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MichaeltheGreat
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Apolyton Grand Executioner
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mooning the house that Ruth built.
Oct 1999
time: 21:28
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I don't know if the ape strength vs. human strength question got answered completely, but Orange, UR, Ramo, were all on partly the right track.
It isn't just apes, AFAIK, humans on average have the worst power to weight ratio among vertebrates.
There are a huge number of reasons, most of which are evolutionary until the late industrial age.
The difference is a lot less distinct earlier in human history, where there are some spectacular feat of recorded strength and endurance. One example in the 1830's was a mountain man (forget the name) in Colorado, 5'4 inches tall and approximately 150 lbs, who was recorded snowshowing around 160 miles over 11 days while carrying 450 pounds of furs on his back. Not to mention the other stuff (axe, knives, musket, powder, lead, clothes) that must have been another 50-60 pounds).
In and around sites of the ancient Greeks, there are several stones that have been found with inscriptions to the effect that in whatever season it was, so-and-so, son of so-and-so, lifted the rock and carried it X distance. The rocks have weighed (there's three I'm aware of) between 854 pounds and 1046 pounds.
In the 14th century, Enguerrand de Coucy, seventh count of Soissons in France, hosted a banquet in which he personally served guests drinks from a tray balanced on the tip of a battle lance he carried horizontally in the normal position for mounted fighting. Taking some conservative guesses at the weight of the lance and tray and drinks, this would be equivalent to walking around doing a 300-400 pound bicep curl and stopping in the halfway up position, forearm horizontal.  The point was simple - a demonstration of fighting power, back in the days when when you had leaders, not commanders.
All of these represent both evolutionary and environmental factors. There is a definite favorable selection for strength when you have societies where the weak are at the mercy of the strong. There's also a definite augmentation of strength when an individual spends almost their entire life doing hard physical work, with no respite.
There are long-term evolutionary changes as well. Bipedalism, increasing height, and environmental diversification (different climates and higher mobility) have caused selection for relatively thinner bone structures and smaller bone caps on joints, leading to smaller and weaker tendon and ligament attachments to bones. The upper bound on human strength now isn't maximum muscle capability, it's connective tissue. Comparison of Neanderthal limb bones and vertebrae to those of modern humans (and Cro-Magnon, etc.) shows much more ape-like bone structure as far as the bone density, cross-section in relation to height, and size of bone caps. Grooving in the bones from the anchoring of connective tissue is also correspondingly longer and deeper. All of this indicates that Neanderthal were more apelike in strength. Recent finds also show they were likely prey animals for other hominids, who were smarter, more agile, better coordinated for tool and weapon use, and more cunning.
The evolution of the brain itself is a major limiting factor, as the brain evolved relatively rapidly, and required a larger percentage of blood flow and oxygen supply, thus limiting what was left over for the voluntary muscular system. Organs and involuntary muscles didn't evolve significantly, nor did the cardiovascular system, so the brain gets it's requirements directly at the expense of the voluntary muscles.
It's possible that evolutionary changes in muscle fiber have a significant factor, as the mixture of fast twitch v slow twitch muscle fibers in humans is (in most cases) much more mixed than those of other primates and higher mammals.
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Willem - hydrogen for fuel cells will need to be obtained from catalysis of hydrogen freeing reactions someplace local to the fuel cell, or as part of the fuel cell device itself. Methanol is commonly used in test applications. Large scale piping and handling of hydrogen is fundamentally impossible - it's too dangerous, too reactive, and due to it's low density and small molecular size, hydrogen leaks everywhere.
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Lincoln
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I always wondered why greens were so into recycling when it uses more energy to send a bunch of trucks around to pick up the trash and melt it down etc.. Is it just a cultural thing? Of course I am not talking about metal but thin plastic bags and all the other little things that really cannot be efficiently recycled (unless reused by the individual).
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Urban Ranger
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Apolyton Duke of Off-Topic
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Because if you don't recycle plastic, not only the landfills get clogged up, but you need digging for more oil to make plastic. Right now, plastic might not be very good to recycle, but that's because the total cost, which include everything such as manufacturing, disposal, environmental cost, and social impact, is not reflected by the price. If a person needs to pay for thousands if not millions of years of renting a spot in a landfill when he throws out a plastic bag, he probably would instantly root for recycling or even reuse.
