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D H

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Everything posted by D H

  1. What ever gave you that idea? Read Dr. Rocket's posts again. If you wouldn't mind telling us, what is the full title of the book and the author? Even better, find the copyright page (very close to the front) and find the ISBN number. It will look something like ISBN 0-13-843557-X.
  2. This (along with your entire post) is utter nonsense. Why do you do that? The correct answer is about 19 minutes, not three days. You'll get about 21 minutes if you assume a constant density. A better assumption is that gravitational acceleration is constant down to about 2890 km below the surface, and then falls linearly to zero. Use the Preliminary Earth Reference Model and you'll get an even better estimate.
  3. Stop. That. You aren't going to learn anything by appealing to ridicule. There are dozens and dozens of books called "Quantum Mechanics." In some whose target audience is graduate students you'll see so much abstract math it will make your head spin. In others aimed at a lay audience you won't even see [math]\Delta x\Delta p \ge \hbar/2[/math] because that's too much math. Those lay descriptions are pop sci. How much math, how much calculus, and how much group theory was in the small book that you read?
  4. You missed an option. To make this experiment a bit more realistic, suppose you release a weather balloon from ground level. Unless you under-fill the balloon, the balloon flight ends when the balloon bursts. Why is that? The balloon doesn't fill with space as a substance. You've sealed it tightly so the helium doesn't leak out.
  5. Baldly asserting something to be true does not make it true. Bald assertions are of course a logical fallacy; perhaps you ought to read the rules of the forum. The fact is science doesn't quite know what space is. Mathematics doesn't tell us. Space is an undefined term, just as are point, line, and plane. Newtonian physics doesn't tell us. Newtonian mechanics assumes Euclidean geometry (where space is an undefined term). General relativity doesn't tell us what it is, either. What space is gets even more murky when you take in the expansion of space, or when you look at space very, very closely.
  6. My main gripe has always been that the moderators and admins bend over backwards to cater to the crackpots. The site has an explicit rule against use of logical fallacies. Yet the speculative members time and time again make bald assertions, create non sequiturs, talk about true Scotsmen, raise false dichotomies; the list goes on and on. Some of our trickier members haven't just taken Introduction to Fallacies; they apparently majored in Logical Fallacies. This goes on for some time, with nary a word from the mods or admins about following our rules. Some non-speculative member will inevitable get frustrated with this nonsense and break some other rule (typically be nice, boys and girls, rule). Whammo! Now the rules are suddenly enforced.
  7. Clear as mud. Describe your proposed experiment, in detail.
  8. Nonsense. I said nothing about the motion of the medium relative to the source because the motion of the light source is immaterial. Re "it could measure the speed of the Earth": What is "it"? Re "velocity of light in the glass": What glass? Be a bit more transparent in your writing. You are paying so much attention to appearance (font and size) that your writing lacks substance.
  9. I don't think you can have it both ways. This site is almost entirely devoted to speculations, and mostly very bad speculations. Speculations is, as you admit, your most popular section. A good chunk of the topics that aren't in speculations should be. This is a turn off to some. It is for me, and apparently lots of others. Traffic at this site is relatively low precisely because speculations is your most popular section. Some of your speculators are apparently kids trying to learn science. Teaching these people science, helping them along: That's a good thing. However, some of your speculators are crackpots who have received the full regimen of immunizations against logic and evidence. The same old crackpots who were here a year ago are still here now, still making the same nonsense arguments, still refusing to listen to logic, still refusing to see evidence. (They're fully immunized!) You moderators and admins would be doing everyone a great service by showing these intransigent crackpots the door.
  10. That is crackpot, end to end. You need to watch what you read on the internet. Not taking care might steer you down the road to crackpotism. You really don't want to follow that road, do you?
  11. It's nonsense because the author is misinterpreting the Michelson Morley experiment and because his "unreal" phenomenon is very real. That the speed of light through a medium depends on the velocity of the medium with respect to the observer was first demonstrated in 1851 in the Fizeau experiment. The Fizeau experiment is an after the fact confirmation of special relativity.
  12. That is an idea submitted to NASA from the outside that passed some minimal baloney filter. You too can submit an idea.
