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ZO RELAXEN UND WATSCHEN DER BLINKENLICHTEN.

I pointed to some blinking Christmas lights and told a couple of kids in our coderdojo that there is software code in those lights. 15 years ago most blinking Christmas lights relied on a bulb filament's heat bending a bimetal contact away from a fixed contact or an analog oscillator. Now it's cheaper, more reliable, efficient and flexible to use microcontrollers and LEDs whose flickering might not be entirely random.

Why not a hydrogen/helium mixture? Everyone seems to be treating this as either/or proposition when it doesn't need to be. For example, helium is a neutral gas, so wouldn't it serve to reduce the flammability of hydrogen?

One immediate problem I can think of would be separation of the gases in to layers, meaning an inconsistent mix. If that's a problem - and I'm not sure that it is - it could be tackled by limiting the height of the gas cells: just make them thinner and flatter. A simple fan could also keep the gas moving if necessary to prevent stratification.

I found an old posting that seems to indicate that you could only have up to 8.7% hydrogen for the mixture to be safe, and that's not enough to make a difference (since the lifting power of hydrogen isn't that much better than helium's. A mix with more hydrogen might then be better classed as "less flammable", rather than setting up an expectation that the gas be totally non-flammable. If some helium can "tame" hydrogen a bit, I think that would be worth pursuing.

I believe you mean 662. Ray Bradbury didn't have the Internet; we do.

This source estimates the number of atoms as 4*10^79, which is between 2^264 and 2^265, which is negligible compared to 2^16384. Even if the estimate should be a few dozen orders of magnitudes wrong, it still wouldn't come anywhere near.

It's a terribly small amount - a few mm a year due to friction and added mass due to debris being picked up by our atmosphere.

http://www.madsci.org/posts/archives/2006-07/1152815859.As.r.html
This is the relevant calculation/formulas. You also have to calculate in the Earth's albedo. Currently it is at ~0.367(that page is slightly off as human structures and pollution also contribute some), but with the ice caps melted, it will be ~0.13(that page is also slightly off because such high heat would also melt ice in glaciers and high altitudes as well). If we set a maximum to the upper limit of 328K instead of 373K (because we're talking about human life and 55C is pretty much the limit of what we can tolerate - 100C is a silly limit, it should be changed to 55C), the inner edge of the "habitable zone" relative to life on Earth for *Humans* is fairly close to our current orbit. We're really "this" close to a greenhouse scenario and most people don't get how something as large and as permanent in their minds, as the Earth is, can be turned into an unlivable mess in a very short time. Even if it's not immediate, it will mean that most of the equator regions will become deserts and too hot to support any sort of stable ecosystem. This means we could see the equatorial rain forests simply vanishing in a few million years(if we don't cut them down first, though that does increase albedo). Oxygen levels drop as well as UV radiation increasing due to our messing with ozone levels, resulting in us having to live underground or in domed cities. We simply are absorbing more energy that we are reflecting back into space at that point. This might not even take 1 million years with human activity added to the equation.

IMO, the only way that we can solve this is to build an artificial ring to block roughly 1-2% of the sun's energy. Everything else just isn't going to solve the issue of the sun getting hotter and the albedo changing. Nothing we do will matter if we can't make less energy hit the surface once the ice caps melt.

So how do you think normal driving for truck looks like ? In europe it is highway driving at constant speed, more or less constant load for hundreds miles.

To avoid each person having a different metric, we use standardized drivecycles. The drivecycle that the EU uses to model how people typically drive for vehicle mpg ratings is called the NEDC -- the New European Drive Cycle. It is a combination of urban and highway driving that approximates typical european driving patterns (which, by the way, are lower energy than typical US driving patterns -- hence the US uses FTP75 (city) and US06 (hwy), which are higher energy, and correspondingly leads to lower MPG figures for the same car in the US). You can see the NEDC here.

