27 JUL 2018 by ideonexus
Norman Borlaug, Giga-Lifesaver
In the 1950s and ’60s, another giga-lifesaver, Norman Borlaug, outsmarted evolution to foment the Green Revolution in the developing world.21 Plants in nature invest a lot of energy and nutrients in woody stalks that raise their leaves and blossoms above the shade of neighboring weeds and of each other. Like fans at a rock concert, everyone stands up, but no one gets a better view. That’s the way evolution works: it myopically selects for individual advantage, not the greater good of the ...02 SEP 2016 by ideonexus
Math Exercise: Comparisons
Select two boxes or cans of food that weigh 8 ounces and 16 ounces, respectively. Have students hold each as you tell them (or they read) the weights of the containers. Give students a box or can with the weight covered and have them compare the weight of the new package to the weight of the 8- and 16-ounce samples. Th ey can then estimate whether the new item’s weight is closer to 8 or 16 ounces. As students become more successful, they may want to predict a more specifi c weight. Ask them...01 MAR 2016 by ideonexus
Economic Principles for Students
Here are some examples of the principles that teachers can use to expand concepts presented in formal course material. These principles don't have to be taught in the context of any particular class. It's an empirical question. This is a comment that ought to terminate many more conversations than it does. For many of the questions and issues we discuss, there is an answer available. Look it up and see. There's no point in discussing the merits of taking multivitamins when there are several ...29 OCT 2014 by ideonexus
Astronomy affords the most extensive example of the conne...
Astronomy affords the most extensive example of the connection of physical sciences. In it are combined the sciences of number and quantity, or rest and motion. In it we perceive the operation of a force which is mixed up with everything that exists in the heavens or on earth; which pervades every atom, rules the motion of animate and inanimate beings, and is a sensible in the descent of the rain-drop as in the falls of Niagara; in the weight of the air, as in the periods of the moon.23 OCT 2013 by ideonexus
Proof that Objects Fall at the Same Rate
Salv. But, even without further experiment, it is possible to prove clearly, by means of a short and conclusive argument, that a heavier body does not move more rapidly than a lighter one provided both bodies are of the same material and in short such as those mentioned by Aristotle. But tell me, Simplicio, whether you admit that each falling body acquires a definite speed fixed by nature, a velocity which cannot be increased or diminished except by the use of force [violenza] or resistance....Galileo's proof is based completely on a thought-experiment, no observation necessary.
23 JUN 2013 by ideonexus
Why You Lose Weight While You Sleep
Here's a simple question: Why do you weigh more when you go to sleep than when you wake up? Because you do... You can check this yourself. Somehow, while doing absolutely nothing all night but sleep, you will wake up lighter. [...] All night long, every time you breathe out, a bunch of carbon atoms, formerly inside your body, leave your insides and take off into the night air. You breathe in oxygen, O2. You breathe out carbon dioxide, (two oxygen atoms with a carbon atom attached), so there...Over the course of the night, through respiration, you lose a pound of weight to the carbon atoms in Carbon Dioxide.
08 JUN 2012 by ideonexus
The Formation of Grains of Sand
On the basis of the results recorded in this review, it can be claimed that the average sand grain has taken many hundreds of millions of years to lose 10 per cent. of its weight by abrasion and become subangular. It is a platitude to point to the slowness of geological processes. But much depends on the way things are put. For it can also be said that a sand grain travelling on the bottom of a river loses 10 million molecules each time it rolls over on its side and that representation impres...Miraculous in numbers.
07 JUN 2012 by ideonexus
Reason Comes After a Plan
When Galileo caused balls, the weights of which he had himself previously determined, to roll down an inclined plane; when Torricelli made the air carry a weight which he had calculated beforehand to be equal to that of a definite volume of water; or in more recent times, when Stahl changed metal into lime, and lime back into metal, by withdrawing something and then restoring it, a light broke upon all students of nature. They learned that reason has insight only into that which it produces a...Folksonomies: experimentation
Folksonomies: experimentation
There must be experiments to guide reason, without which reason will make up it's own explanations.
30 JAN 2012 by ideonexus
Trees are Made of Air
By blending water and minerals from below with sunlight and CO2 from above, green plants link the earth to the sky. We tend to believe that plants grow out of the soil, but in fact most of their substance comes from the air. The bulk of the cellulose and the other organic compounds produced through photosynthesis consists of heavy carbon and oxygen atoms, which plants take directly from the air in the form of CO2. Thus the weight of a wooden log comes almost entirely from the air. When we bur...Sounds much like the Richard Feynman quote.
12 JAN 2012 by ideonexus
The Universe is a Machine for Making Gods
Mankind lies groaning, half-crushed beneath the weight of its own progress. Men do not sufficiently realize that their future is in their own hands. Theirs is the task of determining first of all whether they want to go on living or not. Theirs the responsibility, then, for deciding if they want merely to live, or intend to make just the extra effort required for fulfilling, even on their refractory planet, the essential function of the universe, which is a machine for the making of gods.And we realize this when we realize we have the power of our future.