Green Baron

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  1. O.o., and i was just starting to like your argumentation ... We don't rule the evolution (yet), we use it's mechanisms to control the environment or breed to our satisfaction and especially to do away with organisms, either actively in killing for profit or fun and passively in destroying formerly occupied niches. But if our brain shrinks again we have to step back into the foodchain. The fact that we are influencing natural selection with medicine (i'd call that artificial selection but am sure a purist will stand up and correct me soon (tm)) and so on could even accelerate the process, who knows. Simple, if we assume that such a thing over 4 billion years only occured once (it was and is an incredibly complex and interdependent system that has evolved on earth !) then we have to assume that we are the only ones. Not for long, species come and go. Probabilities don't help us. No. You need an organism that is able to "mutate", to change the code over generations in order for "mutations" to happen. Evolution is a continuous process. Certain "jumps" may be an artifact of our observation methods and the large timespans. But nobody said: "Here is a lung, get out of the soup and walk on land !" :-) btw.: the link didn't work. If not @work any more, could you try to find that 200+°C organism ? ? eruS Oh, come on ! They are all out there waiting to steal our women ? :-) Man i have too much time today :-)
  2. I keep it funny :-) Being "primitive" can have its advantages. They are very, very fit. Ah, so the amniotic egg was that thing #300millionyearsago. Ok, it works until today. Yeah, that brain thing is actually something tricky to explain evolutionwise, it needs a lot of energy and few really use its potential. Mayhaps it'll be sorted out as overkill in the future ...
  3. No offense, ok ? First, unicellulars changed ocean and atmospheric chemisms. Be humble :-) #300millionyearsago: i'll have to guess ... amniotic egg (reptiles) ? an Ice Age ? A supercontinent ? a huge desert ? an earthwide ocean ? Bikini weather ? Cancel that, uninteresting at that time :-)) #severaltensofmillionyearsago ... the list is long ... give us a hint .. the first letter maybe ?
  4. Oh, ok, what i read did not try to explain what happens "inside". Here you left me :-) I apologize for my un-sciency and philosophically choice of words but, hey, this is a game forum and i am trying to use my own words on a complicated matter ! If we assume that as the spaceship approaches the Schwarzschild radius (Sr) and its time in relation to the universe runs faster and faster (it accelerates through the universe's time or crosses all the timelines of the universe) it is ever more shifted into the future of the universe until when really reaching the Sr is taken into the infinite future of the universe because it takes from the universe's reference frame an infinite time to cross the Sr. Am i still with me ? Now, could that happen in a closed universe ? As black holes exist and they do grow but it takes infinite time seen from the universe to cross the Sr then there has to be an infinite future, no ? Which means that the universe cannot be a closed one that one day collapses again, that wouldn't be infinite and couldn't contain full featured black holes, right ? This point is of course not mine, it's from the literature i found on the subject. But it has that aha ! aspect :-)
  5. I know. Just wanted to steer the attention to a possible problem that could arise with something seemingly happening (expansion of Schwarzschild radius) "before" the cause (additional mass of object inside of it). Because i expected that to be the next question ;-) The linked text explains that quite nicely.
  6. Nevermind :-) It was a suggestion against avoidable dust and storage problems.
  7. Dust paints funny patterns on images, it will attract moisture, dust contains pollen which contain humid acids which will damage the coating of lenses as well as the aluminium surface of mirrors. No worries, if the cell holding the mirror is constructed and adjusted correctly nothing will drop out. Schmidt or Maksutovs are closed, dust won't enter too easily, but an open newton tube is a dust catcher. If there are only clips then ok, we probably are not talking about too high a value then ... :-) Refractors depend, oil spaced objectives are very delicate when stored on the side. If the objective's fitting isn't constructed perfectly the oil films can have different thickness over the aperture which will cause a 20.000,- objective to have a strehl of a 200,- mirror (0.8 instead of advertised 0.98). I've seen such an objective from a very well known and high valued brand on the optical bench of an independent tester. The owner was crying, he had spent the price of a midsize car for the tube and waited a long time. Air spaced aren't that prone to storage but still i would not store them on the side for a long time. There are few kg of glass held by screws in hopefully temperature compensated and stable non deforming steel or aluminium fitting. Apart from that, keeping things dry and clean is a must. Of course, the VLT or the Keck telescopes aren't dismounted during daytime :-)
  8. Please ! Highly interested :-)
  9. This can't be understood intuitively (foul excuse :-)). What can be measured from outside is the radiation from such events but this does not come from the Schwarzschild radius but from the area above, accretion disc and so on and this is clearly within the observable universe. The Schwarzschild radius is not, just until short above. So, in principle, the description of what happens at the event horizon is what mathematics imply. The "freeze" is not observable from outside because no information of it can escape (gravitational mass goes to infinite) and so probably your questions cannot be answered in our reference frame (time goes to division by 0). See it like this: the object stops at the event horizon and does not pass though, instead, the event horizon expands (and that without hurting causality, wow :-)). Here is what i found about it. Astrophysics can tell whether an object that is drawn towards a huge gravity well hits an event horizon (no signal) or a solid surface (energy burst on impact). When two black holes collide they are assumed to merge and form a single larger one. To understand more of this experiments to research gravitational waves have been and are being built. Ligo and Virgo for example. Edit: that Kevin Brown guy i linked above is somewhat of a mystery. Apparently he hasn't published more under that name, but was linked in the physics forum as well as in a university course so if you manage to wrap your brain around it then have fun :-)
  10. You don't want dust on your telescope *jedihandwave* :-). Dust will spoil everything, visual and especially photographic. You will have a hard time cleaning all the surfaces, corners, screws, focuser, eyepieces from dust. Store it upside down (main mirror facing down), close all openings with lids. Since lids cost money manufacturers save them frequently, maybe you'd have to fabricate your own ones. When it has completely dried after viewing, strip a large plastic bag over it but leave it open at the bottom to avoid mould and open it every few days or so ...
