60 asteroids have hit since 1990… And we didn’t notice.

In February, an asteroid screamed into the atmosphere above Russia so fast that it exploded in midair. It produced the explosive force of half a million tons of TNT.

It turns out asteroid strikes like the one that injured almost 1500 people this year are much more common than anyone thought. They just usually hit in remote areas — and even with all our technology and 7 billion pairs of eyes we haven’t noticed. An international team of scientists recently found out that “the strike rate of asteroids that are tens of metres in size is between two and 10 times higher than was previously thought.”

Why do meteors sometimes explode in midair? Coming from space, they’re very cold. They’re moving so fast that the air in front of them is compressed so much it produces incredible heat. The difference between extreme heat and extreme cold makes the space rock shatter into thousands of pieces. Those pieces are also moving at incredible speeds and compressing the air, producing even more heat, and you basically have an explosion. It doesn’t work the same way as a chemical explosion or nuclear explosion, but has similar force.

People often think that meteorites are radioactive because media reports often describe the power of meteor explosions in terms of the strength of a nuclear bomb. (February’s midair explosion had the force of twenty-five Hiroshima bombs). Meteor explosions can have similar strengths to nuclear bombs, but meteors are basically never radioactive.

There’s a global network of sensors set up by the US military and other groups to listen for nuclear explosions to enforce a nuclear test ban treaty. Some of those sensors can hear the really loud low-frequency atmospheric rumblings of a nuclear explosion from very far away.

An international team of scientists examined records from those sensors for readings that match the signatures of exploding meteors. They found 60 of them since 1990 that were up to 20 meters across.

Smaller-scale meteors fall on Earth all the time. I just saw a shooting star last week.

Last month, a meteor blew up in midair over Columbus, Ohio.

No damage. We’re lucky these things usually blow up in the sky instead of on the ground.

UPDATE: There was another meteor fireball over California a few hours ago.

There are patterns everywhere.

Even in things that seem totally random, there are still elements of order. Life is all about order emerging from chaos. Patterns are inherent in reality.

Mathematics is the language of nature.

I found this via NPR. I feel the same way as Robert Krulwich:

Non-mathematicians miss all this. We see the flurry of what’s happening, not the tight logic underneath. But now comes this minute-and-a-half little video — a cheat sheet for math-challenged folks like me. It shows us what it’s like to look around as if we were Galileo or Einstein or that kid who always raised his hand first in math class … This is what they get to see …

Math is crazy: 1 = 0.9999…

There’s no difference between the number 1 and the seemingly smaller number 0.9999… (with 9 repeating endlessly). I used to think that there must be some tiny but key difference, but it turns out there just isn’t any. They seem different and are written differently, but they are the same.

Here’s one proof: Multiply 0.999999… by 10.

That’s 9.999999…

Then subtract 0.999999…

The result is 9.

What’s the difference between ten and nine?  One.

It’s true that the solution for 10x-x=9 is 1.

So 0.9999… = 1.  Weird!

You too can get rich working from home! (But probably not).

There are six math problems that will get you a million dollars each if you can solve them.

The Clay Mathematics Institute put together the Millennium Prize in 2000, listing seven important math problems no one had been able to answer.  If solved, they could unlock doors to new areas of mathematics and new real-world technologies.  Three years ago, an eccentric Russian guy solved one of them but turned down the money.  (!)

The problems are hard, but there’s no reason why anyone in the world can’t think about it.

If those look too hard, a different group has smaller prizes for smaller problems.

How to cut the odds of autism almost in half

The Link: Folic Acid For Pregnant Mothers Cuts Kids’ Autism Risk

The Story:

Having an autistic child is hugely difficult.  Doing one simple thing can dramatically reduce the odds of having it happen to you.

A study published this year found that women who took folic acid supplements were  40% less likely to have autistic children.  (The ones who got the most benefit started taking the supplement a month before becoming pregnant and continued taking it for the first two months.)

It’s an amazingly easy, cheap, effective way to improve your odds as a prospective parent.  A forty percent improvement from a single cheap, common pill.

I don’t have any kids yet, but when my fiancee and I decide to have them, we’re definitely doing this.

Wonderful World pt 2: Little heroes of the big picture

The Link: 200 Countries, 200 Years, 4 minutes

The Story:

Trevor Macy has a funny straight-faced blog called DIY Superhero where he details how to become a caped crimefighter, one post at a time.  I love it.  It makes me think of how superheroes relate to real life.

You’re never really going to be Batman, but the world is full of everyday heroes like nurses, firefighters, and teachers.  A lot of little heroes makes a big difference.

With all the terrible events on the news every single day, it’s easy to think the world’s going to Hell in a handbasket.  But looking at the numbers gives a better understanding of the big picture.  Literacy, life expectancy, and prosperity are at higher levels around the world now than ever before.  There have always been terrible things in the world, but the farther back in history you go, the more life was poor, nasty, brutish, and short.  (But not really solitary).

Like I said before: We may not always fully appreciate it, but living in the twenty-first century is awesome.

Every time you blow out a candle, you create a rainbow.

The Link: In fact, you create a whole series of rainbows.

The Story:

Dazzling photographer Grover Schrayer captured something I never knew: A candle always goes out in a small blaze of glory.  For a fraction of a second, the vaporized wax particles are carried along the puff of smoke and refract light to create a rainbow pattern.

Like with most of the rest of the universe, I don’t really understand it.

Flickr_Candle_Rainbow

Image by Grover Schrayer

It passes by so fast, you don’t even notice it.  Life is always like that.

I’m reminded of something Krisi Metzen shared, the work of another photographer who captures the beauty of the fleeting moment.  There is beauty in such things because they reveal underlying patterns–the mathematical structures of nature.  These beautiful patterns are everywhere.