SSELEMAN

Eight New Quadruple Lenses Aren’t Just Gorgeous, They Reveal Dark Matter’s Temperature

“Ever since astronomers first realized that the Universe required the existence of dark matter to explain the cosmos that we see, we’ve sought to understand its nature. While direct detection efforts have still failed to bear fruit, indirect detection through astronomical observations not only reveal the presence of dark matter, but this novel method of using quadruply lensed quasar systems has given us some very strong, meaningful constraints on just how cold dark matter needs to be.

Dark matter that’s too hot or energetic cannot form structures below a certain scale, and the observations of these ultra-distant, quadruple-lens systems show us that dark matter must form clumps on very small scales after all, consistent with them being born as arbitrarily cold as we can imagine. Dark matter’s not hot, nor can it even be very warm. As more of these systems come in and our instruments go beyond what even Hubble’s capabilities are, we might even discover what cosmologists have long suspected: dark matter must not only be cold today, but it must have been born cold.”

We might not yet know the nature of dark matter, as we’ve never been able to detect the particle responsible for it directly. But we know it clumps and gravitates together, with the exact way it would do so dependent on the amount of kinetic energy it had when it was born relative to its mass. Dark matter could have been extremely hot, such as a scenario where it was made from neutrinos, cold, such as from a very heavy WIMP particle (or a born-super-cold axion), or anywhere in between.

From Mark Zuckerberg’s Facebook page:

Five years ago, Facebook started leading an effort called the Open Compute Project to change the way data centers are designed and operated.

Data centers power the internet. They’re the nervous system that allows all kinds of services to run – including Facebook.

But until five years ago, the largest technology companies all designed their data centers and computing infrastructure in secret. They viewed this technology as a competitive advantage to beat others in the industry.

We realized that if we opened up our designs and shared our progress with the industry, we’d all make faster progress together. By working together, we’d produce more efficient designs that would save energy, protect the environment and build better infrastructure for our community.

It has worked. So far, we’ve saved billions of dollars in energy and efficiency improvements. Open Compute now brings together hundreds of companies and thousands of engineers to make progress together even faster.

Today, Google joined the Open Compute Project. Google has always built some of the best infrastructure in the industry, so this is strong symbolic move that our open model of development is the best way forward for everyone.

Over the next decade, we’re going to build experiences that rely more on technology like artificial intelligence and virtual reality. These will require a lot more computing power, and through efforts like OCP, we’re developing a global infrastructure to enable everyone to enjoy them.

“The noises we generate from our shipping traffic, from modern vessels, is clouding — polluting the ocean,” says Christopher Clark, a scientist at Cornell University. “It’s like going to a restaurant, and you and I can barely have a conversation across the table.”

Clark found that whales sometimes stop singing when they hear human-made sound, and sometimes avoid the sources of that sound. He published articles and papers arguing that the sound of ships is a hazard to whales. And in 2013, the International Maritime Organization set guidelines to make ships quieter — with new designs for propellers, for example.

Euler’s Identity: eiπ + 1 = 0. Euler’s Identity is an Equation about constants π and e. Both are “Transcendental” quanti­ties; in decimal form, their digits unspool into Infinity. And both are ubiquitous in scientific laws. But they seem to come from different realms: π (3.14159 …) governs the perfect Symmetry and closure of the Circle; it’s in Planetary Orbits, the endless up and down of light waves. e (2.71828 …) is the foundation of exponential growth, that accelerating trajectory of escape inherent to compound interest, nuclear fission, Moore’s law. It’s used to model everything that grows. What Euler showed is that π and e are deeply related, connected in a dimension perpendicular to the world of real things - a place measured in units of i, the square root of -1, which of course doesn’t … exist. Mathematicians call it an imaginary number. These diagrams are visual metaphors. Imagine a graph with real numbers on the horizontal axis and imaginary ones on the vertical. Exponential function, f(x) = ex, ordinarily it graphs as an upward swooping curve - the very paradigm of progress. But put i in there, Euler showed, and eix instead traces a circle around the origin - an endless wheel of Samsara intercepting Reality at –1 and +1. Add another axis for Time and it’s a helix winding into the Future; viewed from the side, that helix is an oscillating sine wave.The rest is easy: Take that function f(x) = eix, set x = π, and you get eiπ = -1. Rearrange terms and you have the famous identity: eiπ + 1 = 0. That’s the essence of Euler’s alchemy: By ventur­ing off the real number line into this empyrean dimension, he showed that disruptive, exponential change (the land of e) reduces to infinite repeti­tion (π). These diagrams combine the five most fundamental numbers in math - 0, 1, e, i, and π - in a relation of irreducible simplicity. e and π are infinitely long decimals with seemingly nothing in common, et they fit together perfectly - not to a few places, or a hundred, or a million, but all the way to forever. 

Squid Skin Is Way Weirder Than You Ever Imagined

Squid have tiny organs in their skin called chromatophores. When these organs expand, they reveal more color pigment. When they contract, the color shrinks.

Via HuffPost Science

You Might As Well Ignore #KiyiyaVuranInsanlik and the Photos of Dead Refugee Kids

Europe

Photo of drowned toddler sparks fresh horror over Europe’s migrant crisis

Heart-rending pictures of a toddler’s lifeless body washed ashore on a Turkish beach sparked horror on Wednesday as the cost of Europe’s burgeoning refugee crisis hit home. The images of a tiny child lying face down in the surf at one of Turkey’s main tourist resorts has once more put a human face on the dangers faced by tens of thousands of desperate people who risk life and limb to seek a new life in Europe. The child is believed to be one of at least 12 Syrians trying to reach Greece who died when their boats sank.

“If these extraordinarily powerful images of a dead Syrian child washed up on a beach don’t change Europe’s attitude to refugees, what will?

Britain’s Independent newspaper