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N_las

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Everything posted by N_las

  1. Talking about Messier Objects, I took this image of M16 last friday: http://i.imgur.com/op7z9DZ.jpg It contains the quite famous "Pillars of creation". Image from Hubble: https://upload.wikimedia.org/wikipedia/commons/6/68/Pillars_of_creation_2014_HST_WFC3-UVIS_full-res_denoised.jpg Sadly my picture is nowhere near this quality, I guess I just lack a few billion $...
  2. I life in a big city, and with binoculars I can just make out M31. If you are able to see the bright band of the galaxy with the nacked eye, you should be able to see M31 with about any pair of binoculars there is. How big is its aperture? You seem to expect "something definitive to resolve into an object". That is not how messier objects will look through binoculars or small telescopes. M31 looks mostly just like a cloud made of dim light (you only see its very bright center).
  3. Humorous take on this topic: http://www.smbc-comics.com/index.php?id=3732
  4. I made this picture in southern Germany: http://i.imgur.com/s7jvJMJ.png
  5. That would be so useles... The claim that the powder is less heavy than the equivalent liquid alcohol is just nonsense. So instead of buying 50 Liter alcohol fuel at the gas station, you buy at lest the same amount of weight in form of powder. Imagine having big sacks of powder to fill into your car, instead of a simple liquid. And you to add water, you have to mix the fuel yourself in your car. No thanks.
  6. What is that powdered alkohol for? Can't you use just a little bottle of wodka to put into your drinks? Isn't that just a scam? Edit: On wikipedia it says that powder can hold 60% of its own weight in alcohol. So If you have a 1 kg (!) of that stuff, you have 375g of alkohol. That is less than you have in 1 liter of wodka. And 1 kg of that stuff sounds like an insane amount. You sure don't save any transport weight by using it. How much does it cost? Edit: Yes, it clearly is a scam. They market it as if it would be more portable. People jump to the conclusion it would be like concentrated alcohol in powdered form, and they just need to take a small package of powder instead of a big bottle. They say a "liquid is often not convinient" and that powder would safe space and weight..... Clearly it is not. You don't save space and you don't save weight.
  7. I think the video RuBisCo posted is from years ago and does not represent the current tests.
  8. I am pretty sure there are many lobsters who aged one year during the last year.
  9. If the heating effect of cellphone radiation would be any factor, then a hot summer day or a fever or a simple hot beverage would be much more devestating.
  10. I fixed that sentence for you. It was an analogy. You can't escape the natrual background radiation and other natrual sources of cancer. So the road is the only option. If cellphones would increase cancer risk, we would see an increase in cancer cases over the last 20 years (age corrected). We don't. Also, I propose that bouncing castles cause cancer. You disagree, they don't cause cancer? Why? "Because you said so? How do you know that?" (Quote from you) As long as science have no idea how to create life starting with just bunch of atoms, we can't say for sure what kind of castle can harm life and what won't. One more thing... how science checked bouncing castles? Did they put bouncing castle near living cell and were waiting for 10 or 20 years to see what will happen?
  11. Maybe there newer measurements are a hundred times more accurate? I think the claimed 0.1 N per 1 kW was the number reported by the chinese team.
  12. Yes, I want to go by that logic, and I agree more or less with everything you said. Of course all those risks (regarding severity or frequency) pale in comparison to the risk of a car crash on the way to and from the airport.
  13. That would be not important, because it would be indistinguishable from natural cancer occurences. The "noise" of people getting cancer randomly at that level is greater than the "signal" of cancer caused by that radiation. It is like a slippery road. The slippines does increase your risk of losing balance and falling. If you decrease the slippiness slowly, the amount of people that lose balance will also decrease. At a certain level you will see that the randomness of people losing balance (on all sorts of roads, even non-slippy ones) is greater than the few people that actually fall because of the slippiness. At that point it becomes irrational to fear the road. Using a phone and being in range of its radiation does not increase cancer risk.
  14. You really should provide more context to that. Maybe he just doesn't know what he is talking about and he meant something like this:
  15. easiest would be to calculate x,y,z,vx,vy,vz out of the current Orbit O. Then calculate delta_vx,delta_vy,delta_vz out of your manuever N Then just add the delta_v values to the v values. Then calculate the new orbit O_new out of x,y,z,vx_new,vy_new,vz_new
  16. I think sublight warpdrive is possible with only relative contraction, no expansion needed. But I know nothing.
  17. I don't think that sheep and banana example is useful for anyone, no offense
  18. So essentially you are sending out virtual particles in a certain direction, hoping that they will hit something to impart momentum on that object. This is just how the electromagnetic force is working. (with photons as virtual particles). If that's how the drive works, it would be just a complicated perspectiv to describe simple magnetic or electric interaction with the surrounding objects. They virtual photons in that case will only carry actual momentum if they will actually hit a surrounding object. You can't do the same with virtual particles that wouldn't be massless like the photon. The range of "massiv" virtual particles is incredibly small (in the range of the nucleus of an atom). That is why the strong and weak nuclear force have such a small range, they use "massive" virtual particles in their interaction. Another way to hit the andromeda galaxy with your virtual particles is making them real. That is essentially the photon drive.
