Why no two snowflakes are identical

As if to put us in the mood for winter, the Washington Post has a fascinating feature explaining why no two snowflakes are the same:

Newly formed snow crystals with only a handful of molecules would be nearly impossible to distinguish. But that’s not really the issue. We’re talking about real snowflakes, which have something on the order of a quintillion molecules. (That’s the number 1 with 18 zeros.)

Now, it’s not a law of nature that no two snowflakes could be truly identical. So, on a very technical level, it’s possible for two snowflakes to be identical. And it’s entirely possible that two snowflakes have been visibly indistinguishable. But probability dictates that this is incredibly unlikely. Libbrecht draws a helpful visual comparison.

“There are a limited number of ways to arrange a handful of bricks,” he says. “But if you have a lot of bricks, the number of combinations grows very quickly. With enough of them, you can make a driveway, a sidewalk or a house.”

Water molecules in a snowflake are like those bricks. As the number of building blocks increases, the number of possible combinations increases at an incredible rate.

Consider the math, which Libbrecht helps explain using a bookshelf analogy. He points out that, if you have only three books on your bookshelf, there are only six orders in which you can arrange them. (That’s 3 times 2 times 1.) If you have 15 books, there are 1.3 trillion possible arrangements. (Fifteen times 14 times 13, etc.) With 100 books, the number of combinations increases to a number that is far, far greater than the estimated number of atoms in the universe.

An ordinary snowflake has hundreds of branches ribs, and ridges, all arranged in minutely different geometries. To be sure, lots of snowflakes have fallen in the world, but not nearly enough to render two identical snowflakes a reasonable possibility.

If you’re skeptical, you’re more than welcome to undertake your own study. But you might want to block off a pretty big chunk of time. Libbrecht estimates that around a septillion — that’s a 1 with 24 zeros — snowflakes fall every year.

via Why no two snowflakes are the same – The Washington Post.

This also makes me want to re-arrange the books on my bookshelves.  I think I’ll put 15 of them on a shelf and make it my life’s work to put them in every possible order!

 

 

snowflake

Cosmology and the speed of light

We’ve blogged about the discovery of neutrinos that seemed to have traveled faster than light.  As scientists try to replicate and study that event, Joel Aschenbach has a good explanation of what’s at stake if light is not the fastest thing in the universe:

There is logic and beauty in a universe in which space, time, energy and matter are tightly associated with the speed of light. The special status of the speed of light isn’t like an Olympic record, something begging to be broken. Someone could come along who is faster than Usain Bolt, and it wouldn’t change the way we look at the world.

But the speed of light, according to Einstein, is an integral part of the geometry of four-dimensional space-time.

When we discuss the speed of light, we’re not talking about the characteristics of light so much as we’re describing the fabric of the universe. Light speed is the ultimate speed that anything (including things with zero mass, such as light or other electromagnetic radiation) can possibly go.

This also puts a limit on the speed of information, and, as such, helps enforce the fundamental law of causality. There’s an “arrow of time”: Splattered eggs on the kitchen floor don’t reassemble themselves in the shell and leap back onto the countertop.

“The melded nature of space and time is intimately woven with properties of light speed,” Greene says. “The inviolable nature of the speed of light is actually, in Einstein’s hands, talking about the inviolable nature of cause and effect.”

Michael Turner, a University of Chicago physicist, says the universe won’t seem as logical if there are particles that can move faster than light.

“In science we like surprises. We like big surprises. This one is too big to be true,” Turner said. “We really like things that rock the boat and turn us in a new direction, but this one turns the boat upside down and fills it with water.”

via Faster-than-light neutrino poses the ultimate cosmic brain teaser for physicists – The Washington Post.

Perhaps some of you can explain why breaking the cosmic speed limit would undermine cause and effect.  Aschenbach says “that” it would do so, but he doesn’t get into the “hows” and “whys.”

Can natural gas ignite the economy?

New technology is unlocking vast amounts of natural gas in the United States, enough to have a huge economic impact.  Yes, it involves “fracking,” the controversial practice of pumping chemical-laced water into shale deposits, but improvements in that technique are starting to satisfy all but the most zealous environmentalists.  I’m glad to see companies from my native Oklahoma are leading the way.  Businessweek has a big story on the topic with the deck below the headline, “Unlocking vast reserves of shale gas could solve the energy crisis, the jobs crisis, and the deficit.”

“The United States,” [energy company CEO Aubrey] McClendon boasts, “has the capacity to become the Saudi Arabia of natural gas.”

A tall man who wears his wavy silver hair long by CEO standards, McClendon, 52, exudes the confidence of someone who’s certain he’s seen the future. Exploitation of newly accessible supplies of gas embedded in layers of what’s known as shale rock, he predicts, will help revive domestic manufacturing and change the terms of debate about global warming. “It’s a new industrial renaissance,” he says. . . .

Encouraged by the availability of inexpensive and cleaner domestic gas, some electric utilities are replacing their coal-burning capacity with gas-fired units. Energy-intensive manufacturers of chemicals, plastics, and steel are beginning to bring home operations that they exported years ago. “We believe natural gas must be part of any discussion on strengthening our country’s long-term economic health,” Mulva said in Detroit. “It should also be part of any discussion on improving energy security, protecting the environment, and, yes, creating jobs.”

