Latest Posts by riekod - Page 3

Productivity culture will deceive you (especially if you are particularly high-functioning or a former Gifted Kid) into thinking that any use of your time that can’t be monetized or leveraged for your personal advancement is worthless, and I’m here to tell you that’s the devil talking. Do shit because you like it.

Studying physics is essentially being taught a simple structure, and then told ”actually, scratch that, the truth is actually far more complicated” over and over again until we reach the point where we still don’t know the truth, only that we do not have it.

Cloud Chambers: Visualizing Radiation 

The cloud chamber, also known as the Wilson chamber, is a particle detector used for detecting ionizing radiation.

In its most basic form, a cloud chamber is a sealed environment containing a supersaturated vapor of water or alcohol. When a charged particle (for example, an alpha or beta particle) interacts with the mixture, the fluid is ionized. The resulting ions act as condensation nuclei, around which a mist will form (because the mixture is on the point of condensation). 

The high energies of alpha and beta particles mean that a trail is left, due to many ions being produced along the path of the charged particle. These tracks have distinctive shapes, for example, an alpha particle’s track is broad and shows more evidence of deflection by collisions, while an electron’s is thinner and straight. -(x)

More science and gifs on my blog: rudescience Gif made from: This video by The Royal Institution References: (x), (x). 

Credit: NASA/ESA/Hubble Space Telescope

While we’re waiting for some hopefully good news that the amazing instrument is returning to service (down since October 5 due to a gyro dyfugalty) here are some of the Hubble Space Telescope’s top pics.

Enceladus and Saturn

Image credit: Gordan Ugarkovic

After the rain of Hurricane Florence came the rainbow, or rainbows, in this case. Photographer John Entwistle captured this image of a rainbow with several additional supernumerary bows. The inner fringes seen here form when light passes through water droplets that are all close to the same size; given the spread seen here, the droplets are likely smaller than a millimeter in diameter. Supernumerary rainbows cannot be explained with a purely geometric theory of optics; instead, they require acknowledging the wave nature of light. (Image credit: J. Entwistle; via APOD; submitted by Kam-Yung Soh)

A Mesmerizing Model of Monster Black Holes

Just about every galaxy the size of our Milky Way (or bigger) has a supermassive black hole at its center. These objects are ginormous — hundreds of thousands to billions of times the mass of the Sun! Now, we know galaxies merge from time to time, so it follows that some of their black holes should combine too. But we haven’t seen a collision like that yet, and we don’t know exactly what it would look like. 

A new simulation created on the Blue Waters supercomputer — which can do 13 quadrillion calculations per second, 3 million times faster than the average laptop — is helping scientists understand what kind of light would be produced by the gas around these systems as they spiral toward a merger.

The new simulation shows most of the light produced around these two black holes is UV or X-ray light. We can’t see those wavelengths with our own eyes, but many telescopes can. Models like this could tell the scientists what to look for. 

You may have spotted the blank circular region between the two black holes. No, that’s not a third black hole. It’s a spot that wasn’t modeled in this version of the simulation. Future models will include the glowing gas passing between the black holes in that region, but the researchers need more processing power. The current version already required 46 days!

The supermassive black holes have some pretty nifty effects on the light created by the gas in the system. If you view the simulation from the side, you can see that their gravity bends light like a lens. When the black holes are lined up, you even get a double lens!

But what would the view be like from between two black holes? In the 360-degree video above, the system’s gas has been removed and the Gaia star catalog has been added to the background. If you watch the video in the YouTube app on your phone, you can moved the screen around to explore this extreme vista. Learn more about the new simulation here. 

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

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the fact that stars even exist and we can look at them every night for free just makes me go !!!!!!!!!!!!!!

Amazing views from the International Space Station (ISS)

Superfluidity consists of an anomalous liquid state of quantum nature which is under a very low temperature behaving as if it had no viscosity and exhibiting an abnormally high heat transfer. This phenomenon was observed for the first time in liquid helium and has applications not only in theories about liquid helium but also in astrophysics and theories of quantum gravitation.

Helium only ends boiling at 2.2 K and is when it becomes helium-II (superfluid helium), getting a thermal conductivity increased by a million times, in addition to becoming a superconductor. Its viscosity tends to zero, hence, if the liquid were placed in a cubic container it would spread all over the surface. Thus, the liquid can flow upwards, up the walls of the container. If the viscosity is zero, the flexibility of the material is non-existent and the propagation of waves on the material occurs under infinite velocity.

