Convergence II

Could dark energy be caused by frozen neutrinos?

“Since its discovery in 1998, the accelerated expansion has lacked a compelling, simple explanation that didn’t hypothesize a completely new set of forces, properties or interactions. If you wanted a scalar field — a quintessence model — it had to be finely tuned. But in a very clever paper just submitted yesterday by Fergus Simpson, Raul Jimenez, Carlos Pena-Garay, and Licia Verde, they note that if a generic scalar field couples to the neutrinos we have in our Universe, that fine-tuning goes away, and that scalar field will automatically begin behaving as a cosmological constant: as energy inherent to space itself.”

The accelerated expansion of our Universe was one of the biggest surprise discoveries of all-time, and something that still lacks a good physical explanation. While many models of dark energy exist, it remains a completely phenomenological study: everything appears consistent with a cosmological constant, but nothing appears to be a good motivator for why the Universe should have one. Until now, that is! In a new paper by Fergus Simpson, Raul Jimenez, Carlos Pena-Garay and Licia Verde, they note that any generic scalar field that couples to the neutrino sector would dynamically and stably give rise to a type of dark energy that’s indistinguishable from what we’ve observed. The huge advance is that this scenario doesn’t require any fine-tuning, thanks to this dark energy arising from neutrinos “freezing,” or becoming non-relativistic. In addition, there are experimental signatures to look for to confirm it, too, in the form of neutrinoless double-beta decay!

The astro-fashion-loving Internet collectively gasped when ESA’s Hubble twitter account posted three gorgeous gowns, by Czech designer Jirina Tauchmanova with only credit “Photo: Vasek”, which google thinks is a Canadian tennis player. For four long days I couldn’t find anymore images, until, today! Which is why I’m sharing a belated #FashionFriday and #StarrySunday combo.

These gown were shown at Serbia Fashion Week back in December 2015 as Jirina Tauchmanova‘s Spring/Summer 2016 collection – I hope that means they will be available for purchase soon!

I think I recognize at least two of the images, NGC 602 & 30 Doradus, but I’m going to have to see these in person to be sure, yes, definitely, and probably try them on, too.

–Emily

Want to See the Oldest Surviving Video of a Total Solar Eclipse?

It was done in – wait for it – 1900! The first total solar eclipse to be filmed has recently been restored. The film was done by Nevil Maskelyne, an illusionist turned astronomic videographer for the British Royal Astronomical Society.

This 1900 film is actually Maskelyne’s second attempt at filming a total solar eclipse. His first attempt was in 1898, when he traveled all the way to India to be at the right place to view a predicted total eclipse. Maskelyne got there in time, but sadly, his film was stolen, and the crime remains unsolved and the film unrecovered.

Tardigrades: ‘Water bears’ stuck on the moon after crash 

The moon might now be home to thousands of planet Earth’s most indestructible animals.

Tardigrades - often called water bears - are creatures under a millimetre long that can survive being heated to 150C and frozen to almost absolute zero.

They were travelling on an Israeli spacecraft that crash-landed on the moon in April.

And the co-founder of the organisation that put them there thinks they’re almost definitely still alive.

The water bears had been dehydrated to place them in suspended animation and then encased in artificial amber.

“We believe the chances of survival for the tardigrades… are extremely high.”

An eclipse as seen from space. 

9 things to seriously make you re-consider the entire existence of mankind

Source: buzzfeed.com

hubble’s panorama of the carina nebula, some 7500 light years away from earth, and about fifty light years in length here. stars old and new illuminate clouds of cosmic dust and gas, like the clumping hydrogen from which they were born. 

the top star seen at the bisection of the first two panels, part of the eta carinae binary star system (most stars are in binary systems), is estimated  to be more than a hundred times the mass of the sun - large enough to go supernoava in about a million years. 

it also produces four million times as much light as the sun, and was once the second brightest star in the night sky. but surrounding dust and gas has dimmed our view of the star, though it’s still visible in the night sky to all but those in the most light polluted cities.

the fifth panel shows ‘the mystic mountain,’ where nascent stars in the dust cloud are spewing hot ionized gas and dust at 850,000 miles an hour. eventually, the ultraviolet radiation from these stars will blow away the dust, leaving visible the stars, like the cluster seen at the top of the panel, which were formed only half a million years ago.