On the economic potential of the nascent shale revolution, even some career environmentalists sound impressed, if cautious. “This thing is a potential game-changer,” says Fred Krupp, president of the New York-based Environmental Defense Fund (EDF). Shale production in the U.S. has increased from practically nothing in 2000 to more than 13 billion cubic feet per day, or about 30 percent of the country’s natural gas supply. That proportion is heading toward 50 percent in coming years. The U.S. passed Russia in 2009 to become the world’s largest producer of natural gas. An Energy Dept. advisory panel on which Krupp sits estimated in August that more than 200,000 jobs, both direct and indirect, “have been created over the last several years by the development of domestic production of shale gas.” At a moment of 9.1 percent unemployment nationally, additional decently paid work is just one potential benefit. “Natural gas burns cleaner than coal, emits less in the way of greenhouse gases, and avoids mercury and other pollutants from coal,” Krupp points out. “So this could be win-win, if—and this is a big ‘if’—we do it the right way.”

via Could Shale Gas Reignite the U.S. Economy? – Businessweek.

Skeptics find global warming evidence

Often researchers find what they want to find. More persuasive is when researchers find what they do not want to find but report it anyway. A new study of climate change was funded by skeptics of global warming. They took into account the skeptics’ critiques of the methodology and data gathering used by the scientists discredited in the Climategate scandal.  Lo and behold, this new study ended up confirming the earlier research.  Actually, it found slightly higher average temperature increases.  See this report.

So now do you believe in global warming?  If not, what evidence would convince you?

I’ve been skeptical myself, not so much of global warming but of the contention that it is man-made.  Also of the contention that it will prove to be such a big disaster.

Am I reading the chart right, that the rise in temperature over the last century is only 1 degree Celsius?  Is that such a big rise that it would make much of a difference?

But I’m open to correction and enlightenment from my betters.

HT:  Kirk Anderson

 

In praise of the naked mole rat

Scientists have sequenced the genome of a strange little creature, the naked mole rat.  Why?  Because it never gets cancer, lives an unbelievably long life without mental decline, and has many other amazing powers that may hold clues for human health.

Mole rats are hairless, buck-toothed rodents four inches long that live in underground colonies in arid sections of Kenya, Ethiopia, Somalia and Eritrea. Their social structure is the mammalian equivalent of an ant colony. There’s a queen who takes two or three male consorts and is the only female to reproduce. She lords over the rest of the realm — which can be as large as 200 animals — so that the other females cease ovulating and the males give up.

Mole rats can survive in environments low in oxygen (as little as 8 percent as opposed to 21 percent in the atmosphere) and laden with ammonia and carbon dioxide. Unlike other mammals (but like reptiles), they have a hard time regulating their body temperature. They have to move toward the warmer upper reaches of the burrow or huddle with their brethren when they get cold.

But their most unusual features are extreme longevity and apparently complete resistance to developing cancer.

Naked mole rats can live more than 25 years; mice live about four. Buffenstein said she has never found a malignant tumor in a mole rat in her 30-year-old colony, which has 2,000 animals. In a recent experiment, a group of mole rats had patches of skin painted with a chemical carcinogen at a dose 1,000 times stronger than what causes skin cancer in mice. None developed tumors.

A study published in 2009 found that naked mole rats had a molecular anticancer mechanism not present in mice or people. But a first look at the species’ full complement of 22,561 genes shows that’s just the beginning.

There are changes in genes involved in maintaining telomeres, the “tails” of chromosomes that determine how long a cell lives. There are changes in genes involved in marking damaged proteins for destruction. There’s an increase in “chaperone” genes that keep proteins folded into their right shapes. There are genes that appear to let the animals maintain stem cells in their tissues longer than other rodents.

The study looked at 54 human brain genes that become less or more active as a person ages. In the mole rat, 30 of those genes remain stable throughout life, and two others change their activity in a direction opposite to what occurs in human brains.

Mole rats have 96 gene families unique to the species. Interestingly, they and humans also share 178 gene families that neither mice nor other rats have.

via Naked mole rat genome may point way to long, healthy life – The Washington Post.

 

 

What we half perceive and half create

Following up on last week’s post and video of the The McGurk Effect, it would seem that we have in this demonstration of how the mind alters what we hear some empirical evidence to support the philosophy of Immanuel Kant.  Which is ironic because Kant’s philosophy  is questions empirical evidence!  To be more precise, he critiques what philosophers call “naive empiricism,” the assumption that what we take in with our senses is the only kind of reliable truth.

Kant says that we do indeed take in sense perceptions from the outside world.  But then our minds actively shape those perceptions.  What we experience is  sensory data as organized by our minds.  As Wordsworth puts it, “what we half perceive and half create” (“Lines Composed above Tintern Abbey”).

The McGurk video gives an example of that.  An even more common and accessible example would be the way we perceive distance.  If we were naive empiricists, believing just in what we see, we would have to believe that objects get smaller the farther away they are from us.  In reality, of course, the objects remain the same size.   We know this intuitively but not from our senses alone.  This is how our minds process, organize, and present the sense data.

There are other examples.  Colors don’t seem to be essential properties of objects, but rather manifestations of how our eyes and our minds process light frequencies.  Dogs are thought to see in black and white but to smell in some olfactory version of 3-D and Technicolor.  Insects whose multi-faceted eyes are raised above their heads apparently see 360 degrees at once, forward and backward and above and below at the same time, something unimaginable to us humans who look at things framed in one plane.  And yet dogs, insects, and people–despite their different sense perceptions– share the same reality.  (Can you think of other examples?)

Kantian philosophy started us down the slippery slope that has led us to existentialism, subjectivism, and postmodernism.  But those take his points too far.  That we half perceive and half create does NOT mean that we construct our own truth, much less that truth is relative or that truth is whatever we want it to be.  In the McGurk Effect video we hear “ba’s” and “fa’s,” not the Gettysburg Address.  We do receive sensory data from outside ourselves; we do not just make it up.  Naive empiricism sometimes is mistaken for science, but actual scientists know they have to employ the empirical method with many checks and balances–formal experiments with  controls and repeatability requirements–to get reliable findings.  They don’t just base science on what they see.

How does all of this relate to a Christian worldview?


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