Green Baron

Sure, thinking before writing might help :-) Thanks for the correction !

A, well, i get for an observer observing a traveler at 0.99c for 40 years in the travelers reference system "spending 40 years" a relative time of ~283.5 years. Travelling at 0.9999c i get ~2828.5 years, 0.99999999999999999999999c will be a relatively "long time, brother" :-) What am i doing wrong ?

Poetically: at the speed of light you are, from your point af view, everywhere in no time. Above is left to your fantasy. Contraction of space: ll = sqrt( 1-v²/c² ) * l where ll = length in moving system, v is your speed, c is c and l is lenght without relative motion. Now set v = c and you get ... 0. Dilatation of time: tt = 1 / sqrt( 1-v²/c² ) * t. Set v = c and you get an undefined value. Edit: if only a physicist could take a look at this ...

Actually no. If the traveler was a photon at the speed of light from here to there it would travel an infinite short way in an infinite short time, from it's view. But that does not matter as the space contracts in flight direction and the distance between objects becomes infinitely short, as seen from the photon. On the other hand, in the same manner as the space for the traveler contracts, the time for the outside observer stretches. He would actually measure an infinitely long time for the journey, the universe together with the planet had just gone when the traveler arrives. But luckily we don't have to stress our brains over that because anything that has a mass cannot reach light speed. Edit: if the photon had a very little mass and speed of light was not the limiting speed but the limiting speed was just a bit higher than c, then ... i don't know, trying to summon @K^2 ?

For an outside observer it would take 40 years. For the fictitious traveler at light speed the whole time of the universe would just be a flash. That is relativity. But note that anything that has a mass cannot reach light speed. The mass increases with speed and would become infinite when reaching light speed. Edit: this relatively incorrect ...

Hi guys, something to read. http://www.nature.com/news/these-seven-alien-worlds-could-help-explain-how-planets-form-1.21512 Nope, no aliens but could tell a little more about planet forming. Am still reading. Edit: the paper: http://www.nature.com/nature/journal/v542/n7642/full/nature21360.html 'nother edit: oops, thanks for merging. I wasn't aware that it is already covered in here :-)

It's not out of focus, it's physics. A lens cannot focus a broad spectrum of light (like visible through infrared) in a single point, so the broader the spectrum, the blurrier the image. If you filter out visible wavelengths and focus on infrared then the image will be sharp(er) again. Of course, a webcam is not a precision instrument, but an expensive photo apparatus with a good lens has the same problems. Also, lenses usually are corrected for visible light (~green), where human eyes usually are most receptive.

Live long and prosper. You'll live much longer if you switch to weekly birthdays ... :-)

I only count 11 Präsis ...

Orbital parameters are constrained, not the position in that orbit. In order to server as a perturber of the observed bodies it must have a highly excentric orbit with an apoapsis opposite of the apoapsides of the observed bodies. But that means that it is a long time far away near the periapsis and only a short time in an observable range, which in turn makes it improbable to view accidentally. Edit: visit the other thread on planet nine for more info and links :-) 2nd edit: Dwarf planet's orbits are not the only hint to planet nine. The tilt of the planets to the sun's axis can also be explained by a mass far out with a long lever.

1609 meters. Only indirect evidence, but concrete (didn't know that this is an adjective as well, always thought of construction material :-)) enough to postulate it's approximate mass and orbit. Discovery could take until the next generation of telescopes is working.

Thanks, @Steel, yes, i meant twenty thousand years, thought that would be clear at a distance of several hundred AUs ... :-) 20 years orbital period is somewhere between Jupiter and Saturn. :-)

The planet nine thing is no bogus. Many people are working on it and a a lot of serious papers have been written about it. Up to now it has been postulated as a perturber in the outer solar system that might well be responsible for the otherwise unexplained orbits of dwarf planets in the kuiper belt and could explains other observations as well. Direct observation is difficult, maybe impossible with current generation telescopes because it is very far out (100s of AUs with an orbital period of ~20.000 years). Mass and orbital parameters have been estimated. It is, probably, only a question of time until it gets "discovered".

Now i'm wearing the lecturer's hat :-) The real science, sedimentary geology, knows nothing about abiogenic oil on earth. Yeah, maybe such processes exist, but that's guessing, not science, and all that guessing is starting to harm real science. And the original idea was about abiogenic to replace biogenic oil, which has a political aspect in it and does not reflect the natural processes, from a geoscience point of view. Edit: no offense to you guys, don't get me wrong :-) I might be wrong.