The Carina Nebula - A Birthplace Of Stars

The Carina Nebula lies at an estimated distance of 6,500 to 10,000 light years away from Earth in the constellation Carina. This nebula is one of the most well studied in astrophysics and has a high rate of star formation. The star-burst in the Carina region started around three million years ago when the nebula’s first generation of newborn stars condensed and ignited in the middle of a huge cloud of cold molecular hydrogen. Radiation from these stars carved out an expanding bubble of hot gas. The island-like clumps of dark clouds scattered across the nebula are nodules of dust and gas that are resisting being eaten away by photons (particles of light) that are ionizing the surrounding gas (giving it an electrical charge).

Credit: NASA/Hubble

THE TRAPPIST-1 DISCOVERY

NASA’s announcement today was awe-inspiring. We’ve compiled the essential info you want to know about this incredible discovery.

OVERVIEW: 7 PLANETS, 3 HABITABLE

Astronomers have found at least seven Earth-sized planets orbiting the same star 40 light-years away, according to a study published Wednesday in the journal Nature.

The seven exoplanets were all found in tight formation around an ultracool dwarf star called TRAPPIST-1. Estimates of their mass also indicate that they are rocky planets, rather than being gaseous like Jupiter. Three planets are in the habitable zone of the star, known as TRAPPIST-1e, f and g, and may even have oceans on the surface.

“I think we’ve made a crucial step towards finding if there is life out there,” said Amaury Triaud, one of the study authors and an astronomer at the University of Cambridge. “I don’t think any time before we had the right planets to discover and find out if there was (life). Here, if life managed to thrive and releases gases similar to what we have on Earth, we will know.”

ONLY 40 LIGHT YEARS AWAY

The system is just 40 light-years away. On a cosmic scale, that’s right next door. Of course, practically speaking, it would still take us hundreds of millions of years to get there with today’s technology – but again, it is notable in that the find speaks volumes about the potential for life-as-we-know-it beyond Earth.

The Hubble Space Telescope is already being used to search for atmospheres around the planets, and Emmanuël Jehin, a scientist who also worked on the research, asserts that future telescopes could allow us to truly see into the heart of this system: “With the upcoming generation of telescopes, such as ESO’s European Extremely Large Telescope and the NASA/ESA/CSA James Webb Space Telescope, we will soon be able to search for water and perhaps even evidence of life on these worlds.”

ALIEN SKIES

In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water could survive on planets orbiting very close to it, closer than is possible on planets in our solar system. All seven of the TRAPPIST-1 planetary orbits are closer to their host star than Mercury is to our sun. The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth’s sky.

The planets may also be tidally locked to their star, which means the same side of the planet is always facing the star, therefore each side is either perpetual day or night. This could mean they have weather patterns totally unlike those on Earth, such as strong winds blowing from the day side to the night side, and extreme temperature changes.

Antibodies are the secreted form of B-lymphocyte receptors and are a part of adaptive immunity, but how are these proteins formed?

Above is a diagram illustrating Paul Ehlrich’s Side Chain Theory of Antibody Formation. Ehlrich proposed that immunoglobulin molecules, a fundamental component of adaptive immunity, served as membrane bound proteins that bound to particular threats, similarly to the former “key in lock” view of enzymes in catalyzing biological reactions. Ehrlich also suggested that the action of binding a pathogenic molecule to the receptor would generate a signal to stimulate the production of more receptors of the same specificity. These “side chains” that were added on would then break off from the cell surface and become what we call antibodies.

 We now know, however, that soluble immunoglobulin receptors are specially manufactured to be secreted as antibody, rather than just “breaking off” of the lymphocyte, even though they have the same specificity as their membrane-bound counterparts.