Why is a Time Shift also a Phase Rotation in Frequency?

[@Embarking-on-a-new-adventure]

I am glad those formula's were not asked during my Ham exam 😁

[@iain_explains]

I haven't heard of a Ham Exam before. I'm guessing you're not a butcher assessing the quality of a farmer's pigs. (... that's a 'dad joke', I know). But I might check what's asked on such an exam, and see if there are any topics I could cover on my channel. Thanks for the idea.

[@elijahsmith7552]

​@@iain_explains it would be great to see a video explaining some of the more popular digital modes in amateur radio, e.g. VARA or FT8. I found your channel through ham radio topics. Thanks for all the info.

[@iain_explains]

Thanks for the suggestion. I've put it on my "to do" list.

[@stephensu4371]

nice work, i like those transform (L, F, Z) video

[@iain_explains]

Glad you like them!

[@manfredcaranci6234]

At about 2:13, you use the word "wavelength", a spatial term, when I think you meant to say "period", a temporal term.

[@iain_explains]

Yes, thanks ... a verbal "typo".

[@StarF0xPrime]

From certain perspectives those two are one and the same-especially if you’re thinking of displacement.

[@payman_azari]

Thanks Professor, very informative. can you also consider explaining about minimum-phase and excess-phase characteristics of a signal (I see no decent tutorial) I am currently using it to calculate the time delay between signals, and I get good results, but I think there can be a deeper understanding of these concepts.

[@iain_explains]

Thanks for the suggestion. I've put it on my "to do" list.

[@payman_azari]

@@iain_explains Great! 😊

[@StarF0xPrime]

Beautiful videos Iain. Are we assuming that time is linear, in this context?

[@iain_explains]

Glad you like the videos. Not sure what you mean by "assuming that time is linear". I'm not a physicist, but time is a dimension, it's neither linear nor non-linear. Or as Einstein said, "time is an illusion", from a relativity point of view.

[@StarF0xPrime]

@@iain_explainsthe reason i asked was that i wanted to be sure that rotations are “frequency versions” of time shifts, that is, if time were a linear step in “time domain”, in “frequency domain” it would be a rotation.

[@StarF0xPrime]

Presuming, again, that frequency is 2-dimensional by definition, while time is unidimensional.

[@iain_explains]

No, that's not true. Frequency is not 2-dimensional. Perhaps this video might help: "What is Negative Frequency?" kzbin.info/www/bejne/nauZcn6NYrdpb9U

[@kunleiyu3925]

Thank you vary much for making such a wonderful video! But I am not sure about the phase shifting term. An imaginary number seems to be missing there.

[@iain_explains]

Sorry, yes you're right. It's a "typo". Thanks for letting me know. I'll add a comment to the description below the video.