boriz

"If you can get people to believe absurdities, you can get them to commit atrocities." - Voltaire.

I'm pretty poor with maths, and my understanding of General Relativity is basic, but I had this idea, and I'm wondering if it holds water. Many people will have heard of the balloon with dots on it being inflated to illustrate expanding 4d space, redshift and why the universe has no 3d center. Well space isn't just expanding. The expansion is accelerating. This means that there are no truly inertial reference frames in the universe. Everything is always accelerating, in 4d. Could this be the source of gravity? All mass distorts the fabric of spacetime as it resists this acceleration ? I know it's more Issac than Albert, but to create my own rubber sheet analogy... Imagine the ubiquitous rubber sheet inside the ubiquitous space ship without a window, and you are accelerating at 1g. No way to tell you're not standing still on earths surface right? Equivalence principle. So you put a marble in the middle of your rubber sheet and it makes a small dimple, a 3d analogue of a 4d gravity well. It looks exactly like it would look here on earth. But now you tweak the engine to increase the acceleration to say 1.5g. What happens to the dimple? It gets deeper right? It would look like the marble has gained 'weight'. With the engine off, no matter how fast you are travelling, the marble will not distort the sheet, it has lost all of it's 'weight'. If you can picture this all shifted up one dimension, you'd say it had gained/lost mass. My conjecture is that gravity is our 3d perception of the response of spacetime to mass being accelerated through 4d space. If expansion wasn't accelerating, there'd be no gravity. So, what do you think? *Ducks for cover*

"If you wish to make an apple pie from scratch, you must first invent the universe." - Carl Sagan.

Hall sensors, being non-contact and immune to wear 'should' always be better. Any non-linearity can easily be linearised in firmware. The problem is the rest of the hardware and how it is effected by wear and tear. A good Hall joystick can become a turd after six months if the hardware is weak, and a good Pot joystick can remain good for years if the hardware is strong. No substitute for a proper review when choosing peripherals. And by proper, I mean non-sponsored and after lots of use. Early adopters beware.

Dream lost all credibility when he cheated on an official speedrun.

The faster you go, the slower you go. Simples.

"You know what they call alternative medicine that's been proven to work? Medicine." - Tim Minchin.

Thank you all. I have purchased a 'five bug package' from : https://www.etsy.com/ , and (fingers crossed) it should be what I wanted. I Have nothing against Chinese people. I just keep getting poor quality stuff from them. And I think their dictator is a poo.

I have a digital microscope similar to this one: https://www.amazon.co.uk/TOMLOV-Microscope-50X-1000X-Magnification-Observing/dp/B08G43G8ZV It's going to be an Xmas prezzi for a 9yo. I'd like to accompany it with some preserved/pinned samples of exotic creepy crawlies of appropriate size, say between 5mm and 20mm. Please could someone direct me to an online shop that can provide such samples? Preferably not chinese. I have rejected the slide collections available on Amazon. They provide no scale information, only show backlit examples (this microscope has no back light), and could be too small for this microscope. It's claim of 1000x magnification is a typical chinese overestimate.

Thank you.

Thanks peeps. On this occasion, I was building a quad-copter in the VAB (pic1). Each engine was placed upon a 4-sym fuel tank. But since two engines (and rotors) need to revolve in the opposite direction, I was trying to place the engines in 2-sym pairs. I couldn't get it to work. I eventually just placed them in 4-sym, then removed them all from symmetry and set the directions individually. The two rotor co-axial version is better though (pic2).

Thank you miklkit. At least now I know it's not just me. Could it be scatterer, or does everyone have this bad texture?

I'm trying to place two-symmetry parts on a VAB craft, and when the mouse passes over a four-symmetry part, the editor automatically switches me from two-symmetry to four-symmetry before I can place the part. This auto-switching behaviour is frustrating. Is there a way to suspend it? A keyboard shortcut perhaps?

The first image is from V1.12.2 and the second image is from a complete install of V1.12.3. (GOG) When I deleted *.2, I selected the option to keep my saved games. It also retained my mods (Scatterer 'n such). Would that also retain my broken Kerbin Texture? If so, how do I extract the required file(s) only, from the GOG installer? If I do a parallel install, in a different folder, would that reset all the registry entries to the new install and break my 'saved game' install? Is there a way to manually back-up my progress, then do a clean install, then manually restore my progress, so I don't have to select 'keep saved games'?

It runs North/South on the opposite side of Kerbin from the KSP, and it disappears when I get close enough. I have tried '-force-d3d11' and '-force-openg', with no effect. Anyone else have this, or is it unique to my installation?

Why, after I arm my chutes, do large spaces appear between the chute icons? (This is a sandbox test of a 10 seat reusable Mun lander, for career mode tourists.)

