rolling_robot
Re:Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft
on Monday October 16, 2023 @03:57PM (#37905550)
I am curious how are you planning to cope with aeroelasticity issues in near-earth turbulence. Given low air speed, low wing loading, and huge aspect ratio this is going to be an issue. I suspect that most of the previous projects failed because of these issues combined with tight requirements on very light-weight structures.
Re:Launch HN: Radical (YC W23) – Autonomous high-altitude solar aircraft
on Monday October 16, 2023 @03:45PM (#37905337)
Winds up to 20 km are NOT quite calm. They can max out to 60 m/s at height of 10 km, which is more than 3 times than enough to blow a solar aircraft far-far away. You have to choose proper meteo conditions for climbing and descending and plan the trajectory taking into account those winds to be able to land at a given place.
I've been analyzing GFS data a couple of years ago for similar project. The problem is that lack of energy demands to design a really low speed aircraft for low densities that you can find in stratosphere. At 10 km winds are stronger than in stratosphere and density is higer.
You can find the results in https://journals.sagepub.com/eprint/GVXWXDABPE6A8PNRGTBU/ful....
The whole aircraft model probably is not like yours and is subject to many conservative estimates, but I am pretty much sure that wind model is accurate in this publication and generalizable to different regions.
Re:LibGen's Bloat Problem
on Sunday August 21, 2022 @09:58AM (#32540256)
The graph should be in logarithmic scale to be readable, actually.
Re:You can do a lot with an empty file
on Thursday April 07, 2022 @07:15AM (#30943005)
Re:In the end, you're treated like a spy, says MIT scientist
on Friday January 28, 2022 @09:11AM (#30114761)
In US you end up being free, but treated like a spy by some funding agency. In Russia you end up in prison having no hope of getting back. Arrested in April 2021, 69 year old professor Golubkin is still in remand prison. https://meduza.io/en/feature/2021/04/13/another-treason-case accused for governmental treason.
Re:Awesome Self-Reference
on Tuesday January 11, 2022 @01:50AM (#29888399)
Apparently, "contents" line is missing in the contents.
Re:Flutter tutorial for beginners
on Saturday May 02, 2020 @11:04AM (#23052150)
Thought it was about wing aeroelasticity at first.
Re:This Artwork Does Not Exist
on Thursday March 05, 2020 @06:28AM (#22492666)
Take, for example, Tcl brutforce, Clojure and Wolfram which is written to only solve an example with words.
Implementation in D does not seem to be right: they just define a function that takes list of lists and a function, which is not exactly what is required in problem statement.
Hmm, many of the solutions are in fact invalid. Is the list moderated somehow?
AAAI discussion with D.Kahneman: Present and future of decision making
The magic of generating new ideas
Linked Data (2006)
It would be really nice to have emacs package that supports argdown compilation and syntax.
Long working hours and other pressures faced by early-career researchers
Programming Languages Benchmark Using Toy Programs
Russian startup wants to put billboards in space on cubesats
Sherp ATV
Head transplant
ISS astronaut video blog
Big data ethics as new business asset?
New altitude record for non-powered flight of 52000+ft (15km)
Re:Can Happiness Make You Healthier?
on Thursday October 27, 2016 @11:57AM (#12806199)
There is also a beautiful course on EdX "The science of happiness" where they show beneficial impact of happiness on health.
https://courses.edx.org/courses/course-v1:BerkeleyX+GG101x+3...