No. Not over-rated. He was capable of communicating ideas, deep and otherwise, clearly, which is very difficult. Consider how to convey the difference in magnitude between gravity and the electromagnetic force. The example he gives goes something like this:

The above paraphrased lesson emphasizes like nothing I've ever heard before how weak gravity is and how strong the electromagnetic force is. Simply brilliant.

I have a problem with the vagueness of the term "world's fastest man". If the criteria is for a person to reach the maximum speed without the aid of external forces like engine forces or gravity, then I think that Sam Whittingham is the world's fastest man. He rode a recumbant bike 133kph (83mph) over level ground without motor pacing. His bicycle was enclosed by an aerodynamic shell designed by a European sculptor (I can't find his name but he is not an engineer). The record has also been contested by more prestigious university engineering teams but Sam's record still stands. His training runs sometimes took place on Vancouver Island freeways, and it was not uncommon for him to pass cars on the freeway.

LOL... Sigh. Not sure this guy has his tongue in his cheek or is actually as obtuse as he appears.

The graph gives the mean temperature in Antarctica along with the CO2 concentrations versus time. This does show the ice ages. Low temperatures imply an ice age. Warm temperatures imply an interglacial period. The CO2 concentrations slightly lead in time. Given what we know about the physics of the greenhouse effect, this graph gives strong evidence that CO2 is a prime cause of global warming.

Really, sometimes I think posters to this board should have to pass some form of IQ test and a literacy test. It provides support for my "tongue in cheek" hypothesis that the self esteem movement has caused idiots and buffoons to believe that their ideas are on par with those of their more educated betters. In the past, they would have just sulked in the shadows realizing that they just aren't too bright.

A couple of important points: Firstly, 5 million years ago, there weren't 7 billion people living on Earth, people whose food supply was dependent on an agricultural system tightly adapted to today's particular climatic conditons. I will always remember a lecture given by one of my geology professors. He drew a graph on the board, initially without a scale. On the left, the graph fluctuated wildly up and down, going from extreme highs to extreme lows. Then suddenly, the graph settled down to mild up and down variations, and became basically horizontal, continuing to the right. Then he labelled the axes. The vertical axis was local temperature for an area where most humans lived. The horizontal axis was time. The time when the temperature settled down to a relatively constant pattern was about 10 000 years ago, the time when the last ice age ended. Then he asked us what other important event occurred around 8000 to 10000 years ago. Of course, the answer was the dawn of human civilization. Human civilization appeared about 8000 years ago. Civilization can only exist because of agriculture. People begin to plant crops in one area. They grow more food than they can eat, so they can have more children. Not all members of society have to spend time farming; individuals can afford to spend time doing other things like making pottery to store extra food, building better houses, or posting on Slashdot.

The problem for cities comes when the conditions that allowed successful agriculture change. Three or four years of failed crops caused by drought or heat or cold or surplus precipitation will exhaust all stored food. The residents of the cities will have to abandon their cities to begin hunting and gathering again, thus largely shattering any nascent civilization. The lesson from this is that human civilization was not simply the result of the triumph of human intelligence over nature. Civilization appeared 8000 years ago because the climate conditions favored it. During the last ice age, the conditions did not favor the development of cities. Even in areas that were not covered in ice, the climate conditions would have been highly variable thanks to the huge persistent ice sheets to the north. One day the air would come from the warm south, another day, the air would come from the cold northern ice sheets. These unstable conditions would have made sustained agriculture impossible.

My second point is that the well known fact that the climate in the past has shifted from warm to cold to warm should not be comforting to us. In fact, it should be the opposite. The fact that the Earth's climate has shifted in the past indicates that our climate is highly sensitive to relatively small forcings. Tiny changes in the Earth's orbit that cause periodically the Northern hemisphere to get more sunlight, and then tens of thousands of years later less sunlight are thought to have forced the Earth into and then out of ice ages (Milankovic Cycles). The slow collision of the Indian sub-continent with Asia, and its resulting volcanism is thought to have caused a large spike in carbon dioxide concentrations, resulting in a climate where the conditions in the north were near tropical.

