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Android java developer newbie who tries to be as "agile" about it as I read be the current fashion.

I'm also interested in low level (c, assembler) programming of MCU IC's. Especially radio related (such as zigbee and low energy bluetooth).


Mar
25
accepted Aren't there more naked-eye-visible stars in the Milky Way plane?
Mar
23
comment BIG Problem with the Planet definition
This entire exercise should be the basis for a marketing or PR whatever book on how not to do things. The previously anonymous IAU suddenly, and without being prepared, got bogged down in some kind of hopeless "debate". Have a look at their youtube channel, now dominated by titles like: Is Pluto a planet? What is a planet? What is a dwarf planet? Is Pluto a planet again? Ten years ago none of these issues existed. Crying children didn't write threatening letters to astronomers. Any other planet would've been easier to get rid of, but Pluto is American. You don't mess with that unpunished.
Mar
23
comment BIG Problem with the Planet definition
@DavidHammen The basic problem is that the definition mixes different categories, such as orbit and shape. Each criteria is fine on its own, but they don't go hand in hand in nature as neatly as the planet definition pretends. What use is classification which puts Mercury and Jupiter in the same class? And the timing couldn't have been worse, with Alan Stern going to Pluto and thousands of exoplanets being discovered. Is a hot Jupiter a "dwarf planet" if it is intruding on another planets orbit as it spirals towards is star? It was a mistake to even raise the question. But entertaining!
Mar
23
comment BIG Problem with the Planet definition
A planet is literally anything anywhere. If there's a thing there, it's a planet. One cannot define that without getting bogged down in a swamp of lawyers' rhetoric. "-Well, it should be roundish and lonely and..." Good luck! Pluto crosses Neptune's orbit, so neither of them can be a planet if one tries to use the broken logic of the IAU. How long is a string? This is a definitional disaster which should never have been addressed to begin with, don't expect any good answer.
Mar
22
comment What were the challenges for the ancients to observe the orbit of the Moon (instead of Mars)?
I must add that the Moon is special since it actually orbits Earth. If you're geocentric, then Luna is your friend. But it is an exception, one of a kind. Any conclusions drawn from observing it will likely go bad. Astronomy is hard.
Mar
22
comment What were the challenges for the ancients to observe the orbit of the Moon (instead of Mars)?
I'm not convinced that perturbations by Venus and Jupiter is a good explanation to why the orbit of the Moon is hard to understand. Kepler showed that Copernicus' world view was mathematically identical to that of Ptolemy. Deferents and equants, well, we do have center of masses in the middle of empty space today. The "thing" around which everything turns. The ancients actually made up focus points in the circle before they understood that it is an ellipse. And what does a moon if not describing an epicycle? Galileo literally saw epicycles in the sky when he discovered the moons of Jupiter.
Mar
22
comment Lack of planets in the Oort Cloud
What news is that, do you have a link or keyword? The shape of the Oort cloud is inferred from the comets coming from all directions, as if from a cloud surrounding us (or like interstellar vagabonds). I guess that the reason they haven't agglomerated is that it is so empty out there. The distance between comets is of the order of the distance between planets. They don't get together very often.
Mar
22
asked What were the challenges for the ancients to observe the orbit of the Moon (instead of Mars)?
Mar
20
comment Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)
@pela On images from Mars orbit, sand dunes made up of fine tiny particles look dark. As I understand it, because they are tiny, not because they are intrinsically dark individual by individual. And the dark Moon looking white at a distance cannot be an atmospheric phenomenon since images from the Dawn spacecraft approaching Ceres shows the same effect.
Mar
17
awarded  Popular Question
Mar
17
comment Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)
@Py-ser I've added an example image. You know how the Moon looks from Earth.
Mar
17
revised Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)
added 256 characters in body
Mar
17
asked Why do dark objects look white from a distance? (Moon, Ceres, but not Earth!)
Mar
14
comment Expansion of Space
@PeterU It is the bending of space that makes Andromeda and the Milky Way fall toward each other. They don't "pull", that was the Newtonian idea scrapped a century ago. They "fall" down curved spacetime. Space is bent by the mass of matter nearby. Mostly by unknown dark matter. But then there's also unknown dark energy which accelerates the expansion of space. I don't know, I "learn" mostly by watching lectures held by persons who obviously never really left their student lifestyle. It's a most intriguing reality TV show anyway. The one who predicts how it ends wins the Nobel Prize.
Mar
14
comment How should one rationally deal with the issue of space travelling alien civilizations?
@VictorStafusa It took some time for humanity to figure that out too, under a clear sky. And maybe there are other space class thingies around which we still haven't any useful knowledge about. Another potential addition to Lorin's list might be that the universe is paradoxical, that logic is an illusion in our dreaming minds and does not apply to the real reality (like the simulation argument).
Mar
14
accepted How should one rationally deal with the issue of space travelling alien civilizations?
Mar
14
comment Expansion of Space
@PeterU Andromeda is moving through space faster than space expands between it and us.
Mar
14
comment Is it possible that the Sun has a binary partner (the Nemesis Theory) that has eluded detection?
Would it really be so bright? Proxima Centauri at a distance of 4.24 ly and 0.123 sun masses is not visible to the naked eye and wasn't discovered until 1915.
Mar
13
comment Is it likely OMG particle (and those like it) originate from alien spacecraft propulsion systems?
Given our huge data sample of advanced alien propulsion systems, why don't you do the simple math yourself? What kind of answer do you expect? A thousand years ago, exactly the same question was phrased: "If there is a God who makes thunder and lightning in the sky with his hammer, then..." Yes, it is a most interesting question and I'd die to know the answer. But. I think this kind of questions should be welcome here, if the purpose of this site is to make outreach to the well informed public who care about these unsolved mysteries. Other sciences than astronomy don't get much of that.
Mar
13
comment brown dwarfs and planets
In some contexts, an icy atmospheric moon might have more in common with a terrestrial planet, regardless of what it orbits. "Planet" made sense in the ancient times because they were all wandering dots with much in common. Now having Mercury and Jupiter in the same category is hardly a very relevant definition for many purposes. Not that I think it is a real problem, astronomers probably know what they are talking about anyway. (Which means even less reason to make up precise definitions of those words according to the current knowledge about different celestial objects.)