If you want to talk about pure highway driving, even that is not constant speed. Speed on the highway varies based on traffic density, random factors (passing, being passed, etc), current weather conditions, stops (gas, rest, etc), start and end accel/decel, exits (to surface streets or other highways), and driver randomness. Beyond speed, energy consumption varies based on weather and especially altitude changes. For an example, here are actual measurements taken from a vehicle in the US. Here's a test drive that starts with city and progresses to intra-urban freeway. Your mileage may vary.

(I have my own drive data recordings, but I am not at liberty to disclose them, so I'm linking to publicly available ones)

Highway driving runs an engine much more efficiently than city driving. You're closer to the peak efficiency (although not at it), you brake less, idling is basically eliminated, etc. Now, there's obviously a big downside -- your aero drag is *way* higher, and your rolling drag slightly higher (yes). In non-hybrid vehicles, the upsides outweigh the downsides (sometimes significantly). In hybrid vehicles, the downsides usually outweigh the upsides.

No this is not from wiki. It is from book called "Automobile fuels" (translated)

Right. Which is why I said, "If you had cited ... you would have..." instead of "You cited... you did." Understand? I'm pointing out that different sources give different numbers because there is no single correct number because they're not a single chemical mixture. You've picked one source to latch onto, when there *is no single answer*. Check other sources; you'll see what I mean. Mixtures vary from location to location and even day to day (for example, summer versus winter blends). They even change from year to year, as standards and refineries are always changing. Their energy densities vary, too. But overall, the *current global average* is about 15% denser for diesel than gasoline.

I don't know how many times I need to stress this, but let me do so once more: There Is No Single Fuel Called Gasoline Or A Single Fuel Called Diesel. How about this -- how about I cite a bunch of random sources?

Simetric: 820-950kg/m^3
Alan Harvey, National Institutes of Standards and Technology: 850kg/m^3 typical, but 825-890.
Engineering Toolbox: 810-960kg/m^3
MSDS: 810-880kg/m^3

Gasoline:
MSDS: 710-770 kg/m^3
Simetric: 737kg/m^3
Engineering Toolbox: 680-740kg/m^3

basically you do this: http://www.madsci.org/posts/archives/1999-07/932591567.Ag.r.html with castor beans instead of soy beans...

"We are transparent to radio waves..."

The human body is mostly water mixed with salt, which is conductive and therefore opaque to radio waves.

I agree with you. The total amount of energy is tiny, especially when tiny antennas are used.

I think we can all agree that an airship working directly over enemy territory would be terribly vulnerable. Presumably, the ISIS would operate well behind a safety cordon of fighters the same way AWACS and JSTARS planes do.

I assume that the reason the DoD is exploring this option is the operational difficulty in maintaining multiple shifts of AWACS + JSTARS in a warzone. The airship, on the other hand, would be able to maintain its station for days on end, without the need for refueling or returning to base for a new crew.

However, a stickier problem emerges - would it be able to stay on station? According to this site: http://www.madsci.org/posts/archives/1999-09/938402041.Es.r.html, winds in the stratosphere are around 100mph. Would solar-powered engines be able to keep the airship in the same place in the sky?

Karma whoring linky here.

This is one of those old science experiments that you would see on children's TV. It is very easy to test, all you need is a nail, a hammer and a magnet.

If this estimate is anywhere near true and your diesel rig gets about 30 mpg and the good Mr. Ballmer is a hefty 225 pounds, then about 180 miles.

A typical raindrop has a fall velocity of about 8 m/s. Assuming a pretty healthy rainfall of 10cm (4 inches) we get 100 liters of water per square meter of land. 100 liters of water weighs 100kg, of course, and plugging that into the equation for kinetic energy gives us 6400 joules. Spread out over 2 hours, that's a whopping .89 watts per square meter.

All of that assumes 100% conversion efficiency and no losses due to standing water absorbing the impact of the drops. If the overall efficiency is, say, 50%, then you'd need something like 30 square meters to light a single compact fluorescent bulb. To generate a megawatt would require over 2 million square meters (over 500 acres).

