In comments over at my PJM piece today, I find this:
I agreed with Rand’s article, except for this point:
“But every scientist worthy of the name should be a skeptic. Every theory should be subject to challenge on a scientific basis.”
It is true that every “theory” should be regarded skeptically if there is *cause* to do so (ie evidence for doubt). But not every idea about reality is still a theory. For instance, it is no longer a “theory” that the earth is round (rather than flat). That fact has now been established. The idea is no longer a theory, but is true. There is no basis for being skeptical – for doubting – this conclusion.
The question which gets ignored here is at what point does a theory become a truth? At what point does a conclusion go from being possible, to probable, to certain?
To suggest scientists must -always- be skeptical is to claim that certainty can never be reached – about anything. That is simply a false statement. That is not science. That is the acceptance and practice of a particular philosophy – Skepticism – which is something -quite- different from reason.
The actual problem here is that many people are treating an idea which is (at best) a flawed *hypothesis* as if it were not just a theory but an actual certainty – ie as if they somehow know it to be true. In other words, they hold their conclusion not based on the methodology of reason, but by means of faith.
I think there are some nomenclature issues here. There was a time that the notion that the earth was round (or flat) was a theory. There was no direct evidence either way. That is no longer the case not because the “round-earth” theory has been somehow refined, but because we have actually been able to see pictures of a round planet, from various angles. That the earth is round is a fact, not a theory (one of the reasons that Flat-Earth societies are a literal joke). Gravity, however, remains a theory that explains the physical behavior of every object in the universe (as far as we know). It will never become a fact. It will never be more than the best explanation, and something (in theory…) better could still come along. The same thing applies to evolution, which is the best theory (currently) that explains the facts (the fossil record and DNA relationships). Intelligent design is not a theory — it is a critique of a theory (evolution). But one doesn’t have to propose a better theory in order to shoot one down. If the climate data has been tampered with, it makes their theory suspect, regardless of any alternatives that the critics may have.
Sorry to throw out more nomenclature, but ant you being generous calling it a theory , AGW is a hypothesis at best. (Looks like the poster hinted at this too)
I agree, Engineer. I think the misuse of the word ‘theory’ vs. ‘hypothesis’ causes lots of problems, much of it intentional – ‘oh, it’s just a theory . . .’
It is worth keeping in mind that while it is fact that the Earth can’t be described as flat, we continue to refine our understanding of its true shape. So it depends on what you mean by skeptic. It is possible to question the best model for the shape of the Earth without being a flat-earther.
Isaac Asimov wrote one of his best essays on this subject. He started with the flat earth, which is fine for laying out wheat fields. Then the spherical earth, which was better if you’re traveling long distances. Then Newton predicted that the earth would bulge at the equator and be flattened at the poles, and a French expedition proved him right. Not a perfect sphere after all. And there are some additional random bulges that affect satellite orbits.
Asimov’s point is that even the best scientific theory isn’t Truth. It’s good to a certain level of precision. And his conclusion was, “But if you think they’re all wrong, and therefore the spherical earth is no better that the flat earth, you’re more wrong than all of them put together.”
Except proving the Earth wasn’t flat didn’t require seeing it from space. Proving the Earth wasn’t flat merely required sailing out of sight of land, then returning, and watching land “rise” out of the horizon. (Or standing on shore and watching the sailing ships appear, hull-down at first.)
Educated people during the Roman Republic not only knew that the Earth wasn’t flat, they had a good idea what its circumference was. Not perfect, but a useful level of knowledge.
By analogy, waiting to call global warming a fact would require seeing what the temperature and climate is like a century or two from now. Of course, by that time if we don’t like the climate we’re in a world of hurt.
Of course, by that time if we don’t like the climate we’re in a world of hurt.
Unless a bad climate isn’t that painful. Which I think is a likely scenario.
What I would like to know is if it’s ok to like really big cars again.
Proving the Earth wasn’t flat merely required sailing out of sight of land, then returning, and watching land “rise” out of the horizon. (Or standing on shore and watching the sailing ships appear, hull-down at first.
