A Glowing Pool Of Light
"NGC 3132 is a striking example of a planetary nebula. This expanding cloud of gas, surrounding a dying star, is known to amateur astronomers in the southern hemisphere as the "Eight-Burst" or the "Southern Ring" Nebula.
The name “planetary nebula” refers only to the round shape that many of these objects show when examined through a small visual telescope. In reality, these nebulae have little or nothing to do with planets, but are instead huge shells of gas ejected by stars as they near the ends of their lifetimes. NGC 3132 is nearly half a light year in diameter, and at a distance of about 2000 light years is one of the nearer known planetary nebulae. The gases are expanding away from the central star at a speed of 9 miles per second.
This image, captured by NASA’s Hubble Space Telescope, clearly shows two stars near the center of the nebula, a bright white one, and an adjacent, fainter companion to its upper right. (A third, unrelated star lies near the edge of the nebula.) The faint partner is actually the star that has ejected the nebula. This star is now smaller than our own Sun, but extremely hot. The flood of ultraviolet radiation from its surface makes the surrounding gases glow through fluorescence. The brighter star is in an earlier stage of stellar evolution, but in the future it will probably eject its own planetary nebula”
Credit: The Hubble Heritage Team
All the times science fiction became fact
I don’t usually go for these really-big-ads-disguised-as-infographics (Really? Sci-fi ink & toner?), but this one was too cool to pass up.
Unfortunately, no hoverboards yet. But we’ve still got 15 months before time runs out on that one:
Bonus: Why are some science fiction authors so good at predicting the future? Check out this episode of It’s Okay To Be Smart where I talk all about that:
(via io9)
Windswept by Charles Sowers
Though we cannot physically hold wind or see its swirling forms around us, we can definitely feel it.
In order to help visualize wind-currents, artist Charles Sowers created a kinetic installation consisting of 612 aluminum weather vanes called “Windswept” (2011). These were then meticulously placed on the side of the Randall Museum in San Francisco. Through this installation, we are able to see the patterns in the wind; where the currents go, how they turn, and sometimes how wind can abruptly change direction. This gives us a visual representation of the natural, invisible, force which moves around us, and sometimes with enough force, pushes and pulls us.
As the artist states: “Our ordinary experience of wind is as a solitary sample point of a very large invisible phenomenon. Windswept is a kind of large sensor array that samples the wind at its point of interaction with the Randall Museum building and reveals the complexity and structure of that interaction.”
This sort of installation creates a better understanding, and appreciation, of the wind. It is not just one large gust; a single wave can be made up of smaller currents, going in their own directions from the main flow. A dialogue begins to form between the building and the wind, the weather vanes acting as translators.
-Anna Paluch
The eye is a basically a dipole ( a separation of electric charges )
It was observed by Reymond in 1848 that the cornea of the eye is electrically positive relative to the back of the eye.This potential was surprisingly not dependent on the amount of light falling on the eye.
The cornea is the transparent front part of the eye
This means that as the eye moves from side to side, the dipole moves as well. To capture the movement of the dipole, one places two electrodes on both sides of the eye. ( like the one placed on this guy )
If the eye moves from the center position to the right, one of the electrodes becomes slightly positive and the other negative. This leads to a spike in the positive direction.
Source
And if the eye moves from the center position to the left, the polarity of the electrodes reverses. This leads to a spike in the negative direction.
That’s about it. That’s EOG for you all. I hope you guys enjoyed this post.
Have a great day!
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More about EOG
Gif source : The backyard brains
Astronomers have found cosmic clumps so dark, dense and dusty that they throw the deepest shadows ever recorded. Infrared observations from NASA’s Spitzer Space Telescope of these blackest-of-black regions paradoxically light the way to understanding how the brightest stars form.
The clumps represent the darkest portions of a huge, cosmic cloud of gas and dust located about 16,000 light-years away. A new study takes advantage of the shadows cast by these clumps to measure the cloud’s structure and mass.
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NASA logo. April 27, 2015 As the saying goes, timing is everything. More so in 21st-century space exploration where navigating spacecraft precisely to far-flung destinations—say to Mars or even more distant Europa, a moon of Jupiter—is critical. NASA is making great strides...
