Any smooth cubic surface contains 27 lines

Re:Any smooth cubic surface contains 27 lines by amelius on Wednesday February 17, 2016 @08:27AM (#11117646)

Any polynomial of degree n has n roots, but some of them may be degenerate, and some of them may be complex.

So, how would that translate to the cubic-surface situation? Are there cubic-surfaces that are "degenerate", and thus have actually less than 27 lines?

Are all the lines expressible in real numbers? Or do we need complex numbers, like it is the case for polynomial roots?

Just some questions that popped into my mind.

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Re:Any smooth cubic surface contains 27 lines by GFK_of_xmaspast on Wednesday February 17, 2016 @10:20AM (#11118372)

> Any polynomial of degree n has n roots, but some of them may be degenerate, and some of them may be complex

This is not true with multiple variables, consider for example "x2 + y2 - 1"

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