Cap'n Refsmmat

Yeah, I should've drawn the parallel with my you-and-a-rock-in-empty-space example. After all, from someone else's perspective, the Earth is blazing past at a million miles a minute and is incredibly far from the sun, and we're all crazy for thinking otherwise.

I have something to add to my list: battery development. Electric cars, portable electronic devices, and gazillions of other applications could all use batteries with vastly greater energy densities and service lifetimes. I want a smartphone that stays charged as long as my Kindle does.

The point of relativity is that there's absolutely no problem with 150 million km and 19 million km being simultaneously true (in two different reference frames). If you arguing against relativity by saying "but it's 150 million km and that can't change!", you're essentially saying "nuh-uh" without basis. You're implying that the motion causes some force upon the Earth which shrinks it. That is not the case. In one reference frame the Earth is different than in the other reference frame. That's it. No. It is not smoke and mirrors. It's fairly easy to follow if you make the effort; let me demonstrate. We can calculate how much energy the Earth receives from the sun by knowing (a) how much energy the Sun emits and (b) what fraction of that energy hits Earth. We can calculate (b) by imagining a large spherical shell whose radius is the same as Earth's orbital radius. The energy the Sun emits is spread equally over this shell, so we just have to find what portion of the surface area is taken up by Earth. That's what I did in my equations. Now, length contraction only happens in the direction of travel. That spherical shell is not contracted into a smaller spherical shell -- it's contracted into an oblate spheroid, because only one dimension of it is contracted. The light traveling from the Sun at a given instant doesn't go outwards in a sphere -- it moves outward in the oblate spheroid shape because of length contraction. So less extra light hits Earth than you'd expect, because of the oblate spheroid shape having so much surface area. It ends up working out to balance out the distance change. Perhaps you could review my math in some detail and get back to me with specific questions on what you don't understand? It would be easier that way.

Er. That link goes to uxcore.dll, not nssutil3.dll. In any case, the safest route is to get it from a new Firefox install, since you're guaranteed to get the correct version.

Yes, I think that's another approach, but since length contraction doesn't just reduce the Earth-Sun radius but makes an oblate spheroid, I went the long way.

Actually, we don't fry, because of how length contraction works. Let me do a bit of calculation for you to demonstrate. The Sun is a blackbody radiator, roughly, with an effective temperature of 6000 Kelvin. Let's set some approximate constants: [math]\sigma = \text{Stefan-Boltzmann constant} = 5.6704\times 10^{-8}[/math] [math]T_{\text{sun}} = 6000 \text{ Kelvin}[/math] [math]R_{\text{sun}} = 7 \times 10^8 \text{ meters}[/math] [math]R_{\text{earth}} = 6\times 10^6 \text{ meters}[/math] [math]R_{\text{orbit}} = 1.5\times 10^{11} \text{ meters}[/math] [math]\gamma = 1\times 10^8[/math] [math]\alpha = \cos^{-1} \frac {1} {\gamma}[/math] [math]\gamma[/math] is the Lorentz factor, which gives us an idea of relativistic velocity, and [math]\alpha[/math] will come in shortly. A Lorentz factor of the size I gave corresponds to a velocity incredibly close to the speed of light, so the traveler is moving very, very fast. Now, let's calculate how much of the Sun's energy reaches the Earth. According to the Stefan-Boltzmann law, the intensity of energy emitted from the Sun is proportional to: [math]I = \sigma T_{\text{sun}}^4[/math] Multiply by the surface area of the Sun, and you get the total energy emitted: [math]E_{\text{sun}} = 4 \pi \sigma T_{\text{sun}}^4 R_{\text{sun}}^2[/math] Only a fraction of that is intercepted by Earth, of course. That fraction is the surface area of the Earth divided by the total area of the shell with Earth's orbital radius; that is, out of that shell, Earth only composes a small portion. The fraction can hence be represented as: [math]f = \frac{\pi R_{\text{earth}}^2}{4\pi R_{\text{orbit}}^2} = \frac{R_{\text{earth}}^2}{4R_{\text{orbit}}^2}[/math] This means the total energy intercepted by the Earth is [math]E_{\text{sun}}f[/math], or: [math]E_{\text{sun}}f = E_{\text{earth}} = \frac{\pi R_{\text{sun}}^2 R_{\text{earth}}^2 \sigma T^4}{R_{\text{orbit}}^2} = 1.81\times 10^{17} \text{ watts}[/math] If you calculate energy per unit area from this, you get something fairly close to the true value, so it's at least approximately correct. (You'll note I rounded many of the original numbers to make calculation easier.) Now, what happens when the Earth gets vastly closer to the Sun? Well, we must remember that it's not simply a matter of [math]R_{\text{orbit}}[/math] shrinking by a factor of [math]\gamma[/math]. If the traveler is flying from the Earth to the Sun (or vice versa), the length contraction only occurs in the direction of his travel. If he were flying perpendicular to a line connecting the Earth and the Sun, the Earth-Sun distance would not change at all. So the Earth's orbit becomes an ellipse, and the orbital shell becomes an oblate spheroid, with a minor axis of [math]b = \frac{R_{\text{orbit}}}{\gamma}[/math] and a major axis of [math]a=R_{\text{orbit}}[/math]. The [math]\alpha[/math] I mentioned earlier is the angular eccentricity, and is [math]\alpha = \cos^{-1}\left( \frac{a}{b}\right)[/math], which works out as I showed above. And of course the same thing happens to the Sun. I don't have to worry about the Earth because the hemisphere in sunlight does not contract, since its radius is perpendicular to the direction of the traveler. Now we must use the surface area of an oblate spheroid to make this calculation, and the resulting equation is rather nasty, so I have taken a picture of the equation and its calculated result in Mathematica for you: So... no difference in the energy absorbed by Earth when length contraction occurs. The magic of physics! (note to the other physicists around: please correct me if I made any mistakes, since that was rather long and I'm not perfectly certain of my approach) (also, obligatory xkcd: http://xkcd.com/54/)

