Apr 142011
 

Do you know when Easter is?  It’s the first Sunday after the first full moon after the spring equinox.  That can be a complex calculation to make.  In 2011, the full moon in March was the 19th.  About 36 hours before the spring equinox.  29.5 days later will be the next full moon – April 18th.  It happens to be a Monday, which means that Easter is six days later on April 24th, 2011.  I wonder what the latest possible Easter Sunday is?

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Apr 132011
 
Stacked Half Moon

There’s a car dealership in Astropotamus’s home town that claims that you can’t stack cars.  I’d argue that you can, but it’s unlikely that they’ll be very useful after you do so.  But that’s neither here nor there.  You might not be able to stack cars, but you can certainly stack stars!!

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Apr 122011
 
The Big Dipper

If someone said, “find the constellation called the Big Dipper,” would you know where to look?  You probably would.  At least, you think you probably would.  Astropotamuses, however, know that no matter how hard you try, you’ll never find it.  You see, the Big Dipper, and the Little Dipper, aren’t constellations!

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Apr 112011
 
Regulus in Leo

Leo is a nice spring constellation.  During April and into May, it appears right overhead in the southern sky a few hours after the sun goes down, so it is hard to avoid it – you don’t have to stay up late or get up early.  It also contains the 22nd brightest star in the sky, not including our Sun, Regulus.  Regulus means “prince” or “little king,” but there’s more to this bright neighbor whose light reaches our eyes 77 years after it left the star.

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Apr 102011
 
Waxing Crescent Moon

The moon is our nearest celestial neighbor.  Look out the window, day or night, and about 75% of the time, you can see the moon.  Maybe a little less where Astropotamus lives  – My city ranks in the top 25 for “most cloud cover” of all cities in the US with more than 50,000 people.  But I digress.

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Apr 092011
 
Crab Nebula (NASA)

Astropotamus just came back from a most delightful journey.  1000 years ago, a star exploded and we got to see it.  Well, actually more like 7500 years ago, a star exploded and 1000 years ago, we got to see it.  SN 1054 is the birthplace of the Crab Nebula.  Though it’s close to us (about 6500 light years away) it’s still very very far away and somewhat hard to see.  Almost impossible with the naked eye, in fact.  But it has a really good story.

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Apr 082011
 
Bunny Hop

Bunnies hop.  Toads hop.  I hop.  Wait – that might be a trademark.  Lots of things hop.  It’s not only a fun way to get from point A to point B, it’s a fun way to get from star A to star B.  It’s the second in our bag of tricks for finding what we’re looking for through the Time Machine.

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Apr 062011
 
Lite Bright

Digital images are stored as data files that contain information about the colors in the image.  They don’t know anything about the shapes, lines, people, animals, or scenery.  Just how much of each color there is in the image, and where it is in image.  In the same way that you use colored pegs in a black background to make a picture with a Lite-Brite (I’m sure that name is copyrighted), you use picture elements – or “pixels” – in a digital image to make your picture.

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Apr 052011
 

Focal plane imaging is one of the hardest ways to photograph (or image) the things we see when we look back in time.  It’s also one of the more rewarding.  First, the short version about how Time Machines work.

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