The fact that the climate has shifted in the past due to relatively small changes indicates that "relatively small" changes wrought by humans, such as the removal of carbon from under the ground and the dumping of it into the atmosphere are capable of pushing our climate into a very different state, one that is likely to reduce human agricultural output by enough to make our current large scale civilization a dubious proposition.

One of my favorite moments in my formal education came when I took a second year geology elective called "Geologic Time". We spent some time discussing the formation of the solar system. If I may, I'll give a brief summary, as it will give some context to your question.

Many billions of years ago, a large star composed of hydrogen formed. Due to the high pressure and temperature in that star, new elements formed by fusion, with the largest element formed being iron. The star had a relatively short life, collapsed, and exploded in a supernova. During the explosion, neutrons, amongst other things were sprayed around the already existing matter. Those neutrons, being neutral, tended to "stick" to other nuclei. This, combined with beta decay explains the formation of elements larger than iron.

A wisp of the dust from that supernova began to coalesce into a spinning disk, due to gravity and angular momentum. The larger amount of material in the center of the disk was pulled together by gravity strongly enough to create fusion. Thus our sun was born. Within the spinning disk, some material was naturally volatile (e.g. water, methane, etc.). Some of the material tended towards becoming solid. One such material was silicon. The silicon reacted with oxygen to form silicon dioxide (I think). The silicon dioxide tended to form solid spheres in much the same way that hail is formed within a thunderstorm. These little spheres of silicon were commonly the size of ball bearings or actual hailstones. We call them chondrules.

When the sun ignited, it created an outwards stream of particles, which we call the solar wind. The particles in the solar wind easily pushed volatile molecules like water and methane outwards, away from the Sun. However, the solar wind was not able to push silicon chondrules outwards very much, due to their large size (compared to gas molecules). Thus, the inner planets are made of rocky silicon, while the outer planets, beginning with Jupiter, are made of volatile gaseous compounds.

The inner rocky planets slowly expanded in size due to falling rocks (and later comets). Eventually, radioactive decay in the Earth (and Mars) increased the inner temperatures of these planets enough that they melted inside, that is, they changed from largely hetorogenous chunks of rock to something more like today's planets. As the inside of the Earth melted, the most dense elements sank to the center. The most common dense element was iron. Thus the Earth got its iron core. Due to the motion of that solid/liquid iron core, the Earth developed a natural magnetic field. That magnetic field deflected the high speed charged particles in the solar wind around the Earth, thus protecting our atmosphere from being blown away. For some reason that I am not aware of, Mars did not develop a significant magnetic field. Thus, over time, Mars lost its atmosphere due to molecular collisions with particles in the solar wind.

I think the best way to answer your question would be to say that Mars got its atmosphere the same way that Earth did. Likely from some combination of comet collisions bringing volatiles from the outer solar system, and from volcanism releasing volatiles that were initially trapped in the rocky Earth. The solar wind acted on Mars' atmosphere over many billions of years, slowly removing it molecule by molecule. It wouldn't have happened right away...it would have taken a very long time to thin Mar's atmosphere significantly.

There...a bit longer than what I intended, but not bad considering what I described.

I suspect the prize was given to Obama because early in his first term, he was personally spearheading negotiations with Russia to substantially reduce the number of nuclear weapons in the world. The problem of course was that Congress would be unlikely to approve such reductions.

As for Obama being just like Bush, I think that to believe such a thing is intellectually lazy. One thing that is often missed by arm chair pundits is that the American political elite have an existential fear of a nuclear ransom scenario, where some nefarious organization gains control of a handful of nuclear bombs, explodes one in a major city, and then threatens to detonate the others in other American cities. Such an incident would quite literally unwind the threads of American civilization. Such fears cause our leaders to do all sorts of bad things in the name of protecting society. That said, I think it is important that we keep pressure on our leaders and let them know that the population will not be cowed into submission. Thus I think what Snowden did was important, in that it brought a very dangerous surveillance program into the public eye.

