Ciro Santilli's hardware Trek FX 3 2021 Updated 2026-03-05
www.tritoncycles.co.uk/urban-bikes-c4/hybrid-c30/trek-fx-3-equipped-urban-bike-2021-p39860/s102315 XL color Dnister Black. £675.00 plus £35.00 delivery. Disc breaks, 2x9 gears. Bought 2023 on a bit of a sale.
The 2020 one on official website: www.trekbikes.com/gb/en_GB/bikes/hybrid-bikes/fitness-bikes/fx/fx-3-disc/p/28474/ archive.ph/wip/jMDdw TODO find 2021.
Specs upon buying:
Gears: 11-36T on back, 46-30T on front. So min speed is 30/36 = 0.83 and max is 46/11 = 4.18, so range is 4.18 / 0.83 ~= 5. Compared to Kross which was 11-32 on back vs 48-28 on front, so min 28/32 = 0.875 and max 48/11 = 4.36. So the ranges are very comparable! This confirms Ciro's suspicion that 3 speeds on cranckset is just useless.
I was sized just at the lower limit of XL, but decided to go for it. The seatpost goes all the way into the tube, which is a good thing, might help with noises?
Frame serial under bottom bracket: WTU173C0374S. Registered at: www.bikeregister.com/
Initial impressions:
- on city ride: I'm much more inclined forward than on the Kross bicycle (2017) since this is XL might be a good thing. Let's see on longer countryside ride.
- on rain: the pedal performance is terrible, very slippery!
- the breaks are good, a bit better than the Kross, but not as grippy as ones I've seen.
- It is good that it came with lights. But OMG the DUXO back light is impossible to open!!! Front battery also seemed short, to be checked
- Presta valves suck. I can't inflate it without holding it down with my feet!
I'm unable to place a U-lock carrier on this bike in a way that doesn't block one of the two bottles inside frame, or hits leg on if on side. Tried both Kryptonite and Abus ones I have lying around. Shame. Also the Topeak MTS Trunkbag does not fit well on the pannier rack, it is not wide enough to strap: 11cm outer width, 9cm inner width, same geometry as that of the Liv bike.
Log:
2026-02-13: chain reched .7, changed it to new KMC X9. x9 9 speed chain 114 links. www.amazon.co.uk/dp/B07J38GX7L Started slipping like crazy on cassette when I pedaled hard, changed it to www.amazon.co.uk/dp/B073H3DST7 SHIMANO CS-HG400 9-speed cassette (11-36 teeth) which internet said was compatible and it seems to be. Didn't manage to remove it and needed help from bike shop as usual. After that it stopped slipping.
2025-09-30: kickstand broken while taking it on car. Proceeding to buy Bontrager Rear Mount Adjustable Kickstand www.trekbikes.com/gb/en_GB/equipment/bike-accessories/bike-kickstands/bontrager-rear-mount-adjustable-kickstand/p/36015/ 20 pounds + 4 delivery. The new kickstand is slightly different from the previous one, it is less slick looking, but perhaps a bit more sturdy, notably the little arm is shorter which might help prevent the previous failure mode. It came with 3 types of screws, but the two of correct diameter were a bit shorter or longer than the old ones so I just kept the old ones.
2025-09-13: chain reached 0.75, rebuying KMC X9. x9 9 speed chain 114 links. www.amazon.co.uk/dp/B07J38GX7L
2025-08: rear mudgard broke in the exact same way as last time, so I'm saying fuck this bullshit and I just fixed it up with some wire which will likely be more resistant than the shitty metal thing they had.
