Prussian blue, also known as Berlin blue, Turnbull blue, or Paris blue, is a dark blue pigment used by painters, and was the first modern synthetic pigment. It is famous for its complexity and has several uses, including being the shade of blue used in traditional blueprints. Famous paintings making extensive use of Prussian blue include Vincent van Gogh’s Starry Night and  The Great Wave off Kanagawa by Hokusai. 

In medicine, Prussian blue is used as an antidote for certain kinds of heavy metal poisoning, particularly thallium and radioactive isotopes of cesium (such as the Goiânia accident).

Just the Science GCSE

The woman thought I was crazy when I cleared out their stock of flashcards in the Paperchase flagstore totting ham court road .
1600 flashcards.

Been through approx 500 since GCSE and I’m only half way!
Still have history, the last tiny bit of R.S., Human Geography and further maths to go 😫

At least they look pretty
Physicists Set a New Speed Record for Light-Emitting Quantum Dots
Photonic computing is closer than ever.

Researchers at Duke University have developed a light-emitting device that can be switched on and off up to 90 billion times per second. This 90 GHz is roughly twice the speed of the fastest laser diodes in existence, potentially offering a whole new level of optoelectronic computing. Central to the technology are the infinitesimal crystal beads known as quantum dots.

The computing devices we’re used to are based on shuttling electrons around via wires and switches. This has worked out pretty well through the history of computing, but electronics have limits, both in speed and in scale. Optoelectronics swap out electrons for pure light: photons. A computer based on information carried via photon is just by definition optimal, offering the literal fastest thing in the universe. Other advantages over electronic systems: less heat, less power, less noise, less information loss, less wear.

Continue Reading.


The physics community buzzed with excitement July 23 when it was announced that researchers at the European Center for Nuclear Research (CERN) had discovered evidence for a long-hypothesized but never actually observed five-quark object, known as a “pentaquark.” What is this new particle with the exceedingly weird name, and why is it physicists at CERN think they have observed one?

The story begins with what is known as the Standard Model, which is the commonly accepted model of the constituent particles of the universe and the forces that act upon them. It is the world of the very small; it includes indivisible, elementary particles known as quarks. Independently postulated to exist by both Murray Gell-Mann and George Zweig in 1964, quarks are the building blocks of nearly everything in the world around us. There are six kinds (known as “flavors”) of quarks: up, down, strange, charmed, bottom and top. “Flavors” are just labels. They don’t correspond to the same concept of flavor that we are familiar with in our everyday lives.

Elementary particles combine to form more complex composite particles. Gell-Mann’s theory predicted the existence of two, three, four or even five-quark objects. Composite particles made out of a quark and its oppositely-charged equivalent (known as an antiquark) are known as mesons. Three-quark objects are known as hadrons. The hadrons most people are familiar with are known as protons and neutrons; these hadrons are found in the nucleus of atoms, and form most of the ordinary matter you are familiar with.

A proton is composed of two up quarks and a down quark. Up quarks have an electric charge of +2/3 and down quarks have an electric charge of -1/3. These quarks combine to give protons a charge of (+2/3 +2/3 – 1/3) = +1. Likewise, a neutron is two down quarks and an up quark. These quarks combine to give neutrons a charge of (-1/3+ -1/3 + 2/3) = 0.

Objects made out of four quarks known as tetraquarks were confirmed in 2013.

Which brings us to pentaquarks, what we call objects made out of five quarks.

Protons and neutrons aren’t the only hadrons. There are several other more exotic hadrons, one of which is known as a “bottom lambda baryon.” This is a three-quark object composed of an up quark, a down quark, and a bottom quark. Bottom lambda baryons are unstable and decay rapidly.

In 2013, a team of scientists at CERN led by Sheldon Stone was using the Large Hadron Collider (LHC) to examine bottom lambda baryon to understand better how they decay. (The LHC previously discovered the Higgs boson in 2012.)

When a composite particle like the bottom lambda baryon decays, it spontaneously becomes a new set of particles. These new particles are known as “daughter particles.” By measuring them for various qualities such as mass, spin and charge, physicists can identify what specific particles make up subsequent generations of decay.

The pentaquark was one of the objects the CERN team believes they observed. It was found to be made of four quarks and an antiquark, specifically, two ups, one down, a charm and the charm antiparticle known as an anticharm. Structurally, it is not known if these combine to form a single five-quark hadron or more of a “subatomic molecule” with both a baryon and a meson. Like the bottom lambda baryon antecedent, the pentaquark decayed rapidly into daughter paerticles. But before it did, it was measured to have the equivalent mass of approximately 4.5 protons. What is even more remarkable is that they found not one but two pentaquarks in the same experiment.

The pentaquark was found under laboratory conditions as part of an unrelated experiment. In nature, these objects would have to exist in high-energy settings, such as the Big Bang or inside stars collapsing to form black holes.

The paper proposing the finding is still awaiting peer review and its conclusions are not guaranteed to pass muster. A Japanese team thought they discovered a lighter pentaquark in 2002 they called theta+ with a mass of 1.5 times that of a proton, but that discovery was discounted in 2005; the evidence for the theta+ had been misinterpreted. However, the CERN study claims a 9-sigma reliability, that is, its findings are nine standard deviations beyond what scientists would otherwise expect the data to represent, and it is therefore very probably reliable. Since the LHC was upgraded over the last year, it is even more powerful than before, which may aid in the search for more pentaquarks.

