Vera Rubin, The Woman Who Discovered The First Evidence Of Dark Matter, Has Died At 88

The Drake Equation

In 1961, following an early SETI experiment using radio telescopes called Project Ozma, astronomer Frank Drake arranged a historic meeting at the National Radio Astronomy Observatory in Green Bank, West Virginia. The ten attendees - among them a young Carl Sagan - discussed the feasibility and methodology of detecting extraterrestrial civilizations using radio astronomy. They formulated the Drake Equation - a rough, speculative means of estimating the possible number of current technologically-advanced civilizations in the galaxy. 

N = the number of advanced extraterrestrial civilizations potentially detectable by radio signals in the Milky Way Galaxy.   

Depending on the values used for each variable, N can work out to be hundreds of thousands or more, or very few. 

R* = Rate of new star formation. 

One estimate is 7 stars per year.

Fp = Percentage of stars with planetary systems around them.

New solar systems are being discovered every year. 

Ne = Number of planets per star system capable of sustaining life. 

Depending upon the temperature, type, and size of the star, the habitable zone of a planet for Earth-like life may be nearer or further from its star. Based on our own solar system, we might guess 1 or 2.

Fl = Fraction of those planets upon which life appears. 

How many of those habitable planets upon which life has developed is difficult to estimate. In our own solar system, it’s at least 1 - there is a good chance that at one point, life developed on Mars, though traces of it have yet to be found.

Fi = Fraction of those planets where intelligent life appears.

Estimates vary wildly. We know it’s happened at least once here on Earth. As ‘intelligence’ is subjective, it may be that it has developed in other non-human, communicating species, like whales. 

Fc = Fraction of those societies that develop advanced communication technology and send signals into space.

Intentional or unintentional, other civilizations might transmit identifiable signals into outer space that modern Earth technology could pick up.

L = Lifetime of communicative civilizations. 

Do technologically-capable civilizations inevitably self-destruct, or can they last forever? This is an immensely uncertain question. We’ve been communicating with radio waves for fewer than 100 years, with the long-term survival of our species and our status as ‘technological’ uncertain. 

Newest LIGO Signal Raises A Huge Question: Do Merging Black Holes Emit Light?

“The second merger held no such hints of electromagnetic signals, but that was less surprising: the black holes were of significantly lower mass, so any signal arising from them would be expected to be correspondingly lower in magnitude. But the third merger was large in mass again, more comparable to the first than the second. While Fermi has made no announcement, and Integral again reports a non-detection, there are two pieces of evidence that suggest there may have been an electromagnetic counterpart after all. The AGILE satellite from the Italian Space Agency detected a weak, short-lived event that occurred just half a second before the LIGO merger, while X-ray, radio and optical observations combined to identify a strange afterglow less than 24 hours after the merger.”

Whenever there’s a catastrophic, cataclysmic event in space, there’s almost always a tremendous release of energy that accompanies it. A supernova emits light; a neutron star merger emits gamma rays; a quasar emits radio waves; merging black holes emit gravitational waves. But if there’s any sort of matter present outside the event horizons of these black holes, they have the potential to emit electromagnetic radiation, or light signals, too. Our best models and simulations don’t predict much, but sometimes the Universe surprises us! With the third LIGO merger, there were two independent teams that claimed an electromagnetic counterpart within 24 hours of the gravitational wave signal. One was an afterglow in gamma rays and the optical, occurring about 19 hours after-the-fact, while the other was an X-ray burst occurring just half a second before the merger.

Could either of these be connected to these merging black holes? Or are we just grasping at straws here? We need more, better data to know for sure, but here’s what we’ve got so far!

As a paleo-artist, one of my biggest pet peeves are prehistoric whales reconstructed not as whales but as sinewy, snarling, shrink-wrapped marine reptiles. It’s just not a plausible reconstruction, even if it’s highly speculative, and it paints an incorrect image in the public eye. Granted, this is a struggle I’ve exlpored in all forms of paleo-art and reconstructive illustration. But the whales have really been getting to me recently.

Here are some recontructions of Basilosaurus, if you don’t know what I mean (one by Karen Carr, the other by an artist I could not determine):

These snakey, reptilious reconstructions may stem from the fact that Basilosaurus, one of the first early cetaceans to be found, was believed to be a reptile when first discovered (hence the name). Maybe we simply haven’t fully shaken that mindset.

