– How water striders demonstrate the bizarre phenomenon of gravity –
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The water striders are my delight. They are not spiders but insects. Their legs (and entire body) is covered with water repellent chemicals, which makes the water surface just bend around without wetting them. That way they can walk on water, making just these little temporary dents on the surface. Only the two front legs can actually penetrate the surface and reach below and grab things under water. It is the significant tension of the water surface that keeps the bugs suspended like bouncing on a trampoline.
This tension is actually the same mysterious force that holds the water molecules together.
And here’s just another little aspect:
This phenomenon of bending the water surface is in fact a nice example of warping a field and a great way to somehow visualize the so counter intuitive facts of what mass does to space in our universe: As the feet of these water striders bend the surface of water and cause an effect that compensates for its own mass, so, similarily, does our moon and our Earth warp space, which leads to what we call a force and named it gravity. Einstein once set the powerful paradigm in motion: The force we feel as gravity is just an illusion.
There is the crazy phenomenon that empty space – nothing – has actually a geometrical structure, that space can be curved. There is not really a “gravitational glue”, holding us to this earth (or the earth to the sun), (or the bug to the water). The only thing that keeps us stuck here on Earth is the bizarre geometry of space itself, something like the sagging of space. Gravity is a colossal common misconception. It can feel as if the ultimate rug is pulled under our feet when we try to accept it, but gravity is the wrong concept, only the unimaginable curving of space is real. Einstein taught us: mass bends space and causes the effect of gravity this way. Bodies with mass don’t attract each other, but they influence the space between them. Although we always say so, the Earth does not pull at the moon and force it to travel around her. Instead space in their vicinity and thereby between them is warped, deformed, distorted from its usual homogeneousness. I find that what the water striders do to water is a terrific way to visualize what mass does to space.
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I may have taken some bugs with me under water when I jumped into this pool, but I noticed, you can easily submerge them completely under water, they just plop up again, unharmed. The repellent keeps them dry and floating.
I get goose bumps just looking at it! We hear all the news of brutal winter conditions everywhere in the more northern hemisphere. In the US as well as in Europe. I should feel so ashamed to send around all these “warm” pictures and make you jealous. It is tough to stand watch down here in the warmth, but sorry, somebody has to do it!
Klaus Christmas 2008