There are 5: en.wikipedia.org/w/index.php?title=Euclidean_geometry&oldid=1036511366#Axioms, the parallel postulate being the most controversial/interesting.
Shot by Web of Stories.
The amount of detail in which he remembers all that happened is astounding. Not too different from the Murray Gell-Mann interview in that aspect.
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
Ciro Santilli's hardware Mechanical and electrical tools Updated 2025-06-17 +Created 1970-01-01
2020-01 www.amazon.co.uk/dp/B07D318N7Z
2020-01 "Heat Gun, SEEKONE Professional 2000W 50℃- 600℃ Variable Temperature Control Hot Air Gun Kit with 2 Temperature Modes 7 Accessories for D" www.amazon.com/dp/B078S5QMFG Initially for for cell phone repair, but later learnt they are also useful for heat shrink.
2020-11 BOA 13-2612 Strap Wrench, 6-Inch Capacity 8-Inch Long Lever www.amazon.com/dp/B00096JDKS Official: www.boatoolcorp.com/our-products/boa-constrictor-range/boa-constrictor/
2019-09 "Draper Redline 68001 160 mm Heavy Duty Pliers Set with Soft Grip Handles (3-Piece)" web.archive.org/web/20190903191215/https://www.amazon.co.uk/dp/B071JL6LLL (archive)
2019-08: www.amazon.co.uk/dp/B000LFRYG2 (archive) "Silverline SP1236 Combination Spanner, 8-19 mm - 12 Pieces" 8.48 pounds. Because I needed the 15mm for bike pedal, and the price of 1 and the full set were very close.
6 10/11/12/13/14/17 mm Combination Wrench Set WRENCH SET COMBINATION Open-Ended Spanner/Ring Spanner Set www.amazon.co.uk/dp/B07BZLVGX8 (archive) But they sent one wrong, 8 instead of 11. Chrome Vanadium Steel. Markings: "DROP FORGED A". Quality feels crappy, not very smooth.
2017: Teng 621011 Double Open Ended Spanner 10x11mm www.amazon.co.uk/dp/B0001P0VP8 (archive)
2017: Magnusson AMS49 5M TAPE MEASURE 5m retractable flexible rule. www.screwfix.com/p/magnusson-ams49-5m-tape-measure/5315v (archive)
lspci00:00.0 Host bridge: Intel Corporation Xeon E3-1200 v6/7th Gen Core Processor Host Bridge/DRAM Registers (rev 05)
00:01.0 PCI bridge: Intel Corporation 6th-10th Gen Core Processor PCIe Controller (x16) (rev 05)
00:08.0 System peripheral: Intel Corporation Xeon E3-1200 v5/v6 / E3-1500 v5 / 6th/7th/8th Gen Core Processor Gaussian Mixture Model
00:14.0 USB controller: Intel Corporation 100 Series/C230 Series Chipset Family USB 3.0 xHCI Controller (rev 31)
00:14.2 Signal processing controller: Intel Corporation 100 Series/C230 Series Chipset Family Thermal Subsystem (rev 31)
00:15.0 Signal processing controller: Intel Corporation 100 Series/C230 Series Chipset Family Serial IO I2C Controller #0 (rev 31)
00:16.0 Communication controller: Intel Corporation 100 Series/C230 Series Chipset Family MEI Controller #1 (rev 31)
00:17.0 SATA controller: Intel Corporation Q170/Q150/B150/H170/H110/Z170/CM236 Chipset SATA Controller [AHCI Mode] (rev 31)
00:1c.0 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #1 (rev f1)
00:1c.2 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #3 (rev f1)
00:1c.4 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #5 (rev f1)
00:1d.0 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #9 (rev f1)
00:1d.4 PCI bridge: Intel Corporation 100 Series/C230 Series Chipset Family PCI Express Root Port #13 (rev f1)
00:1f.0 ISA bridge: Intel Corporation CM238 Chipset LPC/eSPI Controller (rev 31)
00:1f.2 Memory controller: Intel Corporation 100 Series/C230 Series Chipset Family Power Management Controller (rev 31)
00:1f.3 Audio device: Intel Corporation CM238 HD Audio Controller (rev 31)
00:1f.4 SMBus: Intel Corporation 100 Series/C230 Series Chipset Family SMBus (rev 31)
00:1f.6 Ethernet controller: Intel Corporation Ethernet Connection (5) I219-LM (rev 31)
