Jump to content

Airbrush

Senior Members
  • Posts

    3257
  • Joined

  • Last visited

  • Days Won

    4

Everything posted by Airbrush

  1. Thanks for providing a link and I will check out your other discussion. Your link is not working for me. Can anyone else use it? Could you just summarize a few of the other explanations for Hubble redshift? Interstellar dust?
  2. So we can relax. Since engineers are generally not intelligent, they have enough common sense. I love this Alice in Wonderland logic. Hahahaha. Very interesting, thanks for that. So this means that the helium will fully evaporate sometime in 2013 and then the telescope goes dead? Could it ever be serviced by a mission to deliver helium to it?
  3. Thanks for the info. So what is the answer to the original question? "Stephen Hawking pulls back the Black Hole theory for the Universe." What is the black hole theory for the universe? Hawking admitted he was wrong about something? What does that have to do with how black holes evaporate? "...As an example, a black hole of one solar mass has a temperature of only 60 nanokelvin; in fact, such a black hole would absorb far more cosmic microwave background radiation than it emits. A black hole of 4.5 × 1022 kg (about the mass of the Moon) would be in equilibrium at 2.7 kelvin, absorbing as much radiation as it emits. Yet smaller primordial black holes would emit more than they absorb, and thereby lose mass." http://en.wikipedia.org/wiki/Hawking_radiation Seems strange to me. How 2 virtual particles, positive and negative, pop into existence just outside the event horizon, and one particle escapes and the other falls into the black hole as negative energy which will reduce the mass of the black hole slightly. The two particles are so close together, how does one go one way and the other 180 degrees the other way? Also I'd like to know, does the vacuum around an event horizon create conditions that stimulate particle-antiparticles virtual particle production?
  4. Then why are all the red shifts directly proportional to how far away the galaxies are? The distances are estimated based on certain types of supernovas. If strong gravitational fields are causing the red shifts we see, they should be random. Also, the supermassive black holes at the center of galaxies are far too weak to influence the entire galaxy's red shift. What am I missing?
  5. I appreciate your point of view. How can expansion be "observed"? All they have to work with is red shifts. I'm not sure what you mean by there being no consensus among researchers on where to draw the boundary. I'm thinking the boundary is superclusters of galaxies. Where else can it be? Our instruments of measurement are certainly bound by electromagnetic forces, far stronger than gravity. I just can't understand what your point is, and I would like to, if you would care to expound a little more. What else may cause the red shift? Andromeda is one of the very few galaxies that are blue shifted because it seems to be headed towards us.
  6. Welcome aboard Dishmaster. How frequent are the maneuvers? How long will the fuel last to keep doing that? Any advice to posters here on how to get a job in space programs? How did you find your job? I'd rather sweep up around the telescopes for minimum wage than continue to be full time bookkeeper for a restaurant. I don't have much science education, but I've been bookkeeping and accounting for 20 years, so could that number crunching come in handy anywhere you know?
  7. I find it hard to accept the idea of the mass of the entire visible universe compressed into a region smaller than an atom. Yet, Stephen Hawking stated in his DVD "Into the Universe" that the observable universe expanded from smaller than an atom to the size of an orange in one Trillionth of a second after the Big Bang, and that is the inflated expansion. That is being very specific. It is hard to imagine what exactly can cause such a massive amount of matter to overcome its' own immense gravity to fly apart. I prefer to think in terms of expansion starting from a region of undeterminable size. Or some special quantum fluctuation resulted in a kind of super-rapid chain reaction, rather than a traditional supernova-like explosion, that "turned space over" into matter? Or as you propose a supergiant white hole spewing matter into our universe. If Mr. Hawking is correct in stating that after 10 minutes the universe reached thousands of light years across, then at that rate it would reach the size of 42 Million light years across (which is how big it was when the universe became transparent) in only tens of thousands of minutes, which is about one month after the Big Bang. Yet I have also heard that it took 330,000 years for the universe to become transparent after it reached 42 Million light years across and the CMB began it's journey.
  8. I don't understand what you mean by "there is no consensus on the expanding space view". Could you please elaborate? It seems obvious that galaxies are not flying apart. They are tightly bound and have been for Billions of years. How could they be expanding? Also, our solar system does not seem to be expanding over Billions of years. Even if there was a tiny expansion, the effects would be noticed over long periods of time. http://en.wikipedia.org/wiki/Metric_expansion_of_space "For much of the universe's history the expansion has been due mainly to inertia. The matter in the very early universe was flying apart for unknown reasons (most likely as a result of cosmic inflation) and has simply continued to do so, though at an ever-decreasing rate due to the attractive effect of gravity. In addition to slowing the overall expansion, gravity causes local clumping of matter into stars and galaxies. These stars and galaxies do not subsequently expand, there being no force compelling them to do so."
  9. Within the solar system, also within our galaxy, within our local cluster of galaxies, and within our supercluster of galaxy clusters, there is NO expansion. There is not "realy very small" expansion, because gravity wins on small scales. Only superclusters of galaxies are moving apart from other superclusters. There is absolutely NO expansion within a supercluster of galaxies. The expanding motion from the Big Bang and the acceleration from dark energy are overcome by gravity within superclusters.
  10. There could have been all kinds of "changes" or quantum fluctuations before the BB. The BB obliterated any evidence for that. Probably before the BB there was eternity of insignificant quantum fluctuations, until a very special one resulted in our universe.
  11. This is a fantastic DVD, about 3 hours of Stephen Hawking narrating 3 episodes. One about ETIs, an episode about Time Travel, and a longer episode, The History of Everything. There is also about 15 minutes of questions and answers, even what he likes on TV. He likes crime dramas. This has fantastic graphics and is excellent for the novice. However I have a few questions. Can anyone confirm the following statements Mr. Hawking makes in these episodes? 1. One Trillionth of a second after the Big Bang happened, the universe (I assume he means observable universe) grew from smaller than an atom to the size of an orange, after inflation. 2. After 100 seconds the universe grew to the size of our solar system. 3. After 10 minutes the universe reached thousands of light years across. 4. Our Milky Way is a very old galaxy, which formed about 13 Billion years ago. 5. A stellar mass black hole, of 4 solar masses, is about 15 miles in diameter. 6. The supermassive black hole at the center of the Milky Way is over 4 Million solar masses and has a diameter of about 11 Million miles. Does everyone agree with all of these? I only rented this DVD from Netflix. I watched it twice and I think I need to own a copy of it, so I can see it over and over.
  12. It means the engine can run faster to go a shorter distance. That gives more power for going up hill. In exchange you burn gas faster.
  13. Realitycheck: "...mining them where they are is more efficient. I mean, you're either going to be mining them where they are or mining them in orbit, seems like kind of a waste of energy...." Captain Panic: "...better off to mine the precious metals on the moving asteroid (not in orbit), and attach your nukes and ion thrusters only to the product...." I agree. Leave the asteroids where they are, and mine them where they are. Only expend the energy necessary to ship the valuable materials to Earth. What good is it to ship a lot of useless rocks and debris here? First find the rich deposits by robotic probes. Then either with the help of humans, or totally automated, establish mining equipment on the rock. Ideally, you may even manufacture some of your equipment using the materials on the rock.
  14. Thanks for the links to the experiments to find dark matter and the WIMPs detected. Since WIMPs mean "weakly interacting" massive particles, maybe the weakly interacting characteristic makes them not clump together. Are WIMPs particles that are not atoms with nucleus and electrons? So they may have found dark matter. They just need more confirmation which might take a while.
  15. You are sorry I am oversensitive? Sure, OK, no problem friend. I appreciate your knowledge, which is far beyond my own. Just your manner is rough. If I was listing a number of things you were not apparently aware of, I would certainly not repeat the words "You are ignoring" over and over. I would simply list them after something easy-going like "You might consider...". Forty years in Astronomy and Cosmology is awesome dude! Are you a science teacher? If so, you could be less condescending. My Dad was a high school art teacher for 45 years (except 1942 - 1945 when he was in Army for WWII), until age 70. Now let's get back to Astro & Cosmo. Time travel and life after death are the two great human day dreams. Wanting them doesn't make them exist. But what if? So let's get busy and figure out how to do it.
  16. Airbrush