Given that in most places it rains less often than the sun shines, this seems like an astonishingly inefficient way to generate electricity. There just isn't that much energy in rainfall.

http://www.madsci.org/posts/archives/2001-04/987003940.Ph.r.html

Ah, I see he cites that famous source, "a psychological study."

Here's something slightly more specific, with some references.

http://www.madsci.org/posts/archives/1997-03/858984531.Ns.r.html

Possibly, highschool physics has led people astray before =)
http://www.google.co.nz/search?num=100&hl=en&safe=off&q=%22resonant+frequency+of+water%22&meta=

http://www.physicsforums.com/archive/index.php/t-94766.html
"the microwave oven waves are 2450 MHz, and water has a dipole moment (negative on oxygen, slightly positive on hydrogen side), and when exposed to this electric field the water molecule tries to move to that field, but bumps into another water molecule, thus creating heat. This is not the resonant frequency of water, and the peak absorption of waves decreases as the temperature goes up because of the dielectric properties of water."

But on the other hand...
http://www.madsci.org/posts/archives/2004-11/1100632107.Ph.r.html
"The natural frequency of water is a bit more complicated, because it takes into account the mass of water molecules, the attraction between molecules, the distance between molecules, and some other stuff. Suffice it to say that most microwave ovens put out a frequency of 2.5 gigahertz. ... This isn't the lowest (also known as "primary") resonant frequency for water, but microwave manufacturers use 2.5 GHz because they want the microwave to work at any and all water temperatures. There's lots more techno-babble about resonance, matching, and the engineering of microwaves, but that'll have to be a separate question."

Perhaps what you are trying to say is that it is not the fundemental frequency, but a harmonic =). Either way. 2.5GHz is still *a* resonant frequency of water?

OK, but it is far more efficient as catalase (I mispelled it originally), than in simple solution. See http://www.madsci.org/posts/archives/2000-02/950039812.Bc.r.html

While this at first seems like an interesting challenge, a little math will reveal the futility of it:

Even assuming only a 640x480x256 monitor, you are talking about 307200 pixels -- each of which can have 256 different colors (definately not the photo realism you are looking for).

307200 ^ 256 = 6.023 x 10 ^ 1404

This number is by a wide margin larger than the estimated number of atoms in the known universe.
(4x10^79 according to http://www.madsci.org/posts/archives/oct98/905633072.As.r.html).

Details here : http://www.madsci.org/posts/archives/aug98/9034626 75.Es.r.html

Chromosome count mutations are fairly well understood, and are separate from the genetic mutations they're talking about here.

Your argument has been covered at talk.origins (the standard site for checking background on evolutionary "counter"-arguments.)

Please, find the time to have pride in yourself and humility in your opinions: Be proud enough to not express an opinion until you have checked it, and be humble enough to accept that the sum total of people that work in a field, having deep knowledge of it, have a large chance of having thought about the same things as you - and possibly thought better. Then, when you find a case where they haven't, even when you've checked, you can make a real contribution :)

Eivind.

They have 6000 thousand finger? I knew inbreeding was a problem, but seriously.

http://www.madsci.org/posts/archives/mar97/8589845 31.Ns.r.html

"The upside-down glasses that you describe were first investigated by George Stratton in the 1890s. Since the image that the retina of our eye sees is inverted, he wanted to explore the effect of presenting the retina an upright image. He reported several experiments with a lens system that inverted images both vertically and horizontally. He initially wore the glasses over both eyes but found it too stressful, so he decided to wear a special reversing telescope over one eye and keep the other one covered.

"In his first experiment, he wore the reversing telescope for twenty-one hours. However, his world only occasionally looked normal so he ran another experiment where he wore it for eight days in a row. On the fourth day, things seemed to be upright rather than inverted. On the fifth day, he was able to walk around his house fairly normally but he found that if he looked at objects very carefully, they again seemed to be inverted. On the whole, Stratton reported that his environment never really felt normal especially his body parts, although it was difficult to describe exactly how he felt. He also found that after removing the reversing lenses, it took several hours for his vision to return to normal."

The link has references to the source material.

