This is awesome, nice work! In case it's useful, I made a Python package for calculating solar irradiance at altitude: https://github.com/gusgordon/airmass
Takes into account lots of stuff (e.g. attenuation from air, ozone, and water vapor) with the goal of estimating solar power at any altitude/latitude/day/time.
Totally - right now it's using the USDA food nutrient database [1] which has all nutrients, so all the nutrients on the back-end are there. Calories is the most important thing to the majority of people (in my experience), so there's a balance between showing too much information vs. keeping things simple. Probably should just add a setting to show everything, though.
I got a minimum wingspan of around 8m for self-sustaining flight on the winter solstice with a small payload — pretty close to what you all built.
The biggest problem I ran into when creating this analysis was accurately estimating solar irradiance at different altitudes. Here's the module I built for estimating that, in case you find it useful: https://github.com/gusgordon/airmass
Given that there have been multiple mass extinction events in Earth’s history, it seems reasonable to spend a small fraction of GDP on colonizing another planet. How about something roughly equivalent to the amount we spend on chapstick?
What’s your recommendation in terms of tooling for cases where it’s not just prototype -> production, but an iterative process? I love notebooks for prototyping, but I find it’s a lot of work to make sure notebook code and prod code are in sync. Maybe just debugging with IPython?
Having used this, it's fine, but not that great compared to similar products. I understand some people do like it.
That said, has anyone else noticed the quantity of reMarkable posts here (about once per quarter) with hundreds of votes that are essentially ads for the product? reMarkable clearly has a large advertising budget given the amount of ads I/others see from them on social media. Is it possible that they're purchasing HN votes?
Good question. One requirement for the aircraft in this optimization is that they must have more energy in the battery than they did 24 hours prior. If the aircraft started at full energy, they wouldn't ever be able to satisfy this requirement, so that's why it's an independent variable.
For example, an aircraft could "start" at 50% battery state of charge, then charge to 95% over the course of the day, then come back 24 hours later at 51%, and that would be valid. There are other ways around this, but this is what I came up with at the time.
This is similar to why the starting altitude is allowed to float. The gravitational potential energy of the aircraft can be used as another "battery", but the aircraft is only a valid solution if it's not losing altitude over the course of 24 hours.
For those curious about the physics of these aircraft, here's an analysis I did of the same concept. The goal is to determine the smallest aircraft configuration that can indefinitely sustain flight: https://github.com/gusgordon/atmospheric_satellite#readme
Seems feasible, never went past the analysis phase though :)