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Everything posted by Jay-qu

  1. The sun is just too bright to image directly.. you need some good crossed polarizers or an ND5 filter. The internal reflections of your camera serve this purpose, reflecting only a small amount of the light and so the flares look better than the direct image. Also try some solar viewing with a pinhole, projecting the image onto a surface. Since there is no next time for us, you can just enjoy the images I took :D
  2. Just yesterday a new result was published showing that study to be incorrect. They made an incorrect assumption about how stars move within our galaxy, see here for the details: http://arxiv.org/abs/1205.4033 J
  3. As I'm sure everyone was aware, on Sunday part of the western coast of the united states got to experience an annular eclipse - which was also my first eclipse :) We drove a few hours north to extend 'annularity' to a full 2 minutes. Giving me just enough time to setup - and do a rough align (need to practice more day aligning :\ ). Fortunately I got lucky and the scope only required a nudge every 10 mins or so. With the eclipse finishing at Sunset, the diminishing light meant I had to extend the exposure from about 1/640 to 1/80 and double the ISO... Unfortunately this means the colours cha
  4. I don't think Elburg's point is relevant. The distance measurements are made with the GPS and transformed into the European Terrestrial Reference System (set in 2000 (it changes due to continental drift)), this is routine GPS work requiring special and general relativity. The timing measurements are checked with synchronised Caesium atomic clocks at each lab. I like your idea Qfwfq, but how do you resolve it with supernova neutrino observations?
  5. While this is a potentially exciting result, I am highly sceptical. Fitting the neutrino beam "profile", a mere 16,000 counts over the life of the experiment, to the proton beam is tricky to say the least. Before systematic effects are subtracted there is discrepancy of 1050ns, they account for -990ns, leaving the neutrinos 60ns faster than light over the ~720km. Have a look at figure 11/12 and ask yourself how much difference it makes to the fit if you shift the red line by just 50ns (one division/bin in fig 12) to the right. This would bring the result within error of c. And you don't have t
  6. From the album: google image nesting experiment

    Well I think this is as deep as we can go, the resolution is just too low.
  7. An experiment to see if google can nest an image, like holding a mirror up to a mirror
  8. Welcome aboard :) do not be shy to ask anything, we will be gentle.
  9. This isn't a very complete poll.. we know the Standard Model does not explain everything, but it does do a tremendous job of describing physics within its domain of validity. The current results collected by the LHC have not done much more than the Tevatron has already, but by the end of the year the LHC will have charted some new territory. The 'Standard' Standard Model has a simple form of the Higgs, but it is likely that the Higgs mechanism will be effected by or be part of physics beyond the Standard Model. Unfortunately our current experiments don't give us much to go by, but hopefully
  10. Hello afsred, A quick google search turned up this resource which provided the answer of 436 kJ/mol I hope this helps, J
  11. At this point I would just like to note that I am part of the scientific community researching dark matter and that I agree with everything Craig is saying. In lieu of the reputation system we used to have, I commend you here instead: Craig, your patience matched with your intelligence and fluid prose make you a formidably lucid explainer of all things scientific. I don't know where this site would be without you :thumbs_up
  12. From the album: google image nesting experiment

    The first phase of the google image nesting experiment is complete, here is the first iteration. Unfortunately the google thumbnail quality is going to make the next nested image impossible to see :(
  13. The veracity of their maths is one of the things the peer review process is supposed to check. I cannot vouch for whoever reviewed these papers as I am not an expert in GR, but I can say that something must be going wrong somewhere. GR also predicts DM through the observations of gravitational lensing, I dont think there is an easy way to reconcile these two observations. If we accept that GR is a consistent theory of gravity, then one of the observations must be wrong. Now considering the case of the bullet cluster, it makes it considerably less likely that lensing observations are wrong.
  14. I would take those papers listed with a grain of salt. Only one has been accepted in a peer-reviewed journal and even then it was a pretty low impact journal (IF = 1).
  15. These are good questions JMJones, I will do my best to give you some answers: 1. Quick answer, yes there is dark matter in our solar system, but not much. Since dark matter interacts mostly through gravitation (it is assumed to interact other ways too, albeit weakly) it acts like a pressure-less gas. The effect of this is that it does not 'clump' as much as normal matter. Data suggests the Milky Way galaxy may have ~90% of its mass in a huge dark matter halo that extends far beyond the visible reaches of the galaxy. At the point of our solar system in the galaxy the density of dark matter is
  16. The existence of dark matter is well established beyond just galactic rotation curves. See, for example, the Bullet cluster merger: http://apod.nasa.gov/apod/ap060824.html, which clearly shows that the majority of mass in this system is non-baryonic. There are theories that attempt to reconcile dark matter by modifying gravity, given the name MOND. All I have seen of these theories so far are in-elegant, adhoc solutions that cant cohesively provide a single hypothesis to cover all dark matter observations. If you are still unconvinced have a read of this: http://www.sdss.org/news/releases
  17. This is an amazing innovation, and if they can produce a full sized working prototype vehicle from it, it will revolutionise the auto industry http://www.msnbc.msn.com/id/42460541/ns/technology_and_science-innovation/ Lets hope they can, for all our sakes, I wouldnt mind paying 1/10th my current petrol bill!
  18. Good to see an old friend return, welcome back Alex :)
  19. From the album: google image nesting experiment

    google image nesting experiment this is the base level
  20. I think you are a little confused with the concepts. A moving charge will create a magnetic field. A current is a moving charge. So if your conductor has 50A passing through it, it will have a magnetic field circling it. This is not like a dipole magnet, so the magnetic filings will have a different shape from the traditional dipole shape you may be thinking of. The field lines will be straight across the paper and perpendicular to the direction of current in your conductor. That been said, now we can ask the question of whether spinning the conductor will alter its magnetic field. As Poly
  21. I am concerned about the bad PR this may be giving nuclear technology. These reactors, even though 40 years old, survived a magnitude 8.9 earthquake and large tsunami, only having their diesel backup generators (for cooling) knocked out. People consider this unsafe how? A more robust backup cooling system should be able to prevent such events from occurring again. Thus one would hope this event does not halt progress in using and developing nuclear technologies.
  22. Check out the video and pictures in the following link, taken in Germany during Discovery's last mission. http://legault.perso.sfr.fr/STS-133.html
  23. I fail to see the point of your link Don, this theory is known to be wrong.
  24. When doing calculations in theoretical physics involving the speed of light, c, and if one finds themselves in the US stuck with units of miles per hour, you can work out the approximate answer in km per hour by multiplying by the golden ratio. An amazing connection. :D
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