In degrees Celsius:
- 25+
- 18-25
- "dhb Aeron Short Sleeve Jersey"
- XGC Men's Cycling Shorts
- 2020-04 Giro Rumble VR Off Road Shoe
- 15-18:
- "dhb Aeron Short Sleeve Jersey"
- "dhb Lightweight Mesh Long Sleeve Base Layer"
- XGC Men's Cycling Shorts
- 2020-04 Giro Rumble VR Off Road Shoe
- 10-15:
- dhb Classic Thermal Bib Tights 10 and under. TODO this is a bit too warm for the upper range, need something more intermediate
- "dhb Lightweight Mesh Long Sleeve Base Layer"
- Castelli Perfetto RoS Long Sleeve - Cycling jersey. TODO this is a bit too warm for the upper range, need something more intermediate
- "Karrimor X Lite Run Black Headband"
- "Nike academy hyperwarm gloves"
- "Nevica Skuff". A bit too hot on upper range, but easy to take off.
- 0-10:
- dhb Merino Long Sleeve Base Layer
- Castelli Perfetto RoS Long Sleeve - Cycling jersey
- dhb Classic Thermal Bib Tights 10 and under
- dhb Dorica MTB Shoe (2020-12)
- "Karrimor X Lite Run Black Headband". Head a bit cold on lower range.
- "dhb Neoprene Nylon Overshoes". Feet a bit cold on lower range.
- "Extremities XDRY gloves". Hands a bit cold on lower range.
- "Nevica Skuff"
People love green on black mostly.
2023-07: one of the sides broke near center, rebuying.
2021-07: wire half broke near connector, only works in some positions. The funny thing is: only voices seem to be blocked out! Rebuying.
2021-06: a small bottom piece of the left earpiece broke. Wire seems find, that is like a little extension to protect wire. Let's see for how long.
2020-20: wires at one of ears broke, not sure how.
Look they looked exactly like: "Skullcandy Smokin' Buds 2 In-Ear Audio Earbud Headphones with In-Line Microphone - Black".
Re-buying that one 10 pounds:
Tech specs:
Connection Type: 3.5mm AUX CableImpedence: 32 ohmsDriver Diameter: 9mmSound Pressure Level: 95 dB (1mW/500Hz)Frequency Response: 20kHz - 20HzHeadphone Type: In-Ear
Ciro Santilli with his soon-to-be Ciro Santilli's mother-in-law during his wedding in 2017
. Keep the example/theory ratio high, very, very high.
Kitchen: 2021-04: nine-volt battery battery at 8.79V. Not sounding.
Bought December 2023 for 300 pounds, so 15 pounds / TB. Needs power supply unfrotunately besides USB, the largest one without needing power supply was only 5 TB at the time so not worth it, given that my P14s alreay carriers 2 TB. 10x is a must for the external crap.
www.westerndigital.com/en-gb/products/external-drives/wd-elements-desktop-usb-3-0-hdd?sku=WDBWLG0030HBK-EESN (archive)
Noise: it has a constant pleasant hum, with a not so nice click every 5 seconds or so. Reasonable, but not amazingly incredible.
The size is reasonable, not megaportable, but definitely reasonable.
- Ergobaby Omni Four Position Baby carrier. TODO manual:
- possibly:
- another model, omni 360:
- TRIPP TRAPP Beech, serial 72666145 purchase 30/05/2023 bought from: www.bellababy.co.uk/
- TRIPP TRAPP Newborn set, serial 101BB1280664, purchase 30/05/2023 bought from: www.bellababy.co.uk/
- Silver Cross Dune:
- Silver Cross Balance I-size car seat: www.silvercrossbaby.com/products/balance-i-size-almond
- Chicco Next2Me Magic2 crib, or something similar. Given to us without manual so not 100% sure. www.chicco.co.uk/products/8058664145423.chicco-next2me-magic2-co-sleeping-crib.html Manual: www.manualslib.com/products/Chicco-Next-2-Me-Magic-11096854.html
- kinderkraft.co.uk/products/4trike?color=honey Tricycle 4TRIKE Honey
Ciro's Edict #5 Skip ID extraction and rendering based on database timestamps by 
Ciro Santilli 40 Updated 2025-07-16
Ciro Santilli 40 Updated 2025-07-16This means while developing a website locally with the OurBigBook CLI, if you have a bunch of files with an error in one of them, your first run will run slowly until the error:but further runs will blast through the files that worked, skipping all files that have sucessfully converted:so you can fix file by file and move on quickly.
extract_ids README.ciro
extract_ids README.ciro finished in 73.82836899906397 ms
extract_ids art.ciro
extract_ids art.ciro finished in 671.1738419979811 ms
extract_ids ciro-santilli.ciro
extract_ids ciro-santilli.ciro finished in 1009.6256089992821 ms
extract_ids science.ciro
error: science.ciro:13686:1: named argument "parent" given multiple times
extract_ids science.ciro finished in 1649.6193730011582 msextract_ids README.ciro
extract_ids README.ciro skipped by timestamp
extract_ids art.ciro
extract_ids art.ciro skipped by timestamp
extract_ids ciro-santilli.ciro
extract_ids ciro-santilli.ciro skipped by timestamp
extract_ids science.ciroMore details at: cirosantilli.com/ourbigbook#no-render-timestamp
This was not fully trivial to implement because we had to rework how duplicate IDs are checked. Previously, we just nuked the DB every time on a directory conversion, and then repopulated everything. If a duplicated showed up on a file, it was a duplicate.
