New York to L.A. in less than an hour? Sign us up! The Air Force is trying out a hypersonic unmanned superjet today that could change the way we fly.
If everything goes according to plan, the X-51A WaveRider will soar to an ear-popping 13.26 miles above Earth at an heart-stopping 4,000 mph — six times the speed of sound.
Anyone up for some camping?
Courstesy of Laughingsquid.
Today’s afternoon read:
Image: M81 Spiral galaxy Credit: NASA Spitzer Space Telescope
This is one of the questions we still don’t have a conclusive answer to, but as scientists search the cosmos for clues, the mystery becomes clearer.
Galaxies probably began to form less than a billion years after the Big Bang, which occurred around 13.7 billion years ago. The primordial Universe consisted almost entirely of hydrogen and helium gas, as well as dark matter, and was, for a time, almost completely homogeneous. It is believed that hypothetical dark matter played a major role in the formation of galaxies and the advent of a heterogeneous Universe. Clouds of gas first began clumping together due to the accumulation of primordial fluctuations, which were small changes of the density in certain parts of the early Universe. Through gravity, gas and dark matter were drawn towards the denser regions of the Universe.
There are two main hypotheses on how galaxies began to form, both of which are based on the gravitational effects of collapsing gas. One is called the “bottom-up” theory, in which giant clouds of gas came together in small clumps, which then merged to form larger galaxies. The second theory is the “top-down” one, in which clouds of gas the size of multiple galaxies broke down into individual clumps. This theory would explain why galaxies occur in clusters, and is the most widely accepted model.
Hydrogen and helium gas were then drawn towards the inner part of protogalaxies while dark matter formed a halo surrounding the outer part. The gas within these infant galaxies also began to clump together and heat up, forming the first stars. In the beginning, matter in the Universe was composed almost exclusively of hydrogen and helium. Nuclear fusion within stars (and during supernovae) would help make the rest of the heavier elements.
For those Manhattanites out there, you’re going to have a very nice summer
As Neil deGrasse Tyson ponders:
“What will future civilizations think of Manhattan Island when they dig it up and find a carefully laid out network of streets and avenues?”
Twice a year on either side of the summer solstice, the Manhattan street grid lines up precisely with the setting sun, framing the glowing orb with towering steel and concrete, and creating even more traffic than normal. Last night’s sighting was a washout due to weather, but there will be another opportunity tonight at 8:16 PM to see the marvel of Manhattanhenge.
The path of the sun creeps north and south along with the changing seasons due to the tilt of the Earth on its axis and its orbit around the sun. The 30 degree shift of the Manhattan street grid (and the fact that the island offers uninterrupted horizon on its west side) allow this unique urban view of the sun, perhaps unequaled around the world.
NYC followers, I know you’re out there. Grab a camera and get out there (and feel free to tweet me any good pics)! If the weather messes you up again, well … I guess you can just stare at the 2011 photo above really hard.
courtesy of jtotheizzoe