Green Baron

A quasi satellite is an object a that has the same orbital period around the central body c as another body b that co-obits c together with b. So, seen from b, a stays behind half of the time and runs ahead the other half. That makes it look like a satellite of b, seen from b. Example: 2016 HO3. It orbits the sun together with earth. Since a and b must be in 1:1 resonance they will never get close enough to capture or to be captured. :-) Edit: SOIs are a game concept. Thought that got about. They don't exist in reality. Everything influences everything else in varying magnitude. Otherwise we'd have problems explaining resonance, trojans, lagrange points, planet 9, etc. pp :-)

At least they were decent enough to wait until she came out :-) Every few weeks i get a mail from something paypal related and am asked to visit a .ru site to verify my account. Who falls for that ? (I never had and will never have paypal account)

Buuut .... the "universal law of attraction" is something that works between humans interacting with each other, sympathy, antipathy, you choose places and situations where you feel well, that are convenient, and so quite automatically work towards a goal. Without thinking rational or even sub consciously you put yourself in situations that suit your visions or whatever you'll call it and attract people with a similar vision. Old school people would maybe say: "Always struggle, in the end you'll reach your goal !". That may be wise but .... ... this is a) not a universal law (a looser can still one day decide to let go and do something useful) and b) several abstraction levels above the laws of physics you depicted above. The moon cannot decide to go a different way (at least if you're not a follower of shamanism :-)), two electrons (which are no "balls", just simplifications of probabilities that reveal themselves when measured, see the physicists in the other thread on "Proton star") cannot decide to meet. The natural science you defy is complicated and a person without specific knowledge has to rely on simplified models or concentrate on a small window of the knowledge. That's why the "big things" these days are usually revealed by teams and not individuals, often people from different branches have to work together. An agnostic, hm ? That was not clear to me. Welcome, brother :-) gb Edit: Gravity is relative. It's a pseudo-force. If noone tells you and there are no windows then you cannot tell whether you are in an accelerating car or lying on the ground of a mass that attracts you with a similar force.

Hmm, i'd say, we have all the options in world. If people decide to describe a phenomenon from nature in words, physics or mathematics, set up an experiment, carry it through and in the end get exactly what was predicted (or eventually have to reformulate the premise) than that has brought humanity a small step forward. Of course there are limits to experiments in terms of energy and/or cost, than that experiment has to wait (e. g. bigger accelerator or telescope) or must be observed from afar (extreme conditions in the universe) and limits to understanding as well, e.g. because our tools are insufficient. On the other hand, i find self-imposed limits much more restricting than money or energy ... no offense, personal experience ! Knowledge is increasing, the ancient Greek understanding of atomos as the un-devidible (-devisible ?) is ad acta :-)

The forces in an atom are completely different from the forces in a solar system. On the one side you have the weak and strong interaction as well as electromagnetism. You need extreme conditions to overcome for example electromagnetism, while collisions between large masses may well happen without bending anything. So, while i am partly with you with the last three images (though it is impossible to model the movement of more than two objects exactly over a long time), i find the step from the first to the third one hard to imagine. Btw.: particles are by more than 90% just movement energy of quarks and gluons, no orbiting balls ;-) Aaaand ... if you dislike science, what is your intention of posting in a forum titled "science & spaceflight" ? Asks a friendly :-) Green Baron Edit: let's leave god out of the play because there are too many different conceptions of what is meant with that and it is forbidden in here. Gravity on the other side is one well understood phenomenon. Just drop an apple in a small scale, or estimate movement of galaxies in a large one. No problem here ...

We all have these problems. That happens if you don't let it adapt to the changes. I doubt that too much frost/water will be good for the mirror coating in the long run (mold, bactaria, pollen, etc.), so let it adapt slowly to temperature changes. Put it in the garage or in cool dry place after viewing until the next morning. Don't wipe moisture off with a towel or so, use optical cleaning stuff only if necessary. The reflective coating is not hardened, if will scratch easily, so only clean it if it has visible dirt on it. Leave dust where it is, it'll be back anyway. Blow perpendicular, not directly on the surface. Stow the scope upright with the mirror at the top facing down so it will not serve as a dust shelf. Don't use an ultrasonic cleaning device like the opticians use for our wearing glasses. The coating will be off afterwards :-) Sorry if talking old .... I got a version 0.2 of my orion nebula. Same data, different processing. LRGB composite this time, DSS for stacking and PixInsight for the LRGB. Down with those satellites ... Lots of noise and artifacts. There'll be a version 0.3 soon(tm).