That's a slight misrepresentation of the nature of many psychological studies. They do not evaluate whether a certain treatment "cures" a patient; they define certain criteria to measure (such as long-term anger and anger towards an aggressor, in the studies iNow linked to) and determine whether the therapy alters these criteria. One can then evaluate the claims of a therapy ("by acting out their anger, patients clear their feelings") with the reality ("they just get angrier, really"). Deciding what mental state is ideal is something best left to the patient, I should think. That's why informed consent exists.

It is 19 million km from the Sun, according to the moving observer, and every astronomer with him would agree. The fact that there is not an absolute reference frame in relativity means there is no reason that two observers in different reference frames should agree on measurements of length or time. The universe just doesn't work that way. The Hafele-Keating experiment, GPS, and numerous other tests of relativity have shown this. I'll answer this with a question. Suppose the universe only contains me and a very large rock. There is absolutely nothing else for billions and billions of miles in every direction. Comfortable in my spacesuit, I watch the rock float past me. It appears to be moving at a constant speed, and I have no rockets or thrusters to change directions. Just floating along. Question: Which of the following three options is correct? I am moving and the large rock is stationary as I float past it. I am perfectly stationary and the large rock is floating past me. We're both moving. How would you decide?

What experiments could I perform to confirm your new theory, Mr. Paxton? Please be specific.

It was either that or imagine a four-dimensional loaf that represents three-dimensional space, and usually that doesn't work out well. So, imagine two-dimensional space. Each instant of time in two-dimensional space is represented as a slice of the bread, and you can compile these instants together to get a "loaf." Who said time is an entity? We know the muon's velocity, because we can measure it, and we know its average lifetime, which can be easily determined under any experimental condition you care to try. We also know what the muon decays into, and we can detect the particles it decays into. Hence if you can measure how many muons hit the upper atmosphere, how many reach the ground, and how many decay products reach the ground, you know how many muons decayed in the time it took to get from the upper atmosphere to the ground. And we know the muon velocity, because we measured it, so we know how long that takes. And for some reason we find that the muons decay much less than they should. This can be explained in several ways: From our perspective, what takes a long time (flying through the atmosphere) actually only takes a very short time for the muon, and so it doesn't have time to decay. From the muon's perspective, the atmosphere is just really thin, and it gets through faster. Something about muon decay changes when they're going fast through the atmosphere. The last option can be ruled out through laboratory experiment and through seeing that the same behavior applies to many other particles in many other different kinds of decays, and the simplest explanation is that speed changes the particle's perception of time. I did not agree to that. You would do well to re-read my previous posts more carefully. The Earth does not "move" when someone flies past. Anyone sitting on the Earth will not notice anything. The voyager at ludicrous speed will see the Earth as being close to the Sun. He will not see it "move"; it's been that way for as long as he's been flying fast. No force acts upon the Earth to "move" it or change its orbit; it's just the orbit is perceived differently by those in different reference frames.

No, we require that dissent satisfy Speculations rule 1. You have omitted a key word -- there is no direct experimental verification. The behavior of muon decay through the atmosphere provides indirect verification on scales as large as the height of the atmosphere. Also, length contraction "falls out" of the basic principles of relativity, like the invariant speed of light, and these principles have been incredibly well-tested from the microscopic scale to the astronomical scale.

You have misunderstood my metaphor. The loaf represents two-dimensional space; the third dimension of the loaf (the long dimension) is time. The slice on the far left represents what space was like far in the past; the slice on the far right represents space at the present. If I slice the loaf differently, I have not moved any of its contents. I have not moved any raisins. But suddenly two raisins which existed in the same slice now exist in different slices -- two events which occurred at the same time appear to have occurred at different times.

