Are real numbers really real?

Re:Are real numbers really real? by spiralx on Tuesday June 12, 2018 @01:19PM (#17295484)

> But there is no general law preventing increasing the precision with better instruments and better methods, so as measurement gets more advanced, more data (such as more decimal digits) can be obtained.

That's not true, as at the Planck length both quantum and general relativistic effects are equally important, preventing arbitrary measurements over smaller scales - that's the case even for a continuously-divisible universe. In most quantum gravitational theories today the Planck length truly is a minimum possible distance in the same way the Planck time is the minimum possible duration, representing a quantized space-time with hard limits to the precision of measurements.

[ Parent | on HN ]

Re:Are real numbers really real? by posix_me_less on Tuesday June 12, 2018 @01:44PM (#17295784)

Quantum gravity "theories" are speculative extrapolations of current knowledge for extreme situations, not accepted general laws of physics. They have problems with consistency (discretization of lengths and other quantities breaks relativity postulates) and even bigger problem with lack of experience with phenomena that they describe (minimum possible lengths/times/energy/etc).

[ Parent | on HN ]

Re:Are real numbers really real? by spiralx on Wednesday June 13, 2018 @05:18AM (#17301505)

Yes I know, that's why I made the general point first, then talked about how quantum gravity theories impose even harder limits if true.

[ Parent | on HN ]