That was not proof at all — it was merely evidence. The fact that you don’t understand the difference makes us wonder why we even bother to discourse with you.
watching land “rise” out of the horizon
That can also be caused by refractive effects. In the arctic, it’s not unknown to be able to see land hundreds of miles away, because of the way the inversions keep the light hugging the ground. (See “Fata Morgana” mirage.)
Or check out the old Hal Clement book “Mission of Gravity”, where he describes how and why the inhabitants of Mesklin see their world as a bowl and not an oblate spheroid.
I believe you also need an instinct that the ocean surrounds the world, in some sense, like the Discworld, or like the Greek notion of the Stream of Ocean.
The obvious interpretation of the fact that sails disappear is indeed that gradual downslope of the ocean’s surface obscures them. But why assume that the ocean curves only down? Why not assume it curves up again, perhaps on some length scale too large to see? That is, after all, exactly what one’s experience on land would suggest. If you stand on a hill and someone walks down it, away from you, they disappear from view exactly as the sails of a ship do (from bottom to top). But you know at longer length scales than the hill, the land curves up again, and that, overall, it has no obvious preference for curving up or down — just variations in curvature over length scales from centimeters right on up to hundreds of kilometers.
Certainly it’s a shock to imagine water curving downward, since one’s experience is that still water won’t curve at all. But it’s clearly a very gradual curve, perhaps consistent with an imperceptibly small current. And if you accept that it curves down, why not up, on some very large length scale? Indeed, no other conclusion would be reasonable, if you assumed an infinite universe.
But of course the ancients did not, which is interesting in itself. They posited a finite universe, and a finite world. Given that assumption, then it becomes plausible to imagine that the observed curvature of the ocean is curvature on a unique length scale — the length scale of the size of the “universe” (i.e. the planet).
What’s interesting about this is that positing a finite universe when everyday observation suggests nothing so much as infinite duration and infinite extent is a pure blind act of faith, and contrary to what a neutral rational observer would consider most likely. So if the ancients deduced the curvature of the Earth correctly, it was by making an unreasonable assumption.
But is it reasonable to believe in such a lucky accident? How is it that assuming the universe is finite on a humanish length scale is plausible enough to survive natural selection? It might be reasonable to argue that it’s not an accident — that the length scale of human perception and the size of the Earth are connected. They cannot be too dissimilar, because masses on the length scale of humans or smaller, or conversely far larger than the length scale of humans, are not capable of harboring human life.
What is more interesting is the converse supposition that intelligent life that evolves on a mass of a given size — a planet, for example — must end up being roughly our length scale. That is, that intelligent beings based on DNA and water but that are the size of bacteria or Greenland are impossible. That seems to me plausible, but it would take a lot of thought to work out why.
Carl, cf Anthropic Principle
To expand on this a bit, and briefly, there is, I think, if you think about it, a bit of a peculiarity in that almost all physical scales — length, time, energy, temperature — are most “interesting” (have the most complex and unpredictable phenomena) on scales that are roughly commensurate with us. We’re “perfectly placed,” in some sense, midway between the simplicity of atomic physics and the simplicity of cosmology.
Suppose our perceptions and imagination (plus instruments) can “grasp” a range of length, energy, time, or temperature scales that vary by ten orders of magnitude. For example, we can directly perceive change on the time scale of milliseconds to megaseconds (9 orders of magnitude), or a length scale of millimeters to hundreds of kilometers (8 orders of magnitude), or an energy scale from microjoules (a raindrop) to megajoules (a speeding car or train). With instruments we can do much better. Isn’t it interesting that almost all of the really complex behaviour of the universe seems to fall into that range?
If you get to much smaller scales, or much larger, things get a little…boring. On the time scale of femtoseconds, for example, it’s all just one collision of an atom with another, over and over again, with once in a hundred bazillion an interesting chemical reaction. On the time scale of the age of the universe, it’s all just the slow pinwheeling of black holes and galaxies under the influence of gravity. Beautiful, no doublt, like a complex clock — but lacking in the rich complexity of events that happen on our length scales, birds and waterfalls and babies.