No, I do not. It does not contract and then return to normal shape once the observer has left. Consider a very long loaf of bread. Pretend it's a representation of two-dimensional space, where each slice of the bread is a snapshot of what happened in two-dimensional space at that time. If there's two raisins in the same slice at different places, they represent two events which occurred simultaneously but in different parts of space. Move to the next slice of bread and you see what happened a moment later, and so on. Now slice the bread diagonally instead of straight across. You're certainly still looking at the same loaf, but the distances between objects are different -- and in fact two raisins which were in the same slice previously are no longer both in your new slice. Your altered perspective has sliced reality so that you see different distances and different times between events. Note that while this analogy is useful, it is not necessarily technically perfect, and doesn't represent every detail of relativity. I thought you said you had studied relativity. Consider someone traveling at 0.99 times the speed of light. He flies past the Earth to the Sun and beyond, a distance of approximately 150,000,000 km according to an observer sitting on Earth. The traveler, of course, sees it as a distance of only 21,400,000 km, which takes him just over a minute to fly through. The observer sees it as a distance of 150,000,000 km, which takes the traveler over eight minutes to travel through. At no stage did the traveler travel faster than light. If you strapped a wristwatch to a photon, you'd find that it'd get there in no time at all (from its perspective).

We're talking about the role of fathers in the treatment of schizophrenic young adults, not the role of fathers in the development of young children. The study has nothing to do with the behavior or impact of each parent as the child grew up. Research must break these things down by gender because society has caused differences between the genders, whether we like it or not.

Outbreaks of fecally-transmitted diseases like dysentery and typhoid were not entirely uncommon in those days, so it seems their method had some disadvantages.

That's probably the Kindle lacking JavaScript support in Basic Mode. While in the browser, hit Menu->Settings and enable JavaScript by switching to Advanced Mode. The drop-down should work then.

The past fifty years have seen many remarkable advances in medicine, physics, biology, and chemistry. What advances would you like to see in the coming half-century? Here's my list: Psychiatry. The rise of psychiatric medications seemed miraculous at the time, but it's now clear they're not as powerful as one might hope, and alternative treatments still have not gained widespread traction or huge success. I'd like to see a society in fifty years where far fewer people struggle with chronic mental illness, and where those with problems can get effective treatment. Medicine. Now that we're not all dying of bacterial infections, I hope we can develop new tools to maintain superiority over our new antibiotic-resistant friends. And since we live longer, chronic diseases should be next on the hit list. Perhaps in fifty years we'll be able to treat or prevent senile dementia, Alzheimer's, and similar disorders. Physics. I'm not sure what to put here, since I know that as we solve the current big physics problems we'll only make some more for ourselves. That's just a start. What's on your list?

Let's not be hostile about this, please.

But the research specifically covers mothers, and so you have no evidence to support the claim that the father is just as important. It's not in the data. Furthermore, this study covers children who already suffer from schizophrenia, so clearly their mother's positive attitude has not "inoculated" them from mental illness; it merely serves as an aid to treatment, rather than a preventative measure. Science cannot operate with preconceived notions of what must be true. A scientist cannot say, "Fathers must be as influential as mothers," because he has not conducted the experiment to determine whether that is true. This is not sexist. This is merely a reflection of a society where men and women play different roles (due to sexism in many cases) and hence a society in which differences between genders do exist. I suspect that in this particular case the researchers chose to study mothers because a pre-existing longitudinal study of mothers of psychiatric patients already existed and had collected significant amounts of data they could use in their analysis.

Volume of a sphere: [math]V = \frac{4}{3} \pi r^3[/math] Surface area of a sphere: [math]S = 4\pi r^2[/math] So the ratio of volume to surface area is [imath]\frac{V}{S} = \frac{r}{3}[/imath], which certainly does depend on r.

Er, no, if [imath]\frac{1}{9} = 0.111\ldots[/imath], then [imath]0.0111\ldots = \frac{1}{90}[/imath]. Quoth the Mathematica: And also: Muphry's law strikes again.

No to both questions. There's an option to let users view who gave them reputation, but we disable it -- it tends to cause suspicion and anger. "You gave that guy reputation but you didn't give any to me?!"

You do not understand how relativity works. We won't be sitting here in our air-conditioned living rooms and then suddenly whooosh we're half a mile from the surface of the Sun. We will measure the distance to be the same. Someone flying from the Earth to the Sun at near the speed of light would find the distance to be incredibly short. Measurement does not make the distance change, but your perspective does. Yeah, there's never been a ruler fired at 99% of light speed or anything like that. There's a lot of particle physics that depends on Lorentz contraction behaving as predicted, though. Apparently the Space Interferometry Mission would be able to make accurate measurements, but it was cancelled.

Yes indeed. Lengths actually do contract, and the effect can be experimentally verified with particles moving at very high speeds. http://en.wikipedia.org/wiki/Length_contraction#Experimental_verifications

I've checked his website and found a great deal of information on how to buy his DVDs and very little on the claim that it has been clinically tested. Have his test procedures and results been published? Did he perform a double-blind trial? An American patient may freely choose to take any number of "nutritional supplements" which websites or alternative doctors claim will cure their disease. These products are not regulated by the FDA, apart from the requirement to submit information suggesting they are safe. (Only one "dietary supplement" has ever been rejected.) The regulation is on the companies which claim their products are cures. If a company is free to market a medication with unproven claims that it is highly effective, the patient is denied their right to weigh the risks and benefits accurately, and must rely on potentially false or exaggerated information.