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when I did my math degree in college the profs and grad students called them "complex numbers." I think they know there's a problem so they want to get the stud

when I did my math degree in college the profs and grad students called them "complex numbers." I think they know there's a problem so they want to get the students who would go on to teach used to not calling them "imaginary"

deleted 5y ago
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bee_rider 5y ago
That doesn't quite get at it, though -- a complex number has an imaginary and real part. I guess we could call them "complex numbers with a zero real part," but 1) that's quite a mouthful i) it implies that the other part is something other than real -1) it seems weird to describe something sort of... subtractively like this
- ravi-delia 5y ago
  Eh, it's fair to call i a complex number. I mean C includes the imaginary line.
  - Jtsummers 5y ago
    ai is a complex number and an imaginary, but not all complex numbers are imaginary numbers (like square/rectangle). a+bi is a complex number, but not an imaginary number. And a is a complex number and a real number. Which is the problem with trying to reduce it this way, you lose the ability to distinguish (by name) the two components of a complex number. What are the two parts of a complex number called if we drop real and imaginary?
    - ravi-delia 5y ago
      > What are the two parts of a complex number called if we drop real and imaginary? Real and imaginary! I'm not saying we should never use the work imaginary, I'm just saying that what makes i interesting is not that it's an imaginary number, but that it's a complex number. The imaginaries on their own aren't a number system at all, and rarely come up in isolation. Objecting in introducing sqrt(-1) as a complex number seems a little silly.
  - bee_rider 5y ago
    It is equally fair to call i and 1 complex numbers.
    - ravi-delia 5y ago
      I don't think that's a very fair comparison. You wind up with 1 when trying to make every number system from the naturals up. The imaginaries basically never come up except when using complex numbers in general, and certainly don't in the high-school and undergrad classes where people first learn about them.
throwawayboise 5y ago
FTA: it’s complex as in “military-industrial complex,” speaking of combination—of real and imaginary parts—rather than complication From first introduction in middle school math all the way through undergraduate university math to reading this tonight at age 55, no teacher or professor or book I recall has ever stated that "complex" meant "multi-part." I always thought of it as "complicated." Yes we learned "real part" and "imaginary part" but that was never connected to the name "complex." An exercise left to the reader, I suppose. Math education has a long way to go.
- jacobolus 5y ago
  Yes, as Rich Hickey has pointed out in programming talks, to “complect” originally meant to twist, braid, or weave together. It is a textile metaphor.

deleted 5y ago

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bee_rider 5y ago

That doesn't quite get at it, though -- a complex number has an imaginary and real part. I guess we could call them "complex numbers with a zero real part," but 1) that's quite a mouthful i) it implies that the other part is something other than real -1) it seems weird to describe something sort of... subtractively like this

ravi-delia 5y ago
Eh, it's fair to call i a complex number. I mean C includes the imaginary line.
- Jtsummers 5y ago
  ai is a complex number and an imaginary, but not all complex numbers are imaginary numbers (like square/rectangle). a+bi is a complex number, but not an imaginary number. And a is a complex number and a real number. Which is the problem with trying to reduce it this way, you lose the ability to distinguish (by name) the two components of a complex number. What are the two parts of a complex number called if we drop real and imaginary?
  - ravi-delia 5y ago
    > What are the two parts of a complex number called if we drop real and imaginary? Real and imaginary! I'm not saying we should never use the work imaginary, I'm just saying that what makes i interesting is not that it's an imaginary number, but that it's a complex number. The imaginaries on their own aren't a number system at all, and rarely come up in isolation. Objecting in introducing sqrt(-1) as a complex number seems a little silly.
- bee_rider 5y ago
  It is equally fair to call i and 1 complex numbers.
  - ravi-delia 5y ago
    I don't think that's a very fair comparison. You wind up with 1 when trying to make every number system from the naturals up. The imaginaries basically never come up except when using complex numbers in general, and certainly don't in the high-school and undergrad classes where people first learn about them.

throwawayboise 5y ago

FTA: it’s complex as in “military-industrial complex,” speaking of combination—of real and imaginary parts—rather than complication From first introduction in middle school math all the way through undergraduate university math to reading this tonight at age 55, no teacher or professor or book I recall has ever stated that "complex" meant "multi-part." I always thought of it as "complicated." Yes we learned "real part" and "imaginary part" but that was never connected to the name "complex." An exercise left to the reader, I suppose. Math education has a long way to go.

jacobolus 5y ago
Yes, as Rich Hickey has pointed out in programming talks, to “complect” originally meant to twist, braid, or weave together. It is a textile metaphor.