01:00.0 VGA compatible controller: NVIDIA Corporation GM107GLM [Quadro M1200 Mobile] (rev a2)
01:00.1 Audio device: NVIDIA Corporation GM107 High Definition Audio Controller [GeForce 940MX] (rev a1)
04:00.0 Network controller: Intel Corporation Wireless 8265 / 8275 (rev 78)
3e:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM981/PM981/PM983
3f:00.0 Unassigned class [ff00]: Realtek Semiconductor Co., Ltd. RTS525A PCI Express Card Reader (rev 01)lspci -t-[0000:00]-+-00.0
+-00.2
+-01.0
+-02.0
+-02.1-[01]----00.0
+-02.2-[02]----00.0
+-02.4-[03]----00.0
+-03.0
+-04.0
+-04.1-[04-63]--
+-08.0
+-08.1-[64]--+-00.0
| +-00.1
| +-00.2
| +-00.3
| +-00.4
| +-00.5
| \-00.6
+-08.2-[65]--+-00.0
| \-00.1
+-08.3-[66]--+-00.0
| +-00.3
| +-00.4
| \-00.6
+-14.0
+-14.3
+-18.0
+-18.1
+-18.2
+-18.3
+-18.4
+-18.5
+-18.6
\-18.7 How to teach Exams and homework are useless, only projects matter Updated 2025-06-17 +Created 1970-01-01
See: Section "Exam".
The only thing that matters is that students aim towards the goals described at explain how to make money with the lesson.
Any "homework for which the student cannot use existing resources available online" is a waste of time.
The ideal way to go about it is to reach some intermediate milestone, and then document it. You don't have to do the hole thing! Just go until your patience with it runs out. But while you are doing it, go as deep and wide as you possibly can, without mercy.
This is actually how Ciro Santilli learns new subjects he is curious about, even as an adult! Some examples:
Tell students to:
- make suggestions to the course material themselves, since you have used text and published your source.Review their suggestions, and accept the best ones.
- answer the questions of other students on your online forum. Let them work instead of you.
Praise those that do this very highly, and give them better grades if you have that superpower.
Whatever you do, even if it is playing video games: if you manage to produce related content that will interest other people, and possibly allow you to get paid, it will much much fun to do that thing.
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:
2025-06: rebuying 2x Shimano B05S, 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: 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: rebuying another Topeak Aero Wedge saddle bag for this new bike
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: M - Shimano MT210, 46/30, chain guard, 170 mm length | Size: L, XL - Shimano MT210, 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
- 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
Ciro Santilli's hardware Seagate ST1000LM035-1RK1 1TB hard disk Updated 2025-06-17 +Created 1970-01-01
1TB.
www.disctech.com/Seagate-ST1000LM035-1TB-SATA-Hard-Drive 80 USD | web.archive.org/web/20181224201408/https://www.disctech.com/Seagate-ST1000LM035-1TB-SATA-Hard-Drive
www.seagate.com/www-content/datasheets/pdfs/mobile-hddDS1861-2-1603-en_US.pdf | web.archive.org/web/20181225095438/https://www.seagate.com/www-content/datasheets/pdfs/mobile-hddDS1861-2-1603-en_US.pdf
sudo hdparm -Tt /dev/sda3 on Ubuntu 20.04: Department of Computer Science of the University of Oxford Updated 2025-06-17 +Created 1970-01-01
general linear group over a finite field of order . Remember that due to the classification of finite fields, there is one single field for each prime power .
Exactly as over the real numbers, you just put the finite field elements into a matrix, and then take the invertible ones.
Unlisted articles are being shown, click here to show only listed articles.