But now that we are not necessarily extracing IDs from every file, we can't just nuke the database anymore, otherwise we'd lose the information. Therefore, what we have to do is to convert every file, and only at the end check the duplicates.
Managed to do that with a single query as documented at: stackoverflow.com/questions/71235548/how-to-find-all-rows-that-have-certain-columns-duplicated-in-sequelize/71235550#71235550
Explains how it is possible that everyone observes the same speed of light, even if they are moving towards or opposite to the light!!!
This was first best observed by the Michelson-Morley experiment, which uses the movement of the Earth at different times of the year to try and detect differences in the speed of light.
This leads leads to the following conclusions:
- to length contraction and time dilation
- the speed of light is the maximum speed anything can reach
The "special" in the name refers to the fact that it is a superset of general relativity, which also explains gravity in a single framework.
Since time and space get all messed up together, you have to be very careful to understand what it means to say "I observed this to happen over there at that time", otherwise you will go crazy. A good way to think about is this:
- use Einstein synchronization to setup a bunch of clocks for every position in your frame of reference
- on every point of space, you put a little detector which records events and the time of the event
- each detector can only detect events locally, i.e. events that happen very close to the detector
- then, after the event, the detectors can send a signal to you, who is sitting at the origin, telling you what they detected
What you would see the moving rod look like on a photo of a length contraction experiment, as opposed as using two locally measured separate spacetime events to measure its length.
The key question is: why is this not symmetrical?
One answer is: because one of the twin accelerates, and therefore changes inertial frames.
But the better answer is: understand what happens when the stationary twin sends light signals at constant time intervals to each other. When does the travelling twin receives them?
Another way of understanding it is: you have to make all calculations on a single inertial frame for the entire trip.
Supposing the sibling quickly accelerates out (or magically starts moving at constant speed), travels at constant speed, and quickly accelerates back, and travels at constant speed setup, there are three frames that seem reasonable:
- the frame of the non-accelerating sibling
- the outgoing trip of the accelerating sibling
- the return trip of the accelerating sibling
If you do that, all three calculations give the exact same result, which is reassuring.
Another way to understand it is to do explicit integrations of the acceleration: physics.stackexchange.com/questions/242043/what-is-the-proper-way-to-explain-the-twin-paradox/242044#242044 This is the least insightful however :-)
Bibliography:
TODO arguments, proofs
Here is a vendor showcasing their device. They claim in that video that a single photon is produced and detected:
Concrete device described at: Video "How to use an SiPM - Experiment Video by SensLTech (2018)".
Pinned article: Introduction to the OurBigBook Project
Welcome to the OurBigBook Project! Our goal is to create the perfect publishing platform for STEM subjects, and get university-level students to write the best free STEM tutorials ever.
Everyone is welcome to create an account and play with the site: ourbigbook.com/go/register. We belive that students themselves can write amazing tutorials, but teachers are welcome too. You can write about anything you want, it doesn't have to be STEM or even educational. Silly test content is very welcome and you won't be penalized in any way. Just keep it legal!
Intro to OurBigBook
. Source. We have two killer features:
- topics: topics group articles by different users with the same title, e.g. here is the topic for the "Fundamental Theorem of Calculus" ourbigbook.com/go/topic/fundamental-theorem-of-calculusArticles of different users are sorted by upvote within each article page. This feature is a bit like:
- a Wikipedia where each user can have their own version of each article
- a Q&A website like Stack Overflow, where multiple people can give their views on a given topic, and the best ones are sorted by upvote. Except you don't need to wait for someone to ask first, and any topic goes, no matter how narrow or broad
This feature makes it possible for readers to find better explanations of any topic created by other writers. And it allows writers to create an explanation in a place that readers might actually find it.
Figure 1. Screenshot of the "Derivative" topic page. View it live at: ourbigbook.com/go/topic/derivativeVideo 2. OurBigBook Web topics demo. Source. - local editing: you can store all your personal knowledge base content locally in a plaintext markup format that can be edited locally and published either:This way you can be sure that even if OurBigBook.com were to go down one day (which we have no plans to do as it is quite cheap to host!), your content will still be perfectly readable as a static site.
- to OurBigBook.com to get awesome multi-user features like topics and likes
- as HTML files to a static website, which you can host yourself for free on many external providers like GitHub Pages, and remain in full control
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. Web editor. You can also edit articles on the Web editor without installing anything locally.Video 3. Edit locally and publish demo. Source. This shows editing OurBigBook Markup and publishing it using the Visual Studio Code extension.Video 4. OurBigBook Visual Studio Code extension editing and navigation demo. Source. 
- Infinitely deep tables of contents:
All our software is open source and hosted at: github.com/ourbigbook/ourbigbook
Further documentation can be found at: docs.ourbigbook.com
Feel free to reach our to us for any help or suggestions: docs.ourbigbook.com/#contact