2025-06-26: I suddenly lost the ability to shift the front gear, cable seemed fine, upon inspection I noticed that the pedal could move sideways. Maybe linked to screeching sound that has been coming from that area for a while. As per www.youtube.com/watch?v=cPQyQnNdews leading to www.youtube.com/watch?v=QqBtB8Kyl2U this is a different system from the Kross one, two piece compression slotted rather than 3 piece. The side to side issue is mentioned precisely at: youtu.be/QqBtB8Kyl2U?t=357 Buying the standalone removal tool: www.amazon.co.uk/Professional-Extracto-Compatible-Hollowtech-Maintenance/dp/B0DP6QF11X Fixing it fixed the shift issue, but I noticed that the little plastic piece was broken. Also a few days later it became loose again during a ride, but thankfully I had the tool and put it back mid rid. TODO wanted to rebuy it but it's really hard to find... Going to try this one: www.bikeparts.co.uk/products/shimano-altus-fc-mt210-chainset-46-30-9-speed-black-170-mm-w-o-chainguard 175 mm and see if it comes with both arms. Bought it. has both arms. But I can't fit it, appears to be 1 or 2 mm short compared to the other cranck, the new arm does go on the old crank. There is a small rubber seal that is perhaps not too well inserted which might be to blame? Fuck my life! On the old one, it seems to be fully inserted into a tight hole. I didn't manage to insert the new one enough to make it fit, but if I remove it then it fits... just removing it for now then, how important could that be? Famous last words. Web says 12-14 nM torque on holding screws.
2025-06: rebuying 2x Shimano B05S brake pads, breaking is not too great and I don't want to repeat last year's episode of on-road failure. Will also be bleeding for the second time, God help me. The old pads weren't too bad, but I replaced them anyways. The bleeding was a failure and the brakes were too soft to be useful at the end, fuck. Went to two bike shops, both said bleeding not too bad, one said likely problem was contamination/friction issues. Tried cleaning rotors further, improved. Buying sandpaper and new rotors as well 2x SHIMANO SM-RT26 6-Bolt Disc Rotor and also got two more brake pads, totalling 3 new before I start putting them in with new rotor.
2025-04: rear shift cable snapped near shifter when going over a cattle grid, was already a bit off in the previous days after last adjust I then noticed. I'll buy a SHIMANO Gear Inner Wire Y60098070 on Amazon and might pass by bike shop as well I'll see.
2025-03: rear middle metal connection broke off read mudguard. Rebuying £21.04 from: www.tritoncycles.co.uk/frames-forks-c6/frame-fork-spares-c152/eurofender-snello-700c-fenders-46mm-rear-p33330/s93941 Quite disappointed with that, didn't come with any screws, though perhaps these are frame dependant. And the drilling was a bit different, this model seems to be intended to have some wiring passing inside via some rubber tubes that I removed, and unfortunately the hole on front was too high up and didn't match up with the screw hole on frame. I just removed the broken metal piece from it and put it on the old mudguard.
2024-09: buying CHUMXINY Brake Bleed Kit: www.amazon.co.uk/dp/B0CXDQ2S1S I hope I don't regret this. But I can't find an original one on Amazon either so... £12.74. Quality is a bit crap but seems to work. The 7mm wrench however is so bad that it can't unscrew a 7mm nut.
2024-09: chain reached 0.75, rebuying KMC X9. x9 9 speed chain 114 links: www.amazon.co.uk/dp/B07J38GX7L
2024-09: when going down a hill in intense breaking, noise started coming from back disk brake. Tried to adjust, but made it worse, had to bail out on nearby bike shop. Readjusted, told me to replace back pads and likely bleed. Bought two Shimano B05S brake pads to replace the B01S that came with the bike, Internet says compatible. Brake maintenance finally caught up with me, it was a great summer and I kept putting it off. Changed just the back one for now, front still has life it seems.
2024-06: noticed a sideways lump on back tyre between spoke 23 and 24 when washing. The only sign of damage was internal near grip part, I could see some clear shearing... God those tyres are crap, or at least crap to what I've subjected them. Inner tube and outside seem perfect, so weird. If only the Schawlbe had worked! But OK now I'm forced to get something new and better, thinking:They had a Schwalbe Marathon Plus 700x35c (non-Tour, as that one didn't fit as per previous experiment) on the shop and I went for it. They said 35c was the maximum recommended for that mudgard which is a bit of a shame, but good to know. Also getting one from Amazon to match on front as shop only had one.
- www.trekbikes.com/gb/en_GB/equipment/cycling-components/bike-tyres/hybrid-bike-tyres/bontrager-h2-hard-case-ultimate-reflective-hybrid-tyre/p/31553 seems Schwalbe like, but will it fit?