Some doctors have a name for what happens when modern hi-res imaging causes doctors to think benign irregularities may be harmful: getting "VOMIT"ed on...ie "Victim Of Medical Imaging Technology".

According to this Guardian article, the Instrument Landing System glide slope system was not operating at the time of the crash.

I am fairly sure this means that the automated landing systems on airplanes will not work. Thus, the landing by the pilots would have been a fully manual approach. According to the article, the airplane came in too slow:

From where I am sitting, this looks like full-on pilot error.

I am not a pilot but I used to be able to land the big iron planes fairly reliably on flight simulators. The simple principle is that you control your descent rate with engines and your airspeed with your angle of attack. You are at your slowest before touchdown when you nose up, and your angle of attack reaches its maximum. It sounds to me like the pilot had too large a descent rate and lost too much altitude before the runway. They probably started their flare too soon, and were not watching their airspeed. The fact that the stall alarm went on (indicating too low an airspeed and to large an angle of attack) supports this hypothesis. Their late effort to decrease their descent rate by throttling up the engines failed because it came too late (though likely saved lives by preventing the plane from nosing into the seawall).

The stall hypothesis is also supported by witness accounts of the plane looking "out of control". An airplane that is stalling might look out of control because it is in essence falling. Just google "Bagram 747 crash" to see what happens when a plane stalls. Also, the apparent fact that the pilot was able to throttle up the engines in the end indicates that the engines were functioning properly. The fundamental pilot error here was likely that the pilot did not throttle up the engines sooner to slow his descent rate.

This then leads to a discussion of the fact that many landings pilots make are automated, made possible by Instrument Landing Systems (ILS) on the ground and autopilots on the plane. How many pilots are in fact out of practice when manually landing airplanes? Did the lack of an ILS glide slope signal play a significant role in this crash? It shouldn't have, since the visibility on approach was unobstructed. Were the pilots out of practice? Was there something about the instrument data displays on the 777 that makes such a botched approach more likely?

Our plane landed at SFO last year and according to the pilot the ILS was not functioning. Difficult approach too with 500 foot ceiling...as soon as the pilot saw the runway we made a substantial course correction. I'm sure the pilot had a VFR beacon to guide the approach direction approximately but there was likely no electronic glide slope. I would like to hear whether or not the ILS was functioning during the crash. I also find the flightaware data in another post showing the glide slope for this plane interesting. Apparently the plane was coming in at a fairly steep angle. In my mind this nudges it towards a bad approach by the pilot. We'll see.

You sound fairly certain of that.

I'll bet that most of the time your "SUV" is a single occupant vehicle driving on city roads. With all this wasteful energy use it is no wonder the American economy is crashing.

My Prius uses Pirelli P4's sized P195/65 R15, so they aren't that skinny...they wouldn't look out of place in any other car of its size. They are a decent all around tire, and not the hard "eco" tire that you caricature.

I drive a 2010 Prius. The power is quite acceptable. I actually spun my wheels the other day on wet roads when starting hard from a light. I am able to accelerate safely on freeways, and I can easily cruise at 85 mph if I want (though the fuel economy obviously drops). The other day, I gave the accelerator a kick to get across a changing yellow, and the acceleration was quite good.

The main thing you have to get used to in a Prius is that the engine speed is dependent almost completely on how hard you press the accelerator, and not on how fast the wheels are spinning. This means that you don't get that same increasing engine pitch on accelerating that you do on cars without a continuously variable transmission. This might give some the impression that acceleration isn't taking place, until you look at your speedometer and realize you are going quite fast. I have gotten used to it now, and it seems natural to me.

The main thing that sold me on the Prius, apart from the fuel economy (which has been 50+mpg by the way) is the durability. I spoke with a cab driver in my area who drove his 2008 Prius for 500000 miles without any significant problems...only brakes and similar things. No new battery. No engine troubles. Nothing. He said he would still be driving it if there weren't regulations on the age of taxis in our area.

Fair enough, but you are in the minority.