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Everything posted by Royston

  1. Oh dear, I don't even recall writing this, it doesn't make sense. Going by the date I was celebrating a friends birthday that day...(IOW I was mentally incapacitated). Sorry about that. By way of redemption, neutron stars have exceptionally strong gravitational fields, so anything travelling towards one (be it a comet or asteroid) has the potential to accelerate to a very high velocity (up to a large percent of the speed of light). Energy is conserved, so the kinetic energy of the body impacting the neutron star (which will be huge at those speeds) is balanced by thermal energy et.c on impact, and hence a very high energy explosion. A body in orbit around a star that tips over it's Roche limit will be broken up by tidal forces, and will (for the most part) join the accretion disk. Comets have a low tensile strength, so for the bulk of the debris to crash into the neutron star and not join the accretion disk, would probably require some unique initial conditions. This seems to be along the right lines. EDIT: I don't find GRB's boring, quite the opposite...I have no idea where that came from .
  2. The energy in a comet impact is bugger all compared to a GRB, the last 2/3's of your paragraph is nonsense. GRB's are not really comparable, the energies and the subsequent processes are boring.
  3. I was completely skint when I started dating the daughter of a multi-millionaire. So I bring question to your hypothesis
  4. Logical fallacy. Besides, it is usually the case, (and this is not directly aimed at you), that the worst threads get the most traffic. For example, members who simply won't take advice and keep arguing their case, despite being hopelessly wrong. Other members watching the thread, see this is as a form of entertainment, the thread gets lots of hits...it's harsh, but that's the internet. Unfortunately, this is the problem. You shouldn't treat the speculation forum as your personal note book. Collate your notes in private, then produce a coherent, well structured report to present to the community. Bearing in mind, that it should adopt the same rigour you would expect from a scientific paper, albeit a stripped down version. Diagrams are essential for mathematical models, but art is probably more at home in general discussion, or an art forum. Looking back on this thread, would you, in all seriousness, present that to the department of transport ? I don't mean to sound over critical, but I've seen better work boshed together at the last minute for a GCSE project. That maybe true to an extent, but I've worked with people your age, who have just started studying physics. Their views and appreciation of science and nature has changed, so I really don't see that as an excuse. You used to teach physics, so I find your methodology a bit baffling. I hope this is sound advice, because surely you want to avoid the kind of responses DH has posted.
  5. If the technology became commercially available, I think it would be inevitable somebody would attempt a McMe burger. There's also the possibility of cultivating the cells of endangered species, e.g Snow Leopard sausages, rasher of Rhino, and so on. Needless to say, anything with flesh would be game (no pun intended).
  6. Except that you can make predictions in the macroscopic domain using QM (see Ehrenfest theorem) to a suitable classical limit. Besides, it's GR and QM that are incompatible. Quantum electrodynamics combines SR and QM. EDIT: Cross posted with xyzt
  7. This probably won't help too much, but on the larger scale (i.e dark matter halos in which numerous evolving galaxies can be contained) dark matter evolution can be approximated using the Press-Schechter model and N-body simulations. N-body simulations can be used to track the behaviour of DM halos. Combining N-body simulations with numerical models you can predict certain properties of galaxies, and these are called semi-analytic models. This is more for galaxy evolution, but clearly there's a link to DM distribution and the subsequent properties of a galaxy. This is very new work, and different models require different assumptions. This may give you a starting point to investigate though. Note, that I studied cosmology some time ago, so I'm not sure on the current consensus. There was work carried out by Eduardo Battaner and his team, http://www.alphagalileo.org/ViewItem.aspx?ItemId=58466&CultureCode=en which attempts to resolve what you're asking, but I'm pretty certain it's not accessible (meaning I'm not going to pay for it). But, if you dig around you may find something. Do you have a link ?
  8. It is slightly off putting. It's impossible to use a name that distinguishes it from regular meat, without reminding the consumer that it's produced differently. But Schmeat is a bad choice. Maybe something like 'morally modified meat' or Mmmeat.
  9. As CaptainPanic stated earlier... Out of interest, what do you hope to gain by tracking the number of (human) visitors to your profile ? EDIT: That was in response to krash661
  10. It is far more likely you saw subtle signs of your Mum's health deteriorating, and this would conjure worst case scenarios in your mind. I can sympathize with this, as I've had to endure the same thing, but a different condition. Unfortunately though (and it sounds a bit cold), trying to convince your audience that you have predictive prowess doesn't cut it. You've suggested an idea, and you need to back it up with the same rigor as any other scientific theory or 'theory' in this case . The glaring error, is that your idea is very vague, so it's almost impossible to draw any conclusions from it. There have been a few proposals linking antimatter with dark energy, but not too sure on their validity, that's about as close to your idea that I can think of.
  11. It's clear from this post that you're making the same mistake a good 90% of posters in the speculations forum make. You can't make improvements on a theory or model (although I don't have the slightest idea what you're trying to improve upon) unless you have a thorough understanding of the subject. As an analogy, suppose a musician (say a pianist) wanted to add something to a classical masterpiece. In order to do this, they would have to be able to play this masterpiece to the same precision as the original, before they can start manipulating the notes and timing et.c. You're basically donning a pair of boxing gloves, and randomly hitting the keys, and trying to convince us you have improved upon a masterpiece. Do you, in all honesty, have a thorough understanding of string theory, chemistry and big bang cosmology ? AFAICS, you've sporadically grabbed information off the internet, and lumped it into an incoherent mess.
  12. I'm not sure if this is a homework question, but read the section on density parameters...http://en.wikipedia.org/wiki/Friedmann_equations . If there's any terms or definitions you're not sure about, just ask.