2024-04: micropuncture on front tube? Could not identify during ride, refilled and was OK to get home. Almost no pressure in middle of ride. Passed through some deep water which may have made things worse? Had a small pice of glass-like material stuck in tyre, but didn't seem to penetrate? One day and a half later, was full empty again after full fill without riding, so confirming micropuncture theory. Buying 2x Conti Tube Cross 28 (700C) presta inner tubes.
Tried to put a spare Schwalbe Men's Marathon Plus Tour 700x40C on the bike to get better stability. It seemed to fit the wheel quite well, but unfortunately failed to go well in the fork because it was too tall and hit the mudgard. Without mudgard it might work. Measured height was 6cm for Schwalbe vs 5.3cm for the stock one.
2024-02: another broken spoke... what crappy weak wheels!!! Bought Bavel 290 mm spokes 36pcs 14G J Bend Silver. Broken position was 22nd clockwise from inner tube valve hole.
2023-12: broken spoke! Also had to replace nipple because broke inside nipple. At least learned how to change tire at last.
2023-05: buying another pair of Shimano 324 combination pedals for it: www.wiggle.com/p/shimano-m324-combination-pedals
2023-05: 2x Elite custom race cage water bottle frame cages, felt great, much better than those on the Kross! www.elite-it.com/en/products/bottle-cages/fibre-reinforced-material-frp/custom-race
2023-05: Kask Rapido Medium Black/Yellow fluo helmet, got a more racy helmet too! 69 pounds, way more any previous helmet I've owned: www.kask.com/en/cycling/helmets/rapido_24_2.htm
2023-05: Lezyne hand pump, I think Sport Drive HP? ride.lezyne.com/collections/hand-pumps/products/sport-drive-hp
2023-05: Lezyne V-Pro 10 multi-tool ride.lezyne.com/products/v-pro-tool No spoke wrench unfortunately.
Initial equipment:
Annotated copypasta:Weight limit: This bike has a maximum total weight limit (combined weight of bicycle, rider and cargo) of 136 kg (300 lb)
- Frame: Alpha Gold Aluminium, DuoTrap S-compatible, internal cable routing, flat-mount disc, rack and mudguard mounts, 135x5 mm QR
- Mudguard/rack mounts: Alloy
- Hub front: Formula DC-20, alloy, 6-bolt, 5x100 mm QR
- Hub rear: Formula DC-22, alloy, 6-bolt, Shimano 8/9/10 freehub, 135x5 mm QR
- Rim: Bontrager Tubeless Ready Disc, 32-hole, Presta valve. TODO identify precisely. But presumably something like: www.tritoncycles.co.uk/components-c9/wheels-c126/affinity-tlr-32h-6-bolt-disc-700c-road-wheel-p25441/s79099 which says: Alloy double-wall rim with 21mm internal, 26mm external width
- Spokes: 14 g stainless steel. Not documented, but measured in store: 290mm.
- Tyre: Bontrager H2 Comp, wire bead, 30 tpi, 700x32c. Link was: www.trekbikes.com/us/en_US/equipment/cycling-components/bike-tires/hybrid-bike-tires/bontrager-h2-comp-hybrid-tire/p/31551/ but they don't sell that crap anymore? A bit weak. At shop said 35c is max recommended width.
- Shifter: Size: M, L, XL - Shimano Acera M3000, 9-speed | Size: M, L, XL - Shimano Acera M3000, 2 -speed
- Front derailleur: Shimano Acera T3000, 34.9 mm clamp, top swing, dual pull
- Rear derailleur: Shimano Alivio M3100, long cage
- Crank: Size: Shimano MT210-2, 46/30, chain guard, 175 mm length
- Cassette: Shimano HG200, 11-36, 9-speed
- Chain: KMC X9. x9 9 speed chain. Official page: www.kmcchain.com/en/product/bicycle-chain-x9-9-speed so crappy does not say link count! But presumably the 114 that is most common on most sites.
- Pedal: Bontrager City pedals. www.trekbikes.com/gb/en_GB/equipment/cycling-components/bike-pedals/platform-pedals/bontrager-city-pedal-set/p/35291/ Bontrager City Pedal Set 9/16-inch (15 mm). Installs with a 6 mm hex key or flat 15 mm pedal wrench.
