NGC 6888: The Crescent Nebula

NGC 7380, Wizard in Cepheus

What is a Wormhole?

Wormholes were first theorized in 1916, though that wasn’t what they were called at the time. While reviewing another physicist’s solution to the equations in Albert Einstein’s theory of general relativity, Austrian physicist Ludwig Flamm realized another solution was possible. He described a “white hole,” a theoretical time reversal of a black hole. Entrances to both black and white holes could be connected by a space-time conduit.

In 1935, Einstein and physicist Nathan Rosen used the theory of general relativity to elaborate on the idea, proposing the existence of “bridges” through space-time. These bridges connect two different points in space-time, theoretically creating a shortcut that could reduce travel time and distance. The shortcuts came to be called Einstein-Rosen bridges, or wormholes.

Certain solutions of general relativity allow for the existence of wormholes where the mouth of each is a black hole. However, a naturally occurring black hole, formed by the collapse of a dying star, does not by itself create a wormhole.

Wormholes are consistent with the general theory of relativity, but whether wormholes actually exist remains to be seen.

A wormhole could connect extremely long distances such as a billion light years or more, short distances such as a few meters, different universes, or different points in time

For a simplified notion of a wormhole, space can be visualized as a two-dimensional (2D) surface. In this case, a wormhole would appear as a hole in that surface, lead into a 3D tube (the inside surface of a cylinder), then re-emerge at another location on the 2D surface with a hole similar to the entrance. An actual wormhole would be analogous to this, but with the spatial dimensions raised by one. For example, instead of circular holes on a 2D plane, the entry and exit points could be visualized as spheres in 3D space.

Science fiction is filled with tales of traveling through wormholes. But the reality of such travel is more complicated, and not just because we’ve yet to spot one.

The first problem is size. Primordial wormholes are predicted to exist on microscopic levels, about 10–33 centimeters. However, as the universe expands, it is possible that some may have been stretched to larger sizes.

Another problem comes from stability. The predicted Einstein-Rosen wormholes would be useless for travel because they collapse quickly.

“You would need some very exotic type of matter in order to stabilize a wormhole,” said Hsu, “and it’s not clear whether such matter exists in the universe.”

But more recent research found that a wormhole containing “exotic” matter could stay open and unchanging for longer periods of time.

Exotic matter, which should not be confused with dark matter or antimatter, contains negative energy density and a large negative pressure. Such matter has only been seen in the behavior of certain vacuum states as part of quantum field theory.

If a wormhole contained sufficient exotic matter, whether naturally occurring or artificially added, it could theoretically be used as a method of sending information or travelers through space. Unfortunately, human journeys through the space tunnels may be challenging.

Wormholes may not only connect two separate regions within the universe, they could also connect two different universes. Similarly, some scientists have conjectured that if one mouth of a wormhole is moved in a specific manner, it could allow for time travel.

Although adding exotic matter to a wormhole might stabilize it to the point that human passengers could travel safely through it, there is still the possibility that the addition of “regular” matter would be sufficient to destabilize the portal.

Today’s technology is insufficient to enlarge or stabilize wormholes, even if they could be found. However, scientists continue to explore the concept as a method of space travel with the hope that technology will eventually be able to utilize them.

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Just let Earth enjoy the theory of general relativity, Mars.

P.S. Today (in 1905) the theory of special relativity was revealed!

The highly distorted supernova remnant shown in this image may contain the most recent black hole formed in the Milky Way galaxy. The image combines X-rays from NASA’s Chandra X-ray Observatory in blue and green, radio data from the NSF’s Very Large Array in pink, and infrared data from Caltech’s Palomar Observatory in yellow.

Credits: X-ray: NASA/CXC/MIT/L.Lopez et al; Infrared: Palomar; Radio: NSF/NRAO/VLA

The Orion Bullets via NASA https://ift.tt/2VwwqDm

This year’s winners of Nobel Prize for Physics includes a woman! 🎉🎊

Her name is Donna Strickland. Together with Arthur Ashkin, and Gérard Mourou, they are awarded the Nobel Prize “for their groundbreaking inventions in the field of laser physics” which help open up doors for potential research in biomedical physics.

[The announcement comes one day after a senior scientist with Cern, the academic home to a number of Nobel prize winners, was suspended for saying that physics was invented and built by men.

“We need to celebrate women physicists because we’re out there. I’m honored to be one of those women,” Strickland said in a news conference following the announcement in Stockholm.

Speaking about being the third woman to ever win the award, she said she thought there might have been more, adding: “Hopefully in time it will start to move forward at a faster rate.”]

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October is the time of year for the Orionids Meteor Shower! Pictured here, over two dozen meteors were caught in successively added exposures last October in Inner Mongolia. The featured image shows multiple meteor streaks that can all be connected to a single small region on the sky called the radiant, here visible just above and to the left of the belt of Orion. The Orionids meteors started as sand sized bits expelled from Comet Halley during one of its trips to the inner Solar System. Comet Halley is actually responsible for two known meteor showers, the other known as the Eta Aquarids and visible every May. 

Next month, the Leonids Meteor Shower from Comet Tempel-Tuttle should also result in some bright meteor streaks.

Image Credit & Copyright: Yin Hao

Cherenkov Radiation: When Electrons go Faster than the Speed of Light!

Well faster than light is an overstatement in the sense that it only happens in water. Basically the speed of light in water is 0.75c and although matter can be accelerated faster than that it is still below the speed of light in a vacuum. And that’s what basically causes the blue light or Chernenkov radiation, particles in a medium moving faster than the speed of light in that medium. 

How does that happen though? Well that is due to very excited neutrinos produced by the nuclear reactor colliding with the nuclei of the water that is surrounding it. The collision produces muons and electrons which have the resulting momentum faster than the speed that light can travel in water. Which in turn brings the electrons in the surrounding water atoms/molecules to a higher state, and when they return back to the ground state they emit light in the wavelength of the resulting momentum transfer from those excited particles. 

A common analogy is the sonic boom of a supersonic aircraft or bullet. The sound waves generated by the supersonic body propagate at the speed of sound itself; as such, the waves travel slower than the speeding object and cannot propagate forward from the body, instead forming a shock front. In a similar way, a charged particle can generate a light shock wave as it travels through an insulator.

More science and gifs on my blog: rudescience Gif made from: This video References: (x), (x). You can donate to support more science content on tumblr: here

I want to be a new genre.

(via Etsy)

This is the 4th week of Deep, Dark, Space month!

This week’s entry is a not so “chilling” tale known as:

“The Big Crunch” 

http://www.universetoday.com/37018/big-crunch/

http://www.iflscience.com/physics/big-crunch-back-possible-end-universe