Kessler wears that evil grin and rubs his hands ... :-)

Quoted from Finox. I still have problems with the forum editor. Or the editor with me. Interesting. Care to provide us with a source ? Edit: could as well be 2700m :-)) Don't cite me ! Just one link you can find when looking for water on mars ... i am trying to say that it might be wise to wait until moar data is available. Never judge an outcrop from afar ! :-)

Hi guys, i'm trying to dive deeper into image processing and astro photography. The plan is to upgrade to a monitor with 3840*2160 resolution. Video/movie is not an issue, response time less important to me than contrast and colour reproduction. Size between 30 and 34 inches, price should be under 1k funds. Graphics card is a gtx 970 compatible. Maybe someone has an ear on the market or read an independent test lately and could give me a hint ? cheers gb

... oh, well, none of those can capture any image at all right now :-)) E-ELT is planned to have a superb infrared instrumentation. I hope Planet Nine a) exists and b) radiates or reflects enough to be detectable.

Not big enough i'd say. Needs moar surface area. I put my bet on one of the large terrestrials like GMT, E-ELT, TMT, LSST with a new generation of adaptive and active optics. They will be quasi as good as a space telescope of the same size and definitely worth the diameter, resolution wise i mean. E-ELT with a diameter of almost 40m and a main mirror focal ratio of ~0.9 will be one nasty photon-collector.

Do you really think this is serious ? You guys struggle to help but only get half sentences without much information about what's going on in detail on op's side. The tin can part doesn't really stimulate the confidence. Op: no offense, but how about trying a solid fuel driven vapour machine, but don't make your own solid fuel yet. If you get cylinder, tubes and boiler pressure tight without changing the room climate too much you will be better than i once was :-). Skills/tools needed: working with soft metal (copper, mild steel), saws, files, borers, bend tubes without breaking (hehe), soldering (not necessarily welding). Screw things together so that vibrations don't loosen them ("after 'tight' comes 'off' !"). Lubrication, valve and a pressure gauge (you buy can these with the right pressure range), and, if it runs and you're still at it, a transmission line with all sorts off stuff that rings, hammers, moves and makes sounds ... ;-) Edit: i mean a small one, boiler bottle size (don't use a tin can, it won't stand the heat of the fire of several hundred degrees !), not industrial-age size :-)

Those are the hopes & dreams. To be precise: there may be an ocean and temperature may be in favour of liquid water under the icy shell of Europa (and Ganymede, Enceladus, ....). But it is not necessary to explain vapour vents and surface structures, if you care to search the publications ;-)

That is the speculative part, hopes are that that this might be the case but evidence for "life support" on Europa is lacking :-) Edit: given a surface temp of 100K ...

I know, this is a computer game forum, so i don't take everything too serious. I'm just adding my (euro-)cents while science and fantasy come together :-) What i wanted to say is that nobody knows whether there is an ocean of liquid water on Europa. It might be the case under certain circumstances, but the water layer is probably solid, though the moon might have something like "tectonics". Also, life on earth took >3 billion years from monocellular to complex life forms, 3 billion years in which the surface temperature was +/- 15 degrees celsius despite of a changing temperature of the sun as well as changing atmospheric- and ocean chemism.

There is life on Europa ? Who knows in detail about the conditions for life ? Edit: it was an ironic question. I'm just pointing out that it mere speculation/fantasy. There is nowhere life except on earth and nobody knows about the conditions for life, only rough parameters like energy, a system of circulations, temperature ranges, etc. While microbes might exist elsewhere (speculation) there is little chance for another evolution like that on earth. As far as we know by now a life sustaining world should be somewhat earth-like. Which is rather improbable (but not impossible) given the circumstances.