- Saddle: Bontrager H1
- Seatpost: Bontrager alloy, 27.2 mm, 12 mm offset, 330 mm length
- Handlebar: Size: M - Bontrager Satellite Plus IsoZone, alloy, 31.8 mm, 15 mm rise, 600 mm width | Size: L, XL - Bontrager Satellite Plus IsoZone, alloy, 31.8 mm, 15 mm rise, 660 mm width
- Grips: Bontrager Satellite IsoZone Plus, lock-on, ergonomic
- Stem: Size: M, L - Bontrager Elite, 31.8 mm clamp, Blendr-compatible, 7-degree, 100 mm length | Size: XL - Bontrager Elite, 31.8 mm clamp, Blendr-compatible, 7-degree, 110 mm length
- Headset: 1-1/8" threadless, sealed cartridge bearings
- Brake: Shimano MT201 hydraulic disc, flat-mount, 160 mm rotor
- Brake rotor: Shimano RT26, 6-bolt,160 mm
- Brake pad: Brake Pad Shimano Resin Disc Pad B01S RESIN
- Light: Size: M, L, XL - Spanninga Duxo XB, battery-powered | Size: M, L, XL - AXA Greenline 35, USB rechargeable
- Kickstand: Alloy, rear-mount kickstand. More precisely looks like: Bontrager Rear Mount Adjustable Kickstand www.trekbikes.com/gb/en_GB/equipment/bike-accessories/bike-kickstands/bontrager-rear-mount-adjustable-kickstand/p/36015/
- Cargo rack: Alloy rear rack
- Mudguard: Eurofender Snello. Looks like this one: www.trekbikes.com/gb/en_GB/equipment/bike-accessories/bike-mudguards-and-accessories/bike-mudguards/eurofender-snello-700c-fender-set/p/31699/
- Approx. Weight: L - 13.17 kg / 29.04 lbs
British pragmatism Updated 2026-03-05
For example, a good effect is that many things work pretty well, such as the government. This also helped industry develop.
A bad effect is that they sometimes settle on local minima forever. Examples:If it ain't totally broken, just let it continue forever! See also: Section "History of the University of Oxford".
- written Constitution? Who needs a written constitution!
- as of 2020, they are still using imperial units in everyday life, rather than International System of Units, which was setup by the French, who are much more idealistic, and can therefore can break from such insanity more often.
- the persistence of the insane system of colleges of the University of Oxford
- the incredibly late date of the decimal day in 1971, and that was partly due to the advent of the computer. That one was too much, even for the Brits, or maybe it helped that the greedy financiers were involved
- the British train system as of the 2010's, which is completely not unified, each part operated by a different company with different standards. Private and public unification efforts are ongoing, Trainline being one of the best/only private buy from any line unification approaches.
- Church of England priests can marry, which reduces the proportion of pedophiles. Also women were accepted starting in the 1970's in certain dioceses (non uniform rules as usual, typical of English pragmatism), including for bishop
Ciro Santilli's hardware Bicycle products Updated 2026-03-05
2022-02: lost my Karrimor REFLEKT, must have fallen off from trouses somewhere.
2022-02: bought Burg Wachter Sold Secure Bike Chain, Lock and Ground Anchor Kit 1m, 10mm chain width: www.amazon.co.uk/Burg-Wachter-Sold-Secure-Gold-Chain/dp/B09MMGL9B7
2022-02 bought Kryptonite Kryptoflex double loop cable 1.2m length 10mm diameter braided steel cable: www.kryptonitelock.com/en/products/product-information/current-key/210818.html
2022-02: bought a Trelock BC 115/110/4 chain white for my saddle after Liv Flourish 2 (2018) the saddle of was stolen at home. Same as this but white: www.trelock.com/en/lock/locks/chain-locks/bc-115-110-4-green. The keys are a bit larger than I'd like.
2021-11: buying a Cateye ViZ450 www.cateye.com/intl/products/safety_lights/TL-LD820/ 51 dollars after CatEye RAPID X2 was stolen. Unfortunately, it is not very compatible with my Topeak saddle bag... the attachment is to wide to fit the saddble bag, and even if it did it is slanted to account for seat tube slant so it would not be very verfical. Arghh, they have futher options on the website: www.cateye.com/intl/products/parts/5342460/ that is the one I need, Clip C-2 or Clip C-1N. On Amazon it didn't have clear choices for that... mine came with the BracketSP-15. Ah, can buy on Amazon for 3 dollars, OK then.
