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Tiki

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Everything posted by Tiki

  1. eg. Ask a computer scientist and he'll tell you 1+1=10 An old joke: There are 10 types of people in this world: those that understand binary and those that don't. (Excuse me).
  2. If a passenger on the train decides to map the stars he might well notice a repeating pattern and realize that he is not travelling on an endless plane under endless stars (at he very least).
  3. I'm not too sure of this, since the value of G is not known to a very high degree of precision (scarcely better than one part in a thousand). That a discernible difference in clock rates can be measured at a one foot difference in altitude is astonishing though. That QED has so very little 'conceptually descriptive power' I feel is just the nature of the beast: a convenient rule which just happens to work. It would certainly be nice if some bright spark could come up with some meaningful physical motivation for the rules.
  4. Great Pluto capture. It would be nice to see another snap so as to discern its 'wandering' nature. Do you know the approximate separation of Pluto and the 'bright' star to the SE?
  5. Great capture. It would be nice if you could snap it again sometime soon so as to discern its wander.
  6. What then is time? If no one asks me, I know what it is. If I wish to explain it to him who asks, I do not know. Saint Augustine (about 400AD) The definition of time is an age old problem. Another approach to define time draws on the idea of there being more than the observable universe (ie. some sort of multiverse). So instead trying to understand the universe as beginning in a state of very low entropy, some cosmologists ask what is hoped to be a more tractable question: 'Why did part of the universe pass through a state of very low entropy?' All pretty deep but very interesting. I could imagine that a good definition of time would answer a fair few cosmological questions.
  7. I would of thought that unless your LP is really bad you should be able to pick it up in your finder quite easily. How bad is your LP? Can you see any of the stars in Sagitta naked-eye? The star hop that I use is to follow a line from gamma Sagittae in the direction of eta Cygni for a distance approximately equal to the length of the 'arrow' part of Sagitta. Even if you can't see too much of Sagitta naked-eye it should be very easy with your finder. It should be pretty easy to pick up in your main scope even without a filter unless your LP is truly terrible. M27 is a nice object and well worth tracking down. Good luck.
  8. I thought I caught a tiny glimpse of this on an exceptional night with a TV101/ Lumicon UHC/ (probably) 24mm panoptic combination from my back garden about 3 years ago. I haven't been able to repeat this since. Was this sighting a figment of my imagination? To give an idea of my back garden observing conditions, I can just about make out M31 naked eye direct vision when the transparency is excellent.
  9. Yes and yes. It has more information than my scopes and skies will ever warrant. It even goes into details of dark nebulae.
  10. Yes there is. If chart 33 shows the Blinking Planetary in the top left hand corner of your single volume atlas then the corresponding guide book has ISBN 0943396735. For my modest scopes it is a complete reference.
  11. Apparently M33 does. (This can be inferred from the graph on the top right-hand side of this page: https://en.wikipedia.org/wiki/Galaxy_rotation_curve)
  12. I believe your presumption is also the consensus of opinion amongst scientists. It is thought that elliptical galaxies are very old structures and have undergone loads of collisions and mergers, hence their relatively high prevalence in crowded regions of the cosmos. Well spotted. BTW, your galaxy count is very impressive.
  13. For me at least, maths is the science of all possible patterns.
  14. Thanks for posting the video Ollie, I felt that both the interviewer and interviewee were excellent. Twenty minutes well spent for me. cf. 6 min, 11.20 and 14.50 in the video. It is interesting to note that Lee Smolin's other main beef with string theory is that is simply not beautiful in the way that the relativity and quantum mechanics are. (Much follows from the Principle of Relativity and the Uncertainty Principle).
  15. Much science(and mathematics for that matter) begins with a supposition. Eg. Einstein supposes that he is riding along next to a light ray. Reduction ad absurdam in mathematics. Etc etc... Suppositions are just so useful.
  16. Definitely the ball-bearing and torch method. Once you have it calibrated for one BB-torch distance it will be very easy to vary the magnitude in a controlled way by simply varying the BB-torch distance and applying the inverse square law.
  17. I have the 17.3 and it is an excellent performer. I also have 5 and 8mm LVW's which are not too far behind the Delos in any respect except price.
  18. If you could jump 0.8m on the earths surface then a similar jump at the earth's centre would take you about 1600m (assuming the earth has a constant density and I have the units right). As Acey says, if you jump down a shaft which passes through the centre of the earth you will not touch the sides. Imagine you are at the centre of the earth looking up the shaft and someone drops in a stone. The stone will hit you at about 7900m/sec unless you move. The coriolis force is a pseudo force and will not save you. If you are able to watch this sequence events from afar then the angular momentum of the stone will appear to change (and the coriolis force is invoked to explain matters). If you jump into a shaft that doesn't go straight down then the force of gravity is that which might propel you into the walls. Idealized gravity trains (no friction and constant density) are pretty cool and illustrate quite nicely the deep relationship between inertial and gravitational mass. Edit: 3200m not 1600m
  19. No. Symbiotic stars incorporate quite a broad range of binary systems whereas dwarf novae have more specific attributes.
  20. Thanks Chris. Would it be necessary to machine a piece of Teflon round bar or would it be possible to bend a piece of sheet to the required radius (18mm) ? Is there a type of adhesive best suited to Teflon? I could imagine that Teflon is a bit tricky to bond. Paul
  21. Pictured below is my older style TV Gibraltar alt-az mount. The 36mm diameter lug on the base ordinarily sits in a 'plastic' lined bearing with friction being controlled by a single thumb-screw. I would like to build a pier extension with an adjustable friction bearing on the top. Something along the lines of a split bearing with a suitable lining bonded in place perhaps. I am really not too sure. Any suggestions would be most welcome.
  22. Just the same as the physically possible. If it didn't then it wouldn't be physics. OP: When you remove the source of the field (earth) everywhere has the same potential. It is the same as if you were to hold a nail close to an electromagnet and then turn off the electric. No field no pull on the nail.
  23. Very nice images. I particularly like the fourth.
  24. Consider the following thought experiment: We are in a rocket and hover above a test particle located half way between two streams of matter . We notice that the only forces that act upon the particle come from the gravitational influence of the two matter streams. We notice that the two matter streams are composed of identical particles which move with the same speed but in opposite directions. We are able to ascertain that the density of the two matter streams are identical and therefore influence the test particle in equal but opposite ways. It is no surprise that the particle remains at rest in such a symmetrical situation. We now zoom off in the rocket in a big loop and pass by the test particle, however this time we are moving at the same velocity of one of the matter streams. By the symmetry of the situation and the fact that our idealized rocket doesn't interact with the test particle we are again not surprised to see the particle still at rest just as before. Why shouldn't it be? When we whizzed by, we took a whole bunch of measurements. The upshot is that the densities of the matter streams no longer appear to be the same! On our flypast one of the matter streams appeared as a stationary line of particles whilst the other appeared to be composed of particles moving at twice the original speed. The moving particles would appear more dense for two reasons: a slight increase in mass of each particle and because we would measure the distance between particles to be less than in the static stream. (special relativity) Why doesn't the test particle move towards the moving matter stream? Ans: Because there is a pushing force which exactly counters the effects of the increase in density of the moving matter stream.
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