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Unifies both special relativity and gravity.
Not compatible with the Standard Model, and the 2020 unification attempts are called theory of everything.
One of the main motivations for it was likely having forces not be instantaneous, but rather mediated by field to maintain the principle of locality, just like electromagnetism did earlier.
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:
Weight after bought measured differentially on bathroom scale: 13.5 kg
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 thatn on the Kross bicycle (2017) since this is XL might be a good thing. Let's see on longer countrysie 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 seemd 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:
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.
2024-09: chain reached 0.75, rebuying KMC X9. x9 9 speed chain 114 links.
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: chain reached 0.75, rebuying KMC X9. x9 9 speed chain 114 links.
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: ParkTool TR1 tyre levers + GP-2 super patch kit
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
- Approx. Weight: L - 13.17 kg / 29.04 lbs
One of the best ways to think about it is the transversal time dilation thought experiment.
Same motivation as Galilean invariance, but relativistic version of that: we want the laws of physics to have the same form on all inertial frames, so we really want to write them in a way that is Lorentz covariant.
This is just the relativistic version of that which takes the Lorentz transformation into account instead of just the old Galilean transformation.
Pinned article: ourbigbook/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!
We have two killer features:
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- a Wikipedia where each user can have their own version of each article
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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/derivative - 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 2. You can publish local OurBigBook lightweight markup files to either OurBigBook.com or as a static website.
Figure 3. Visual Studio Code extension installation.
Figure 4. Visual Studio Code extension tree navigation.
Figure 5. . 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. - Internal cross file references done right:
- Infinitely deep tables of contents:
Figure 6. Dynamic article tree with infinitely deep table of contents.Live URL: ourbigbook.com/cirosantilli/chordateDescendant pages can also show up as toplevel e.g.: ourbigbook.com/cirosantilli/chordate-subclade
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