2021-11: COZYROOMY multitool broke apart already, like before, but much sooner this time. What a piece of junk!!! Buying the Topeak Mini 18+ Bike Multitool www.topeak.com/global/en/products/75-Mini-Tools/173-mini-18+ Has a spoke wrench.
2021-09: COZYROOMY multitool stolen, even though it was completely in pieces already. 2021-09-21 12:30PM discovered, seat bag open, one tool on floor, and some leftovers inside, but black bag gone. Bicycle last seen 2021-09-20 6PM. Would likely have spotted it if it had happened before. Bicycle last used: 2021-09-19 6PM. Would almost for sure have seen it if it had happened by then. Rebought it.
2021-07 Topeak MTS Trunkbag EX Strap Type www.topeak.com/global/en/products/192-Rear-Rack-Bags/859-MTX-TRUNKBAG-EX Fit nicely on the back of the Kross bicycle (2017). 8L. Originally to carry some extra food and water on a long summer trip. 36 pounds.
2020-11-30: Bought more "Finish Line DRY Teflon Bicycle Chain Lube" 8oz/240ml www.amazon.com/dp/B00Z779GMO/ after previous disaster with the bottle because lock is a bit hard to open.
2020-11-30 WD-40 Bike, All Conditions Lube Bicycle Lubricant, 250ml. Markings: "Contains PTFE". www.amazon.com/dp/B00O8QF3PY Sprays out of bottle, so very thin.
2020-11: Park Tool CC-2 Chain Checker Tool www.amazon.co.uk/dp/B000OZFILW 24 pounds www.parktool.com/product/chain-checker-cc-2
2020-04: www.amazon.co.uk/gp/product/B014LC7HS0 "Park Tool HPG-1 High Performance Grease", 113 g, blue. www.parktool.com/product/high-performance-grease-hpg-1#tabbed-section | www.parktool.com/assets/doc/product/HPG-1_SDS.pdf
2020-02: CatEye AMPP500 45 pounds www.cateye.com/intl/products/headlights/HL-EL085RC/ High mode 500 lumens: 1.5hrs, Daytime HyperConstant mode 500/250 lumens: 5hrs. 2020-11: noticed it was cracked on top front between button and light, I think I dropped it the other day from waist height.
2020-02: Karrimor REFLEKT Band 2 pounds from Sports Direct to replace old that I destroyed by playing with it with hands on work desk www.karrimor.com/karrimor-reflect-band-765007
2020-01: Muc-Off Drivetrain Cleaner - 500ml www.halfords.com/cycling/bike-maintenance/bike-cleaning/muc-off-drivetrain-cleaner-500ml
2020-01: Halfords Microfibre Heavy Duty Cloths www.halfords.com/motoring/car-cleaning/sponges-brushes-buckets/halfords-microfibre-heavy-duty-cloths (archive) 87% polyester, 13% polyamide.
2019-12: www.amazon.co.uk/gp/product/B07GQSXN8B SENZEAL Bicycle Spoke Wrench Tool Spoke Key Spanner 6 in 1 for Bike Wheel Cycle Wrench 10-15 Gauge. TODO 2024: can't find those for the life in me.
2019-12: Halford's Bike Hut Chain Cleaning Kit: www.halfords.com/cycling/bike-maintenance/bike-cleaning/bikehut-chain-cleaning-kit 18 pounds. GCN video using it: www.youtube.com/watch?v=KM6mzE5lQ0w Review video saying it is useless: www.youtube.com/watch?v=rCo41pftAjU
2019-11: Multitool: www.amazon.co.uk/dp/B07MW3K2GK "COZYROOMY Bike Repair Kits - Bicycle tool kit with 10 in 1 Multi-Function Bike Tool, multi-purpose bone wrench And related spare tools, 1 Portable tool bag, 6 Month Warranty". No spoke wrench unfortunately. But does have 15mm bone wrench, which opens Kross front wheel. Some months later, the thing came apart, quality was a bit shit. But I kept it in the saddle bag anyways for a long time, and just used it by putting part of it manually together.
