Stardust Can’t Live on Sunshine

Day and night, the sun is something most of us take for granted. But on Respectful Insolence, disciples stare at it intently in order to gain its energy. Orac writes “sun gazers seem to think that mammals are like plants in possessing an ability to absorb energy directly from the sun”—and diehard gurus claim to have lived for years without food or water. Earnest practitioners risk blindness, dehydration, starvation and death. Orac says “Sun gazing also leaves out the fact that plants get the organic building blocks they use to produce their actual structures from the ground in which they grow. Humans have no such capacity.” As the sun grows to a red giant it will boil our oceans and strip off the atmosphere; later it “will die in a fiery, catastrophic explosion, one which will quite possibly obliterate our entire planet, and then eventually cease to shine at all.” But as Ethan Siegel reveals on Starts With a Bang, there’s a silver lining to that future planetary nebula. He says “everything that makes up you, me, and the entire planet—the tiniest parts of everything we’ve ever known—they were all made inside a star.” Ashes to ashes, dust to dust, and solar system to solar system.

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Just a Drop to Drink

According to UN Water, “Each of us needs to drink 2 to 4 litres of water every day. But it takes 2000 to 5000 litres of water to produce one person’s daily food.” If that seems like a lot, it is. But it’s funny how much depends on your perspective. A graphic from the USGS shows what it would look like if all the water on Earth were gathered into one drop. On A Few Things Ill-Considered, Coby Beck discusses the even smaller drop that represents all fresh water. Coby writes, “A full 74.5% of that much smaller ball is locked away in ice caps and glaciers and 24.7% is groundwater (much of that out of reach). There is only .56% of the world’s freshwater circulating in lakes, rivers, rainfall, soil and the biosphere.” The sight of so little water against the rocky backdrop of Earth might inspire some to keep our water clean. But on Starts With a Bang, supervillain types dream of apocalypse. Ethan Siegel writes, “The ability to have liquid water is relatively rare: we need the proper temperatures and the proper pressures!” Without our 5.3 quadrillion ton atmosphere, there would be no water on the surface of the Earth, and without the magnetosphere generated by the planet’s core, we would have no atmosphere. Ethan continues, “Charged particles are bent by magnetic fields in very predictable ways […] if we could create a large enough magnetic field on Earth, we could poke a hole in the magnetosphere and allow the solar wind to strip our atmosphere away!”

Standardization Walks a Fine Line

On Denialism Blog, Mark Hoofnagle argues that unless homeschooling is better regulated, it should be banned altogether.  He writes “universal primary and secondary education is part of why our country has been so successful.”  While Rick Santorum can teach his kids that global warming is a hoax and the earth was created in a day, other parents can withhold sexual education, or, in one example, forbid their daughters from getting a GED.  Hoofnagle concludes, “for parents to say it’s a matter of religious freedom to deny their children education, or a future outside their home, can not be justified.”  Meanwhile, in an actual classroom or lecture hall, too much regulation can drag the learning experience down.  Ethan Siegel writes “the most difficult course to teach is the one where you, the teacher, cannot control what or how you are teaching.”  He calls such courses unreasonably standardized, and says they result in a shallow understanding of the curriculum, or the omission of important topics.  The most important thing, says Siegel, is to have a great teacher.  His post was inspired when Chad Orzel originally asked what course is most difficult for students on Uncertain Principles.  The answer—well, pick your poison.  Classical electromagnetism or literary theory?

Genetic Strength in Numbers

On the Weizmann Wave, researchers have made a discovery surrounding exons—”bits of genetic code that are snipped out of the sequence and spliced together to make the protein instruction list.” When a cell needs to make a protein, it pulls exons out of pre-messenger RNA and stitches them together to form messenger RNA. Alternating sequences called introns are left out. By tracking the unused introns, researchers observed that “in some cases, pre-mRNA production shot straight up – to ten times or more than that of the mRNA that followed.” They call this “production overshoot,” for when “the cell needs a rush job on the manufacture of certain proteins.” On Pharyngula, PZ Myers tackles the phylogeny of modern primates. Although chimpanzees are our closest living relatives, 30% of the newly-sequenced gorilla genome is closer than chimp to human. This is the result of Independent Lineage Sorting, which Myers calls an expected outcome of evolution, not an obstacle to its acceptance. Myers says “The only way you would fail to see ILS is if every genetic difference between two species emerged simultaneously, in lockstep, in one grand swoop.” Like mRNA production, speciation in practice is a lot more messy.

Cost, Cause & Effect

Cause and effect weave a tangled web, but a new data analysis tool called MIC can help make sense of it all.  The Weizmann Institute writes that “Large data sets with thousands of variables are increasingly common in fields as diverse as genomics, physics, political science, economics and more.”  Evaluating pairs of variables from among the thousands, MIC assigns each a score based on the strength of the relation between its variables.  For example, while combing through an incredibly complex dataset from the World Health Organization, MIC observed that “obesity increases monotonically with income in the Pacific Islands,” where girth is a sign of status.  MIC could also be used to build baseball rosters, Moneyball style.  Meanwhile, on Denialism Blog, Mark Hoofnagle explains why healthcare is so expensive in the United States.  Hospitals must treat all comers, so the uninsured are more likely to enter the most expensive point of care (the emergency room), at the most advanced stage of illness or injury, and end up incurring the highest bill.  Hoofnagle writes, “As a result, to pay for excessive care of the uninsured, all procedures, all tests, all imaging, and all hospitalizations cost more.”  Furthermore, healthcare providers are encouraged to order more tests and perform more procedures in order to maximize revenue and hedge their bets.