So why does the universe have this finiteness about it, just like the world the ancients imagined? Why don’t interesting things happen on the time scale of, say, 1e-50 or 1e+50 seconds? Or is it just that what does happen out there (or down there) is somehow outside our mental light cone, not even conceptually reachable?
“What I would like to know is if it’s ok to like really big cars again.”
Sure it is. Of course, for that to be OK you have to be OK with the idea of playing Russian roulette with your children’s future. You also have to be OK with the idea of giving money to people who want to make you either a corpse or a slave, and they are not particular which.
Never mind that, eh? Much more important to have a car with about as much internal space as a European midsize, but much more importantly a six-foot hood and a four-foot trunk (that, incidentally, probably has about as much usable space as that of the aforesaid European midsize).
Just what are Americans, particularly men, compensating for? Does any American ever actually grow up?
Chri Gerrib wrote: “By analogy, waiting to call global warming a fact would require seeing what the temperature and climate is like a century or two from now. Of course, by that time if we don’t like the climate we’re in a world of hurt.”
Well, if that’s the only way to check the AGW hypothesis, isn’t it telling you something about the fundamental level of uncertainty behind it.
One of they basic requirements of a scientific theory or hypothesis is to show how it can be falsified (i.e. how can we tell if it’s wrong). My understanding is that, because of the huge range of the predictions, there is no way of falsifying AWG.
The only “prediction” that we can test today is the one about temperatures ~10km above the tropics, which should show a “hot spot”. Unfortunately, the measured data shows that there is no clear indication of this and so, for the moment, we must conclude that the AGW theory/hypothesis has been falsified.
Unfortunately for Chris, what we really want to know is if anthropogenic global warming is true. Even watching the global temperature rise for a century will not establish AGW as fact, because natural climate variations can be so dramatic over similar time spans. What would be far more telling is to create a model that will accurately predict global temperatures for a century.
“You also have to be OK with the idea of giving money to people who want to make you either a corpse or a slave, and they are not particular which.”
Socialists?
It’s a good exercise to go through the catalog of “facts” to validate them from time to time.
Rand – actually, observing ships sailing over the horizon is proof.
Carl Pham – the ancients knew water seeks its own level, so that ruled out water curving up.
Dave Salt – I didn’t say AGW could only be proved by waiting for it to happen. I said that using Rand’s “it’s only a fact if I can see it” analogy, the equivalent for AGW would be waiting for it to happen.
Bill Hensley – developing that global temperature model is exactly what climatologists are working on.
Dave P. – I was thinking Fletcher was talking about radical Islamists, but your mileage may vary.
…observing ships sailing over the horizon is proof.
No, it’s not. It is evidence, but it’s not proof.
Just what are Americans, particularly men, compensating for? Does any American ever actually grow up?
What sort of immaturity would result in you’re imagining that Americans are “compensating for” something? When you are going to actually grow up?
Rand – the only explanation that fits what we observe when ships sail over the horizon is that the Earth is round. If that’s not proof, I don’t know what is.
No, that’s not the only explanation, unless you make other assumptions. It could be that land has a quality that causes water to rise as it approaches it.
Just what are Americans, particularly men, compensating for?
In the case of my first car, an eight year old 1972 Pontiac Catalina, I was compensating for lack of cash. $800 and I drove it for eight years. In the case of my second car, a 1987 Honda Civic, I was compensating for lack of reliability and operating cost – including gasoline over time. In the case of our fourth car, a 1992 Honda Civic, my wife and I were compensating for the same things as with her first car and my second. In the case of our fifth car, 1996 Dodge Caravan, we were compensating for the width of three child safety seats.
Why do you ask?
What are critics of Americans, particularly American men, compensating for, Fletcher Christian?
Yours,
Tom DeGisi
P.S. In the case of our proposed sixth car I expect us to be compensating for lack of reliability and operating cost – including gasoline over time again. Old cars do stop working more often.
If that’s not proof, I don’t know what is.
