Monday, December 17, 2007

Spherectangular Geometry


None of my jabbering would add to the wonder of a dew covered spider web.
Still, it does make me wonder ...
Why are the drops so wonderfully spherical? Gravity should be making them drip shaped ... do spiders possess antigravity field generators? Do I watch too much SciFi?
What keeps the drops separate from each other? At the bottom of the web curve, shouldn't they be clumping together?
Water loves itself ... it's sticky thanks to little hydrogen bonds between each water molecule that cause each water molecule to stick to the next water molecule.
Try this:
Get an eye dropper and a penny to see what I mean. Lay the penny down and slowly add drops of water to the penny while counting each drop. When the water runs off the penny, stop counting (duh).
Go ahead, do it. I'll wait.
It was a lot wasn't it?
Admit it, A LOT more drops than you imagined went on that penny before it finally poured off onto the table.
That's because of those hydrogen bonds between each water molecule.
Other liquids don't do that.
So now why isn't the water on the web in big globby clumps instead of close to perfect spheres?
Why such beautiful, evenly spaced water pearls?
I don't know either, but maybe there are textural things about the surface of spider silk that are evenly spaced ... hence the droplets form around them ... ??? ... maybe?
Obviously I haven't Googled this.
In fact, my intention this morning was to let the photo speak for itself and not write anymore than the first sentence above ... I do write a lot here after all and should be allowed a break once in a while ... but,
... the more I looked at the photo, the more questions it inspired.
It seems I jabbered after all.

21 comments:

Rurality said...

I probably could have told you the answer if I hadn't fallen asleep yesterday during that science show I was watching.

Really, I was very interested to know all about how gravity was not really a force, but a fabric in space-time. But a stray dog fight had kept me awake in the middle of the night, and strange horizontal-sofa forces made me nap.

Otherwise I'm sure I could have told you.

Rurality said...

Oh I totally forgot to say, great pic!

Doug Taron said...

The drops would be droplet shaped if they were larger. The small size of these means that the surface tension is able to pull them into the most compact form- a sphere. I'll guess that the spacing is due to a static charge on the individual droplets, and that they are electrostatically repelling each other. That would also explain why the spacing is so even. Really nice picture.

Thunder Dave said...

OK, I'll agree with Doug to a point; the surface tension of the water will cause the formation of a sphere because it is the most stable structure for a liquid to form upon itself. However, I believe you've hit the nail on the head with the texture of the web itself. SORRY BUT THIS IS GOING TO BE A BIT LONG WINDED!
The only way to prove this is with a powerful microscope, by that I mean an electron microscope (EM), or Scaning Electron Microscope (SEM). I'm going to guess that it was either heavilly dewy or foggy just prior to the photo. The micro structure of the web allows it to capture water particles out of the air, and that same structure dictates the size of the droplets that will form.
An interesting similarity is a desert beetle that has tiny little bumps on it's hard shelled wing covers that when looked at under the microscope actually look like mountains. In the early mornings the air is at it's most humid (even in the desert) and the beetle will stand with it's wing covers open, water droplets will form on the peaks of the bumps and then when they get large enough they roll down into the gaps between and towards the beetle's mouth so that it can drink! Believe it or not construction materials companies are trying to duplicate this same technology right now!

Thunder Dave said...

Oh, I forgot to add Awesome Photo!

Also, it's 10:30PM (9:30AM your time) and about 30F here in Beijing. The wind has stopped so it's actually not too bad.

threecollie said...

Wonderful photo...puzzling questions. My brain is frozen so I am not going to be any help at all.

Sharon said...

I don't know about all the scientific reasons behind it. All I know is dew-covered spider webs make beautiful pics, yours is outstanding!

lesle said...

This post, and comments, particularly Thunder Dave's, jogged my memory...for more than you may want to know, google "fog harvesting".

FC, another great photo! (I must have missed 'spherectangular' when I made that A in geometry.)

robin andrea said...

Beautiful photograph, fc. Great observations and questions, too. I don't know why the droplets stay like that, but I am glad for the stunning aesthetics.

Enemy of Carp said...

The H2O molecule has both a positive and negative charge. One is weaker than the other.

Therein lies your answer.

Deb said...

That's an amazing photograph. And water is amazing stuff. I had never thought about why dew drops don't just run off spider webs. I'm glad they don't.

Wren said...

What a fabulous picture!

I appreciate your analytical approach but am happy to enjoy with understanding.

Mrs Mecomber said...

LOL, your questions are interesting. Short answer: God made them that way.

All the other, "naturalist" explanations are explaining the processes-- but who made the laws for those processes?

edifice rex said...

Well, I don't know but that is just the coolest. And we humans think that we can build the most impressive things!

Floridacracker said...

Rurality,
The couch force is a powerful attractant. You were wise to yield to it rather than risk being rendered asunder.

Doug,
Ahhh, in the same way that gravity doesn't really exist for tiny insects. Drop a grasshopper off a tall building and he's fine, drop a cat and ... not so good.

ThunderD,
I now have an international audience.
Thanks dude.

3C,
Hope your brain unfreezes or that your fatwood arrives in time to warm it.

Sharon,
If you want to see good dew photos, check out a photographer named John Shaw.

Lesle,
Will Google.
You made an A in geometry!
Wow!
In awe here.

Robin,
It is beautiful and fleeting too.

Carpfoe,
Yeah, I know it's a polar molecule, I was just wondering about the fine details.
Welcome to Pure Florida!

Deb,
Me too.
Glad for dewy webs.

Wren,
Me too. It may be all the more wonderous if you don't delve into the physics.

Mrs. MC,
Well, I wish he'd made dog lives longer while he was working on webs.

Edifice,
YOU do build the coolest things. The rest of us are behind the spider.
:)

amarkonmywall said...

Loved catching up. Smiled at toddler Katy, laughed at daughter's hair (remembering some red dreds we had here for a brief stint a few years ago), groaned at the food post, felt your pain over the mall trip (home of the devil's spawn) and the icing on the cake is this spectacular photograph. Simply stunning. We have golden orb spiders at the zoo: the only critters who are not restrained. Their giant webs are in an alcove but nothing else between them and the public. They are big, so are their webs so sometimes I stand there for a long time and marvel at the architecture. They don't ever leave because the keepers drop live food onto the webs so they're content. That's in theory and what we tell the public. In reality, there's a spider count several times a day and sometimes it comes up one short...

amarkonmywall said...

Oh! BTW- it's interesting that the comments run to the properties of water rather than the properties of webs. Some of the silk is sticky and some is not and there's a very specific pattern to it, depending on the species. The spiders are careful to only move on the non-sticky threads. Watch one sometime (when you have time to spare) and you'll figure out the pattern. That stickyness- wouldn't that have an effect on the water droplet formation?

Floridacracker said...

Vicki,
Wonderful to have you back in the neighborhood!
It does seem like web texture and stickiness could ... should... be a factor.
I fussed about golden orbs everywhere this summer, but now their empty web remnants are kind of sad ...

SwampAngel65 said...

That's the neatest picture I've seen in a long time. How something so seemingly simple can also be so complex...amazing.

Floridacracker said...

Swampangel,
Thanks! It was pure serendipity. I was rushing out to leave for work and there it hung in a young chestnut tree.
I was late for work as usual ...
but I got the pic.

ldybug said...

cool shot