  19. Yes exactly. I even made a diagramm: http://imgur.com/uSw6cUM But we are only talking about left/right movement here. In that experiment, upward/downward movement or rotations are possible.
  20. The vanishing air on the other side of the dish isn't going straigt up, but slightly horizontal. The dish will move. But if you would change your experiment, so that the air has to go exactly upwards after leaving the dish, and you would but a lid on the dish so no air can "secretly" leave the dish in a horizontal direction, then the dish won't move.
  21. On a macroscopic level this wouldn't look like the box having momentum for a short time, then stopping, then having momentum, then stopping. The box isn't one big rigid object. It would look like the opposite walls imparting a force on each other, like a pressure inside the cavity. The forces on the opposite walls would be exactly identical.
  22. For example a laser resonator. You have a standing em-wave in them. The em-intensity in the middle of the resonator is in most cases much greater than to the edges of the resonator (near the mirrors). If that would create any thrust, like described for the em-drive, it would slightly squish or streach the resonator. We would have definetly be able to measure that, because the coherence length of the laser-light is easily measurable and dependent on the length of the resonator. We would always be wondering why the coherence length is always slightly different than expected. That question would come up in almost every single laser, so we would have surly noticed it.
  23. Sorry, but you are simply wrong. In sum, virtual particles don't have any rest-mass. If you wan't to impart permanent momentum from the drive to virtual particles, you need to spend the amount of energy needed to create that rest mass. In the process, the virtual particles become real particles, that is why I am using the word "creation". I used the hawking radiation just as an example: The hawking radiation carries momentum, but the black hole lost the amount of energy needed to create the rest-mass (and the momentum) of the (real, but former virtual) particle. Your explanation why the optimal exhaust velocity is the ships velocity is flawed, because it only takes into consideration that energy is spend for the kinetic energy of the exhaust. If you would take into consideration that you must spend the energy to create the invariant mass your explanation doesn't work anymore and photon drive becomes the most "efficent". You will still say: "BUT YOU DON'T HAVE TO CREATE THE PARTICLES, YOU JUST USE THE VIRTUAL PARTICLES THAT ARE ALREADY THERE!!!" But you are simply wrong with that. The virtual particles are there, but they have no ability to impart net momentum. You may invent a sort of zombi-virtual particle that is able to hold momentum like a real particle but will "pop" out of existence. But that is just fantasy! If the particle can hold momentum in that way, it has to become real, and someone had to bay the bill, someone had to spend the energy for that mass. For example a virtual photon can hold momentum (that it took from an electron), but only if it gives that momentum "immediately" back to maybe another electron. From the outside it looks like the electrons were exchanging momentum directly (over the electromagnetic force). You don't need to spend the energy for that photon, because it keeps beeing virtual because it gives that momentum back immediately. And it can't vanish as long as it holds that momentum, because then one electron would feels a force and the other won't. If you would use any clever mechanism to "trick" that photon into not giving that momentum to another electron, you do have to spend the amount of energy necessary for that photon to exist (E=hf), and the electron changes mometum without another immediate partner (the momentum is then "really" in the photon). That is a way to visualize accelerating charges sending out photons. You can't have your cake and eat it to, you can't give net momentum to a bunch of virtual particles without giving them the necessary energy to "exist" as real particles (that is what I mean with "creation" of reaction mass). You are simply wrong about that. If that were how virtual particles could behave, you could have accelerated charges without them sending out photons. You could have particles giving of momentum in radom directions to nonexistent partners. You could have the opposite: Particles suddenly gaining momentum without any discernable reason. And that would be constantly happening, all around us, or what is it that makes those em-drive virtual particles more special than any other virtual particle? The forces would work completely different. The reason the strong force has such a short range is, that the corresponding virtual particles will "pop out of existens" before they could reach another real particle, so they can't actually take any momentum from their source. But if virtual particles could take momentum and "pop out of existens" regardless, all particles would always change their momentum randomly because they will give it to random virtual particles that stop existing before they paid their momentum back.
  24. Random measurment artifact is a very good explanation. There is just something about the experiment that everybody has overlooked until now. Just like those ftl neutrinos a few years back. They had it easy, because the error was easy to find. Maybe this time the error is much more hidden. It is in any case a far more plausible explanation than virtual particles.
  25. Yes, and that is the only reason. And it is a very stupid reason. As ZetaX said in the previous post, this is a total random explanation. And many people knowing someting about quantum field theory said that from the beginning. To quote John Baez: Or Sean Carroll: It may have sounded "realistic" for some people, but only because the bit of knowledge they have about virtual particles is from Stephen Hawkings "A brief history of time". For experts, it doesn't sound "realistic" at all. If you watch an episode of star trek, the writers come up with realistic sounding explanations for so many things. But that is just that: Realistic sounding stuff that can satisfy an audience as plausible enough. It would never hold as actual explanation.
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