2019-11: "CatEye RAPID X2" real lights, 40 dollars. Hopefully to increase side visibility at night, and day visibility on fast roads when cycling further on weekends. www.cateye.com/intl/products/safety_lights/TL-LD710-R/ (archive) USB rechargeable. 80 lumens in high mode lasting 1 hour, 5 hours in low mode, 30 hours flashing, 16 hours rapid/pulse. Lost 2021-11 in a big city, didn't know the path well, had to cross a bunch of streets, was on back of back bag, likely stolen.
2019-10 Finish Line Dry Teflon Tube www.amazon.com/dp/B00B704LZW (archive) Tube broke while opening the first day. I glued it with some superglue, but two months later found it leaked into my "oils bag", so I threw it away... it must have penetrated through the super glue.
2019-08: "CatEye CA475RAPMIN Rapid Mini Rear Lights and Reflectors, Black" stolen: www.amazon.co.uk/dp/B01I4193PY (archive). Very good quality. Those USB rechargeable lights you just have got to take off with you whenever parked in town or else drug addicts will steal them because they are easy to remove for recharging. Tempted to just stick to dynamo ones that are screwed in. Re-bought original back light: AXA Basta, was a bit different from previous one, cannot take in lamps anymore, even though there is the plastic casing for them! Just not metal / wires.
Possible new effects in superconductive tunnelling Updated 2025-07-16
The inaugural that predicted the Josephson effect.
Published on Physics Letters, then a new journal, before they split into Physics Letters A and Physics Letters B. True Genius: The Life and Science of John Bardeen mentions that this choice was made rather than the more prestigious Physical Review Letters because they were not yet so confident about the results.
Git design rationale Updated 2025-07-16
The fundamental insight of Git design is: a SHA represents not only current state, but also the full history due to the Merkle tree implementation, see notably:
This makes it so that you will always notice if you are overwriting history on the remote, even if you are developing from two separate local computers (or more commonly, two people in two different local computers) and therefore will never lose any work accidentally.
It is very hard to achieve that without the Merkle tree.
Consider for example the most naive approach possible of marking versions with consecutive numbers:
GitHub's replacement of
master branch with main (2020) Updated 2025-07-16By GitHub around Black Lives Matter, due to a possible ludicrous relationship with slavery of black people:
For the love of God, the word "master" is much more general than black slavery. If you are going to ban it, you might as well ban the word "evil".
GitLab Updated 2025-07-16
See also: Ciro Santilli's minor projects.
Git tips
git mergetool with meld or kdiff3 Updated 2025-07-16These are good free newbie GUI options:
sudo apt install meld
git mergetool --tool meld
sudo apt install kdiff3
git mergetool --tool kdiff3git-tips-2.sh
#!/usr/bin/env bash
set -eux
add() (
rm -f f
for i in `seq 10`; do
printf "before $i\n\n" >> f
done
printf "conflict 1 $1\n\n" >> f
for i in `seq 10`; do
printf "middle $i\n\n" >> f
done
printf "conflict 2 $2\n\n" >> f
for i in `seq 10`; do
printf "after $i\n\n" >> f
done
git add f
)
rm -rf git-tips-2
mkdir git-tips-2
cd git-tips-2
git init
for i in 1 2 3; do
add $i $i
git commit -m $i
done
add 3 4
git commit -m 4
add 5 4
git commit -m 5
git checkout HEAD~2
git checkout -b my-feature
add 3 6
git commit -m 6
add 7 6
git commit -m 7 Good targets for amateur astronomy Updated 2025-07-16
Looking at most astronomical object through a telescope is boring because you only see a white ball or point every time. Such targets would likely only be interesting with spectroscopy analysis.
There are however some objects that you can see the structure of even with an amateur telescope, and that makes them very exciting.
Some good ones:
- The Moon, notably crater detail.
- Saturn. Clearly visible to the naked eye, but looks like a ball. But under an amateur telescope, you can clearly see that there is a disk. Clearly discerning that the disk is a ring, i.e. seeing the gap, is a bit harder though.
