Wikipedia:Reference desk/Archives/Science/2021 December 14

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December 14

Why power units used in telecommunications

I believe the frequency is the base factor in telecommunications. But this [1] says: Watt is used as a common unit used to express the electromagnetic power output of broadcast radio and television transmitters. Rizosome (talk) 09:54, 14 December 2021 (UTC)

The frequency is used by the public to tune in their radios etc. However, Watts gives an indication of the range of the signal, just like a 1Watt light bulb can be seen a short distance in total darkness, and a 10kW floodlight can be seen at 100 times the distance. The units are normally dBm, where 0 dBm corresponds to a radiated power of 1 mW, a 30 dBm 1W, 60 dBm 1kWm etc LongHairedFop (talk) 11:34, 14 December 2021 (UTC)

• Frequency and power are different measurements of an electromagnetic signal. Frequency is the number of vibrations per second in the electromagnetic signal, in telecommunications the frequency quoted is usually that of the carrier wave. The power of a signal is how strong the signal is; it is unrelated to its frequency. Functionally, a telecommunications transmitter is not really any different than a lightbulb. Both give off electromagnetic radiation, though of different frequencies and power. The frequency is exactly analogous to the color of the lightbulb, while the power of the radio transmitter is akin to the watts of the lightbulb, and just as in a lightbulb where the watts are a good indicator of brightness, the watts of a radio transmitter are an indicator of its range. It's not exactly that simple, as range is also frequency-dependent, but all other things being equal, if there two radio stations broadcasting at the same frequency, the higher-powered station will be able to be picked up by a receiver further from the transmitter. --Jayron32 15:20, 14 December 2021 (UTC)

coffee grounds to track dogs

Yes, coffee grounds have the potential to be toxic to dogs because they contain high levels of caffeine what? give me a wrong statement about dogs can smell coffee grounds over long distance. ow man google AI showed me an exact opposite question. What if dog eats the coffee grounds? That's distracting. but the AI gives me a wrong answer according to google. is the coffee grounds useful for follow your dogs? at least don't let the dogs eats the coffee i mean. But the google says that dog are very toxic coffee grounds BUT they don't show me a right answer: the dog is able to track the coffee grounds' path. the website can be seen here below: https://www.loveyourdog.com/dog-ate-coffee-grounds/#:~:text=Dog%20Be%20OK%3F-,Are%20Coffee%20Grounds%20Dangerous%20to%20Dogs%3F,as%20methylxanthine)%20is%20a%20stimulant. 2404:8000:1005:555:C0EE:F0EE:B396:6DF3 (talk) 15:09, 14 December 2021 (UTC)

What is your question? If it is about Google not giving you the right answer, well, we aren't Google and don't control that. --OuroborosCobra (talk) 15:11, 14 December 2021 (UTC)

To the OP: I can't follow your question that well, but I did find this article about the ability of dogs to pick other scents through the scent of coffee. Is that what you are asking about? --Jayron32 15:13, 14 December 2021 (UTC)

Caffeine is dangerous for both dogs and cats. — Preceding unsigned comment added by Baseball Bugs (talk • contribs) 16:54, 14 December 2021 (UTC)

Please note that smelling coffee is not the same thing as ingesting coffee. MarnetteD|Talk 17:02, 14 December 2021 (UTC)

If you can figure out what he's asking (here and with his short list of other posts), feel free to explain. ←Baseball Bugs ^{What's up, Doc?} carrots→ 17:20, 14 December 2021 (UTC)

OK. In short, the question is "are dogs able to smell coffee grounds over long distances, and track a path along which the coffee grounds have been carried?". Or, a blow-by-blow description of the post goes like this: (1) Here is a quote about toxicity, from a website OP found by googling the question. (2) OP is annoyed about how irrelevant the quote is to the real question about tracking. (3) OP supposes it might have some relevance in one respect. (4) OP repeats the real question again, fighting to stay on topic. (5) OP refers back to the distracting sidetrack again, just to discount it. (6) OP further acknowledges the seriousness of this irrelevant concern about toxicity, but re-iterates the actual question too. (7) Link to the irrelevant website, for clarity.  Card Zero  (talk) 17:36, 14 December 2021 (UTC)

Excellent work Card Zero. The original post is as twisty turny as anything I've ever read and you have pulled apart those threads in fine fashion. Regards. MarnetteD|Talk 19:20, 14 December 2021 (UTC)

I wonder what the answer is?  Card Zero  (talk) 20:50, 14 December 2021 (UTC)

Dogs are known for their very developed sense of smell, and relatively fresh coffee grounds have a strong scent, so if a dog is able to follow the scent track left by a person, they should surely be able to do the same with the scent track of coffee grounds. Of course, there are limits. Eventually, the scent disappears from the track. Coffee is so ubiquitous that a different source of the same smell could throw the dog off track.  --Lambiam 23:04, 14 December 2021 (UTC)

Various sources claim that dogs often dislike the smell of coffee (and citrus, and anything bitter), so that might be a problem with whatever the plan is here (or not, if it's about hiding drugs). On the other hand, lots of people seem to think puppies' breath smells like coffee, implying that dogs dislike the smell of puppies, which would be awkward. I also found an item about dogs trained to sniff out diseases in citrus trees, so I don't see why they couldn't be trained to seek coffee. However, as you say, coffee is pretty much everywhere, and humans usually have a keen awareness of where the coffee is located without having to train dogs to help, which is probably why I couldn't find any examples.  Card Zero  (talk) 02:09, 15 December 2021 (UTC)