请问是否存在用于表示时空的国际单位制（SI）单位？

Hey there, solid observation here!

Since we now commonly frame space and time together as spacetime, it makes intuitive sense that the SI units for length (米) and time (秒) could be combined into a single unified SI unit—something like [米-秒], for example.

But after digging through SI documentation and standard references, I haven't been able to find any official, recognized SI unit that fits this exact combination so far.

内容的提问来源于stack exchange，提问作者John McAndrew