  13. More likely it's the NASA technical transfer office not knowing that they stepped in a quagmire. Apparently Zawodny's day job is designing remote sensors. Lots of NASA civil servants have on-the-side avocations that they pursue mostly on their own time and mostly with equipment requisitioned on the ultra cheap. NASA encourages this behavior so long as it doesn't interfere with a civil servant's day job because on occasion it pays off, sometimes big time. Even when such work is done completely on their own time, civil servants must still report any innovations as NASA's intellectual property. That's not so different from the IP agreements one has to sign to gain employment with a private company. "Any idea you come up with is ours, even that ultra-zany idea you came up with at 3AM during a bad night's sleep from eating a bad batch of seafood."
  14. Back to? You've never been there. This thread is about your Aristotelian (not even Newtonian!) view of the universe versus modern science. I haven't the foggiest why you are ranting and railing against relativity. Relativity is at its core a realistic theory, but obviously not a naive Aristotelian realistic theory. That boat sailed 400+ years ago. What you should be ranting and railing against is the Copenhagen interpretation of quantum mechanics, which is at its core a logical positivistic theory.
  15. Oh my. This kind of nonsense is why I've been absent from this site for so long.
  16. It's the other way around. If velocities added vectorially (i.e., how we add velocity vectors in Newtonian mechanics) it would be easy to make something go faster than the speed of light. Use a two-stage rocket, each of which can accelerate it's payload to 3/4 c. The first stage takes the entire rocket (1st stage rocket + 2nd stage rocket + 2nd stage payload) from at rest with respect to some observer to 3/4 c with respect to that observer. The second stage starts firing when the first stage burns out. It takes the second stage (2nd stage rocket + 2nd stage payload) from at rest with respect to the burnt-out first stage to 3/4 c with respect to that burnt-out first stage. If velocities added in the Newtonian sense our payload would now be going at 3/2 c. That's not how things work in the relativistic world. Strictly speaking, it's not even how things work in our slow Newtonian world. Suppose you are driving along at 60 miles per hour and a motorcycle races past you at 40 mph relative to you. How fast is the motorcycle going with respect to the ground? Newtonian physics says 100 mph. Relativity theory says 99.999999999999466 mph, not 100. The difference between those sums per Newtonian mechanics versus relativity theory is immeasurably small at our slow paced (relative to c) world. The difference becomes significant once speeds reach a significant fraction of the speed of light.
  17. The rest frame of a photon doesn't make sense. This is being discussed in another active thread, http://www.scienceforums.net/topic/63263-why-is-the-speed-of-light/ (post 18 and on). You are assuming velocities add as 1+1=2. Suppose you're driving along at 60 miles per hour and a motorcycle zooms past you, going 20 mph faster than you. How fast is the motorcycle going? Simple: 60+20=80. That isn't how velocities add in relativity. Suppose you are in a spaceship going at 3/4 the speed of light relative to some observer. Another spaceship going in the same direction zooms past you at 3/4 of the speed of light relative to your spaceship. Naively adding these velocities suggests that observer who sees you moving at 3/4 c will see that other spaceship as moving at 1.5 times the speed of light. That's not how it works. That observer will see that other spaceship as moving at 24/25 c.
  18. The only false premises here are those made in that crackpot article. From the article, If the speed of light in air, shown by the Michelson-Morley experiment and in later experiments, is indeed constant in every direction and not depend on motion of the Earth, it is also legitimate to say that the speed of light measured in stationary water (~230 000 km/s), or glass (~170 000 km/s), also must be constant in each direction and independent of the speed of light source. If that were not true, it would have discovered long time ago, and then would be possible to construct universal speedmeters, based only on changes of the light speed, which is unreal. On the other hand, if as shown, the speed of light is independent of the direction and of the movement of the light source, for each medium, then the light-clock uses eg. glass, in a rocket moving with any speed, will always indicate the same time as on Earth. Thus arguments of the special theory of relativity, about for example time dilation, are wrong. It can be assumed then that the special theory of relativity, proposed by Albert Einstein in 1905, is based on false premises. This is utter nonsense. The premise of special relativity theory is that the speed of light in vacuum is the same to all observers. Special relativity says nothing about the speed of light through matter. Getting a complete picture of how light interacts with matter took another than 40 years after Einstein's 1905 paper. You might want to study quantum electrodynamics, not some crackpot nonsense on the internet.