Ok. My 'gut' was wrong. 21km@1200m/s gets you about twice as far as 13km@900m/s. The test: A single whiplash engine with a single Mk1 liquid fuel fuselage holding 400 units of fuel and the minimum of aircraft around it. Mechjeb2 autopilot did all the flying. I manually started the takeoff run, and once I was sure the aircraft was rolling straight, I engaged MJ. MJ did the rotation, climb, the entire flight. All flights were runway heading, 090. I did four flights of different speeds (300m/s, 600m/s, 900m/s, 1200m/s), at each of six different altitudes (6km, 9km, 12km, 15km, 18km, 21km), for a total of twenty-four flights. 1200m/s was the limit for overheating. When the fuel ran out and the engine cut off, I immediately pressed F3 to record the range data. After many hours, I learned four things. Firstly, as was said, the higher and faster, the better. Heat friction losses are negligible. Secondly, the heating effects are exactly the same for a particular speed, regardless of altitude. The 1200m/s run would always end with the Mk1 inline cockpit moments away from exploding (full heat bar). Thirdly, I should have used bigger wings. I repeated the last (highest and fastest) run with the same aircraft, but twice the wing area, and got a significant range improvement because of the lower AoA. But this is just supposed to be a test of the engine. And lastly, perhaps most surprisingly (for me), 400 units of fuel and one Whiplash is more than enough to circumnavigate Kerbin along its equator and land back at the KSC with fuel to spare. Who'd have thunk it? The 18km and 21km data is missing a 300m/s run because the autopilot couldn't cope with the extreme angle of attack required when going so slow in such thin air. I spent ages trying to tune the PID but eventually gave up. The results: Horizontal scale is Range in Kilometres. Vertical scale is altitude subdivided into speeds. The duration of each flight was also recorded, but omitted on the chart, since it can be easily calculated. The testbed:

Thanks guys. The twin engine plane in the picture in my OP, is my 'fast recon', and can easily go fast enough to melt. My 'gut' speed of 900m/s is because beyond that, I get some serious heating effects. This implies a lot of energy lost to drag, but I don't know how KSP models that. I've built a small test plane to do some experiments at various speeds and altitudes. Using MJ autopilot for consistency. Assuming I don't get bored, I'll post my results here. BTW. I never use the Rapier. I feel it's 'cheating' to use future tech. My testbed:

Made it with fuel to spare. Thank you. The second plane is my fast recon, used to find and mark the site so my VTOL could head straight there. Now to refuel and fly back to KSC. Is there a complete list of these discoverable sites?

This engine is pretty inefficient at low speeds, but where is the sweet spot? By efficient I mean greatest distance covered for least fuel used. At the moment, my gut says around 900m/s@13000m. Has anyone done experiments?

Very helpful. Thank you.

I challenged myself to build a crewed super sonic VTOL that can take off vertically, fly supersonic*, land vertically at the North pole, plant a flag, then return and land vertically at the KSC. I managed to get the flag planted, and I have used about three quarters of my fuel. I'm not expecting to get all the way back to the KSC with this mission, but my problem is this: Which direction do I head? At the north pole, everywhere is south. Where's the closest airfield, and which direction is it? https://ibb.co/zPN9Qzh (*About Mach 2.7) https://ibb.co/zPpL49t https://ibb.co/yF1RjMM

Draft rules updated. Thank you sevenperforce. I like the scoring idea too, though before a final system is agreed upon, I think some balance testing should take place. Might change the name to 'Matryoshka challenge'. Currently, I'm up to two stages, with a third in the works. I think this challenge might end up with some massive first stages that don't fly very far, but boost the score for successive stages.

I have been playing with VTOLs recently, and have made some progress, but I'm still working on a system to carry a small VTOL in, deploy it from, and recover to, a larger VTOL. The larger being the transport for the smaller. Think luxury yacht with deployable Jet ski. It should ultimately allow me to fly anywhere (on Kerbin), land almost anywhere, and deploy the sub-craft to visit the local science waypoints (Career mode style). This set me wondering just how far it could be taken. How many nested VTOLs could be deployed from a VTOL? By nested, I mean a VTOL inside a VTOL inside a VTOL. A typical entry would take off from KSC, fly a straight course until fuel forces a landing, where the sub-VTOL is deployed, and it flies along the same course, until it is forced to land, then it deploys it's sub-VTOL, etc. I'm thinking there should be a scoring system based upon total horizontal distance covered (D) and number of VTOLs deployed (N), favouring the VTOL number. Perhaps D*N or D*(N*2), even D*(N^2). Draft rules: Each VTOL will be piloted. (It will have its own command seat, and must be flown from there). Each VTOL will take off vertically, fly horizontally for some distance and land undamaged, vertically, under power before that leg is counted. A leg ends when a flag is planted. No rockets. No RTG's or solar panels. No decoupling parts, except the sub-VTOL. No major clipping. (Cheesing extra fuel or engines or fully clipped aerodynamic parts, for example.) RCS and/or RW's ok. Fuel transfer ok. No facility for re-nesting (recovery of sub-vtol) needs to be provided for. Both DLCs allowed. Only passive Mods allowed. (Telemetry and such, no part or performance Mods.) What do you think? Could this be an appropriate challenge for this topic?