"We are so close to Chimpanzee's that a human/ape hybrid is possible without the help of genetic manipulation,"

No. That's not possible.

If you eat your cake, do you still have it?

Rough comparison here. Short answer: DNA is far more dense information storage than this technology. Never mind that human white blood cells also contain the machinery to both compute and replicate data stored within DNA (as well as replicating the computation machinery).

Biology still wins. But nanotechnology creeps ever closer year by year...

The Water Wiggle was a toy which would attach to the end of a garden hose, and jet the water out of a plastic hood looking thing in such a manner as to chaotically fly around the lawn. Responsible for at least one death according to this page.

I am not old enough to have experienced this thing myself, but have heard horror stories both from my parents and a and the mother of a friend of mine. She actually knew someone who was seriously messed up by one when she was growing up. Surprising it wasn't mentioned in this particular article.

Answer. Enjoy!

One benefit to this would be that it doesn't dump 3.5 million pounds of burned fuel into the atmosphere, although apparently that's not much of a problem since the waste byproducs seem to be pretty innocuous.

When you say the idea is laughtable, you're understandable from your perspective. Alas, again, this perspective is missing a point: The simulation occurs at a much higher level. We look at what kind of variation occurs, in nature, at the cellular level, from individual to individual inside a sexually reproducing species. Then we simulate this level of difference accumulating through reproduction and natural selection. You're continually missing natural selection in your arguments - and natural selection is KEY. It's ABSOLUTELY crucial. You can almost ignore mutations - they're fairly much irrelevant. It's natural selection you have to understand.

As for mutations, WE KNOW THEY OCCUR. We've seen what happens in nature. Genetically identical mice start breeding apart, with measurable differences of the kind necessary for natural selection, inside 3-4 generations. Different proportions of legs, slight overall size difference, that kind of things.

When it comes to chromozome counts, this is covered here. I feel you're fairly arrogant when you're attacking something that is generally accepted without doing a trivial Google search to see how your extremely obvious counterarguments are handled. Scientists think of these kind of problems THEMSELVES. Attacking scientific theories/hypotheses is the primary hobby (nay, job) of scientists. They're happy about it.

Just yesterday, I sent an email attacking the hypothesis of an UCLA professor for mortality rates in married vs unmarried people. This was basically shooting down the conclusions he'd drawn in a paper he'd published. The response I got from him was "Very interesting explanation! Thanks!"

And yes, evolution IS about minor changes to properties. Evolution is effectively ONLY about minor changes to properties, stacked on top of each other one after each other, for billions of years. Do you get that number? If you took the whole evolutionary timeline and put it between your outstretched arms, the whole of human history would be gone with a single brush of a nail file. Easily.

The minor, minor changes to properties is introduced by mutations.

Also, "Most mutations are neutral" is generally accepted. It is the basis for the molecular clock. I can ask my girl, of course, but she'd probably just laught at you ;)

Eivind.

This is a very good question. there are lots of differences between
animal & plant DNA, but what they are depends on at what you are looking.
Chemically, plant, human, animal, bacteria, fungi, and even many viruses
have identical DNA. DNA is composed of a backbone made from deoxyribose
(A sugar) and phosphate. The individual base pairs that encode the
genetic information are adenine, guanine, cytosine, and thymine (AGCT). A
base pairs with T, and G base pairs with C, which defines specificity for
DNA, and allows one strand to direct the replication of an exact
complementary strand, so an organism can make another set of DNA and
divide/reproduce. This was elegently demonstrated by Meselson & Stahl, a
observation for which they recieved a Nobel Prize, and it agreed perfectly
with the Watson & Crick model of DNA.
          So, in many ways, structurally, chemically, and in the nature of
reproduction/synthesis, plant DNA and animal DNA are very similar, if not
identical. So much so, that when we place genes from plants and animals
inside of bacteria, they will often follow those instructions and produce
a foreign protein instead. This is how human insulin for the treatment of
diabetes is produced in a bacteria.
          The main difference between plant and animal DNA is in the
organization of genes and the size of the total genome, or how many base
pairs of DNA the organism has. As a rule, plants tend to have much larger
genomes than their animal counterparts, and they have a lerger portion of
garbage and intron DNA. Very few genes are present in this DNA, and it
tends to contain regions that are spliced out, or perhaps serve a
structural role in the shape, packing, and placement of the genome.
          In terms of size for example, the human genome contains about 3-4
billion base pairs of DNA, whereas corn or maize, is perhaps a less
complex organism contains a similar number of base pairs. Some pine trees
and lilly plants contain 10-100 times as much DNA as a human, most of
which does not appear to encode any genes.
          The manner in which DNA is chemically modified in the cell is
different in plants and animals. Although many of the same modifications
occur in both plants and animals, such as adding methyl (CH3) groups to
the DNA, occurs under different circumstances or for different reasons.
          I hope this is helpful to you for your project. Let us know if there
is anything else we can answer for you. Thanks.

