicry.

German automation company Festo has created a Flying Fox (Fruit Bat) made of a 580g foam body with a carbon fibre skeleton and a membrane like material for the wings.

This robot imitates the exact body and wing movements of an actual bad in order for it to fly. This idea of bio-mimicry is one that is paving the way for a host of natural moving, nature inspired machines. 

The upper atmosphere of the Sun is dominated by plasma filled magnetic loops (coronal loops) whose temperature and pressure vary over a wide range. The appearance of coronal loops follows the emergence of magnetic flux, which is generated by dynamo processes inside the Sun. Emerging flux regions (EFRs) appear when magnetic flux bundles emerge from the solar interior through the photosphere and into the upper atmosphere (chromosphere and the corona). The characteristic feature of EFR is the Ω-shaped loops (created by the magnetic buoyancy/Parker instability), they appear as developing bipolar sunspots in magnetograms, and as arch filament systems in Hα. EFRs interact with pre-existing magnetic fields in the corona and produce small flares (plasma heating) and collimated plasma jets. The GIFs above show multiple energetic jets in three different wavelengths. The light has been colorized in red, green and blue, corresponding to three coronal temperature regimes ranging from ~0.8Mk to 2MK. 

Image Credit: SDO/U. Aberystwyth