It’s not proof. Carl explained why. All you know is that there’s a local patch of positive curvature and hence locally the world is round. You can’t extend from that single observation to show the entire world is round. If you do as the maritime countries did and construct maps of the entire world, then you have a proof that the world is topologically equivalent to a sphere (though you’d still be unsure of its actual shape). It’d be a more complex matter for sailors to accurately measure the shape at sufficient points on the globe to demonstrate the general oblate spheroid shape.
For example, sending a weather balloon up 20 miles confirms local positive curvature out to around 400 miles in radius. One can then repeat the process at other spots on the surface of the Earth to confirm that the Earth is bounded and roughly spherical. Theoretically, this would take at least 400 launches (in practice a considerable number more to insure sufficient overlap of the patches).
If you just want to show the Earth is bounded in size (a weaker question), then you need only two balloons (or other systems at a reasonable height above Earth’s surface) at antipodes, plus some sort of very precise position measurement system (perhaps a really good inertial measurement system) to determine that the two measurements (which see the Earth inside a cone) are facing one another. The two observations will show that the Earth resides in the intersection of two very shallow cones that open towards each other. Even if the Earth should completely fill out that intersection, it would have the shape of a pancake of finite breadth.
A satellite in a polar orbit quickly will demonstrate that the Earth is round and with some decent measuring equipment, determine the Earth’s deviation from a perfect sphere.
Karl Hallowell – or you could just:
1) Observe that the sun is directly overhead at one spot on a given day at noon
2) The sun is not directly overhead on the same day at noon at a different spot to the north
3) Measure the angle and the distance between the two spots
4) Use geometry and calculate the circumference of the sphere (Earth) that you happen to be standing on.
It’s both a proof and useful information.
Rand – I, and the ancients, make no other assumptions but that water acts the same in a river, a lake and an ocean. I for one have never seen lake or pond where the water level rises to meet the shoreline.
I’m amazed that we’re arguing over facts covered in the fifth grade. Perhaps we do have a problem with science education in the US…
Chris,
Have you ever heard of the problem of induction? You keep using this word ‘proof’. I do not think it means what you think it means.
I wrote a long response, but Karl, I think, gave a better answer. I checked before putting mine in, but it centers around the concept that all a ship’s mast going below the horizon suggests is a local curvature. It doesn’t mean the earth is round. Indeed, we know that for centuries, mariners thought you could sail far enough and drop off the sides of the ocean. They suspected the ocean was curved, but they’ve seen waterfalls, and so assumed those observations could occur on a larger scale.
What I find interesting is the claim about what the “ancients knew”, because my understanding of the history of the earth’s size and shape includes the story of how Egyptians learned to put a stick in the ground to determine the curvature of the earth. They followed the lengths of shadow as the sun passed over, and determined those lengths could change depending on how far north or south you went, but not how far east or west. From these observations, they could determine earth’s approximate radius, latitude, and even time. This concept was noted and developed by Euclid, who lived long before any well known mariner sailed around the curve to discover land on the other side.
Gravity, on the other hand, took awhile longer to learn. And without understanding gravity, it’s hard to explain how water both “finds its own level” and follows the curvature of earth. We won’t discuss quantum mechanics, which explains how water can curve above the lip of a glass without going over the sides.
Chris, what you seem to be missing is that even if you observe that the earth’s surface appears to be locally curved, that doesn’t necessarily mean the entire earth is round. From that limited perspective, other hypotheses are possible. Yes, the Greeks believed the earth was a sphere, and Eratosthenes estimated its diameter by the method you describe. But they couldn’t prove their model. Much more extensive measurements, available many centuries later, were required. And, as we now know, it isn’t exactly spherical anyway. So their intuition was good, but not perfect.
Problem of induction – actually, I hadn’t heard of it. Sounds like a great idea, except for all of the billions and trillions of times humanity has used induction to figure out how the world works. More to the point, if the Earth was only locally curved, any other geometrical shape would mean that we’d see parts of the Earth that we don’t.
Leland – gravity was understood as a general principle. The specifics of acceleration, drag and the like had to wait until Galileo.
