people who think that planets align sometimes is “mind-blowing” makes me want to blow my brains.
While doing some reasearch on Thorium, I came across this interesting little fact that I wasn’t familiar with, so I thought I’d pass it along. Many people fear radiation, sometimes the fear is irrational, based on the erroneous concept that we live in a “radiation free lifestyle”. I’ll never forget one time when I showed my geiger counter to a neighbor who was shocked when it started clicking. She was horrified to learn that cosmic rays were in fact zipping right through her body right that very second. I didn’t have the heart to tell her about neutrinos.
But, along the same lines, this little factoid might drive some people “bananas” when they read it. But, it illustrates a fact of life: radiation is everywhere.
A banana equivalent dose is a concept occasionally used by nuclear powerproponents[1][2] to place in scale the dangers of radiation by comparing exposures to the radiation generated by a common banana.
Many foods are naturally radioactive, and bananas are particularly so, due to the radioactive potassium-40 they contain. The banana equivalent dose is the radiation exposure received by eating a single banana. Radiation leaks from nuclear plants are often measured in extraordinarily small units (the picocurie, a millionth of a millionth of a curie, is typical). By comparing the exposure from these events to a banana equivalent dose, a more intuitive assessment of the actual risk can sometimes be obtained.
The average radiologic profile of bananas is 3520 picocuries per kg, or roughly 520 picocuries per 150g banana.[3] The equivalent dose for 365 bananas (one per day for a year) is 3.6 millirems (36 μSv).
Bananas are radioactive enough to regularly cause false alarms on radiation sensors used to detect possible illegal smuggling of nuclear material at US ports.[4]
Another way to consider the concept is by comparing the risk from radiation-induced cancer to that from cancer from other sources. For instance, a radiation exposure of 10 mrems (10,000,000,000 picorems) increases your risk of death by about one in one million—the same risk as eating 40 tablespoons of peanut butter, or of smoking 1.4 cigarettes.[5]
After the Three Mile Island nuclear accident, the NRC detected radioactive iodine in localmilk at levels of 20 picocuries/liter,[6] a dose much less than one would receive from ingesting a single banana. Thus a 12 fl oz glass of the slightly radioactive milk would have about 1/75th BED (banana equivalent dose).
Nearly all foods are slightly radioactive. All food sources combined expose a person to around 40 millirems per year on average, or more than 10% of the total dose from all natural and man-made sources.[7]
Some other foods that have above-average levels are potatoes, kidney beans, nuts, andsunflower seeds.[8] Among the most naturally radioactive food known are brazil nuts, with activity levels that can exceed 12,000 picocuries per kg.[9][10]
It has been suggested[11] that since the body homeostatically regulates the amount of potassium it contains, bananas do not cause a higher dose. However, the body takes time to remove excess potassium, time during which a dose is accumulating. In fact, the biological half-life of potassium is longer than it is for tritium,[12][13] a radioactive material sometimes leaked or intentionally vented in small quantities by nuclear plants. Also, bananas cause radiation exposure even when not ingested; for instance, standing next to a crate of bananas causes a measurable dose. Finally, the banana equivalent dose concept is about the prevalence of radiation sources in our food and environment, not about bananas specifically. Some foods (brazil nuts for example) are radioactive because of radium or other isotopes that the body does not keep under homeostatic regulation.[14]
tattoo idea.
At Bizarre Learning Center, we really appreciate advancements in SCIENCE… and also witchcraft (don’t tell Cave). Here’s an entertaining video featuring a couple members of our band and another local musician: Danielle Ate the Sandwich.
Whether or not you play Portal, you’ll find this is a hilarious portrayal of a for-profit science factory that makes, uh, science.
P.S. Can you spot the Lost references?
(Source: syntheticph.com)
Please watch this time-lapse video if you haven’t yet: images of Earth, taken from the International Space Station, stitched together into a 60-second “flyover” that would make Superman envious.
The cities lighted; the lightning strikes; the deep, dark blue of our oceans as backdrop for white, woven clouds.
It’s a beautiful reminder that yes, we live on a dynamic, wondrous planet.
New skeleton discovery may prompt shuffling of the story of human evolution
The 1.9 million-year-old fossil remnants of Australopithicus sebida in 2010 was already an important discovery. But a deeper analysis of the remains could hold a clue about the appearance of a direct human ancestor, bucking the previously held narrative. A. sebida is similar to humans and human ancestors in the anatomy of its feet, hands, brain and pelvis. While each similarity is not necessarily remarkable, all being present in the same species is highly unlikely to be a lucky convergence. The proposal that the new fossil is a direct ancestor to humans is a big one, dethroning several species that already claim the position. And if it is the case that A. sebida is a direct human ancestor, that has some important implications for how we thought humans evolved; the fossil belies the notion that our brains and our upright posture evolved in tandem, since A. sebida has a fully upright pelvis and yet a small brain.
Science has five open access papers coming out this month on the find, as well as a few news items on its website. Click here to read more.
This was found on the newsgroup: rec.humor.funny
H2O: Dangerous Chemical!
A student at Eagle Rock Junior High won first prize at the Greater Idaho Falls Science Fair, April 26. He was attempting to show how conditioned we have become to alarmists practicing junk science and spreading fear of…
I won second place at this city science fair when I was in sixth grade.
(Source: the-great-wall)
Polar Bears Trace Ancestry to Ireland
July 23, 2011
Nearly 12 percent of Americans claim some Irish ancestry. Even President Obama has a little Irish in him. But we’ve got nothing on polar bears.
According to a study in the journal Current Biology, every polar bear alive today can trace its ancestry to one mama bear that lived in Ireland during the last Ice Age. And what’s more, she wasn’t even a polar bear: She was a brown bear.
Study co-author Beth Shapiro, an associate professor of biology at Penn State University, tells Guy Raz, host of weekends on All Things Considered, that her team studied DNA extracted from ancient bear bones.
“In every cell, there are two different sources of DNA. There’s the mitochondrial DNA, which you inherit from your mother,” she says, “and there’s the nuclear DNA, which is a mix of the DNA that you get from your mother and your father.”
When Shapiro looked at the nuclear DNA, she found that brown bears and polar bears began to evolve separately from each other around a million years ago. But the mitochondrial DNA, the kind you inherit from your mother, told a very different story.
“They diverged only about 20- or 30,000 years ago,” she says. “And that difference is intriguing, and it means there’s something weird going on in the history of polar bears.
Shapiro says what probably happened is that the Ice Age brought polar bears and brown bears back together, as encroaching ice drove both kinds of bears to the very edges of their habitats. “And when they overlapped, they were able to breed,” she says.
But when the ice receded, the brown bears went back to being brown bears, and the polar bears went back to their icy habitat and bred with each other to produce more polar bears — just with a little extra DNA.
That hybridization is starting to happen again today, but for a different reason. As the Arctic ice melts, polar bears are coming farther south to search for food, Shapiro says, and they’re beginning to crossbreed with brown bears, producing hybrids known either as “pizzly” or “grolar” bears.
That could be the end of polar bears as we know them, Shapiro says. “They can’t return to the ice and act like polar bears because that habitat isn’t going to exist anymore,” she says.
“If the only way that polar bears can reproduce is by hybridizing with brown bears, then we’re not going to have any more polar bears.”
(Source: NPR)
