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About pavelcherepan

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  • Birthday 08/09/1984

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    Geology, Physics

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  1. Oh boy... falling into a black hole

    That's the whole reason I started this discussion. There is obviously something wrong with my reasoning and I want to know what it is. Indeed, the Schwarzchild radius of the BH will increase somewhat. If we take a 2-solar-mass BH, the radius of EH will be 5932.(4) m, but if we throw in a 100 kg object, it will increase to 5932.44444444444444444444444459. Then, if the measurable extent of space-time curvature caused by this 100 kg object prior to falling into the BH is greater than the difference between these numbers, we should still be able to detect it as being outside EH, regardless of its expansion. And this would still result in "duplicating" the object's mass-energy. I'm very confused.
  2. Oh boy... falling into a black hole

    Thanks everyone for your inputs. Now can we please look into the conundrum I'm looking at. I think I shouldn't have brought infinity into question, it will be easier without it: 1) Object falls into a black hole 2) After a finite time it reaches singularity and its mass is added to the mass of BH 3) In EM spectrum we should still be able to see it stuck just above EH. We can't see into BH, so there is only one copy of the object in the observable universe in EM spectrum. 4) If, like MigL commented, gravitational information is subject to the same time dilation as any other information, we might still be able to measure space-time curvature of the object outside EH 5) Then we have "two copies" of the object's mass-energy in the universe. One being a part of BH mass and the other causing curvature outside EH. How is that possible?
  3. Oh boy... falling into a black hole

    Visibility aside, I'm still more interested in gravitational effects on the curvature of space-time from the body.
  4. Oh boy... falling into a black hole

    But as far as I understand the photons emitted close to EH will get more and more red-shifted and if we use something like a Penrose diagram for illustrative purposes, then final light will arrive infinitely far in the future. OK, this makes sense, but let's assume we're dealing with very lonesome BH that's not feeding on anything, except CMB and its event horizon is expanding extremely slowly.
  5. Oh boy... falling into a black hole

    Ok, but then an infalling object will have increased the mass of the BH. So in this case we'd have once "copy" of the object that became a part of the BH and another just hanging out at the event horizon? This doesn't happen with EM radiation, because we simply can't see the object inside the BH, but gravitationally it would then appear to have created duplicates. This is what confuses me the most.
  6. Handedness of Charge

    So "they" have observations that confirm mathematical models and you have your "belief". It's a lousy science critique, when your critique is coming from non-scientific domains. One of the properties of an orbit is that it's always convex towards the central orbiting body. In the case you described, orbits will be in many cases concave. Also, as stated by other people, your beliefs don't matter in a scientific discussion and you don't have any arguments to support your position except you believe it to be a fallacy.
  7. Oh boy... falling into a black hole

    Say we have an object falling into a black hole. As it approaches the even horizon external observers who are farther away from EH than the object in question will see it slow down and get progressively red-shifted the closer it gets to EH. Then finally, the from the perspective of the object it will cross the horizon, but all external observers will disagree, as they will see it forever stuck just above the EH. The object will go more and more dim, but as I understand, with an infinitely sensitive devices, external observers should be able to observe it being stuck at the same spot indefinitely. Is that correct? Now, the object, before venturing on this one-way trip would have had a mass and energy and would cause the local space-time to curve, however small that effect might have been. So the question is: if my previous statements were correct, we should be able to observe electromagnetic radiation of the object as being stuck above EH indefinitely, but would we be able to observe the curvature of space-time corresponding to that object in that same location?
  8. The effect of additional neutrons

    Well, chemical properties of an atom are all related to the valence electrons and in turn the configuration of an electron shell depends on the number of protons in the nucleus. Note, number of neutrons in the nucleus doesn't affect chemical properties much which can be seen from different isotopes of atoms participating in the same chemical reactions with the same results. I'm not an expert on this matter, but in modern understanding nucleus is not just some different colored balls attached to one another as it's often portrayed. Instead, the nucleus is a 'soup' of mostly two flavours of lighter quarks (up and down) with gluons zipping around between those. Quarks regularly change flavours and it's all very complex. Now to your question - usually a nucleus can have more of fewer protons than needed is either by simply being created that way, possibly as a decay product of another radioactive nucleus; it can absorb neutrons coming off of another nucleus which is how nuclear fission works or it can even be created by clamping together couple lighter nuclei as in case of fusion. As I said before, there's little differences in terms of chemical properties between isotopes as they all have exactly the same electron configuration.
  9. New White Dwarf Mass Limit

    Interesting. If that were true, it would have large implications in general cosmology as lambda-CDM model was based on observation of Ia supernovae. This is a big can of worms to be dealt with.
  10. Deuterium star?

    Here's the quote from wiki page on brown dwarfs: The size, though, will be more or less the same as the Jupiter, which is as I understand is more or less as big as a gas giant can get. After that it won't increase the size much, just will become more and more dense. Even smaller M-class red dwarfs like Proxima Centauri are only ~20% larger than Jupiter in size. Not sure about 3He though.
  11. Photosynthsis efficiency limit

    Well, I guess, if plant photosynthesis had increased in efficiency, the said plant should produce more sugars, have faster growth and more CO2 absorption. We could then solve world hunger issues and also quickly reduce the amount of CO2 in the atmosphere . In which case we wouldn't even need to stop burning fossil fuels! Yay! Everyone wins! Not sure how it can be done though.
  12. Yes, you can use something like PuTTY. It's multi-platform, do it should work on most systems.
  13. Mass in black holes (split from Mass)

    Just about two years ago LIGO has detected gravitational waves from the merger of back holes that acted as black holes should in GR. And since then there were several more detections that match predictions very well. Seems like a good evidence that they exist and act as GR predicts. And what would that be?
  14. Black Hole Polar Jets:

    Simulations look great. I wonder why accretion disks end up being so very torus-like, rather than disks. I thought that due to conservation of momentum, they would flatten out. I need to read the study in detail.
  15. Another take on creating gravity in space.

    If you want to constantly accelerate in your direction of travel the fuel requirements will be immense, it's not plausible as it will require a significant portion of all matter in Solar System as fuel. On the other hand if you go for the spinning arrangement then in ideal case only energy you'd need to expend is the amount you need to start the spin. After that since you'd be travelling in vacuum, it should keep going for extremely long period of time, and by that I mean millennia.