Wikipedia:Reference desk/Archives/Science/2021 August 16

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August 16

Signal processing term to describe a signal with just one mode or three or more modes

If a signal that has two modes (states) is "discrete", what is the correct term to describe a signal which has only one mode or three or more modes? Thanks, 2001:44C8:42C6:DD01:680D:94D6:1457:A605 (talk) 02:52, 16 August 2021 (UTC)

3 is still discrete. Discrete has a choice of a finite number of values. If there is only 1 possible state there is no information, perhaps you have a carrier wave. The opposite situation is continuous, where any value in a range is possible, eg a pointer on a meter, or the position of a hand on an analogue clock. Both discrete and continuous are subtypes of symbolic where one thing represent information about something else. Graeme Bartlett (talk) 07:57, 16 August 2021 (UTC)

I like your answer ! Thanks again, 2001:44C8:42C6:DD01:BC35:5658:6E14:5770 (talk) 11:03, 16 August 2021 (UTC)

Why signal lamps not intended to send signals in morse codes?

From Signal lamp, it says: they are not intended to be used for transmitting messages in Morse code.

Why so? Rizosome (talk) 04:54, 16 August 2021 (UTC)

That's in the specific context of communication with airplane pilots. It should be obvious that pilots are not required to learn Morse code, and even if they happened know it, keeping their eyes on a single flashing light long enough to receive a message might be dangerously distracting. --184.144.99.72 (talk) 07:20, 16 August 2021 (UTC)

Traffic lights use colours to send signals to humans driving or riding vehicles (proceed/caution/stop), just like the signal light guns used by air traffic control for sending aviation light signals to pilots. Traffic lights are not intended to be used for transmitting messages in Morse code to car drivers. Why so? In an emergency situation, if it is imperative that one make a hole in a leather belt, and the only instrument available is a corkscrew, then one may perhaps succeed in piercing the belt with the corkscrew. But corkscrews are not intended for making holes in leather belts. Why so? The questions are meaningless.  --Lambiam 08:53, 16 August 2021 (UTC)

• Just to clarify that those signal lamps "used today for aviation light signals in air traffic control" are what are not used for Morse Code. Many other kinds of signal lamps have been, and still are used for Morse Code signals. Just that one usage is not. --Jayron32 18:07, 16 August 2021 (UTC)

• It's also worth remembering that Morse code was developed to complement forms of high speed (comparative to the time), long distance communication. Telegraph wires can be laid over long distance, and certain wavelengths of non-visible light (such as AM radio) can travel over the horizon by bouncing off the ionosphere. Even other forms of radio transmission can at least get through some amount of obstacles, such as some buildings or trees. Visible light, on the other hand, is extremely limited to line of site. Using visible light lamps for Morse code would be little better than just shouting, or smoke signals. --OuroborosCobra (talk) 13:47, 17 August 2021 (UTC)

Good job we never had to rely on Aldis lamps then!--Phil Holmes (talk) 07:11, 18 August 2021 (UTC)

The ocean is one of the few situations where you don't generally have buildings, trees, and mountains in the way. --OuroborosCobra (talk) 12:55, 18 August 2021 (UTC)

• It comes in handy sometimes, though, I remember a key scene in The Hunt for Red October where morse code via signal light is a key plot point. --Jayron32 16:52, 17 August 2021 (UTC)

Also in Executive Decision (in the exact context in which they are not intended to be used in this manner) :-) 2601:646:8A81:6070:7484:4D7C:C258:55B2 (talk) 10:49, 22 August 2021 (UTC)

Sertraline and grapefruit juice

Is it safe to drink grapefruit juice while taking sertraline? The Wikipedia article on Sertraline does not say anything. Thank you. 81.153.151.90 (talk) 18:45, 16 August 2021 (UTC)

What leads you to think it's not safe? And if in doubt, ask your doctor. ←Baseball Bugs ^{What's up, Doc?} carrots→ 19:51, 16 August 2021 (UTC)

The advice printed on the box that says "avoid drinking grapefruit juice". 81.153.151.90 (talk) 20:08, 16 August 2021 (UTC)

If it says so on the box, then don't drink grapefruit juice. The relevant Wikipedia article is Grapefruit–drug interactions. --Wrongfilter (talk) 20:23, 16 August 2021 (UTC)

I'm very curious as to why you think anonymous people on the internet would be able to say that the printed advice on medication can be safely ignored. What medical training or authority would they have that could possibly counteract the advice provided by the manufacturer? -- Jack of Oz ^{[pleasantries]} 01:30, 21 August 2021 (UTC)

[Edit Conflict x2] It's a reasonable concern, since grapefruit juice in particular, and other citrus or other fruit juices to a lesser extent, are known to interfere with the actions of many drugs – see Grapefruit–drug interactions.

Sertraline is indeed one of the drugs mentioned in that linked article, in the section Grapefruit–drug interactions#Incomplete list of affected drugs. There's not much point in taking a pharmacological drug while also consuming something that will prevent it from working properly. {The poster formerly known as 87.81.230.195} 90.197.27.112 (talk) 20:25, 16 August 2021 (UTC)

Well maybe the Sertraline article ought to say something? I asked my doctor if I would be able to swim while taking sertraline and he said yes. I'm quite looking forward to that, as I've never been able to swim before. :) 81.153.151.90 (talk) 20:32, 16 August 2021 (UTC)

Maybe you were too depressed to swim. As for the article, you could add the reference that's in the Interactions article linked a couple of times here. ←Baseball Bugs ^{What's up, Doc?} carrots→ 20:34, 16 August 2021 (UTC)

I have added a sentence. So the conclusion seems to be that it is probably safe, but that it might reduce the effectiveness of the medication. 81.153.151.90 (talk) 21:50, 16 August 2021 (UTC)

Grapefruit interactions increase the effect of some drugs, though. --184.144.99.72 (talk) 08:37, 17 August 2021 (UTC)

Yes, "not working properly" could encompass "not working as well," "working too well," or "doing something unintended." {The poster formerly known as 87.81.230.195} 90.197.27.112 (talk) 09:34, 17 August 2021 (UTC)