Author Topic: Nature's Challenge  (Read 2494 times)

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Sister Marie

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Nature's Challenge
« on: August 25, 2006, 09:36:00 AM »
Plants teach big lessons about how to get going
By Robert C. Cowen

Engineers who want to design devices that move quickly should consult with plants. Our green friends have evolved in simple ways to make some of the fastest movements known in nature.
Take the Venus' flytrap. It snaps up its prey in a few tenths of a second. The title of "fastest plant on Earth," however, goes to the bunchberry dogwood. When launching its pollen, this tiny plant moves more than 100 times as fast as the flytrap.

A fresh look at such familiar but poorly understood phenomena would uncover a treasure trove of examples to fire a designer's imagination, says Harvard mechanical engineer Lakshminarayanan Mahadevan. In January, Professor Mahadevan and several colleagues published in Nature the first detailed description of how the Venus' flytrap snaps. It's a simple system based on hydrologic pressure and release of pent-up elastic energy.

When resting, the two leaves of the hinged trap bend outward in a concave shape. The trap is open to admit unsuspecting insects. When an intruding fly trips trigger hairs inside the trap, movement of fluid within leaf cells builds up elastic strains in the leaf. When the leaves can no longer sustain the strains, they snap into their other stable shape, curving inward to form a concave enclosure. Voilá! A trapped insect and a tasty meal.

The system is a little like the pressure indicator on the lid of a jar of jam. As the jar is being sealed, the metal indicator is popped upward. But as the jar cools, internal pressure drops and the elastic strain in the top changes. At some point, the top snaps into its other stable position, inward, and stays that way until you open the jar and break the seal.

Canadian bunchberry dogwood is even trickier. Joan Edwards at Williams College in Williamstown, Mass., and colleagues have shown it to be the fastest-moving plant on the planet. It opens its petals and releases pollen in a few thousandths of a second. Their report last month in Nature explains that this action also involves hydrological and elastic forces with a twist: Its pollen launcher works like a trebuchet. That's a medieval catapult that carries its payload in a sling attached to the top of the catapult's arm. This design gives extra oomph to the missile tossed by the trebuchet.

Thanks to a similar scientific principle, the bunchberry's stamen tosses pollen grains 10 times as high as a tiny flower can. Internal hydrological pressures prepare the mechanical energy needed to open the flower petals explosively. It is the release of elastic energy that lofts the pollen.

Botanical engineers still have a lot to learn about the details of these and other rapid plant actions. They are making progress. Mahadevan and Jan Skotheim at the University of Cambridge in England have derived mathematical descriptions for hydraulically driven and elastically assisted plant motions. They explained last month in Science how the size of a plant - or plant part - determines when rapid motion needs an assist.

Whereas smaller plants can change their shape readily, larger plants, such as the Venus' flytrap, must rely on buckling or on the rapid release of stresses caused by internal fluids to snap shut.

The two scientists say their work provides a physical basis for classifying the hydrodynamics involved in plant motion. It also shows the limits on what speeds such motion can attain.

That's a helpful engineering guide. The challenge now for engineers is to use these processes in practical ways. As the two scientists note: "Nature has already implemented many such designs exquisitely; we simply need to follow her lead."
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So what about us as Christian's. If God can make the plants to move so fast.... with perfect movement.... is it not possible for Him to help us move faster, surer, stronger and with great faith and hope that will bring us to the end "In Him?" Can He not get us up and running for Him?

If the plants can do the job the Lord made them to do, then why can't we? Or are we still, too old, too tired, too uneducated, too busy to do the work He gives us to do?

What lessons in the plants are there for us?
Share them with us here.


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With Christian Love,
Sister Marie

[This message has been edited by Sister Glass (edited 08-25-2006).]

With Christian Love,
Marie

Sister Marie

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Nature's Challenge
« Reply #1 on: January 26, 2007, 07:48:00 PM »
Stay with me ...

One day , a boy waited that his dad return to home !
& he said :
Papa , can i ask you one question ?
He said : ask ?
The boy said : how much you get money if you work one hour ?
So the father got angry & he shout his son , that run away to his room crying ...
After that , the father felt that he is guilty , he entered to his son to ask him forgivness & to ask what he want from that ?
So the boy said : can u Papa give me 10 $.The dad said , i work for one hour to get 20 $ & you are asking me now to give 10 $ to you.
So the child started to cry again.
The dad , took 10 $ from his pocket & gave it to his son ...
Then the son took from his pocket 10 $ & added it to the dad 10 $.& gave them to his papa , saying :
Papa , those are 20 $ , can you stay with me one hour...  

Author Unknown
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From the mouth of babs
Comes tremendous need,
From the hearts of Children
Comes the caring seed
From need in a child
Where the heart does bleed.

How much real time do we spend with our children?

by,
M.D.Glass
1-26-07

[This message has been edited by Sister Glass (edited 01-26-2007).]

With Christian Love,
Marie

Richard Myers

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Nature's Challenge
« Reply #2 on: January 26, 2007, 08:21:00 PM »
Sad, very very sad! For many it is too late, but not for all. Thanks for sharing dear Sister Marie.
Jesus receives His reward when we reflect His character, the fruits of the Spirit......We deny Jesus His reward when we do not.