I, and the ancients, make no other assumptions but that water acts the same in a river, a lake and an ocean.
But those are assumptions, and not ones that must be made. You are apparently unable to get into the mind of an ancient.
I’m amazed that we’re arguing over facts covered in the fifth grade.
We aren’t “arguing over facts covered in the fifth grade.” We are arguing over epistemology, something you apparently don’t understand (which would also explain your mindless credulity over the AGW scam).
the ancients knew water seeks its own level, so that ruled out water curving up.
Er…Chris, you do realize, I hope, that your observation of ships disappearing as they sail from shore is a direct observation of water curving down, right? So clearly water is not always level. Sometimes, at least, it curves down.
Very, very gradually of course. So gradually that the curve is only visible if you look out over many dozens of miles of sea.
Now what’s your argument for why, given water is observed to curve down, it can’t curve up over some still larger distance? There isn’t one.
Honestly, you need to think the logic out much more carefully. You’re kind of reasoning backward from what you now know to be true, thinking that the logic that leads there is totally obvious. But it’s much harder to see what will later be “obvious” in hindsight when you’re looking forward. Which is what we’re doing with AGW theories. In such a situation, it pays to think very carefully about what you know, and what you don’t, what’s a direct measurement, and what’s an unexamined assumption.
If that’s not proof, I don’t know what is….
…Perhaps we do have a problem with science education in the US…
The irony here is that you don’t recognize that your (correct) statement that you don’t know what proof is is indeed evidence of a problem with science education in the US. Part of science education is (for example) an understanding of both the power, and the limitations of inductive reasoning, something with which you admit you were unfamiliar until today. Consider what else you many not know that you have always thought you did.
Was the roundness of the Earth proved in ancient times?
Depends on your standard of proof. In a court of law there are different standards of proof, depending on the case. Did the ancients prove the Earth round according to the preponderance of the evidence? Yes. Beyond a reasonable doubt? Depends on the jury in question, I guess. Geometrically? Nope.
Yours,
Tom DeGisi
Karl Hallowell – or you could just:
1) Observe that the sun is directly overhead at one spot on a given day at noon
2) The sun is not directly overhead on the same day at noon at a different spot to the north
3) Measure the angle and the distance between the two spots
4) Use geometry and calculate the circumference of the sphere (Earth) that you happen to be standing on.
Or you could be on a elliptic paraboloid which is infinite in extent. Once again, local information is not in itself sufficient to tell you the global structure.
Chris Gerrib wrote: “I didn’t say AGW could only be proved by waiting for it to happen. I said that using Rand’s “it’s only a fact if I can see it” analogy, the equivalent for AGW would be waiting for it to happen.”
Chris, given your above clarification, I’d be interested to know exactly what evidence makes you believe that AGW is a fact? Note that I’m not talking about evidence of warming itself, but evidence that it’s primarily due to CO2.
Oh, and please don’t point me to some web page like RealClimate or the IPCC. I’d like you to tell me in plain and simple terms what measurable phenomena you believe provides us with clear and unambiguous evidence that AGW is real?
Carl Pham – land also has the same “bending” – we see mountaintops before the bottoms. Also, when looking across a bay or strait, the land at the other end “rises.” It really is a simple observation.
Karl Hallowell – in an elliptic paraboloid, Polaris would always be visible and always at the same height relative to the horizon. (It took me a minute to realize that point, I grant you.) The ancients were quite familiar with Polaris.
Dave Salt – the evidence for AGW is:
1) CO2 is a greenhouse gas
2) High CO2 levels in past eras have yielded high temperatures, with resultant climatic effects
3) CO2 levels are rising
4) Even non-heat island temperatures (Armagh observatory) are rising
5) The only apparent cause for CO2 level increase at this time is burning of fossil fuels.
Point #5 is the weakest link, and the level of warming is quite debatable. But it’s hard to argue that humans adding CO2 to the atmosphere isn’t causing any portion of the observed increase.
My point is that we can reduce our carbon emissions at a relatively low cost while also reducing our dependence on foreign oil. In as much as reducing carbon comes from reducing energy consumption via efficiency gains, we can also save money.
