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7kayon Bouncing a LoRa message off the moon

As others have already pointed out this exercise used a huge dish(a radio telescope[1]) and significant power. This is in no way an economically viable mode of communication. Using satellites in low earth orbit requires less power and a significantly smaller antenna. Putting LoRa on satellites has been done before, see e.g. [2].

[1]: https://en.wikipedia.org/wiki/Dwingeloo_Radio_Observatory

[2]: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4...

7kayon Bouncing a LoRa message off the moon

No, the radio waves bounce off the moon's surface. The retroreflectors are not necessary for that, otherwise stuff like Earth-Venus-Earth bounces[1] would not be possible.

[1]: https://amsat-dl.org/en/earth-venus-earth-experiment-of-amsa...

7kayon ImageMagick: CLI for Image Editing

For reference (mostly for me as I need this from time to time), you can do the same on dpkg-based distros with

     $ dpkg -L imagemagick-6.q16 | grep bin
     /usr/bin
     /usr/bin/animate-im6.q16
     /usr/bin/compare-im6.q16
     /usr/bin/composite-im6.q16
     /usr/bin/conjure-im6.q16
     /usr/bin/convert-im6.q16
     /usr/bin/display-im6.q16
     /usr/bin/identify-im6.q16
     /usr/bin/import-im6.q16
     /usr/bin/mogrify-im6.q16
     /usr/bin/montage-im6.q16
     /usr/bin/stream-im6.q16

Similarly, you get

     $ dpkg-query -S /usr/bin/convert-im6.q16 
     imagemagick-6.q16: /usr/bin/convert-im6.q16

This does not work for the canonical executables though as they are just symlinks to /etc/alternatives/foobar

7kayon Lazygit: A simple terminal UI for Git commands

May I ask what made you choose lazygit instead of fugitive? I'm using the latter and am quite happy with it, but I'm keen to learn what I'm missing out on.

7kayon EmacsConf 2021 – Live Now

Do you use the native-comp branch of emacs? This probably doesn't make any difference when it comes to multithreading but it should make the experience a bit more smooth.

7kayon RasPBX Installation for Beginners

You might want to consider using the BR2_EXTERNAL feature[1] to keep your customizations outside of the buildroot tree.

[1]: https://buildroot.org/downloads/manual/manual.html#outside-b...

7kayon Nvui: A NeoVim GUI written in C++ and Qt

I guess this is a thing you could achieve with neovim-remote[1]. My main use case for it avoiding nested neovim processes in the inbuilt terminal, though

[1]: https://github.com/mhinz/neovim-remote

7kayon Tupolev Tu-144: The Soviets' doomed rival to Concorde (2017)

Speyer has the Buran as well

https://speyer.technik-museum.de/en/spaceshuttle-buran

7kayon LimeSDR

The easiest way to leave the gray zone would be to get a ham radio license. Although this might vary from country to country, generally you are allowed to use selfbuilt transmitters in specific frequency ranges, which also includes noncertified hardware.

7kayon Why does it take so long to get to Mercury?

They use GMAT, the General Mission Analysis Tool https://opensource.gsfc.nasa.gov/projects/GMAT/index.php

7kayon Linux Hypervisor Setup (Libvirt/QEMU/KVM)

Do I guess correctly that you have cockpit running on the host and manage guests via the cockpit-machines plugin? If so, do you have any hints on where to find documentation about that? A cursory glance at the repo didn't produce much information.

7kayon OpenStreetMap in Realtime

You might wanna tell the people of Oulu that Finns don't see cycling as a means of transportation: https://youtu.be/Uhx-26GfCBU

You don't maintain extensive bike infrastructure during harsh winters just for a few leisure cyclists. Although I agree that no one comes close to the Dutch, the situation in Germany is not as grim as you describe it. The quality of cycling infrastructure varies from city to city and I guess it's safe to say that infrastructure is the main driving force in getting people on the bike. Münster isn't famous for nothing, right?

7kayon Ham Radio Forms a Planet-Sized Space Weather Sensor Network

Each country's member association of the International Amateur Radio Union[0] likely provides information on ways to get your ham radio license in the specific country.

Germany: https://www.darc.de/einsteiger/amateurfunkausbildung/

UK: https://rsgb.org/main/get-started-in-amateur-radio/

France: https://promocom.r-e-f.org/

Sweden: https://www.ssa.se/amatorradio/bli-radioamator/

[0]: https://www.iaru.org/reference/member-societies/

7kayon Show HN: Time tracking with plain text files

This reminded me of ledger, the plain text accounting tool. FWIW, ledger has time tracking and billing capabilities, too.

For example: https://github.com/anarcat/ledger-timetracking

You can also use the aforementioned org-clock-in with it.

7kayon Maddy: Composable all-in-one mail server in Go

You're right, that's the basic ingredient #1 I forgot to mention. Functional rDNS is essential. You don't want to have your mail server running at home anyhow. A friend of mine had a janky setup at home until I convinced him it's a bad idea.

7kayon Maddy: Composable all-in-one mail server in Go

I run my own mail server and have never experienced such issues. The important thing is that your mail server is not an open relay and you set up DKIM and SPF. Oh, and never run a mail server with an ip originating in a residential area, you'll get blacklisted almost instantly by virtually any mail provider.

7kayon Naming Law

I'm gonna assume said Jörg is German. Quoting from Wikipedia

> German names containing umlauts (ä, ö, ü) and/or ß are spelled in the correct way in the non-machine-readable zone of the passport, but with AE, OE, UE, and/or SS in the machine-readable zone

In my EU driver's license the umlauts are spelled in the correct way, these aren't in my name, though.

https://en.wikipedia.org/wiki/German_passport#Different_spel...

7kayon What’s New in Thunderbird 78

I know of expression-search(https://github.com/wangvisual/expression-search) but it is not supported in recent versions of Thunderbird. I'd be interested as well as I've been longing for a proper keyboard UI. For quickly switching folders there is Nostalgy(https://github.com/nostalgy/nostalgy).

7kayon Ask HN: What kind of math do you study in your free time?

I'm interested in fractional calculus.

It all started with an argument I had with my high school math teacher about whether something like a half derivative is a thing. Turns out fractional calculus is a real thing and shows up in many applied areas of math. The Fractional Calculus by Oldham and Spanier I have lying around treats its applications to diffusion problems, for example. As an EE student fractional PID controller design and fractional signal processing are interesting as well.

For a quick peek into that subject I would recommend watching Dr Peyam's videos on half derivatives[0].

[0]: https://www.youtube.com/watch?v=eB3OUl5TVSY

7kayon Ask HN: Which tools have made you a much better programmer?

One other method to quickly exit insert mode if you can't remap keys is ^C. I did not know this even though I used gvim on Windows computers not under my control for years.

7kayon Snabb: 100 Gbit/s pure software switching using Lua (2019)

Interesting, thanks for sharing. It's always nice to see Lua in the wild. This headline immediately reminded me of this[0] talk from CCC 2018 comparing different high level languages for writing userspace network drivers.

[0]: https://media.ccc.de/v/35c3-9670-safe_and_secure_drivers_in_...

7kayon Receiving images of Earth from satellites with software defined radio

The title first suggested that the article is about a security vulnerability of a satellite. The DoD actually held a CTF recently focused on the security of space systems. Information is on https://www.hackasat.com/ I'm looking forward to the public release of the exercises from the qualifying round which will be on June 19.