-Matt Champion-

>>...These atoms might even be destroyed, and new ones created later.

I think we can reasonably neglect nuclear processes.

>>...I actually find it extremely unlikely that most human beings end up sharing oxygen with each other in a short period of time...

What you don't see is the effect of the sheer number of atoms in a breath. 1 mole of molecules in a liter of air. A mole is 6 x 10^23 molecules. The volume of the atmosphere is 7 x 10^23 liters ( http://www.madsci.org/posts/archives/nov99/9432887 49.Es.r.html ). So roughly 1 liter of air, when distributed evenly throughout earth's atmosphere, will be enough to put 1 molecule/liter throuout the atmosphere. So the question becomes how long does a liter of air takke to diffuse through the atmosphere.

You misunderstand basic physics.

http://www.madsci.org/posts/archives/feb98/8870610 65.Ph.r.html

Yeah, Zero G can be a boon and a bane, it has positive and negative aspects.

I think building a spacedock at La Grange point L1 is the best idea, and a moonbase to get most of the materials for the spacedock, and intrastellar craft.

Also satellites built and launched from the spacedock/moonbase would have a lower cost to put in high earth geosynch orbit.

Although Stratallites are probably and even cheaper and easier to maintain scenario vs. satellites. http://www.21stcenturyairships.com/AirshipFAQ

I would consider putting most of the moonbase far underground as it would give it some defense against meteor/asteroid impact and most radiation.

o2 could be acquired from lunar soil as part of the helium-3 mining process, saving hauling it to orbit.

Storing the fuel would be best done in multiple cylinders/containers so if you have failure it does not compromise your entire fuel supply, ie. redundancy.

Meteorite impacts on a fuel cylinder would be very bad, and some kind or defense protection against this would be needed .

A deflection system or decceleration system, like armor or layered airbags or combination of both. Layered airbags to slow it some, armor to deal with remaining inertia.

Multiple fueling stations intead of one to avoid the single point of failure scenario.

Like 8 arms on a spider coming out from the central hub of the spacedock.

Integrate with the spacedock on the outer reaches of something similar to piers like ships dock with on earth. Long tunnels connecting to the main spacedock, and if there is an accident at worst the tunnel and fuel pod is lost vs. the entire station. Multiple airlocks in tunnel protect the spacedock from most explosions.

The fuel pods could be attached on the end of the tunnel offset from where it would connect to the door of the docking crafts.

Ships could be brought inside the spacedock as well, but it would be preferred they leave their explosive fuel outside the spacedock in the independent fuel pods.

Getting water up into space could be done by magnetic coil launcher mass drivers tossing canisters of it into low orbit, and then have some kind of craft ferry it from low orbit to the la grange points near the moon wear the spacedock would have a long term stable orbit .

Water could be split into hydrogen and oxygen via electrolysis or other methods such as the extreme heat method recently discovered.

http://en.wikipedia.org/wiki/Hydrogen_economy#High -temperature_electrolysis_.28HTC.29

A passive parabolic reflector on the moon or in space could achieve extreme heat at its focal point, and high temperature on the moon reaches over 120 celsius.