I use Wikipedia for hard facts only, things that are difficult to debate. In this case, the abiogenic oil thing was partly advertised by a soviet group, so the danger is to fall for propaganda ... I have absolutely no problem with a lecture :-), but I keep things the other way round, if i find nothing in the scientific journals then it doesn't exist. Not that i pretend that this is the right way and i might miss many things.

Well, like reactionless thrusters, or so :-) Sorry, not that i knew, it was sort of a debate long ago, though it would be nice. Ninja'd. @KSK, Wikipedia, really ? ;-/ :-) But we could start a discussion on what is biogenic and what is abiogenic ... Edit: *scratchhead* didn't we have that some time ago ? *toolazytosearch*

Another hint in favour of a "perturber" of the trans neptunians: https://academic.oup.com/mnrasl/article-lookup/doi/10.1093/mnrasl/slx003 Just because the observatory up on the hill here was involved :-) Compressed version: objects that are so far away (hundreds of au from the sun) that they cannot be gravitationally influenced by Neptune, but have a highly eccentric orbit, are likely to be/have been influenced by a "perturber".

Nonsense. if the profile is not completely messed up straight wings are more efficient than swept ones. See top gliders e.g. Swept wings need helpers like flaps to keep a plane flying at low speed. From the website: "The Stratolaunch Carrier Aircraft is constructed using state-of-the-art composite materials in order to be light, strong, and fuel efficient. Once complete, Stratolaunch will have the largest wing span of any airplane ever built and will be the world's largest composite aircraft." underline mine I mean, that is exactly what it looks like, isn't it ?

*Cough*, well, that what we pave the roads with are the remains of that what once did live. I only hope nobody draws an analogy now :-)

This is probably the source: http://science.sciencemag.org/content/355/6326/692 To make this clear once and for all, before everyone cries out "Life !! I knew it !!". That is not necessarily a surprise and these molecules are not rare in our solar system.

Try the primary focus, no eyepiece, no correctors, no filters, no bottoms of glass bottles. That means to directly fix the camera to the focusser tube with the appropriate adapter. Will post a photo link later of what i mean. Eyepiece projection complicates things because you have two foci to hit. Also it adds to the stack of possible errors and mistakes :-) Like balance, focal plane, distortion by lenses, etc. Good luck tonight ! Edit: if you mean with cannon xti the canon eos400d here's what you need to get the camera in the primary focus: http://www.telescope.com/Accessories/Adapters-Cables/Orion-Superwide-2-Prime-Focus-Adapter-for-Canon-EOS-Cameras/pc/-1/c/3/sc/40/p/115062.uts Just an example, doesn't have to be that brand, i just searched these because you already have an orion telescope. The above is a one piece adapter. For more flexibility in the future it might be wise to split the adapters in two: http://www.telescope.com/Orion-T-Ring-for-Canon-EOS-Camera/p/5224.uts?keyword=t adapter and then http://www.telescope.com/Orion-Tapered-2-to-T-thread-Adapter/p/113926.uts?keyword=2 adapter t

Yep, it is ok for a first try, but it's not ready for stacking. You didn't tell us how you made the photos, but in any case you'll need to find the primary focus first (use a Bahtinov mask), and the camera chip must be aligned exactly perpendicular to the optical axis. Check the collimation and be sure that nothing shakes camera or scope during exposure. Was it windy or did you hold the camera by hand ? Edit: btw., the star on the right looks like a typical coma-star (comatic aberration, typical for short newtons with a parabolic mirror). But before taking care of this have the above criteria corrected first, especially alignment and collimation. What camera did you use ? Don't loose patience. It took me over a year. And try to gather all information you can get. I would try cloudy nights for example or another community specialised on all things astro as well !

Always a pleasure to visit this thread. I must admit, i wasn't aware that Uranus had a visit and was wandering where that photo of Miranda came from: Voyager 2.

Well, what i should have said is that the probabilitiy for a profound answer is higher at the source than in a computer game forum :-)

Yeah, well a possible "moving the center of lift back" is of course compensated by other means, like moving the root of the wing forward. I can speculate about many reasons while the designer built/will build this thing like he did/will do. This one looks pretty straightforward for me, except for the multi-hull. Wingsweep has advantages and disadvantages and aircrafts are designed to serve a purpose. I am sure that all criteria like lift, drag, structural considerations, stability, etc. were taken into account, so the initial question is somewhat obsolete. I mean, we know that Rutan's contraptions actually do fly ... If you really want to know then ask Rutan. Write a friendly email, like interested, lay, model maker, whatever. Worst case: you don't get an answer. I tried something similar once with the making of a model of a historic sailing boat, wrote to the national museum in Paris, France and actually got copies of historic plans ! :-) Great service.