  19. It makes no sense. Suppose you were riding along a beam of light. From your perspective, the photons that comprise that beam of light are not moving. There's a big problem here. One of the major tenets of relativity theory is that the speed of light is the same to all observers. So which is it: Are the photons moving at rest (v=0) or are they moving moving at c (299,792,458 meters per second)? This is a contradiction. The concept makes no sense. Just the opposite. He tried imagining riding along a beam of light at age 16. He realized then that big problems arose from this thought experiment. It took him a a decade to resolve those issues. By 1905 he had it figured out. He realized that the concept of riding alongside a beam of light makes no sense. No matter how much faster you try to go, light will always appear to travel at the same speed. As far as superluminal particles are concerned, it's important to keep in mind that most physicists don't think they exist.
  20. Space is not matter. It is something else.
  21. Not really. The temperature of an object (if it has one) is just a measure of the average kinetic energy of the individual atoms/molecules in that object. You said so yourself: So which is it: Is temperature something different than kinetic energy, or a measure of the average kinetic energy? You can't have it both ways. One of the key moves afoot in metrology is to make several of the currently measured physical constants into defined constants. Example: The speed of light is now a defined constant. The latest meeting of the CGPM proposed making the Boltzmann constant k a defined constant, along with several others. Making the Boltzmann constant a defined value would explicitly tie temperature to kinetic energy, by definition. You appear to still be hung up on the idea of absolute motion. Drop that notion. Galileo (not Einstein) showed that this concept has limited validity. Einstein showed that it has no validity. None, zero, zip, nada. You need to drop this Aristotelian notion before you can make any progress in understanding the physics of the last 400 years.
  22. Individual atoms do not have a temperature. Temperature is a macroscopic phenomenon, not a microscopic one. You are still mis-mixing and mismatching a number of different concepts. There is no such thing as absolute rest or absolute motion. Get those notions out of your mind.
  23. I realize that the participants in this thread are anything but representative of philosophy. At least that is my hope. What we have in this thread (24 wasted pages) are some who argue for an Aristotelian kind of realism, others who tell us not to ignore the wonders of solipsism, and yet others who talk about who knows what. Some of the ramblings in this thread are quite remarkable. Perhaps a brief history of physics is in order. Galileo: Aristotle was wrong. Newton: Aristotle was very, very wrong. Einstein: Newton was only correct in a very narrow domain. The universe is quite weird outside of that narrow domain. Schrödinger: The universe is even weirder than Einstein imagined. Bell: Much, much weirder. Mermin: "Shut up and calculate."
  24. The speed of light is the same to all observers. What this means is that velocities don't add the way you think the do. Suppose you see two spaceships moving straight away from you in opposite directions, each going at 3/4 the speed of light. The people in either of those spaceships will see you as moving away from their spaceship at 3/4 the speed of light. They will not see the other spaceship as moving at 3/2 the speed of light. They will instead see it as moving at 24/25 the speed of light. You are leaping to conclusions based on a false premise. In fact, [math]E=mc^2[/math] (better said: [math]E^2 = (pc)^2 + (m_0c^2)^2[/math]) is a direct result of relativity. Before leaping to more conclusions, you should study physics a bit more.
  25. Achieving absolute zero is impossible per the third law of thermodynamics, one statement of which is It is impossible by any procedure, no matter how idealized, to reduce any system to the absolute zero of temperature (0 K) in a finite number of operations. This is not proven fact (no scientific theory is), so let's look at the hypothesis that time stops at T=0. This is exactly backwards. Time moves fastest at T=0. Imagine a diamond of pure carbon 14. (Diamonds are forever? Not if they're made of C-14.) An observer at rest with respect to the diamond will observe the diamond decay into nitrogen 14 with a half-life of 5,730 years. A relativistic observer will observe a longer half-life. If the diamond has a non-zero temperature, the atoms in the diamond will be vibrating back and forth. An observer at rest with respect to the diamond as a whole is a relativistic observer. The mean velocity is so low that these relativistic effects are not observed, but they nonetheless do exist. These relativistic effects become smaller and smaller as T→0. The decay rate increases (by an imperceptible amount) as temperature decreases. Time moves fastest at T=0.
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