Because it is a noble gas, helium exhibits little intermolecular interaction. The interactions that it presents are the interactions of Van der Waals. As the relative intensity of these forces is small, and the mass of the two isotopes of helium is small, the quantum effects, usually disguised under the thermal agitation, begin to appear, leaving the liquid in a state in which the particles behave jointly, under effect of a single wave function. In the two liquids in which cases of superfluidity are known, that is, in isotopes 3 and 4 of helium, the first is composed of fermions whereas the second is composed of bosons. In both cases, the explanation requires the existence of bosons. In the case of helium-3, the fermions group in pairs, similar to what happens in the superconductivity with the Cooper pairs, to form bosons.

Helium’s liquidity at low temperatures allows it to carry out a transformation called Bose–Einstein condensation, in which individual particles overlap until they behave like one big particle.

Superfluid in astrophysics

The idea of superfluids existed within neutron stars was proposed by Russian physicist Arkady Migdal  in 1959. Making an analogy with Cooper pairs that form within superconductors, it is expected that protons and neutrons in the nucleus of a star of neutrons with sufficient high pressure and low temperature behave in a similar way forming pairs of Cooper and generate the phenomena of superfluidity and superconductivity.

The existence of this phenomenon was proven by NASA  in 2011 when analyzing the neutron star left by supernova Cassiopeia A.

sources: 1, 2, 3 & 4 animation: 1 & 2

A view you’d see from an asteroid’s surface!

Japan’s space agency (JAXA) has successfully landed two small rovers on the asteroid Ryugu. Their “mothership” Hayabusa 2 reached the asteroid in summer at a distance of 313 million km (194 million miles) from Earth, a journey which took 3.5 years. Rover-1B captured this video of 15 frames on September 23, 2018. 

Another spectacular sight was the Hayabusa 2 spacecraft’s shadow visible on the surface before releasing the rovers:  

The mission’s goal is to study this potentially hazardous asteroid, and bring back a sample in 2020! Asteroids are not only space rocks that might collide with our planet, though. They are remnants from our solar system’s formation and help to investigate the origin of life and the Earth’s oceans.

⭐ Stay connected with Sci-universe on Tumblr and Instagram 📸: JAXA / Roman Tkachenko via @haya2e_jaxa

VV 340, pair of interacting galaxies in Boötes. The two galaxies shown here are in the early stage of an interaction that will eventually lead to them merging in millions of years.

Credit: NASA/STScI/NRAO/A.Evans et al     

Pacific Ocean seen from Gemini 7

Credit: NASA

Remnants from a star that exploded thousands of years ago created a celestial abstract portrait, as captured in this NASA Hubble Space Telescope image of the Pencil Nebula.

Credit: NASA and The Hubble Heritage Team (STScI/AURA)

Once wounded, plants use calcium signals to warn distant tissues of future attacks.

What is a protostar?

The formation of stars begins with the collapse and fragmentation of molecular clouds into very dense clumps.  These clumps initially contain ~0.01 solar masses of material, but increase in mass as surrounding material is accumulated through accretion.  The temperature of the material also increases while the area over which it is spread decreases as gravitational contraction continues, forming a more stellar-like object in the process.  During this time, and up until hydrogen burning begins and it joins the main sequence, the object is known as a protostar.

This stage of stellar evolution may last for between 100,000 and 10 million years depending on the size of the star being formed. If the final result is a protostar with more than 0.08 solar masses, it will go on to begin hydrogen burning and will join the main sequence as a normal star.  For protostars with masses less than this, temperatures are not sufficient for hydrogen burning to begin and they become brown dwarf stars.

Protostars are enshrouded in gas and dust and are not detectable at visible wavelengths.  To study this very early stage of stellar evolution, astronomers must use infrared or microwave wavelengths.

Protostars are also known as Young Stellar Objects (YSOs).

Same but different: Spiral Galaxies NGC6935 and NGC6937 [OC] [1528x1081]

“I confess I do not know why, but looking at the stars always makes me dream.”

—

Vincent van Gogh

(via adrenaline)

Today the Cassini mission has reached its end…

Our planet seen from Saturn, captured by the Cassini spacecraft

Image credit: NASA 

Jupiter and 4 of her moons peaking out from behind our moon! 

““The reason T-Rex’s have no love life [they have short arms and can’t hold hands] is the same reason second row elements can’t make pi bonds with third row elements [not enough orbital overlap].””

— Organic chemistry prof

Saturn and its moons at opposition (The visible moons are (from left to right) Dione, Enceladus, Tethys, Janus, Epimetheus and Mimas

Credit: NASA, ESA, A. Simon (GSFC) and the OPAL Team, and J. DePasquale (STScI)

my type of meme