  13. My example was to show that charge has inherent properties (displayed by the dynamics of the electron / positron). For instance, if they curve in opposite directions this implies symmetry, no ? Charge. Not really, charge is well defined in physics, so it's certainly more than 'just a statement' http://en.wikipedia.org/wiki/Charge_(physics)
  14. You seem to be caught up with the word 'form'. If you mean attributes like spin, mass et.c they're identical. However, it shows on the diagram they have opposite charge, so that's the difference. Well, a demonstration of this difference would be to fire them through a magnetic field. The electron will curve in an opposite direction to a positron, which shows they have opposite charge. EDIT: swansont replied while I was posting.
  15. What does Benoit B. Mandelbrot's middle initial stand for ? Benoit B. Mandelbrot
  16. It states the distinction in the abstract... 'However, the most massive NSs known today reside in long-period binaries or other systems unsuitable for GW (gravitational wave) radiation tests. Identifying a massive NS in a compact, relativistic binary is thus of key importance for understanding gravity-matter coupling under extreme conditions' From the discussion... 'The orbital period of PSR J0348+0432 is only 15 seconds longer than that of the double pulsar system, but it has 2 times more fractional gravitational binding energy than each of the double pulsar NSs. This places it far outside the presently tested binding energy range [see Fig. 4a & (8)].Because the magnitude of strong-field effects generally depends non-linearly on the binding energy, the measurement of orbital decay transforms the system into a gravitational laboratory for a previously untested regime, qualitatively very different from what was accessible in the past.' It goes on to explain that if GR becomes invalid at these extreme conditions, there would be a violation of the strong equivalence principle i.e the gravitational field is independent of an objects position and velocity. Such a violation would lead to GW emission deviating from the predictions of GR. I assume this rules out Brans-Dicke theory, not sure on the details though. EDIT: On further reading it doesn't rule out Brans-Dicke theory.
  17. Surely these terms are defined prior to the question ? In any case, all you need to do is check your units. For instance, p and v are in imperial units for pressure and specific volume respectively, so check the imperial units for work, and see what happens when you multiply p and v. As for the 728 and small k. Given that the equation for specific kinetic energy is [math]K=\frac{u^2}{2}[/math] where u is *velocity, this points to either a proportionality constant or a conversion factor, so work through your units. Hint: look up conversion factors for 1 Btu/lbm I'll leave it to you to suss out k. *In your question velocity is given as v1 measured in fps (feet per second).
  18. Velocity is described by a vector (speed isn't), as for the rest of your post, it's not really chemistry based. If you want to discuss cosmology, then start another thread.
  19. It depends what you mean by that. A physical theory should be mathematically consistent, it's a basic requirement. However it needs to hold up to experiment and be provable / falsifiable. It's the latter where MWI doesn't really hold. In this case, a massive assumption is required to explain the results. Do you have a link or citation for this ?
  20. In the same way that velocity or momentum is a property. It's hardly surprising that energy is confusing, when you hear terms such as 'pure energy' on Discovery and Horizon et.c (it's not a substance). I think this term arises because it is quite an abstract way of book keeping in physics. Have you ever heard the term 'pure velocity' ? Why ? Quantum theory is without doubt the most successful theory in physics to date, in any case, in certain circumstances it reduces down to Newtonian mechanics.
  21. It's the Carpenters, and it's completely synonymous with sticking tweezers in your eyes.
  22. There shouldn't be any rule changes due to the fact that posting a video is no different to posting a body of text i.e it is a discussion (and funnily enough a Science) forum, you should read/watch then come up with your own conclusions to present an argument. I happen to agree with this...http://www2011.mpe.mpg.de/ir/irretreat2011/read/2009_schawinski_b.pdf. But so what...unless I narrow down the specifics, then it muddies the discussion.
  23. True, but that's clearly beside the point...the context of the thread is finding information that is (for the most part) trustworthy. I can't see that I even argued that, or more to the point, why you assumed that I was arguing that. As much as it's reassuring that my citations are not based solely on the source, or a tentative link to the subject, I still can't see why (from an undergrad perspective) that a name and shame of certain journals would not be useful. IOW, I simply don't have the technical ability to differentiate nonsense from legitimate. Sticking to reputable journals, at least, increases the probability that the information is more trustworthy than a free-for-all journal. I guess, but one of the main learning outcomes of my dissertation, is that you have the ability to use and facilitate checkable and credible sources. So it is (to a certain degree) up to the student. That really depends on the search term. Besides, the only reason I've devoted 12 hours of my time each day to investigate complicated AGN feedback that agrees with cosmological timescales, is to say, hey look, I study astrofizzics....aren't I clever.
  24. Royston

    Weird world

    Hi eric, Muslims are a highly evolved alien race who descended from the planet, Klackshudrrrr. They were transported to Earth through a collimated proton beam. I found one the other night, disguised as a used tissue. Luckily I managed to fend it off, before it's huge throbbing proboscis entered my face and forced me to write unintelligible shite on a science forum.
  25. I've been buried in research, so sorry for the late response...but thanks all for the replies. I guess from my perspective, it's grabbing information that is 'to the best of my knowledge' (and therefore) less likely to be littered with poor papers. It's not so much elitism, more, it's the best I can go on (at my level). I can see why it would be considered elitism, but I'm perfectly aware that the peer review process is far from water tight. I overlooked the money aspect...so all I need is a web designer and a Baez filter I'm not sure how broad a statement that is, i.e whether that's applicable to other fields of science (over physics). But again, from an undergrad point of view, would such a list not be useful ? Of course not, I gave the Lancet example for a reason. However, I agree with your other points, except that Perelman had reached notoriety in the mid nineties, long before his work on the Poincare conjecture.
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