The most crowded place in the Milky Way

This new NASA/ESA Hubble Space Telescope image presents the Arches Cluster, the densest known star cluster in the Milky Way. It is located about 25 000 light-years from Earth in the constellation of Sagittarius (The Archer), close to the heart of our galaxy, the Milky Way. It is, like its neighbour the Quintuplet Cluster, a fairly young astronomical object at between two and four million years old.

The Arches cluster is so dense that in a region with a radius equal to the distance between the Sun and its nearest star there would be over 100 000 stars!

At least 150 stars within the cluster are among the brightest ever discovered in the the Milky Way. These stars are so bright and massive, that they will burn their fuel within a short time, on a cosmological scale, just a few million years, and die in spectacular supernova explosions

In the sixth century B.C., in Ionia, a new concept developed, one of the great ideas of the human species. The universe is knowable, the ancient Ionians argued, because it exhibits an internal order: there are regularities in Nature that permit its secrets to be uncovered. Nature is not entirely unpredictable; there are rules even she must obey. This ordered and admirable character of the universe was called Cosmos.
—  Carl Sagan

NASA Astronomy Picture of the Day 2015 May 29

Saturn at Opposition 

Telescopic observers on Earth have been treated to spectacular views of Saturn lately as the ringed planet reached its 2015 opposition on May 23 at 0200 UT. Of course opposition means opposite the Sun in Earth’s sky. So near opposition Saturn is up all night, at its closest and brightest for the year. These sharp images taken within hours of the Sun-Earth-Saturn alignment also show the strong brightening of Saturn’s rings known as the opposition surge or the Seeliger Effect. Directly illuminated, the ring’s icy particles cast no shadows and strongly backscatter sunlight toward planet Earth, creating the dramatic surge in brightness. Saturn currently stands in the sky not far from bright Antares, alpha star of the constellation Sagittarius.

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Wonderful. Chromoscope:

Ever wanted X-ray specs or super-human vision? Chromoscope lets you explore our Galaxy (the Milky Way) and the distant Universe in a range of wavelengths from gamma-rays to the longest radio waves.

From top to down:

Quick Tour of Chromoscope

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The Shape of the Universe that Sends Chills Down your Spine

According to Einstein’s theory of relativity, gravity and energy effect the shape of space.

You can imagine this by looking at gravity not as a ‘force’ but as a downwards indentation in space. If you take a towel and have it pulled flat then drop a bowling ball in the middle, the area around the bowling ball will have been pressed down. The Moon orbiting Earth is just following a straight trajectory around this downward curvature of space.

Energy does the opposite of gravity. It makes a positive curvature.

When you look at the big picture, you’ve got a universe whose overall shape is dictated by whether or not it’s got an overall positive, negative or zero amount of energy.

We know, thanks to measuring the gravity of regular matter, dark matter and the strange anti-gravitational force called 'dark energy’, that we can make an equation with energy on one side and gravity on the other.

This equation will tell us the shape of the universe.

A negative answer means our universe is shaped like a saddle. A positive one means our universe is shaped like a globe (closed). An answer of zero means the universe has flat geometry.

Want the mysterious part?

Scientists have found that the universe is somehow, shockingly *perfectly tuned*. The measured amount of dark energy combined with the average density of matter is approximately zero. Our universe is flat.

With a flat universe, a universe with a net total of zero energy, we have a case of an entire universe being created out of nothing.

Somehow the matter and gravitational energies that otherwise cancelled each other out in a state of 'zero-ness’ were separated. Our universe may have in fact been created out of nothing.

It gets more odd. If you were to add (which we can’t) a single gram of matter (just one gram) it totally changes the entire shape of the universe. Our universe would be a closed one that would end in a 'Big Crunch’ where all things collapse and fall into a singularity: a perfect opposite of the Big Bang.

Scientists don’t like it when things seem to be fine tuned. It usually means we’re missing something. This means that our universe is many times more incredible and mysterious than you may have ever imagined before…

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Best of 2014!

January

February

March

April

May

June

July

August

September

October

November

December

Still not satisfied? Relive the previous year in science!

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Google honors Sally Ride

May 26th is the birthday of Sally Ride, who was an American physicist and astronaut. She was the first American woman and the youngest American astronaut to travel space. She also served on the committees that investigated the Challenger and Columbia space shuttle disasters, being the only person to participate on both.

Ride was also the first known LGBT astronaut.

Sally Ride passed away July 23, 2012, at the age of 61.

Big Bang May Have Created a Mirror Universe Where Time Runs Backwards

By Tim De Chant

Why does time seem to move forward? It’s a riddle that’s puzzled physicists for well over a century, and they’ve come up with numerous theories to explain time’s arrow. The latest, though, suggests that while time moves forward in our universe, it may run backwards in another, mirror universe that was created on the “other side” of the Big Bang.

Two leading theories propose to explain the direction of time by way of the relatively uniform conditions of the Big Bang. At the very start, what is now the universe was homogeneously hot, so much so that matter didn’t really exist. It was all just a superheated soup. But as the universe expanded and cooled, stars, galaxies, planets, and other celestial bodies formed, birthing the universe’s irregular structure and raising its entropy.

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NASA Astronomy Picture of the Day 2015 January 28

Comet Lovejoy in a Winter Sky

Which of these night sky icons can you find in this beautiful and deep exposure of the northern winter sky? Skylights include the stars in Orion’s belt, the Orion Nebula, the Pleiades star cluster, the bright stars Betelgeuse and Rigel, the California Nebula, Barnard’s Loop, and Comet Lovejoy. The belt stars of Orion are nearly vertical in the central line between the horizon and the image center, with the lowest belt star obscured by the red glowing Flame Nebula. To the belt’s left is the red arc of Barnard’s Loop followed by the bright orange star Betelgeuse, while to the belt’s right is the colorful Orion Nebula followed by the bright blue star Rigel. The blue cluster of bright stars near the top center is the Pleiades, and the red nebula to its left is the California nebula. The bright orange dot above the image center is the star Aldebaran, while the green object with the long tail to its right is Comet C/2014 Q2 (Lovejoy). The featured image was taken about two weeks ago near Palau village in Spain.

The Search For Neutrons That Leak Into Our World From Other Universes

“Braneworld” theories predict that matter can leak into and out of other universes. So physicists are searching for the first evidence

One of the more exciting ideas in high energy physics is the possibility that our three-dimensional universe is embedded in a much bigger multidimensional cosmos. Physicists call these embedded universes “branes” and say that it should be possible for stuff from our brane to leak into other branes nearby and vice versa.

Today, Michael Sarrazin at the University of Namur in Belgium and a few pals say they have worked out to detect this leakage by measuring whether neutrons can bypass barriers by leaping into another brane and back again.

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