SOURCES: 1, 2, 3, 4

By Adam Nieman (Flickr) [CC BY-SA 2.0 (x)], via Wikimedia Commons

210 years ago born in Dublin sir William Rowan Hamilton, one of the greats minds in the XIX century, and hence of the History of Physics and Mathematics. You might learn about his life and influences in modern Physics, and enjoy reading this funny (but accurate) Hamilton’s biography at this blog post in TRF.

Image caption: The plaque marks the spot where quaternions were invented in 1843. Via Atlas of Ingenious Ireland (A Eureka! moment: Broome Bridge).


Second Law of Thermodynamics

Paul Andersen explains how the second law of thermodynamics applies to reversible and irreversible processes. In a reversible process the net change in entropy is zero. In and irreversible process the entropy will always increase in a closed system. The entropy measures the disorder in the entire system and will move in the direction of time’s arrow. Several example videos of increasing entropy are included.

By: Bozeman Science.
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If the sun disappeared, when would we know about it?

Here’s an insightful thought experiment: if the sun suddenly disappeared, how would we know – by seeing its light go out, or by feeling its gravitational pull vanish? Brian Greene briefly explains the answer emerging from Einstein’s breakthrough.

By: World Science U.

Discrete dynamic modeling...

I decided to start off my coverage of the Algebraic and Combinatorial Approaches in Systems Biology conference with its winner, Réka Albert, who gave the talk titled “Discrete dynamic modeling elucidates the outcomes of signal transduction networks and helps to control them”. I give a lot of flak to people who make their talk titles excessively long, but in fairness to Albert, this one is at least helpful. She cited Jorge Zañudo as a collaborator.

She is not a mathematician, but rather a biophysicist, although I vaguely remember her talk being understandable. It didn’t seem to translate to my notes, however, which read like a hot mess and I’m not sure how followable this story is. Worth a shot anyway.


She begins with several examples from biology, which I’m going to write down but not explain because heck if I know what this means:

  • survival of cytotoxic T-cells in T-LGL leukemia
  • cell fate change that starts cancer metastasis

In both arenas she recovered known results but also made new predictions. Of course, mathematical biology is different than mathematics in this way: theoretical results are not celebrated in and of themselves. They must first be validated by experiments. She didn’t mention the state of these experiments so I can only assume that they haven’t been carried out yet.

She talks about a particular technique for making directed graphs that permit composition and negation (my notes describe one such method as the “NOT-OR model”, which may make some sense of that description).

In these graphs, a stable motif is defines as a connected component that

  • never contains both $x$ and $\lnot x$, and
  • if it contains composite models, it also contains their parts

The stable motifs are the only possible candidates for the steady states (of some dynamical system on the graph, presumably). Hence we can simplify the analysis of the graph by replacing a stable motif by a steady state and recursing. I’m not really sure how this makes sense, but they’ve done a lot of these; analyzing all networks with fewer than 1000 nodes (!).

Once the motifs which are steady states are determined, we now can look at an easier problem: are there any motifs in the graph that completely control the outcome, and if not, find minimal sets that do.

For simplicity, she phrased everything in the talk as if it required a boolean model; that various nodes are either on or off. In real life this is not quite how it works, and she stated that they had achieved similar results with continuous (sigmoidal) models.

Wanna hang out with me for a weekend, learn about women in physics and see the full results of my sociology research presented?

Apply to the CUWiP taking place at a university from which I live a few miles away. Applications open this September.

I honestly wouldn’t mind meeting ya’ll.

OMG CHURCH DECLINE! Our congregations are getting older! People don’t tithe so we can’t afford our staff and buildings! What solutions can we create from business models and hired experts to shake up our congregations so they’ll get some new (hopefully wealthy and generous) faces in the door?

The physics principles of Newton’s cradle (you’ve seen it on someone’s desk) can apply to any attempt to church change. When someone drops a ball, the kinetic energy flows through the group (which remains largely unmoved), straight into the ball on the opposite side that responds with all the force to come back and fight. The two balls on the end go at it for a while and everyone in the middle watches.

Maybe this seems meaningless. A chase after the wind. And so some don’t put forth the effort to shake things up because it’s not worth their energy. One key to the success of the Wesleyan movement was that it was based in small accountability groups (class meetings), that were accountable to larger societies where lay preaching happened. The church was not stepping up to produce Christians, so the Wesley’s took Christianity out of the church buildings and into the streets, fields, and homes of the people. Instead of a wet-blanket attitude about grace, the Wesley’s emphasized our responsibility in light of grace. Instead of privatized faith, class members asked each other hard questions and answered with honesty. Their three rules were to do no harm, to do good, and to attain to all the ordinances of God (that is, to obey the commands of Christ). The church leaders thought this made Christians too enthusiastic about their faith, thought it was too divisive, thought it was to personal. But the number of Christians who took their faith seriously went through the roof…and it wasn’t until the Methodist Americans started to build expensive buildings over a century later that the movement lost its momentum and became the new establishment.

Now here we are again, afraid to challenge people, afraid to hold one another accountable, afraid to say a convicting word because the world is already so harsh and we should just play nicely. We’re afraid to take the church out of the building. We’ve just got so much history in these expensive buildings. We’re afraid to give the lay people better education and control of the church because we hire staff and clergy to be our experts. We’re afraid to focus less on programs and committees and more on spiritual disciplines. We’ll talk and argue till we’re blue in the face, but we won’t spend equal time in prayer over it. I could go on, but I think there’s plenty here for one of you out there to pick up the ball and roll with it.


Could We Make Artificial Gravity?

It’s a staple of scifi, and a requirement if we’re going to travel long-term in space. Will we ever develop artificial gravity?


By: Fraser Cain.
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