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We May All Be Made of Stardust, But What Makes Stardust? Most of my followers should know that the atoms that comprise your body and just about everything around you were forged in stars. If you didn’t know this I urge you to spend more time avidly watching Cosmos. But how does this process actually occur? The secret lies in nuclear fusion which is essentially the opposite to fission (which causes radioactive decay). Fusion is simply the combination of two nuclei into one larger nuclei. In the process a large amount of energy is released. The energy that is released is what powers stars and gives you sunlight. The cornerstone of this process lies in a property called binding energy, which is essentially the energy that holds together an atom’s nucleus. The important thing is to relate this to the mass of nucleus by referring to it as "binding energy per nucleon" (protons and neutrons essentially). Of all the elements iron has the highest binding energy per nucleon which means that combining atoms smaller than iron releases energy, whilst combining atoms that are larger requires an energy input. Heavier elements than iron are typically only produced during supernovas (a remnant of which is pictured above) which also have the effect of distributing the atoms in shells or jets.
Fission (“splitting”) occurs when the nucleus of large, unstable atoms, like uranium and plutonium, break into smaller atoms, releasing energetic radiation and neutrons. Fission powers the “atomic” bomb that destroyed Hiroshima, and all nuclear power reactors.
Fusion (“joining”) occurs when light atoms, primarily isotopes of hydrogen, fuse into larger atoms, releasing fantastic quantities of energy. Fusion powers the sun and “hydrogen” bombs, which are called “thermonuclear” for the intense heat needed to overcome electrical repulsion between positively-charged hydrogen nuclei. Fusion, however, is extremely difficult to control; although billions have been spent to tame fusion for electricity, practical reactors are decades away.
We knew the world would not be the same. A few people laughed, a few people cried, most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita… “Now, I am become Death, the destroyer of worlds.”
- Robert Oppenheimer
Scares some, isn’t it?… Z-pinch at Sandia National Laboratories Z machine.
Fusion, anyone? Not quite yet, but researchers show just how close we’ve come
The dream of igniting a self-sustained fusion reaction with high yields of energy, a feat likened to creating a miniature star on Earth, is getting closer to becoming reality, according the authors of a new review article in the journal Physics of Plasmas.
Researchers at the National Ignition Facility (NIF) engaged in a collaborative project led by the Department of Energy’s Lawrence Livermore National Laboratory, report that while there is at least one significant obstacle to overcome before achieving the highly stable, precisely directed implosion required for ignition, they have met many of the demanding challenges leading up to that goal since experiments began in 2010.
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Synchrophasotron control center, Dubna, Russia, 1968
Operation Dominic - Sunset (1962)
The Soviet Union had abrogated the 34 month old de facto nuclear testing moratorium on 1 September 1961 by initiating an unprecedented series of atmospheric nuclear tests. The initial U.S. response was to commence its own test series (Operation Nougat) two weeks later. Nougat was an underground series however, restricted to very low yield devices.
Numerous atmospheric tests, many at high yield, were of course on the drawing board at the weapons labs, some carried over from planning for previous test series. The Dominic Sunset test successfully reached the full design yield with a yield-to-weight ratio of 4.06 kt/kg. The vapor cloud rose to over 60,000 feet.
Nuclear detonations produced high above the ground do not create mushroom clouds. The heads of the clouds themselves consist of highly radioactive particles, primarily the fission products, and are usually dispersed by the wind, though weather patterns (especially rain) can produce problematic nuclear fallout.
Nuclear explosions are often accompanied by short-lived vapor clouds known variously as “Wilson clouds”, condensation clouds, or vapor rings. The low pressure region causes a sharp drop in temperature, causing moisture in the air to condense in a shell surrounding the explosion. When the pressure and temperature return to normal, the Wilson cloud dissipates.
Positive kaon (K+) decay in bubble chamber.
Credit: CERN
For a pretty naive info visit the source (Yin Yang) at UC DavisNuclear Physics Group, no offense intended, I loved the site.
The Morgentaler abortion clinic in Fredericton will close the end of July following a 20-year fight with the New Brunswick government over funding for the procedure.
The only abortion clinic in New Brunswick, Canada has just announced its closing today, which will be in July of this year. As a citizen of New Brunswick, and the city where it is located, I had always felt slightly comforted that if something were to happen and I ended up with an unwanted pregnancy that there was something near by, despite the extremely high cost of the procedure (ranging from $700-$850). But the founder of this clinic, Dr. Henry Morgentaler, had a policy in which no woman was to be turned down and there are recordings of pro-bono operations.
There has been a refusal of funding for the clinic, leaving citizens of New Brunswick, and neighbouring province of PEI without access to safe abortions.
In order to receive an abortion in the province after the clinic shuts down, it must be an absolute medical necessity with referral from two doctors (i.e. Family doctor and Gynecologist).
Today, in the year 2014, a giant step back away from female reproductive rights, and human rights in general, occurred and it is utterly disappointing.
A leveler playing field for men and women — so that men and women doing the same job, over the same hours, are entitled to the same compensation — is a matter of basic human dignity, as well as something that regulation could fix relatively easily and cheaply.
Yes, the gender pay gap is real (via theweekmagazine)
Saudi Arabian authorities have been asked to consider lifting a nationwide ban on sports for girls in schools, according to the official SPA news agency, in a religiously conservative country that included women in its Olympic team for the first time only two years ago.
Under a strict interpretation of Sharia, or Islamic law, Saudi women are banned from driving and must gain formal permission from a male relative to leave the country, start a job or open a bank account. But King Abdullah is pushing cautious social reforms on women’s rights in the face of conservative resistance.
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Pouring an ice cube using supercooled water:
The temperature of the liquid water is reduced below its freezing point, without becoming a solid. The ice wont form without the presence of a nucleation point (a crystal or impurity around which an ice crystal can begin to grow). However, on contact with another surface, the water instantly freezes. Check out how to make instant ice at home in this video: http://youtu.be/sBFK5-JvBAc
(via Ross Exton)
kīlauea, one of hawaii’s youngest and most active volcanoes, has been spewing lava continuously for over thirty years, making it the longest rift zone eruption of the last two hundred years.
despite a melted tripod and shoes, toxic gases (which can become lethal should the winds change direction), and scolding ocean steam, miles morgan captured these shots of the volcano’s crater and of the lava which spews from it for a six mile, four hour journey to the sea. (also captured by chance was a meteor seen in the first photo)
said miles, “when you are within about two hundred yards of the ocean’s edge, you are standing on nothing but cooled lava of questionable thickness, called the bench, which is massively unstable. if you happen to be on the bench when it collapses [which happens often, in chunks measured in acres], there is no chance for survival.”