    Power

    As Marqq stated above, summarized, 3,000 pounds at 7 feet is 21,000 foot/pounds. Horse Power is 550 foot/pounds/second. If the weight takes one second to reach the ground, you will have about 38 horse power available, or 28,484 watts.
  17. Thanks for reinforcing your issue of how ignorant I am, as to how ETI's could get here. Repeating "you have ignored" 4 times is a good way to annoy anyone. I hinted at "some kind of time compression" which allows for other ways besides traveling near light speed. I had not thought of #2, 3, and 4, thanks for those, but I had #1 in mind when I made my post. Or #5 they send self-replicating Von Neumann probes. Nice to know how good you are at detecting BS from parsecs away. I'm not so clairvoyant, and will rely on you for BS detection.
  18. Please give us a link to these Italian scientists' results.
  19. Suppose intelligent alien beings or probes have been visiting Earth for thousands of years, as the Ancient Aliens enthusiasts believe. How did they get here if they could not manupulate time passage? Probably their planet would be too far away to reach here without some kind of time compression. If you consider the "Montauk Project" conspiracy theory (see Preston Nichols, Peter Moon, K. Wells), time travel would be here and now, but very secret, above top secret stuff. Anyone with the ability to time travel could easily go back in time and remove all evidence for time travel. http://en.wikipedia.org/wiki/Montauk_Project Most scientists don't believe significant time travel is possible for humans at this time and not in the near future, but what is possible thousands of years from now? Wormholes are believed to be such extreme phenomena that humans could not survive passage through one. Passing through a wormhole is about as safe as jumping into a black hole.
  20. Then is it correct to say that from a point source to the edge of our observable universe, at 380,000 years after the Big Bang, is a radius of 42 Million LY. This implies at average speed of expansion of 42 Million LY in 380,000 years, or 110,526 LY per year, or 303 LY per day, or the faster-than-light speed of 12.6 light years per hour!
  21. Imatfaal: ".....The radiation that alien astronomer detects will have travelled for 13.7ish billion years and crossed a distance that was 42 Mlyr and is now 46 Glyrs...." Does this mean that it took the Big Bang 380,000 years for the observable portion of the universe to expand to a size with a radius of 42 Million light years? If everything was together at the moment of the Big Bang, then after 380,000 years of expansion the distance between our position in space and the edge of our observable universe grew to 42 Million light years.
  22. Good answer! I believe the world's top engineer is the person who can do the most, using the least. But that would be in a positive, human and environmental, problem solving, direction.
  23. Interesting thought. Does this mean that 380,000 years after the Big Bang, when space became transparent, the "edge" of the universe was 42 Million light years from the center of the expansion?
  24. Dark energy is the repulsive property of empty space. The more empty space you have, the more repulsion. When the space is great enough the repulsion overcomes gravity, which only happens between superclusters of galaxies.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.