The Andromeda Galaxy Floats Above The Dawn Clouds - May 6, 2017

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.

It’s sad how much of what is taught in school is useless to over 99% of the population.

There are literally math concepts taught in high school and middle school that are only used in extremely specialized fields or that are even so outdated they aren’t used anymore!

How Big is Our Galaxy, the Milky Way?

When we talk about the enormity of the cosmos, it’s easy to toss out big numbers – but far harder to wrap our minds around just how large, how far and how numerous celestial bodies like exoplanets – planets beyond our solar system – really are.

So. How big is our Milky Way Galaxy?

We use light-time to measure the vast distances of space.

It’s the distance that light travels in a specific period of time. Also: LIGHT IS FAST, nothing travels faster than light.

How far can light travel in one second? 186,000 miles. It might look even faster in metric: 300,000 kilometers in one second. See? FAST.

How far can light travel in one minute? 11,160,000 miles. We’re moving now! Light could go around the Earth a bit more than 448 times in one minute.

Speaking of Earth, how long does it take light from the Sun to reach our planet? 8.3 minutes. (It takes 43.2 minutes for sunlight to reach Jupiter, about 484 million miles away.) Light is fast, but the distances are VAST.

In an hour, light can travel 671 million miles. We’re still light-years from the nearest exoplanet, by the way. Proxima Centauri b is 4.2 light-years away. So… how far is a light-year? 5.8 TRILLION MILES.

A trip at light speed to the very edge of our solar system – the farthest reaches of the Oort Cloud, a collection of dormant comets way, WAY out there – would take about 1.87 years.

Our galaxy contains 100 to 400 billion stars and is about 100,000 light-years across!

One of the most distant exoplanets known to us in the Milky Way is Kepler-443b. Traveling at light speed, it would take 3,000 years to get there. Or 28 billion years, going 60 mph. So, you know, far.

SPACE IS BIG.

Read more here: go.nasa.gov/2FTyhgH

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

The Surprising Reason Why Neutron Stars Don’t All Collapse To Form Black Holes

“The measurements of the enormous pressure inside the proton, as well as the distribution of that pressure, show us what’s responsible for preventing the collapse of neutron stars. It’s the internal pressure inside each proton and neutron, arising from the strong force, that holds up neutron stars when white dwarfs have long given out. Determining exactly where that mass threshold is just got a great boost. Rather than solely relying on astrophysical observations, the experimental side of nuclear physics may provide the guidepost we need to theoretically understand where the limits of neutron stars actually lie.”

If you take a large, massive collection of matter and compress it down into a small space, it’s going to attempt to form a black hole. The only thing that can stop it is some sort of internal pressure that pushes back. For stars, that’s thermal, radiation pressure. For white dwarfs, that’s the quantum degeneracy pressure from the electrons. And for neutron stars, there’s quantum degeneracy pressure between the neutrons (or quarks) themselves. Only, if that last case were the only factor at play, neutron stars wouldn’t be able to get more massive than white dwarfs, and there’s strong evidence that they can reach almost twice the Chandrasekhar mass limit of 1.4 solar masses. Instead, there must be a big contribution from the internal pressure each the individual nucleon to resist collapse.

For the first time, we’ve measured that pressure distribution inside the proton, paving the way to understanding why massive neutron stars don’t all form black holes.

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

Arp 188 and the Tadpole’s Tail

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

List of extrasolar candidates for liquid water

The following list contains candidates from the list of confirmed objects that meet the following criteria:

Confirmed object orbiting within a circumstellar habitable zone of Earth mass or greater (because smaller objects may not have the gravitational means to retain water) but not a star

Has been studied for more than a year

Confirmed surface with strong evidence for it being either solid or liquid

Water vapour detected in its atmosphere

Gravitational, radio or differentation models that predict a wet stratum

55 Cancri f

With a mass half that of Saturn, 55 Cancri f is likely to be a gas giant with no solid surface. It orbits in the so-called “habitable zone,” which means that liquid water could exist on the surface of a possible moon. ]

Proxima Centauri b

Proxima Centauri b is an exoplanet orbiting in the habitable zone of the red dwarfstar Proxima Centauri, which is the closest star to the Sun and part of a triple star system. It is located about 4.2 light-years from Earth in the constellation of Centaurus, making it the closest known exoplanet to the Solar System.

Gliese 581c

Gliese 581c gained interest from astronomers because it was reported to be the first potentially Earth-like planet in the habitable zone of its star, with a temperature right for liquid water on its surface, and by extension, potentially capable of supporting extremophile forms of Earth-like life.

Gliese 667 Cc

Gliese 667 Cc is an exoplanet orbiting within the habitable zone of the red dwarf star Gliese 667 C, which is a member of the Gliese 667 triple star system, approximately 23.62 light-years away in the constellation of Scorpius.

Gliese 1214 b

Gliese 1214 b is an exoplanet that orbits the star Gliese 1214, and was discovered in December 2009. Its parent star is 48 light-years from the Sun, in the constellation Ophiuchus. As of 2017, GJ 1214 b is the most likely known candidate for being an ocean planet. For that reason, scientists have nicknamed the planet “the waterworld”.

HD 85512 b

HD 85512 b is an exoplanet orbiting HD 85512, a K-type main-sequence star approximately 36 light-years from Earth in the constellation of Vela.

Due to its mass of at least 3.6 times the mass of Earth, HD 85512 b is classified as a rocky Earth-size exoplanet (<5M⊕) and is one of the smallest exoplanets discovered to be just outside the inner edge of the habitable zone.

MOA-2007-BLG-192Lb

MOA-2007-BLG-192Lb, occasionally shortened to MOA-192 b, is an extrasolar planet approximately 3,000 light-years away in the constellation of Sagittarius. The planet was discovered orbiting the brown dwarf or low-mass star MOA-2007-BLG-192L. At a mass of approximately 3.3 times Earth, it is one of the lowest-mass extrasolar planets at the time of discovery. It was found when it caused a gravitational microlensing event on May 24, 2007, which was detected as part of the MOA-II microlensing survey at the Mount John University Observatory in New Zealand.

Kepler-22b

Kepler-22b, also known by its Kepler object of interest designation KOI-087.01, is an extrasolar planet orbiting within the habitable zone of the Sun-like star Kepler-22. It is located about 587 light-years (180 pc) from Earth in the constellation of Cygnus. source