That's where physics and metaphysics blend. Experiments, the very basic principle of natural science to test a hypothesis, are difficult or in the case of black holes impossible. Thought experiments instead are only a weak substitute. They depend, like the geoscientists beloved simulations, on available data and knowledge. Quantum entanglement: if your partner drives with you to the airport, then boards a plane, you return to the car but do not find the key you immediately know that it is on the plane :-)

It's probably a self-reference, or, with your question, you made a self-reference out of it. This thread is about complaining, so liking your post is completely off-topic because it's not complaining, witch gives a meaning to the self-reference because it complained about not complaining. Or so. :-) I am out of school since some time, i could, as most people my age do, complain about the weather but i know it's useless. I would complain about the stupidity of the stock markets, it's useless. I could complain about the actions of our leaders/heads of state/industry/whatever, it's forbidden (and useless). I could complain about the (felt) lack of education in many people my age, who are unwilling to adopt new findings, it's useless. And, i tell you, i am sometimes surprised about the limitations some people impose on their selves (flat earthers, space deniers, "ptolemaians", ..), but it's useless. They think the same about me. Remains only to complain about my server that does not want to accept the new Spanish kezboard, i mean keyboard. Small problem.

ToE ? Vertebrate distal parts of the skeleton come to my mind :-) Edit: i got it "Theory of Everything" !

First: i do not pretend that i understand that much of the matter, so i can only add to the list questions. If you mean with "black hole" the event horizon, then if it is bigger than the singularity (singularity smaller than the Schwarzschild-Radius) why couldn't things exist under the event horizon ? Everything has a Schwarzschild-Radius, but usually no singularity, or am i understanding something wrong ? For the sun it is 3km i read, but nobody assumes a black hole in the sun. As to what happens to matter in the singularity: as far as i understand it does not exist. If a collapse of a large mass continues from the neutron-star stage towards the singularity then the formulas we use for describing the state stop working, so "we don't know".

Yes, something must have been misinterpreted with the faster than light thing. And it is actually the mass that increases with speed. The mass is as relative as time and distance with m(v) = m0 / sqrt( 1 - v²/c² ) or m0 times Lorentz-factor if you like, where m0 is rest mass and v is the speed of the reference system. Maybe it is easier to accept if we say that the rest mass (f.e. of a particle) is fixed in every reference system, but the v-dependent mass changes. I could not find an explanation about relativity that states anything about what happens at the speed of light. The formulas only serve until very short before. It is nice to play with "everywhere at no time" at the speed of light, but right now i doubt it's still physics ... I wish a physicist would show up :-) p.s.: Bach, really ? I would have taken Beethoven. Edit: as to the inflationary expansion: nothing moved in a relative sense during that phase, as the galaxies outside of our hubble sphere are not actually moving ftl. It is the space itself that expands, taking everything with it. So, if you accelerate in any direction, you will still take your personal "hubble sphere" with you, but it is at any speed impossible to catch up with this expansion. The last thing i read from cosmologists is that it might well be possible that there is no limit to the expansion of space. I know, it is against intuition, but nevertheless it is :-) Relativity is not harmed by the expansion, since any acceleration you give to an object ends short before c.

Well, it was a play of thoughts. Yes, it's a bit like asking "what does physics say if we ignore physics ?" :-)

Exactly, 3 of the planets seem to pass in front of the star. So for these there is a chance to get a spectrum of a possible atmosphere when the star's light passes through. If that is the case, i am sure that someone will soon(tm) obtain such spectra, maybe after the discovery has been verified. 6 of the planets are assumed not to have formed in situ but farther out and migrated inwards. So they were not always under the conditions they are assumed to be now.

Well, the original question was "if we could travel at the speed of light". I understand it like this: as the traveler approaches c space contracts ever more and time passes ever faster, relative to an outside observer. At c (or better at the speed limit, which is strongly assumed to be c but might be just a little bit above) space is infinitely contracted and time infinitely compressed. Imagine, no space, no entropy, no time. Edit: "10 years into the journey" indeed does not make sense since the journey at the speed of light does not take time. On the other hand, for an outside observer, it takes infinite time. This is for a fictitious traveler at exactly the speed limit and does not contradict the calculations for a journey with a speed just below c. Hope that was not totally wrong ...