Slashdot Mirror
New Theory on Water Strider Propulsion
capt.Hij writes "There is an interesting
article at the Christian Science Monitor about how water skimmers are able to move the way they do. This new theory debunks the previously accepted theory and answers why smaller, younger water skimmers are also able to move the same way as their elders: 'As he looked into the question, he adds, he learned that the reigning explanation leaves an unsolved puzzle: If these tiny insects propel themselves in the way many researchers think they do, then baby water striders should go nowhere fast.'" There's also a BBC story with pictures.
Are water striders one of those bugs they have everywhere like flies/mosquitos/etc. We have them in oz, here in the UK, in asia and the US. Anywhere else.
-- Karma Karma Karma Karma, Karma Chameleon - Boy George
Thanks. I absolutely HATE articles like the one linked to in the story. In essence, it says "There was a previous theory which doesn't work. But we're not going to explain what the previous theory was because you're probably too stupid to understand it anyway. Now, there's a new thoery. But you're too stupid to understand it too."
"The legitimate powers of government extend only to such acts as are injurious to others." Thomas Jefferson.
Yep I can, or at least could. When I was a kid I used to do this all the time in small rowing boats. And you don't actually make circular or elliptical movements, but something resembling an 'infinity' symbol (fgures eight). That is with your hands; the blade of the oar starts making an elliptical form through this, with the blade pressing against the water when you move 'along' the eight and slicing through the water when you turn the 'corners' of your figure eight.
Sorry for the rather vague description, but it's the best I can come up with at the moment
I've been doing sweep oar rowing and sculling for years... It's something that anyone can do, but few can master. The blade (the oar) moves in a roughly ellpitical track in the water, over a very small range, as the boat is propelled forwards. The range of motion is dependant upon the skill of the oarsman, and how he/she appiles pressure to the stroke. Too much too soon, and you 'rip', causing turbulence, and allowing the blade to move excessively through the water... Too little, and the blade won't lock onto the water, and will just float through the water... Of course, this is neglecting balance etc., which is no mean feat in a boat some 5 inches wide at the waterline!
A few of my colleagues have been looking into the effects of surface tension in various liquids and you'll be amazed to learn what you can do if you have the right circumstances.
H20 doesn't have that much surface tension becuase of its low valency, but other liquids such as bromine are held together by strong Van der Waals attractions meaning that they have much stronger surface tensions. In one famous experiment at MIT researches showed just how strong the surface tension could be by placing a cat onto a large pool of bromine and observing that not only did it not sink but that it could also move abount (albeit with difficulty). Some people have suggested (tongue in cheek) that if Jesus could have introduced bromine into the red sea then that would explain how he could have walked on water.
All that glitters has a high refractive index.
They move because they put their faith in jesus and he spirits them along over the water on the wings of christ.
Damn dude, it said the CHRISTIAN science monitor.
You remember.. the people who don't believe in evolution? Or stem cell research? Or cloning?
That would certainly be most people's first impression, but I find that the CSM is probably the *most* objective reporting I've ever seen to date. There doesn't seem to be any particular bias that I can see. I'm glad I found the CSM, and I really enjoy reading it, even though I'm agnostic. I highly recommend everyone take a look with an open mind.
"I have never let my schooling interfere with my education." - Mark Twain
Go take a gander at the original BBC article with the photos. The one with the blue dye in the water showing the eddies created by the movement is practically a natural reproduction of Van Gogh's brushwork!
It's like having insects do impressionist painting. Truly beautiful. If I can find a high-res photo, I think I've got my new wallpaper.
Design for Use, not Construction!
Sometimes it takes a lot of scientific training to work out things country people have known for a long time - digitalis, willow bark, cowpox, and all those interesting rain-forest rmedies the drugs companies are "patenting".
Panurge has posted for the last time. Thanks for the positive moderations.
I should clarify. I do believe God is a being and not just a creator of forces. Larry Wall described it much better than I can in his answer to question #7 in his Slashdot interview. One part I'd like to modify or add to concerning Larry's statements. He makes the assertion that "God is good to people who really look for him." I agree with that statement, but it's necessary to define what "good" is. One of the problems about discussing an all-powerful God and anything his existence affects (which is everything) is that we are each "gods" in respect to how we view such words as 'good' and 'evil', and 'right' and 'wrong'.
:)
When it comes to right and wrong, good and evil, no matter what someone else believes, in the end, might is right. It may sounds kind of weird for a Christian to say that, but I think about it this way. To say something is wrong (or right) is an imposition of belief on nother people (who have their own definitions). You can only get away with this imposing your beliefs on others through two ways.
1. They can wilingly let you (for reasons known only to them) and accept your definitions OR
2. If you are strong/powerful enough you can make them follow your definition (punish them when they disobey/reward them when they don't).
So, I have a definition of good, you have a definition of good, everybody has a definition of good, the strong oppress the weak. But, if there is an all powerful God who is capable of imposing his views (read as "punish or reward") on others, then his definition of "good" wins. That's all I'll really say about that because I think Larry does a really 'good' job of explaining it.
You've probably noticed that I haven't really answered the question you asked yet. I will. I will try at least.
Some of what I've said so far is basically ground work (if I've made sense)
Here's the question I'm trying to answer.
How is your view different from a non-religious one? It sounds as though you're saying that God put into place the workings of this universe. That being the case, doesn't that simply shift driving curiosity of science from discovering minute details of the universe to the makings of the creators? In essence, is that proof not simply a semantical argument defining nature as God?
Yes, I believe that science is basically discovering observable attributes of the forces God has instituted. But I don't believe that God is just nature. I don't believe that he's just a force.
Where my views differ from a non-religious one is that once God's existence is acknowledged, it changes the realm of the possible. Most of science does not acknowledge God, or if they do, they use him only to create the framework, but his involvement ends there. I truly believe that God is a being who wishes to have a relationship with man. I believe that Jesus Christ is the Son of God.
I don't have more time to write. I hope I answered your question. (And I do realize that I'm not instructing you, but merely relaying what I believe to be true) If I haven't aswered satisfactorily, ask again, or email me. I'd be glad to carry on the discussion, with you or anyone.
Take care,
Charles
--
Was it the sheep climbing onto the altar, or the cattle lowing to be slain,
or the Son of God hanging dead and bloodied on a cross that told me this was a world condemned, but loved and bought with blood.