With a focused reflector temperatures much higher than achieved at the solar collector in france could be achieved.

http://www.madsci.org/posts/archives/2004-07/10908 57033.Ph.r.html

With power near 12 million watts per cu cm inside the earth's atmosphere, it would be impressive what could be achieved outside it.

The moon would most likely be the easier place to build the series of reflecting mirrors and the tracking control system could be mostly underground to shield it from surface impacts.

With virtually unlimited solar power to process lunar soil and water sent their via mass drivers from earth, it would be a safe underground compartmentalized and redundant facility if built that way.

Ex-MislTech

Your premise that a pixel is not visible using a 3840x2400 in 24" monitor is not correct. The average human eye can resolve close to 343 pixels per inch at a throw distance of 10 inches. The monitor you speak of is at best 160 pixels per inch (3840/24), which is not even half the maximum resolution that the eye can appreciate.

The 343 dpi number is based on data from:
http://www.madsci.org/posts/archives/may97/8644462 41.Ph.r.html [madsci.org]

The artificiality of a temperature read from a pure substance is nothing really compared to the inaccuracy and value-fudging the Farenheit scale needed to get those "landmarks" in place.

http://www.madsci.org/posts/archives/nov99/9418367 17.Zo.r.html

To a scientist, a "theory" is a hypothesis that has survivied experimental tests sufficiently to be adopted, employed and taught by the scientific community.

A very common misconception. This discussion makes the following interesting points:

Laws are generalizations about what has happened, from which we can generalize about what we expect to happen. They pertain to observational data. The ability of the ancients to predict eclipses had nothing to do with whether they knew just how they happened; they had a law but not a theory.

Theories are explanations of observations (or of laws). The fact that we have a pretty good understanding of how stars explode doesn't necessarily mean we could predict the next supernova; we have a theory but not a law.

Gravity, it says, is an example of a well-established law for which no really satisfying theory is available.

This issue is also dealt with in William McComus' Ten Myths of Science, Myth #1 being "Hypotheses Become Theories Which Become Laws".

Of course there is a relationship between laws and theories, but one simply does not become the other--no matter how much empirical evidence is amassed. Laws are generalizations, principles or patterns in nature and theories are the explanations of those generalizations.

In the evolution debate, evolution (species evolve over time) would be the law and natural selection would be theory that explains how it works.

Yes they would. Blue/green lasers are used for underwater communications and detection.

billy - I never underestimate the stupidity of our government

sure the desert is cold at night but you're not going to make some thing colder than the air around it

Actually air is a pretty good insulator. It has relatively low thermal conductivity, that's why we need blankets, to reflect the heat back at our bodies at night. generally speaking, water by it's own will radiate it's own heat into space, and cool off below the temperature of the air. My aunt and uncle had a pool, one summer night the temp got down to 60 and someone forgot to put the pool cover on, and by morning the pool temp was down to about 40F that was just from the radiant/evaporate effect of standing water.

so yeah, having a container and array designed to allow even more heat to radiate away, would allow ice to form anywhere where the temp gets to 60F on a clear summer night the bags they used for that probably would have been unnecesary, although they would help prevent convection warming from the 'cold air' becomming heavier and dropping from around the jar and creating a current.

http://www.madsci.org/posts/archives/jan2000/94898 5221.Ph.r.html

The Romans used to make ice in the deserts of Palestine and North Africa. It seems to me they were around before electricity and Frigidaire.

http://www.madsci.org/posts/archives/nov99/9417235 40.Sh.r.html

Of course, the large temperature difference between the day and night in the desert it what drives it. That method probably won't work in tropical climates.

  -Charles

"Species" is an abstraction. Abstractions leak. Consider the sexual crossing of genes, the non-uniform application of environmental pressures across a population, the importation of new DNA via cross-breeding/microevolution, the occasional mutation... with the various forces of differentiation at work, it's hard to imagine how a species could keep itself together unchanged for the long haul. The miracle of life is not that species split apart but that their individuals members are--for a time--able to spawn new members despite everybody having different DNA.