A hypothesis might perhaps be defined as a theory absent any evidence one way or another. Personally I prefer to test a theory than a hypothesis where possible – slightly better ROI.
A theory is just a theory, and never anything more, though some theories are much better than others. For example, 1+1=2 is just a theory – a good theory but still just a theory that is yet to be proven wrong. My first year mathematics lecturer taught me this many years ago (Carl Popper attended my university during WWII, his influence lingers).
A science “fact” might perhaps be defined as a widely accepted science theory, but that is an ugly definition, it is generally better to not use the term “fact” at all. A “fact” is generally construed by the population at large to be the science equivalent of a religious “belief”, this destroys science. Use of the term “fact” encourages the perversion of science into a faith based religion (like say Scientology, or Christian “science”).
If it can not be tested it is not science. Absolute tests are not possible (proving a negative, like the non existence of Santa Claus – proving that there are no exceptions to a theory) therefore absolute facts are not possible.
Science, by definition, does not speak in absolutes. Absolute facts are by definition, not science.
Sorry that should have been “Karl Popper”…
And by ROI I mean predictive capability – the objective of science.
Chris, first let me thank you for trying to provide a reasonable answer to my question: you’re clearly arguing in a sceptic’s forum and I can understand the obvious frustrations.
Now, let me try and walk through your answers and give you my own views on them.
1) CO2 is a greenhouse gas
This is true but be aware what this means because there are two distinct “mechanisms” that drive the conclusions.
A) CO2 absorbs infra-red radiation, traps heat and thereby raises the temperature of Earth’s atmosphere.
B) positive feedback mechanisms then amplify this warming by a factor of two or more.
Based upon measured changes in CO2, Mechanism A) predicts a temperature rise of 1-2C, more than half of which should have already taken place. The resulting impacts on both environment and society are expected to be relatively small and, therefore, insufficient to justify the proposed remedial actions. My understanding is that most scientists agree that Mechanism A) is valid, based upon experimental evidence.
Mechanism B) builds upon this to predict a temperature rise of 4C or more, the majority of which we have yet to experience. The resulting impacts on both environment and society are expected to be relatively large and, therefore, sufficient to justify the proposed remedial actions. My understanding is that a significant number of scientists are not yet convinced that Mechanism B) is valid, based upon observational evidence.
2) High CO2 levels in past eras have yielded high temperatures, with resultant climatic effects
Ice core records show that temperature rise/fall actually lead the CO2 rise/fall with a lag of several centuries, so you cannot use this as evidence to show the effects of CO2.
3) CO2 levels are rising
True
4) Even non-heat island temperatures (Armagh observatory) are rising
Probably true, but this says nothing about the effects of CO2: correlation does not prove causation.
5) The only apparent cause for CO2 level increase at this time is burning of fossil fuels.
Probably true, but this says nothing about the impact of CO2.
You say “it’s hard to argue that humans adding CO2 to the atmosphere isn’t causing any portion of the observed increase” but I’d claim that my above comments have done precisely that.
You then say “we can reduce our carbon emissions at a relatively low cost while also reducing our dependence on foreign oil” but, from what I read, the costs will be far from low. I fully agree about the need to reduce dependence on foreign oil but, because of the AGW arguments against alternate carbon-based fuels, the most practical low-cost solutions will likely be outlawed (e.g. methane from sea floor hydrate deposits).
As for reducing energy consumption, I certainly agree this would be good if it’s achieved by efficiency improvements, but not through forced cuts and the accompanying impoverishment of large sections of the western world.
Mr. DeGisi; all very interesting no doubt, but also irrelevant except in the case of the 3 safety seats. Why exactly is typical Detroit iron twice the weight, twice the fuel consumption and no bigger inside than a medium-sized Fiat or VW? That’s the real question. For you to have bought a really big second-hand car, someone must have wanted to buy it new.
Karl Hallowell – in an elliptic paraboloid, Polaris would always be visible and always at the same height relative to the horizon. (It took me a minute to realize that point, I grant you.) The ancients were quite familiar with Polaris.