  11. The ship. It can cross it if not destroyed by gravitational forces or radiation of the accretion disc. In its reference frame it is not even aware that it has crossed an event horizon. But it cannot return. As it reaches the horizon time outside reaches infinity. Much has been speculated about what is inside but as far as i know physics cannot tell yet. Great unified quantum field bla theory is missing. Btw. gravitational time dilation as well as that by speed (which is essentially the same) is as real as the mouse you are holding. It is responsible for the orbit changes of Mercury, it was measured by satellites, it must be taken into account by the GPS. It is not magic :-) Nobody can watch it because energy from the Schwarzschild radius does not go anywhere except towards the gravitational center. All lines lead inwards, sotosay. Yeah, what you say describes it pretty well i think. I tried to avoid wikipedia except for the links i posted above. I have my half baked knowledge from cosmology books. Nope. The ships clock ticks just normal inside the ship. See above. The standstill is relative to an observer at rest (in the flat universe around). Physics doesn't say what happens at the event horizon, only short before. Just take a look at the formula on time dilation, when reaching speed of light it collapses into a 0 denominator, but just before it climbs very fast. In this wikipedia and my cosmology book agree that the ship stand s still at the event horizon relative to an observer in the flat universe. So, on the other hand, as that happens, the time of the universe has passed when the ship tries to cross the horizon. Sounds logical to me ...
  12. idk But the Schwarzschild radius is actually a radius. The sun's is 3km (or was that the diameter ?), mine is smaller :-) It can't be observed directly because it does not reflect or radiate anything except maybe the hypothetical hawking radiation, but this is so faint that it can't be measured. Radiation of surrounding stuff is what deceives it, or jets from active galaxy cores, and indirect hints like movement of surrounding objects (Sagitarius A*). Stellar black holes are mostly incidents to find. Edit: Another one is See mass and caclculated event horizon diameter. The "object" itself can be smaller than the horizon, if that answers your question. I read that with the new generation of telescopes it might be possible to actually get an images of the effects of black holes, accretion disc, gravity lens, these sort of things. Interferometry - EHT laid/lais the foundations -, is the key to new insights. Onsights. Whatever. Patience we must have :-)
  13. Spaceballs's Mega Maid comes to my mind :-) Nope, needs a ludicrous long cable.
  14. To be precise, from my lay understanding: nothing with a rest mass can reach the limiting speed because its relativistic mass would become infinite (good old Lorentz-factor applies) and its impossible to accelerate an infinite mass. I am ignoring causality between reference frames here. (On the other hand, everything without a restmass has to travel at the limiting speed but that's not important here). So, to develop @sevenperforce idea further, you can accelerate from an elliptical orbit to a hyperbolic and thus leave a body, or fly by on a hyberbolic orbit and use gravity for acceleration (or deceleration). That's Newton's mechanics modeled as conic sections. But at the Schwarzschild radius Newton gives up and relativity takes over. A ship has to accelerate to the speed of light to hold position (which is impossible if it has restmass). But relativity says: for the outside universe watching such a ship it stands still as it reaches the horizon and will never cross it (this answers part one of op's question, you cannot dip below in the reference frame of a distant observer). Passengers inside the ship will not be aware of the standstill, time outside just passes faster and faster until it literally runs out, and this should answer the second part, that there is no coming back from the event horizon. Valid until a physicist overlooks this :-)
  15. Wouldn't that have a better place in the lounge ? Cause it seems to be about a movie. At least it's far from science ... Edit: just read a critique about the movie. Life on the iss evolves that played part in an extinction on mars and now threatens earth. Aha. I see. :-) Yet another "alien". Not science. We'd have to discuss evolution and origins of life and i think this is fruitless in connection with a movie meant to entertain.