Métaphore d’un voyage initiatique au coeur de l’oreille adapté aux enfants :
- traversée de l’onde aérienne en avion à l’intérieur du conduit auditif jusqu’à la membrane du tympan
- découverte de l’onde mécanique sur la chaîne des osselets en vue de la fenêtre ovale
- plongée de l’onde de pression dans la cochlée qui contient l’organe de l’audition relié au cerveau
sich wie die Axt im Wald benehmen
to behave like the axe in the forest
to behave like a bull in the china shop
(via thatswhywelovegermany)
S-IC Built for Apollo 19
by Ian E. Abbott
The making of Polylion
Cosmic horseshoe is not the lucky beacon
A UC Riverside-led team of astronomers use observations of a gravitationally lensed galaxy to measure the properties of the early universe
Although the universe started out with a bang it quickly evolved to a relatively cool, dark place. After a few hundred thousand years the lights came back on and scientists are still trying to figure out why.
Astronomers know that reionization made the universe transparent by allowing light from distant galaxies to travel almost freely through the cosmos to reach us.
However, astronomers don’t fully understand the escape rate of ionizing photons from early galaxies. That escape rate is a crucial, but still a poorly constrained value, meaning there are a wide range of upper and lower limits in the models developed by astronomers.
That limitation is in part due to the fact that astronomers have been limited to indirect methods of observation of ionizing photons, meaning they may only see a few pixels of the object and then make assumptions about unseen aspects. Direct detection, or directly observing an object such as a galaxy with a telescope, would provide a much better estimate of their escape rate.
In a just-published paper, a team of researchers, led by a University of California, Riverside graduate student, used a direct detection method and found the previously used constraints have been overestimated by five times.
“This finding opens questions on whether galaxies alone are responsible for the reionization of the universe or if faint dwarf galaxies beyond our current detection limits have higher escape fractions to explain radiation budget necessary for the reionization of the universe,” said Kaveh Vasei, the graduate student who is the lead author of the study.
It is difficult to understand the properties of the early universe in large part because this was more than 12 billion year ago. It is known that around 380,000 years after the Big Bang, electrons and protons bound together to form hydrogen atoms for the first time. They make up more than 90 percent of the atoms in the universe, and can very efficiently absorb high energy photons and become ionized.
However, there were very few sources to ionize these atoms in the early universe. One billion years after the Big Bang, the material between the galaxies was reionized and became more transparent. The main energy source of the reionization is widely believed to be massive stars formed within early galaxies. These stars had a short lifespan and were usually born in the midst of dense gas clouds, which made it very hard for ionizing photons to escape their host galaxies.
Previous studies suggested that about 20 percent of these ionizing photons need to escape the dense gas environment of their host galaxies to significantly contribute to the reionization of the material between galaxies.
Unfortunately, a direct detection of these ionizing photons is very challenging and previous efforts have not been very successful. Therefore, the mechanisms leading to their escape are poorly understood.
This has led many astrophysicists to use indirect methods to estimate the fraction of ionizing photons that escape the galaxies. In one popular method, the gas is assumed to have a “picket fence” distribution, where the space within galaxies is assumed to be composed of either regions of very little gas, which are transparent to ionizing light, or regions of dense gas, which are opaque. Researchers can determine the fraction of each of these regions by studying the light (spectra) emerging from the galaxies.
In this new UC Riverside-led study, astronomers directly measured the fraction of ionizing photons escaping from the Cosmic Horseshoe, a distant galaxy that is gravitationally lensed. Gravitational lensing is the deformation and amplification of a background object by the curving of space and time due to the mass of a foreground galaxy. The details of the galaxy in the background are therefore magnified, allowing researchers to study its light and physical properties more clearly.
Based on the picket fence model, an escape fraction of 40 percent for ionizing photons from the Horseshoe was expected. Therefore, the Horseshoe represented an ideal opportunity to get for the first time a clear, resolved image of leaking ionizing photons to help understand the mechanisms by which they escape their host galaxies.
The research team obtained a deep image of the Horseshoe with the Hubble Space Telescope in an ultraviolet filter, enabling them to directly detect escaping ionizing photons. Surprisingly, the image did not detect ionizing photons coming from the Horseshoe. This team constrained the fraction of escaping photons to be less than 8 percent, five times smaller than what had been inferred by indirect methods widely used by astronomers.
“The study concludes that the previously determined fraction of escaping ionizing radiation of galaxies, as estimated by the most popular indirect method, is likely overestimated in many galaxies,” said Brian Siana, co-author of the research paper and an assistant professor at UC Riverside.
“The team is now focusing on direct determination the fraction of escaping ionizing photons that do not rely on indirect estimates.”