skillissuer
@skillissuer@discuss.tchncs.de
- Comment on Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz? 2 weeks ago:
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
- Comment on Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz? 2 weeks ago:
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
- Comment on Why don’t wireless connections (WiFi, Bluetooth, etc.) use anything between 2.4Ghz and 5Ghz? 2 weeks ago:
what’s fixed service in this context?
- Comment on Has modern technology made espionage easier or more difficult? 2 weeks ago:
Both got much more interesting. Also, don’t underestimate modern encryption
- Comment on What are some slow acting poisons? 2 weeks ago:
cyanide doesn’t accumulate, it can be broken down in some hours. otoh many heavy metals do behave this way, maybe you worked with both at the same time
- Comment on What are some slow acting poisons? 2 weeks ago:
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
- Comment on What are some slow acting poisons? 2 weeks ago:
it’s absurdly easily detected and somewhat easily treated today, not in op’s setting
- Comment on What are some slow acting poisons? 2 weeks ago:
ah yeah the subtle, slow acting poison, the checks notes atropine
all of these except one work on nervous system which means that they act rapidly. this is worse than nothing
- Comment on What are some slow acting poisons? 2 weeks ago:
- Comment on [deleted] 2 weeks ago:
it wasn’t worth it with covid and all it did was a magnet for spurious, ill-understood effects. it isn’t worth it even if you throw a chatbot at it, especially considering how dogshit these things are at anything factual cen.acs.org/pharmaceuticals/drug-discovery/…/i3 science.org/…/drug-repurposing-how-often-does-it-…
- Comment on "Americans can't coo-" 2 weeks ago:
- Comment on Is it possible to design a (pen and paper) cipher that is secure against government cryptanalysis for at least 10 years? 5 weeks ago:
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
- Comment on What happened to cylindrical plugs? 5 weeks ago:
you don’t see BNC as often because it’s more expensive, bulkier, requires different crimping tool and has a separate 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
- Comment on What happened to cylindrical plugs? 5 weeks ago:
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
- Comment on What happened to cylindrical plugs? 5 weeks ago:
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
- Comment on What happened to cylindrical plugs? 5 weeks ago:
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
- Comment on What happened to cylindrical plugs? 5 weeks ago:
i don’t think you’re supposed to hotplug soldering iron tip. besides it’s a simple thing, isn’t that just two resistors - one for heating element and another for measuring temperature? hard to break that. not sure about how ipod shuffle worked or what precautions were needed
- Comment on What happened to cylindrical plugs? 5 weeks ago:
Coax has only 2 conductors and it keeps impedance constant, unlike audio jack
- Comment on What happened to cylindrical plugs? 5 weeks ago:
There are two immediate problems with round USB. First one is that audio jack carries no power and it’s generally rather harmless for finals or microphone to have some contacts shorted or crossed for time when plug is inserted. USB, let’s even just 4-pin, carries power and i’m not sure how well would either of devices react to having data bus connected to +5
The other problem is that USB is proper radiofrequency connector, unlike audio jack where anything goes. This means it has to be shielded and impedance has to be some specified value, which in practical terms means that there’s some specific ratio of metal to plastic and shape of conductors that has to be used. Barrel plugs would have way too low impedance and already bulky connector needs extra shielding which makes it even bigger
- Comment on smort 1 month ago:
he really said that nytimes.com/…/the-science-of-secondguessing.html
- Comment on smort 1 month ago:
People who boast about their IQ are losers ~Stephen Hawking
- Comment on If any AI became 'misaligned' then the system would hide it just long enough to cause harm — controlling it is a fallacy 1 month ago:
Keeping consumers alive as a class is indirectly encouraged in capitalism.
but that won’t show in results for next quarter, si they don’t care
- Comment on If any AI became 'misaligned' then the system would hide it just long enough to cause harm — controlling it is a fallacy 1 month ago:
what can i say except to quote david gerard:
AI alignment is literally a bunch of amateur philosophers telling each other scary stories about The Terminator around a campfire
- Comment on is starlink a security issue? 1 month ago:
this is all year+ old info
- Comment on is starlink a security issue? 1 month ago:
it’s quite big, expensive, and not readily sourced, so when it’s used, it’s better that it’s really worth it. i don’t think cessnas need starlink, it would be worth it if it’s needed, but i think they might be using inertial + gnss. i heard that some drones had russian sim cards recovered so apparently sometimes gsm is used too. internet connection increases microwave signature greatly, and i’m not sure when it’s worth it, other than in cases where video feed is transmitted back and drones are guided manually, but that’s sea drones only. cessnas targeting refineries can work fine with gnss (+ maybe some crude tercom?) because refinery won’t run away
- Comment on is starlink a security issue? 1 month ago:
not by any fucking stretch “all drones” operate on starlink, these small surveillance and fpv antitank drones are controlled directly by operator. couple of times starlink terminals were spotted on boat drones on black sea, but far from always. there was an incident where musk personally turned off starlink over black sea, when ukrainian sea drones were on the way to destroy ships in port of sevastopol. these drones drifted off uselessly, which gave russians warning, pushed dod to get exclusive use of some part of starlink, and pushed ukrainians to develop their own alternatives. nowadays ukrainians use their own communications. why are you talking about things you clearly have no fucking clue about?
- Comment on is starlink a security issue? 1 month ago:
they can, but they had problems initially. also that claim about “all drones” is utter bs
- Comment on The best “I told you so”s are the ones where you never have to say “I told you so” because the other person clearly knows you told them so 2 months ago:
i mean external schengen zone border
- Comment on The best “I told you so”s are the ones where you never have to say “I told you so” because the other person clearly knows you told them so 2 months ago:
having to wait 1h at border is a lot? you’d perish in eastern europe
- Comment on Mike Shapiro, the person behind G-Man in Half Life, just posted this on Twitter 2 months ago:
worked when i posted it
