Allegory of The Cave (Reflections on Science Education)

Socrates: To them, I said, the truth would be literally nothing but the shadows of the images.
Glaucon: That is certain.

There is a wonderful tale written by Plato called “The Allegory of the Cave”. To summarize the story, a man makes a discovery and wishes to tell everyone he knows. But his description goes against the beliefs of those around him and he feels his knowledge separates him from them. Eventually, he realizes that the only way for them to understand him is for them to find the truth themselves.

The crux of the story is that our characters in need of truth have always been prisoners in a cave where they have had very little light.  In order to find the truth, they must exit the cave.  Shady descriptions of the outside world will not do.  But with a bright sun, this will be quite painful …so they wait until night.  The dimmest of light, the stars, then becomes the first thing they gain knowledge to.  As their eyes acclimate to their new environment, many things — things whose existence had been mere suggestion — become very real to them.  After a time their eyes can handle brighter lights and they can see many more things.  And finally, after much patience and some discomfort, they can view their world in full sunlight.

The rest of the story is rather convoluted and a bit of a strain to swallow, but what Plato was trying to do was set up an allegory for how discovery works.

It’s been 20 years since I first read The Allegory of the Cave from Plato’s The Republic.  I read it while in Governor’s School, where we then had a lively discussion about whether it was possible to fully explain a new discovery to someone without any direct proof.  Could they be persuaded that you weren’t misleading them?  Could they believe in something that went against their everyday perception if you drew out your argument logically and without flaw, though you had not a shred of tangible evidence to support you?  In the end, the man who left the cave and made a discovery viewed the others as being ignorant, but conversely (and here’s the real kicker!) the ones left behind who did not see the truth viewed the one with knowledge as being ridiculous.

I spoke with a preacher friend of mine this past week, who also happens to be a science teacher.  While debating the efficacy of hands-on versus verbal strategies, he said something quite profound.  He said, “Our perceptions become our reality.”

That’s really deep.  I’ve been thinking about all the topics it could be applied to — science, politics, religion, those crazy Tea Party-ers, and of course our self-perceptions.  It’s something so universally true.  Wish I had thought it up.  (I realize he surely didn’t think it up first; but like when Einstein published E = mc² and said that it’s simplicity revealed it’s truth, it’s one of those things that just sounds profoundly awesome because of it’s simplicity.)

[Tons more after the jump]

Planetary grouping for the Perseids

You can see by this image I stole from Sky & Telescope that we’re due for a really cool planetary grouping in the west over the next few days.  It’ll be a real challenge to pull Mercury out of the glare of the setting sun (if not impossible without binoculars), but see if you can spot the other three planets this week.  They’ll be approaching the horizon around 9:30, so you’ll have to look before then.

And be sure to catch Jupiter rising in the east around 10pm.  It’s the brightest thing in the sky from that time until dawn this week, so you can’t miss it!

After 10pm you can start looking for Perseids.  The peak is Thursday night/Friday morning, but you can catch elevated rates of meteors all week.  Perseids tend to be quite fast, and the brighter ones look yellow to me.  About a third of them will leave persistent trains, which can leave an indelible memory for any witness.  Remember, even though they can light up the sky and leave a brilliant streak across the heavens, they’re rarely larger than your fingernail.  And Perseids almost never make it to the ground.  Each one will burn up at least 25 miles over your head.  Amazing, huh?

Let me know if you see something spectacular!

Boring title.  Awesome topic!

Perseids 2010!

The spectacular Perseids meteor shower is almost upon us!  This year the best rates for the American continent will occur on the morning of Friday, August 13.

Remember last year? I told you all about the really good rates, but even I didn’t go out for more than a casual look.  Most likely, neither did you.  We had a glaringly bright full moon that just made observing near impossible!  This year the rates are still high; and — good news, everyone! — there’s no moon to worry about.

The meteors within this shower were shed from comet Swift-Tuttle, which passes across Earth’s orbit every 135 years.  The last time it was here was 1993 when observers in Europe saw 200-500 meteors/hour!  We won’t get nearly that number this year, but the rates will still be substantial.  And with the peak occurring just two days after new moon, the only thing keeping you from seeing a smattering of your own Perseids will be the weather.

The Perseids will be falling all night with an expected rate of 60 meteors/hour.  Remember that as with most meteor showers, you will sometimes go for 5-10 min. without seeing a thing, then four or five will zip across the sky all at once!  As the evening turns toward deepest night, the rates will increase dramatically; and near dawn you can expect almost 120 meteors/hour.  Remember that the farther north you are, the higher the radiant will climb and the more you’ll be able to see.  But also the farther north you are, the sooner night turns into day.  So those living around 30 – 35 degrees north latitude (MY latitude!) probably get the best overall show.

So set aside some time Thursday night to relax outside with a reclining lawn chair and some bug repellent.  You don’t want another year getting by without watching this ancient event.  It’s really special.

…

Most folks, like yourself, only want to lay back and see how many they can count.  What a serious observer like me would do is take good notes and file a detailed report with one of the major meteor organizations.  (how nerdy am I?)  But there *is* a group in Britain trying to get the public to help them gather data by using Twitter.  I have a bit of a problem with this as I would prefer people to not take their eyes off the sky long enough to punch characters on their phones.  Also, unless your phone has a deep-red-only display, you’ll kill your night vision the moment you look at the screen.  But… maybe it’s a worthwhile effort.  And if we can get a bunch of people actually interested in looking beyond just the pretty and trying to contribute some real science — well, who am I to complain?

Here’s their warm-up video.  It’s a little on the “sensational” side, but awesomely entertaining!

[You gotta watch it fullscreen!]

All Eyes On Enceladus

Here’s the new awesomeness:

[click to huge-ify]

This image shows water-ice geysers erupting on Enceladus, a moon of Saturn.  It was taken by the Cassini spacecraft on a close flyby back in November, so obviously I’m behind everyone else on this.  The pass was only 1000 mi above its surface, revealing some pretty spectacular stuff — like these geysers.

Enceladus has been known to have these kinds of geysers for a while, but this pass confirmed 30 of them total.  And what you’re looking at in this image is them spewing water all the way into space!

I’ve always been fascinated by Enceladus because of the mix of elements you can find there.  It’s one of those places in the solar system that could has the slightest of chances of being able to harbor primitive life.  I’m really looking forward to future reports of the molecular makeup of this material.

Check out more about Cassini’s mission at ciclops.org

Our Earth As Art

Our Earth As Art is a joint project from the USGS and NASA.  With that in mind, I bet you can guess it involves satellite images of the Earth.  I was going to put up one of the several images of craters that give a stunning reminder of the dangers of meteor impacts, but then I came across this…

This gorgeous view is an ‘icefall’ off Lambert Glacier in Antarctica.  From the website:

The Lambert Glacier in Antarctica is the world’s largest glacier. The focal point of this image is an icefall that feeds into the Lambert glacier from the vast ice sheet covering the polar plateau. Ice flows like water, albeit much more slowly. Cracks can be seen in this icefall as it bends and twists on its slow-motion descent 1300 feet (400 meters) to the glacier below.

Each of the images contains a description and a link to a much larger, printer-quality image.  And best of all, they’re all free to use as long as you include proper credit.

Image courtesy of USGS National Center for EROS and NASA Landsat Project Science Office