This is an academic seminar, so not much razzle-dazzle, but the subject matter is certainly cool!
Space-based solar power is the idea to put PV panels on satellites in orbit and beam the power down to the surface.

Do you think that sounds outlandish? Well, there is nothing technical stopping us - just a matter of financing and politics. Not like fusion which is still an unsolved problem. In my book space-based solar would be smarter, cheaper, and more sustainable than even nuclear power.

I have archived a copy of the seminar recording on my Nextcloud (in case you have any problems using the Zoom-provided recording).

When writing in R Markdown format I often would like to comment out one or more lines of text (for example to quickly test variations on sentences or paragraphs) in a way that these comments do not show in the generated HTML file.

The R Markdown Cookbook only mentions HTML comment syntax <!-- your comment --> which does not stop the comment from remaining in the generated HTML file.

Best solutions, as far as I know:

Additional YAML blocks

Add a YAML block with commented out lines (baptiste's suggestion):

Some text in the document.

---
# commented out text
# and such
---

This works fine, it is just slightly verbose to use.
But it is the only option that works without any issues.

Abuse the markdown link labels syntax

This is the most popular answer (by far) on SO:

Some text in the document.

[//]: # (commented out text)

[//]: # (another comment)

According to other answers/comments, this sort of comment line should always have a blank line before it to be proper.
The drawback for Rmd appears as soon as we have more than one such comment line; knitr spits out a very visible warning in the standard output:
[WARNING] Duplicate link reference '[//]' at ... line ....

The only(?) way to avoid those warnings is to differentiate the link labels, but that quickly becomes tedious.

Some text in the document.

[//1]: # (commented out text)

[//2]: # (another comment, now without a knitr warning)

If you know of a less verbose method than adding YAML blocks, or an easier way to circumvent the knitr warnings, I would love to learn about it.

• Due to rules severely limiting the allowed sulfur content in fossil fuels for (see, acid rain) over 80% of all sulfur produced globally is a side-product of fossil oil and fossil gas refinement. Unless we find another way to produce sulfur (sulfuric acid is a critical industrial feedstock), the change to renewables could seriously hamper our access to sulfur. Maslin & Day, The Conversation (2022).
• Shell got a lot of good PR a few years ago on the back of news that they would install hydrogen filling stations across California in cooperation with Toyota. Now they have announced their complete withdrawal from light-duty (read: private cars) hydrogen filling stations in the state.

Kartläggningen ger en bild av nuläget i 200 tätorter med fler än 5000 invånare. Boverket refererar till den allt oftare uppmärksammade 3-30-300-regeln, det vill säga att man ska kunna se tre träd från sitt fönster, att 30 procent av stadsdelen ska vara täckt av träd och att de boende ska ha max 300 meter till ett grönområde.

Via Arkitekten.se

• Ny nationell kartläggning av träd i städer och tätorter
• Nationell kartläggning av trädtäckning i större tätorter
• Karttjänst som visar trädens placering och storlek
• Karttjänst som visar trädtäckningsgrad per stadsdelsnivå (demografiskt statistikområde, DeSO)

Art courtesy of blog.akhbarak.net.

The post title is the translation of the meaning of verse 5 of chapter 42 (Ash-Shuraa) of the Holy Quran.

• حديث سيد الاستغفار
• https://en.wikipedia.org/wiki/Istighfar

Sounds interesting, but unfortunately the Encyclopedia website appears to be broken.

I sent a question to their webmaster through their contact form.

For the individual owning the car, It is very high. When we take the societal costs into consideration, it is even higher.

• A paper from Gössling et al., 2019, "The Social Cost of Automobility, Cycling and Walking in the European Union", 10.1016/j.ecolecon.2018.12.016, via CityNerd (youtube video).
• Another paper by Gössling et al. in Ecological Economics, 2022 was really eye-opening. Over 50 years, the total lifetime cost of ownership of a "cheap" car will reach 600,000 EUR, out of which almost a third is effectively a subsidy from society to the car's owner. If you are considering owning your own car, I strongly recommend to at least skim this paper (CC license, HTML and PDF freely available).
• Another paper (Mattioli et al., Energy Research & Social Science, 2020), this is one is a review that considers our car dependence from a systems of provision approach. Quite interesting if you want to learn more about the of the political-economic underpinnings of car dependence (CC license, HTML and PDF freely available).
• A 2023 paper that tells how the car industry has deliberately pushed motorists into greater debt in order to save itself: The financialisation of car consumption. Nice summary in this Mastodon thread.

The Gössling paper generated some news items across the web, for example

• Kea Wilson, StreetsBlog USA, 2022. Takes an American perspective, which mainly means that everything gets worse.
• Carlton Reid, Forbes, 2022. Again, puts an American perspective on the numbers, but correctly states that "cars suck more cash than most people imagine".

I also remember a Youtuber doing a nice video on the Gössling paper, but I cannot recall enough about it to find it at the moment. Maybe I will find it later.