Polaris is so from the Northern hemisphere. And an elliptic paraboloid would have the same local effect of the north star declining towards the horizon as you move south and rising towards the top of the sky as you head north.
If I may add to Dave: the evidence for AGW is:
1) CO2 is a greenhouse gas
Yes, it is, but a minor one. CO2 absorbs Infrared in a narrow band, a band that happens to be enveloped by water vapor, a much more prevalent greenhouse species; yet noone is suggesting controlling water vapor. If all the CO2 in the world was eliminated, water vapor would still perform its function in absorbing at that range. AGW’s weakest link was to tie into CO2.
2) High CO2 levels in past eras have yielded high temperatures, with resultant climatic effects
More correct to say that high temperatures in the past have yielded higher CO2 levels, simply explained by CO2s lower solubility in the oceans at higher temps.
3) CO2 levels are rising
At the moment, but then again, they are cyclic as is temperature.
4) Even non-heat island temperatures (Armagh observatory) are rising
And yet, strangely enough the overall average temperature is going down. But that too can change for as yet poorly understood reasons
5) The only apparent cause for CO2 level increase at this time is burning of fossil fuels.
Really? I think you mean to say that the burning of fossil fuels adds to the CO2 content of the atmosphere. But, of course, nobody knows what to do with this information.
I should add here that it is the expectation that everything behaves in a certain fashion that made some theories popular. Since it is “obvious” that rock does not float, but falls down, obviously the Moon must be made of some other material – let us call it “ether”, which floats up in the sky. You cannot easily extrapolate from local behaviour. If you want an hilarious portrayal of this phenomenon of fallacious non-sequitur see the witch burning episode in Monty Python and the Holy Grail.
Fletcher,
Why exactly is typical Detroit iron twice the weight, twice the fuel consumption and no bigger inside than a medium-sized Fiat or VW? That’s the real question.
Next time ask the real question first. Here are some factors:
1. City planning differences. Big cars don’t fit cramped European cities.
2. The vastness of America. A big car is comfortable on long trips. In 1972, your comment about interior room was false. Bigger on the outside meant bigger on the inside. I fit six full size adults in my Pontiac with plenty of room. I fit eight once. That was a bit cramped. It did help that we were all young and thin. That was not true of my 87 Honda. My parent’s Maverick and my brother’s TR-6 were objectively smaller on the inside than my Pontiac. And we haven’t even discussed the cavern that was the Pontiac trunk – even with a full size space tire. These days your comment about interior room is false again. There was a period when Detroit had not learned what foreign car companies had learned about maximizing interior space and maximizing fuel economy. That period was over a long time ago, but perception has not caught up with reality. Again you may be certain that our Dodge Caravan has an objectively bigger interior than our (92) Honda. When we take the twelve hour drive to Wisconsin, we drive the Caravan. When take the eight hour drive to Denver (one state over), we drive the Caravan. Around town we take the Honda.
3. European gas taxes.
4. Americans are actually taller, and lately, wider.
5. Different cultural status cues. America is more optimistic, individualistic and rural. All three traits mean more Americans believe bigger is better.
6. Safety. If other factors allow larger vehicles, than safety via size is cheaper than safety via tech. And safety via both size and tech? Even safer!
7. Family size. American families are larger.
The reason Americans buy bigger cars is that bigger cars make economic sense here, although there are some cultural differences. Why be boringly the same as Europe?
Yours,
Tom DeGisi
As someone who does geodesy and mapping for a living, I can assure you that the ancients had plenty of evidence to sufficiently prove that the Earth is a sphere (more accurately a geoid), without directly observing the entire planet. Eratosthenes wasn’t just assuming the world was spherical when he calculated the circumference, because other philosophers had observed that during lunar eclipses the Earth always threw a round shadow on the Moon, which no other shape could do, if it were simultaneously orbiting or being orbited. Travelling south meant that southern constellations rise higher in the sky, suggesting a curvature. And of course the much discussed example of ships disappearing over the horizon.