- Jupiter. Clearly visible to the naked eye, it is quite huge. The four Galilean moons, being Earth-sized, are incredibly clearly visible, tested on Celestron NexStar 4SE 25mm/9mm eyepiece. Colored gas clouds are hard though, you will likely just see it bright white. www.reddit.com/r/telescopes/comments/35xrbb/how_can_i_see_the_color_of_jupiter_with_my/
- a double star. As mentioned at www.relativelyinteresting.com/10-astronomical-targets-new-telescope/ Albireo are incredibly separated. Also it is is easy to find manually being in a major well known constellation. It is no wonder it is not quite even known if they are gravitationally bound or not!
- Andromeda Galaxy. This is when things start getting hard. You can see a faint cloud, but it is not super clear that it has a center.One important understanding is that it is not possible to see stars outside of the Milky Way by naked eye.It is at this point that you start to learn that pictures of faint objects require longer term exposure and averaging of the images taken. For this you need:Just looking through the scope to immediately see something is not enough.
- a digital camera attached to the scope
- a computerized scope that slowly moves to track the point of interest
- image processing software that does the averaging
Video "Andromeda Galaxy with only a Camera, Lens, & Tripod by Nebula Photos (2020)" gives a good notion of expectation adjustment.
Good video game to watch Updated 2025-07-16
Google X Updated 2025-07-16
Wikipedia reads:so basically exactly what Ciro Santilli wants to do on OurBigBook.com. Ominous.
Any contributor could create and own new Knol articles, and there could be multiple articles on the same topic with each written by a different author.
Like any closed source "failure", everything was deleted. wiki.archiveteam.org/index.php/Knol
History of special relativity Updated 2025-07-16
Bibliography:
- Subtle is the Lord by Abraham Pais (1982) chapter III "Relativity, the special theory" has a good sketch as you may imagine.
History of the United States Updated 2025-07-16
Video codec Updated 2025-11-18
History of Wikipedia Updated 2025-07-16
Hofstadter's law Updated 2025-07-16
As "deadlines" approach, feature sets get cut down, then there are delays, and finally a feasible feature set is delivered some time after the deadline.
The only deadlines that can be met are those of tasks which have already been done but not announced.
This is of course Hofstadter's law.
How can a chemical substance be unstable but not flammable? Updated 2025-07-16
How to store data in the Bitcoin blockchain Updated 2025-07-16
There are apparently two methods:
- in the script, e.g. as in the Genesis block message
- in output addresses
Specific implementations:
- eternitywall.it/ Eternity WallLaunched 2015 www.newsbtc.com/news/bitcoin/eternity-wall-records-1150-documents-blockchain-first-year/Shutdown sometime after 2019, working archive: web.archive.org/web/20190417074034/https://eternitywall.it/ says "Sorry, the service is not properly working at the moment..." and last working message timestamped "April 16, 2019 8:02 PM GMT".
How to teach and learn physics Updated 2025-07-16
The approach many courses take to physics, specially "modern Physics" is really bad, this is how it should be taught:
- start by describing experiments that the previous best theory did not explain, see also: Section "Physics education needs more focus on understanding experiments and their history"
- then, give the final formula for the next best theory
- then, give all the important final implications of that formula, and how it amazingly describes the experiments. In particular this means: doing physics means calculating a number
- then, give some mathematical intuition on the formulas, and how the main equation could have been derived
- finally, then and only then, start deriving the outcomes of the main formula in detail
This is likely because at some point, experiments get more and more complicated, and so people are tempted to say "this is the truth" instead of "this is why we think this is the truth", which is much harder.
Related:
- settheory.net/learnphysics and www.youtube.com/watch?v=5MKjPYuD60I&list=PLJcTRymdlUQPwx8qU4ln83huPx-6Y3XxH from settheory.net
- math.ucr.edu/home/baez/books.html by John Baez. Mentions:Ciro Santilli is trying to change that: OurBigBook.com.
This webpage doesn't have lots of links to websites. Websites just don't have the sort of in-depth material you need to learn technical subjects like advanced math and physics — at least, not yet. To learn this stuff, you need to read lots of books
- web.archive.org/web/20210324182549/http://jakobschwichtenberg.com/one-thing/ by Jakob Schwichtenberg
How to teach Explain why the subject is beautiful Updated 2025-07-16
And if you really can't make money from a subject, there is only one other thing people crave: beauty.
You have to give the beauty motivations upfront, before boring people to death with endless prerequisites, otherwise no one will ever want to learn it.
There are unlisted articles, also show them or only show them.

