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George Jones

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About George Jones

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  • Gender
    Not Telling
  • Interests
    General relativity and cosmology; observational astronomy; quantum physics; mathematics; mystery novels and movies.
  • Location
    Prince George, BC, Canada, lat. 54N, GMT - 7
  1. If it's the temperature, then your set-up would not like it here; 4C this morning and 2C yesterday morning. Should be at least a few mornings in Dec. and Jan. when the (actual) temperature is in the -30Cs. I will still go for my 20-minute morning walk, but I will not do any (sedentary) observing. The electronics in my goto works at -15C, but I have no desire to check it at colder temperatures!
  2. When I lived in the US Virgin Islands, I had many bats outside my ground-floor apartment door and also at my place of employment. Take care, however. See https://www.cbc.ca/news/canada/british-columbia/rabies-death-bc-vancouver-island-bat-1.5213460
  3. I have used one scope and three eyepieces for the last ten years. Evolution of my kit: 1976 10x50 bins; 2006 15x70 bins and camera tripod; 2009 C8SE scope and 3 Hyperion eyepieces. It seems that compared many folks, I am a minimalist! That notwithstanding, my visual observing sessions mean more to me than I can express in words.
  4. Does Jupiter have cloud belts? My last several sessions have been with hazy, turbulent conditions, and I was starting to wonder. After the great conditions last night, my faith has been reaffirmed. Nice, crisp views of Jupiter and Saturn and lots of other stuff. The Wild Duck (M11) was amazing at x254.
  5. It depends on what you mean by "good understanding" with respect to a mathematical treatment of quantum mechanics. The most used text for upper-level undergraduate quantum mechanics courses in North America is "Introduction to Quantum Mechanics" by David Griffiths. From its preface: "The reader must be familiar with the rudiments of linear algebra, complex numbers, and calculus up through partial derivatives; some acquaintance with Fourier analysis and the Dirac delta function would help." A European quantum mechanics course might require more. The lectures and books that @vlaiv gave above are interesting. From the website: "A number of years ago I became aware of the large number of physics enthusiasts out there who have no venue to learn modern physics and cosmology. Fat advanced textbooks are not suitable to people who have no teacher to ask questions of, and the popular literature does not go deeply enough to satisfy these curious people. So I started a series of courses on modern physics at Stanford University where I am a professor of physics. The courses are specifically aimed at people who know, or once knew, a bit of algebra and calculus, but are more or less beginners." I might be able to find references that use some math, but less math than the above. Our intuition is based largely on our experiences. Quantum mechanics is also mind-stretching because it so counter-intuitive, as many quantum phenomena are far away from everyday experience. Some of this can be discussed without maths. I often have to this.
  6. Sorry, I don't know what bacteria on petri dishes look like. Point your C5 at a brightish star, and take the star out of focus. You should see an image with a dark circular disk in the centre with the disk surround by a concentric bright circular band. If you don't see circles, then your scope needs collimating.
  7. If you have questions, there are folks here who have substantial knowledge of quantum theory, but don't expect uniform answers! Recipe for a pub brawl: 1) take some physicists down the pub; 2) feed them beer for several hours; 3) ask "What does quantum mechanics really mean?". This is a fun bit of hyperbole, but there is a grain of truth to it. The second edition of the book "Do We Really Understand Quantum Mechanics?" by Franck Laloe was published this year. This book is meant for folks who studied university-level quantum mechanics. Also, the greatest living physicist, Steven Weinberg, in his fairly recent postgrad-level book "Lectures on "Quantum Mechanics" made clear his deep dissatisfaction with the foundations of quantum theory. A huge shock for me! This type of thing is part of what makes quantum theory so interesting, so I hope that you have some fun.
  8. "no maths" does not equal "dumb". Two of the books mentioned above ('Quantum Mechanics" by Susskind and Friedman, "Quantum Mechanics for Dummies") , do require some maths. Another interesting book is "the Quantum Universe" by physicists Brian Cox and Jeff Forshaw. This book uses little mathematics, but I wouldn't say that the book is an easy read. Reviewed in The Guardian and the Independent: https://www.theguardian.com/books/2011/nov/16/quantum-universe-cox-forshaw-review https://www.independent.co.uk/arts-entertainment/books/reviews/the-quantum-universe-everything-that-can-happen-does-happen-by-brian-cox-and-jeff-forshaw-2374486.html
  9. At what level do you want the maths pitched? Examples could include, but are not limited to: no maths; elementary rearangement of early high school equations; elementary calculus; more advanced calculus and elementary linear algebra.
  10. Interesting! I know nothing about the astrophysical processes involved, but, assuming speed is constant, and, using these numbers, I get the same result (see below). According to NASA, the shockwave speed is 1.5 million km/h = 420 km/s. If the shockwave is slowing down, this almost seems reasonable. https://www.spacetelescope.org/news/heic1520/ The speed of light is 300000 km/s), so average speed = (50 ly/8000y) (300000 km/s) = (1/16) * (300000 km/s) = 1875 km/s
  11. This is off-topic for the thread, but I am really curious: For visual observing, how much of a difference is there between the C8 and the C11?
  12. More seriously, I got the only scope that I have ever owned, a C8, ten years ago. When I got my scope, I lived in a third-floor apartment, and I had to carry my equipment down the stairs and outside (and the reverse at the end of a session!). I now have a house, and I keep my C8 on its tripod in the back garden shed. An easy grab and go. Now, that I have a house, I am thinking about getting a larger second scope, but, if this doesn't happen, my C8 will keep me happily occupied (I am strictly visual) for the rest of my life.
  13. It's possible to have more than scope??? Tell my wife.
  14. When you say "mostly formulas and mathematics", do you mean including calculus, or no calculus?
  15. For a person on the Earth, the trip would take at least 4 years, but, due to time dilation/length contraction, a person on the ship can experience an arbitrarily small duration of time for the trip.
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