But still! Even the damn Smithsonian, which has such a wonderful collection of ancient cetaceans, is at fault in this:

Don’t even get me started on their recently-closed dinosaur hall. Thank the lord they’re finally renovating that dated piece of crap.

I have struggled to find a way to reconstruct these animals so that they are just a little bit more believeable. Up top I’ve done a really really quick sketch of Dorudon. I tried to not only make its body more streamlined and whale-like (because Dorudon has a lovely, almost but not quite modern-looking skeleton), but I also tried to give it markings similar to what we find on modern cetaceans for camouflage. Because hey, who’s to say they didn’t have ‘em? I tried to make them familiar but not directly copied from any modern species.

Aaaaand end rant.

Physicists: we don’t really understand how the big bang happened

Secondary media:

Vera Rubin, the groundbreaking astrophysicist who discovered evidence of dark matter, died Sunday night at the age of 88, the Carnegie Institution confirms.

Rubin did much of her revelatory work at Carnegie. The organization’s president calls her a “national treasure.”

In the 1960s and 1970s, Rubin was working with astronomer Kent Ford, studying the behavior of spiral galaxies, when they discovered something entirely unexpected — the stars at the outside of the galaxy were moving as fast as the ones in the middle, which didn’t fit with Newtonian gravitational theory.

The explanation: Dark matter.

Adam Frank, an astrophysicist who writes for NPR’s 13.7 blog, described dark matter by comparing it to a ghost in a horror movie. You can’t see it, he writes — “but you know it’s with you because it messes with the things you can see.”

Adam continued:

“It was Vera Rubin’s famous work in the 1970s that showed pretty much all spiral galaxies were spinning way too fast to be accounted for by the gravitational pull of the their ‘luminous’ matter (the stuff we see in a telescope). Rubin and others reasoned there had to be a giant sphere of invisible stuff surrounding the stars in these galaxies, tugging on them and speeding up their orbits around the galaxy’s center.”

Vera Rubin, Who Confirmed Existence Of Dark Matter, Dies At 88

Photographer Endangers His Life To Capture Lava, Meteor, Milky Way And Moon In One Shot

culturenlifestyle:

American adventure photographer Mike Mezeul II has captured what is arguably one of the most stunning images of Mother Nature at work.

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IT's Official: NASA's Peer-Reviewed EM Drive Paper Has Finally Been Published

After months of speculation and leaked documents , NASA's long-awaited EM Drive paper has finally been peer-reviewed and published . And it shows that the 'impossible' propulsion system really does appear to work.

I’m serious

Cristobalite, Hematite

SiO2, Fe2O3

Locality:

Caspar quarry, Bellerberg volcano, Ettringen, Mayen, Eifel, Rhineland-Palatinate, Germany

An interesting homoepitactic intergrowth from brown and black hematite  

Photo: Michael Förch

Cristobalite is a silica polymorph that is thermodynamically stable only at temperatures above 1470°C, up to the melting point at 1705°C, at atmospheric pressures. It commonly metastably persists or even forms at much lower temperatures in silica-rich volcanic and sedimentary environments. It can form crystals in cavities, probably vapour-deposited, or spherulites in obsidian or other silicic volcanics.

Hematite is rather variable in its appearance - it can be in reddish brown, ocherous masses, dark silvery-grey scaled masses, silvery-grey to black crystals, and dark-grey masses, to name a few. What they all have in common is a rust-red streak.

Yes, sure its fun to see a lady spin around like that, but I had one of my friends ask me - “Where do you even use this mate?”

Here’s one application that I know very well off.

Spin Stabilization

If you have ever seen a rocket launch, you might know that sometimes the rockets are given a spin while launching. This is known as spin stabilization.

Basically, the rotational inertia of the rotating body will stabilize the rocket against any disturbances and help maintain its intended heading.

The same principle is used in rifling of firearms as well. **

YoYo DeSpin

Okay, now there is the question how to “De-spin” the rocket:

Well, you do what the lady does: stretch out your arms and you will slow down !

The rocket has weights connected to a cable that stretch out and almost immediately the rocket slows down. This maneuver is known as the YoYo DeSpin. ( Damn good name ! )

All thanks to the conservation of angular momentum !

Have a good one !

* Another method to stabilization : 3-axis stabilization

** Bullets spin stabilization - post

** Source rocket launch video

The world’s smallest snowman is only 2.7 microns tall (for comparison, a human hair is 75 microns thick). To create it, scientists stacked 3 tiny silica spheres, added a nose and arms made of platinum, and cut the eyes and mouth with a focused ion beam. Source