If you have difficulty relating to this, look at human languages. They work in mostly the same way... if, for instance, you were to geographically isolate two groups of English speakers for several centuries, you would likely get two child languages that were mutually unintelligible.

You may find this post to be more applicable to your original question. Also, I am not a geneticist, but I believe that you are overestimating the role of mutations in driving change.

I googled for this, it may not be science but I'm sure the source is credible:

http://www.madsci.org/posts/archives/dec97/8774397 99.Es.r.html

So I think the fact that it is a naturally occuring phenomenon should necessitate that we don't try and "fix" it. As the old saying goes, if it aint broke...

Scientifically, an embryo is, strictly speaking "human life"

Ever heard of "HeLa cells"? A woman named Henrietta Lacks died of cervical cancer in the 1950s, but her cancer cells have been cultured ever since. They are, strictly speaking, "human life"—they are genetically human, and they are indisputably alive—but it's hard for me to imagine what ethically significant distinction could be made between HeLa cells and any single-celled organism—say, Escherichia coli.

so, when and why is it ok to end such life, regardless of the state it may be in?

I find it difficult to understand why genetic "humanness" should be ethically relevant; embryos are no more able to feel pain, or fear, or to regret their deaths, than are HeLa cells, or stem cells, or the millions of skin cells I shed each day. Embryos do have the potential to develop into walking, conscious humans—but, with advances in cloning technology, so will every cell in my body (save erythrocytes and sperm).

Why should we not examine the important ethical questions?

Certainly we should. But to imagine that it is human molecules rather than human consciousness that define humanness is to engage in magical thinking, not ethical reasoning.

Speaking of which—

The ethical considerations are important: should we also clone humans?

Assuming the problem of telomere damage is dealt with, human clones will be equivalent to time-delayed twins (natural clones), so the question "should we clone humans?" is essentially equivalent to the question, "should we have children?". If we are [creating clones/having kids] to harvest their organs, or to "replace" dead children, then there are certainly ethical questions to answer. But cloning, per se, is not the primary issue. The ethical questions that relate to cloning as such derive from the unknown health consequences—clones may be prone to cancer and premature ageing. But substantially the same ethical concerns apply to any medical experimentation involving reproduction or children.

There's a simple example of E = MC^2:

Burn something. Thanks to the Law of Conservation of Energy -- a special case of relativity -- the total energy of the system remains constant, even though some mass was converted to heat (energy)!

For example, if you burn a log, E(unburnt log) = E(released heat) + E(smoke and other released gasses) + E(charred remains of log). Every time you light a cigarette, you're converting mass to energy.

Similarly, the atomic bomb uses this same principal (but far more efficiently) to convert a very small mass of plutonium to a massive ammount of energy.

And hey, Energy being converted into matter!

According to an older explanation (photographers don't seem to jump on new technology very fast, so I imagine that's still reasonably accurate), 4"x5" film works out to about 24 megapixels. You can't magically add extra detail by running the prints through a hi-res scanner. By your logic, my little Sony digital is really 110MP, since I could make an 8"x10" print and scan it on my 1200DPI scanner.

Just one more...

This article is almost tailor made for you.

http://www.madsci.org/posts/archives/apr2000/95572 4300.Ev.r.html

Just to add to what others have said about that claim.

The human body is no where near 98% water.
"In adult men, about 60% of their bodies are water." - Jeffrey Utz, M.D., Neuroscience, pediatrics, Allegheny University (link)

Other sources: Boston Globe & Encarta

While we're on the subject, I might as well reply to myself and point out a selective advantage to multi-stage lifecycles, namely that the different stages do not compete with each other: they eat different food, and fill different evolutionary niches. This means that in times of scarcity there is little advantage in adults behaving like those of some non-metamorphising species, who will kill youngsters, as they are in direct competition with them for resources.

It is also very unlikely that full-blown metamorphosis arrived on the scene ex nilho. There is apparently ample evidence in the historical record for incomplete metamorphosis, via a 'nymph' stage.

You may find the following page interesting: "How did the process of metamorphosis evolve?".