Skip Navigation

User banner

skillissuer

@ skillissuer @discuss.tchncs.de

Posts
10
Comments
315
Joined
2 yr. ago

i should be writing

  • What's so important about keeping military operations secret?

    Jump

  • Another good example would be actions Brits took in order to protect the fact that Enigma was broken. For example, when Enigma deciphering indicated that there's warship in a specific area, they would send spotter plane first before attacking it, in order to provide enemy alternative explanation as of how they were discovered. Some operations were aborted entirely for this reason

  • Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz?

    Jump

  • sorry for being unclear, i forgor a word. what i meant that certain antenna designs would have specific fractional bandwidth, so that just scaling that design to higher frequency makes usable bandwidth wider in kHz terms. in order to get higher fractional bandwidth more complex or bulkier designs would be required, like thicker conductors, added parasitics, something LPDA-shaped, or maybe elaborate matching circuit, all of which cost money. i guess that while resonant amplifiers are a thing, probably bigger limitation would be bandwidth of mixer

  • Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz?

    Jump

  • i'd also note that antennas, amplifiers and so on have bandwidth that is some % of carrier frequency, depending on design, so just going up in frequency makes bandwidth bigger. getting higher % of bandwidth requires more sophisticated, more expensive, heavier designs. LoRa is much slower, caused by narrowed bandwidth but also because it's more noise-resistant

  • Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz?

    Jump

  • but there's separate category for "broadcast", so it's more of point-to-point thing?

  • Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz?

    Jump

  • what's fixed service in this context?

  • Has modern technology made espionage easier or more difficult?

    Jump

  • Both got much more interesting. Also, don't underestimate modern encryption

  • What are some slow acting poisons?

    Jump

  • cyanide doesn't accumulate, it can be broken down in some hours (very small amounts of course). otoh many heavy metals do behave this way, maybe you worked with both at the same time

  • What are some slow acting poisons?

    Jump

  • all metals that bind to sulfur well are to some degree poisonous. these are lead, mercury, thallium, some platinides (in salt form), arsenic, and also copper, but less than others. some metals have other mechanisms of toxicity, like nickel, hexavalent chromium, cadmium, beryllium or barium. some of these accumulate in brain or bones, and some don't. some are more toxic when inhaled like zinc or chromium

  • What are some slow acting poisons?

    Jump

  • it's absurdly easily detected and somewhat easily treated today, not in op's setting

  • What are some slow acting poisons?

    Jump

  • ah yeah the subtle, slow acting poison, the checks notes atropine

    all of these work on nervous system which means that they act rapidly. this is worse than useless

  • What are some slow acting poisons?

    Jump

  • https://en.wikipedia.org/wiki/Amanita_phalloides

    you also get points for historical accuracy, as it was used as far back as ancient rome

    also, how low tech is low tech? Litvinenko was dying for three weeks after polonium poisoning, and radium will have similar effects, first extracted 1898

  • Deleted

    Permanently Deleted

    Jump

  • Naleśniki are 1:1 crepes, we don't have something that americans call pancakes. there are racuchy that are halfway between american pancakes and apple fritter (with less oil, and not deep fried)

  • What are the options for a house with these well water test results?

    Jump

  • acidic water can leach some metals from ground, so maybe that's what's going on. in that case there might be no lead in pipes and it'll still get in water because it got there before touching piping

  • What are the options for a house with these well water test results?

    Jump

  • maybe they have no idea. do you live near mines?

  • What are the options for a house with these well water test results?

    Jump

  • maybe you can make ion exchange filter work. remember to maintain it regularly and test water for lead content after filter is installed to make sure it works. ion exchange resins work best if water flow through them is slow

  • Is it possible to design a (pen and paper) cipher that is secure against government cryptanalysis for at least 10 years?

    Jump

  • You can do RC4 on pen and paper, more precisely 256 pieces of paper. There's also a variant of this cipher that uses deck of cards instead, RC4-52. There's also another stream cipher that uses deck of cards to store state and it's called Pontifex/Solitaire. Both have some weaknesses

    VIC has way too short key for modern uses, but maybe there's a way to strenghten it

    On related note, i guess that it would be possible to implement modern stream cipher with NLFSR in electromechanical machine, no silicon needed. WW2 era cryptography like this (enigma, M209 etc) were in a way stream ciphers and these require some of least hardware. Key storage and scheduling becomes bigger problem

  • What happened to cylindrical plugs?

    Jump

  • you don't see BNC as often because it's more expensive, bulkier, requires different crimping tool and has a separate soldered pin. but if you need to connect and disconnect things often and quickly, then it's a good connector. i bet you've seen (RP-)SMA a lot instead, but this one is also more expensive than F, has separate pin and is too small to easily make a connector for common 75 ohm cables. reducing diameter would mean higher loss

  • What happened to cylindrical plugs?

    Jump

  • i keep hearing that F stands for Flimsy. no idea where that came from, unless something is seriously wrong with crimping technique. i guess there's a tradeoff between CCS or copper cable with durability of pin/center conductor vs bending radius, and some people don't like how it turns out, while ignoring that it's cheap and not really designed for multiple disconnections

    but yeah, as long as everything is matched good-enough then it's a cheap way to connect low loss, cheap cable (75 ohm only. otherwise i'm in the N/SMA/BNC camp, UHF connectors are unreasonably obsolete)

  • What happened to cylindrical plugs?

    Jump

  • The context of the whole thread, though, was end-user, repeated, frequent connections for people who have to be reminded by a manual that the thing needs to be plugged in. Coax is horrible for that.

    so you want BNC

  • What happened to cylindrical plugs?

    Jump

  • power plug with 3 wires or 5 wires (3-phase) could be made safe-ish if there was a button at the very end that connected to a relay or something. but plug like this would be comically long for any practical power

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    mopup rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    4k ultrahd rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    suspicious rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    foraged rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    pain rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    throw away "do not eat" rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    cyberpunk is now rule

  • 196 @lemmy.blahaj.zone
    skillissuer @discuss.tchncs.de

    2:28 am rule

  • Buttcoin - The Crypto-Critical Comedy GODL Mine @kbin.social
    skillissuer @discuss.tchncs.de

    Purchasers of worthless digital monkeys sue worthless digital monkey auction house after realizing that digital monkeys are worthless

    arstechnica.com /tech-policy/2023/08/buyers-of-bored-ape-nfts-sue-after-digital-apes-turn-out-to-be-bad-investment/
  • Buttcoin - The Crypto-Critical Comedy GODL Mine @kbin.social
    skillissuer @discuss.tchncs.de

    Sam Bankman-Fried is going to jail

    arstechnica.com /tech-policy/2023/08/sam-bankman-fried-is-going-to-jail/