we-are-star-stuff:

What Would Happen if Oxygen Were to Disappear for Five Seconds?

A few things:

• Everyone at the beach would get sunburns. Ozone is molecular oxygen and blocks the majority of UV light. Without it, we are toast.
• The daytime sky would get darker. With fewer particles in the atmosphere to scatter blue light, the sky would get a bit less blue and a bit more black.
• Every internal combustion engine would stall. This means that every airplane taking off from a runway would likely crash to the ground, while planes in flight could glide for some time.
• All pieces of untreated metal would instantly spot-weld to one another. This is one of the more interesting side effects. The reason metals don’t weld on contact is they are coated in a layer of oxidation. In vacuum conditions, metal welds without any intermediate liquid phase (Cold welding).
• Everyone’s inner ear would explode. As mentioned, we would lose about 21 percent of the air pressure in an instant, equivalent to being teleported to the top of the high Andes (elevation, about 2,000 meters).
• Every building made out of concrete would turn to dust. Oxygen is an important binder in concrete structures (really, the CO2 is), and without it, the compounds do not hold their rigidity.
• Every living cell would explode in a haze of hydrogen gas. Water is one third oxygen; without it, the hydrogen turns into gaseous state and expands in volume.
• The oceans would evaporate and bleed into space. As oxygen disappears from the oceans’ water, the hydrogen component becomes an unbound free gas. Hydrogen gas, being the lightest, will rise to the upper troposphere and slowly bleed into space through Atmospheric escape.
• Everything above ground would immediately go into free fall. As oxygen makes up about 45 percent of the Earth’s crust and mantle, there is suddenly a lot less “stuff” beneath your feet to hold everything up.

To sum, it wouldn’t be pretty.

astronomy-to-zoology:

Opabinia (Opabinia regalis) another unique arthropod from the Cambrian period, noted for its five eyes and proboscis.

From David Attenbrough’s First Life watch it like right now!

sciencesoup:

Supernova are the explosions of massive stars more than 8 times the mass of our sun. Their cores run out of fuel, and because nothing is pushing out and opposing their own gravitational pull, the stars just collapse in on themselves, forming either a neutron star or a black hole. As they go supernova, they produce a hugely powerful shock wave that basically explodes the star.

Mostly, astronomers just see the aftermath of supernovas because the estimated rate of supernova production in our galaxy is about one every 50 years, and the explosions happen in a very short timespan of only about 100 seconds. The remnants they leave behind remain bright for some time, and their peak brightness can last for months, so it depends what you mean by “seeing” a star go supernova—seeing the star in the initial stage of the explosion is very, very rare; we’re much more likely to see the remnants. Many well-known nebulae are supernova remnants, including the Crab Nebula:

But one of the first such remnants to be discovered soon after its star went supernova was SN 1987A, in the outskirts of the Tarantula Nebula in the Large Magellanic Cloud. The light from it first reached Earth on February 23, 1987. It was the first supernova to be observed across every band of the electromagnetic spectrum, and because it was so close, it could be seen with the naked eye. It was the first opportunity for astronomers to observe a supernova up close, and it gave them fascinating insight into the process of stellar evolution, allowing them to test theories against observations.

But the first time astronomers have witnessed a star go supernova in real-time was in 2008. NASA’s orbiting Swift telescope spotted the extremely luminous blast of X-rays of SN 2008D while watching another older supernova.

Astronomers were able to observe the evolution of the explosion right from the start, catching the initial X-ray signature of the stellar death of SN 2008D, which means they now know what X-ray patterns to look for, and can hopefully in the future spot more supernovae at the same critical moment.

ilovecharts:

Things you contemplate while washing your hair when you own a periodic table shower curtain.

-elli m