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Lincoln
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I almost started a tire recycling business once. You can burn the tires and run the smoke through some type of catalytic filter and use the heat to make electricity and heat you home. But the cost is prohibitive. They are finding more and more that the solution to garbage (besides limiting packaging) is simply to burn it and use the heat for a useful purpose. But I am amazed at the several layers of packaging now in almost everything we use. It seems like the old fashioned barrells full of beans and rice etc. produced much less waste, especialy if you bring your own container to the store.
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Lincoln
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There is technology to burn them "cleanly" but what are you talking about?
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DAVOUT
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AUERSTADT
Jun 2002
time: 05:28
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quote:
Originally posted by Urban Ranger
Because if you don't recycle plastic, not only the landfills get clogged up, but you need digging for more oil to make plastic. Right now, plastic might not be very good to recycle, but that's because the total cost, which include everything such as manufacturing, disposal, environmental cost, and social impact, is not reflected by the price. If a person needs to pay for thousands if not millions of years of renting a spot in a landfill when he throws out a plastic bag, he probably would instantly root for recycling or even reuse. |
This is where capitalism and ecology should make peace : actual costs have to be paid by the end user.
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CyberGnu
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of the Virtual Serengeti
Apr 1999
time: 05:28
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quote:
How do adhesives work? What makes stuff sticky? What determines how strong a glue is? How does stuff like blutack/rubber cerment work? |
Adhesives can work chemically, physically or both. There are several different modes of adhesion: mechanical interlocking, covalent bonding, electrostatic interaction, adsorption, diffusion of polymer chains, weak boundry layers, and interphase regions. So how a particular adhesive bond is formed depends on the substrate, adhesive, surface preparation, environmental conditions and even the geometry of the bond.
But I'm guesing you are most interested in "sticky" adhesives, not glue or epoxy, right?
Sticky tape works through a combination of high viscosity and mechanical interlocking.
Mechanical interlocking is a pretty simple concept. You take two surfaces with plently of ridges and bumps, you pour some kind of liquid (the adhesive) between them, and when the liquid solidifies, all the ridges and bumps sort of anchor the surfaces to the adhesive.
The trick with sticky tape is that the liquid is very viscous, so it takes a long time for it to flow into position, unless you apply pressure to it. That's why you usually run your finger on the outside of the tape after you attached somthing, to press the liquid into place.
Does this make sense?
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SpencerH
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Co-Ruler of my patch of land south of Birmingham Alabama
Feb 2002
time: 23:28
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quote:
Originally posted by GePap
I will start:
why are humans so physically weak when compared to other apes? A 200 lb chimp or orangutan is much stronger than a 200 lb man (a fit, healthy one, even a muscle bound one)..so, again, why is this? |
I'm not sure that a 200lb chimp is stronger than a 200lb human. How would that have been tested?
I have heard many people comment on how strong monkeys are for their size. It is possible that monkeys and non-human apes have evolved with more fast-twitch muscle and with ligament/tendon attachments and flexibilities that give more strength than humans. I think, though, that the answer is mental/social rather than physical.
Factors governing the application of strength for both monkeys/apes and us will include learned reponses (ie if you grab a berry too hard you'll crush it to pulp) and fear of injury (ie nerve responses to stretched muscles and tendons). More importantly, humans also learn very early on from their parents to not apply their strength for various social/societal reasons. Thus, a monkey has less mental inhibition to exerting itself than we do, will exert a more substantial portion of its potential strength than we will (without training), and will seem very strong for its size. On the other hand, I doubt that a 200lb chimp could be trained to bench press 400lbs (as I can). Not because it isnt as physiologically strong, but because it isnt as mentally capable of pushing itself beyond its mental inhibitions against injury. In fact, overcoming the various mental inhibitions to exerting your strength is a big factor that separates experienced from inexperienced weightlifters.
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17-05-2003 20:44
Extremely polluting. Degalvanize 'em!
Were we trying to make H2 ?
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