Even critics of Columbus knew the Earth was round, unlike the popular misconception that they opposed him because they thought it was flat. The main reason Columbus faced so much trouble getting funding for a voyage was because critics charged he had miscalculated the circumference of the Earth, and would never make it to Japan sailing West, and a voyage would be a pointless waste of royal money. They were completely right, as Columbus had calculated the earth was 15,000 km smaller than in actuality, and this was widely known at the time. Luckily for Columbus there happened to be a large landmass a little to the west of where he figured Japan was supposed to be. He mistook it for India, but within a year of discovery, European cartographers had already established that it was in fact a new continent, not Asia.
Most importantly of all, is that you cannot accurately navigate any major distance without assuming that the Earth is a sphere. The success of long distance maritime commerce from the 1400s onward gives us thousands of individual experiments that the world had to be a sphere, because it is not possible to navigate from Lisbon to Goa assuming a spherical Earth if the Earth were non spherical. The suggestion that without direct planetary observation an elliptic paraboloid is a valid assumption because of how it can mimic spherical curvature in local areas is ridiculous, because even the ancients could quickly demonstrate the obvious falsity of such a proposition by simply going sailing. They knew as well as us, that north-lines must always converge at the poles, and navigated accordingly.
As someone who does geodesy and mapping for a living, I can assure you that the ancients had plenty of evidence to sufficiently prove that the Earth is a sphere (more accurately a geoid), without directly observing the entire planet.
Everything you write is nothing new to any of us. But it doesn’t constitute “proof” that the earth is spherical. It is simply a lot of independent evidence for which the theory that the earth is spherical is the best fit. Words mean things.
OK, having read jetx, I believe he has shown that (some of) the ancients knew the Earth was round beyond a reasonable doubt. And Rand, I think he has established that they knew it was round with comparable certainty to that Newton had about gravity.
As a scientific theory, of course we now know the Earth is slightly pear shaped, and that Newton’s theory of gravity must be modified by Einstein.
But really this seems a semantic argument that comes down to how rigorous a standard of proof you pick. Pete’s standard is amazing. He is more rigorous than logical positivists. I didn’t think that was possible.
Yours,
Tom Degisi
OK, having read jetx, I believe he has shown that (some of) the ancients knew the Earth was round beyond a reasonable doubt. And Rand, I think he has established that they knew it was round with comparable certainty to that Newton had about gravity.
I agree. That remains a different thing than “proving” it. It remained (at that time) an inductive argument. Newton’s theory remains that. As does Einstein’s. The shape of the earth, on the other hand, is amenable to precise measurement. That was the whole point of this post.
Dave Salt and Thomas – the warmup period from ice age to “normal” (or maybe better “non-ice age”) is around 5,000 years. The CO2 lag is 800 years – the first 1/6 of the warmup. It appears that something (volcanic activity, solar activity, unknown?) starts the warm-up, and CO2 accelerates it.
The temperature trends have leveled off or dropped slightly over the last two or three years. If you look at the data, that short-term spike happens all the time. The question, and it’s an open one, is “is this a spike or the start of something significant?” Absent a reason to think it’s significant, I vote “spike.”
Yes, water vapor is a greenhouse gas. So is methane. There are a number of greenhouse gases. The current thinking on water vapor is that higher temperatures lead to more water vapor (higher relative humidities).
Lastly, I certainly don’t think we should impoverish ourselves to reduce greenhouse gases. But I have a hard time figuring out why we would do so. Something like half of our CO2 emissions are from electrical power plants, which could be migrated to nuclear and stimulate our economy while we’re building the plants.
Chris Gerrib wrote: “It appears that something (volcanic activity, solar activity, unknown?) starts the warm-up, and CO2 accelerates it.”
It’s clear that warming increases the CO2 level but I’ve never read anything that provides evidence to show that the CO2 then “accelerates” it. Do you have a reference that would support this theory?
However, assuming this acceleration mechanism did indeed occur, if it’s also true that only positive feed-backs dominate the CO2 warming process (i.e. the basis for all our current concerns), what mechanism halted/reversed this acceleration and so prevented a runaway greenhouse?