gusgordon

I was doing some analysis of a solar-electric plane that can fly indefinitely: https://github.com/gusgordon/atmospheric_satellite

Seems feasible, never went past the analysis phase though :)

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.

[1] https://fdc.nal.usda.gov/download-datasets.html

Stopping by to say this is super cool! I've been pretty obsessed with this idea for a while — here's an analysis I did a few years back: https://github.com/gusgordon/atmospheric_satellite

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

Congrats and good luck!

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?

Yeah, that’s basically what I do, but I often find I need to play around with intermediary data within functions.

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?

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.

Yes it's a lot easier at lower altitudes since you can get more lift, but you might run into some extra regulatory issues with that :)

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

Here's a fairly in-depth analysis of supersonic electric VTOL aircraft: https://github.com/gusgordon/electric_jet

tldr; they become "practical" with a battery specific energy of around 1500 Wh/kg. However, if you just want to do a demonstration, they are practical now (as this post suggests).

The primary goal of RCV in the US is to address the hostile partisan divide. Making more parties viable is secondary.

When you have a ranked choice system (even if it's only in a fraction of states), it incentivizes the candidates to not disparage each other. If candidate A attacks B, it means the B supporters will rank A lower. RCV draws candidates closer together.

It’s expensive to get access to a GDS API and, from what I’ve heard, the data they provide is quite difficult to work with. There’s a reason Google bought ITA for $700m, right? If this project ever grows, it could make sense to pull from a GDS.