Danijel Gorupec

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About Danijel Gorupec

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  1. Danijel Gorupec

    SFN Slogan

    Not the topic her, but yes, it does bother me. It seems that people are associating atheism with these prominent and men - but, sadly, mostly to the aggressive part of their image... I noticed that I started to feel bad about revealing my own atheism, or if I am forced to reveal, I quickly say "atheist, but not anti-theist".
  2. Danijel Gorupec

    SFN Slogan

    Hmm... but isn't it that you should be explaining this to new forum visitors? They will be judging this forum by its quotation choice. They will judge that this is a fighting forum and will take the fighting stance (some of them happily and readily). They won't make their judgement by what is quoted, but by who said it.... This is the practical side of my reasoning against the quote. Yes, I know I am exaggerating (very few people will actually read the quote... and if we also write the author's name in a very fine print...)
  3. Danijel Gorupec

    SFN Slogan

    If this can be done, it would be much better But my advice to the owner of the forum remains the same.
  4. Danijel Gorupec

    SFN Slogan

    True... but my point is something else... Even if author is all perfect (which I think is not) and even if its quote is polite, reasonable and beautiful (which I think it is), this still is not enough... as long as there is a large group of people who might be offended by the choice, we should refrain from forcing it. Even if this large group of people is all wrong... That was my point. (I am not being a coward, I just think that SFN is not that kind of forum; not an anti-theist forum... not a fighting forum, but just a discussion forum... but this is only how I see the SFN, other members might have other ideas.) Agreed (but I did use it intentionally, because I am skeptical about how much good did Hitchens do for me. I am not sure if I feel comfortable calling myself an atheist if this is enough to evoke a fight-or-flight response in other people.)
  5. Danijel Gorupec

    SFN Slogan

    And this is exactly why I would advice against... The quotation itself is mild and nice, but its author is some sort of atheist god of war.
  6. Danijel Gorupec

    Energy contained in the magnetic field

    Yes, but I don't know how much is this 10^11 estimation reliable. Also, it might be the density figure within the magnetar's body (wikipedia is not clear about it). It is also very unlikely that our magnetar will be perfectly aligned to make optimal conditions for our measurements. That's why I opted for the more conservative 10^10 value. Another obstacle, I think, is that the physical size of the field is way too small - several tens of kilometers in diamter. How much would an occultation from such a small object last - a fraction of a second? I guess it is too small to make measurement, but I actually don't know.
  7. Danijel Gorupec

    Energy contained in the magnetic field

    I understand the method, great! In fact, it occurs to me that even one single light source, passing slowly through the magnetic field, can be used - its light should, if conditions are preferable, display larger wobbling amplitude as it approaches the magnetar's surface. This actually could provide some mass-energy distribution information. Edit: I still think, however, that our instruments cannot do it - eight orders of magnitude, calculated by Swansont, seems as a too large obstacle.
  8. Danijel Gorupec

    Energy contained in the magnetic field

    Yes, I need to accept that it would be too difficult to detect light-beam path deviation due to field mass. Thanks.
  9. Danijel Gorupec

    Energy contained in the magnetic field

    Wikipedia claims some 10^10 tesla.
  10. Danijel Gorupec

    Energy contained in the magnetic field

    Ok, I will interpret the answer from the Q+A site in favorable manner: magnetic field, by itself, should not affect light (but the answer, as I understand it, does not take in account light-bending due to mass-energy of the field). Although, the field strength of a magnetar is so high that I don't think any scientist would dare to guarantee that there won't be any unknown effect. No, I don't care to bend light - I care to test the energy density formula for the magnetic field... I started to think about observational possibilities when I read on Wikipedia that energy density of magnetar's field can be thousand times that of lead.
  11. Danijel Gorupec

    Energy contained in the magnetic field

    Thanks. My thinking is that even with our current knowledge some rough estimates could be made on what percentage of magnetar's mass is contained in its magnetic field outside of its compact body. Probably then someone could estimate how much a light beam (passing close to magnetar compact body) would deflect - that is, what is the difference in this deflection depending on the mass distribution (all mass within the compact body versus some mass outside of the compact body)... My math knowledge is probably way too limited to make such an estimation. The general idea is to have observational confirmation that mass-energy really is spread in the field. But i cannot estimate if such observation is only a distant dream or something that is achievable. Absolutely agree that there is a fear that such strong magnetic fields might act on light by other means than by space-curving (causing too much 'noise' for precise measurement). One thing that I am just thinking about - if the magnetic field of a magnetar quickly wobbles somehow (as that of a pulsar), the path of a light beam could wobble at the same frequency. Maybe this wobbling could help us with our measurements (it is sometimes easier to measure some oscillatory signal).
  12. What is your hunch about the following... If we could observe, from relative vicinity, a magnetar or some other neutron star that has a strong magnetic field - so that we are able to precisely track paths of compact objects closely encircling it or just making a close flyby - could we deduce, from paths of these object, whether the magnetic field curves the space or not (that is, if the magnetic field has mass-energy or not)? I am imagining that path of an object entering deeply into magnetic field of a magnetar would look differently if there is mass-energy in magnetar's magnetic field than if all mass-energy is only within the compact body of the magnetar. (I think, this is analogue to how presence of dark mater changes paths of stars encircling galactic centers). I however don't have any hunch whether the effect would be observable. And I am wondering if such an object that is entering magnetar's magnetic field could be a light beam - would it curvature differently if there is mass-energy in the magnetic field. (Happy New Year)
  13. Danijel Gorupec

    Doppler shift and photons

    Clear. The two observer don't have to agree about photon energy. I was, however, more interested about single observer in a lab. He makes the experiment and notes that the source gives off energy quanta E1, and the detector receives energy quanta E2 (E2<E1). Where he should look for the energy difference - from your answer I infer that he should look into change of kinetic energy (recoil) of detector (and possibly source), right?
  14. Danijel Gorupec

    Doppler shift and photons

    I have some problems understanding the following scenario: Suppose there is a source that emits a single high-energy photon. Suppose that this source is monochromatic and can only emit photons of single energy level, E=hf. The photon travels some time through space and is then detected at some detector (suppose, for example, detectors are all around, and the photon will surely be detected). My question is what if the detector (all of them) is receding farther away from the source at some constant speed? My understanding is that, due to Doppler shift, the detector should detect a photon of longer wavelength - of lower energy. What happened with the rest of the energy?
  15. Um.. am I late already to point out that Silvestru might be a polar bear?