there is no third dimension, either. Now, by that I don't mean that there aren't three

也沒有所謂第三象限；但我並不是指三維象限不存在

dimensions… there are, but just we can't tell these dimensions apart: there's no special

它們的確存在，但我們無法將象限區分開來：沒有特定的

direction you can call "the 1st dimension," [north? east? up?] so it doesn't make sense

方向可以叫「第一象限」(北方？東方？上方？) 所以那種說法並不合理

to say "this is the 2nd one," or "what's the fourth one?"

不能去說「這是第二象限」或「什麼是第四象限？」

It's like if you have a jug with three cups of water in it... it's easy to tell that there

就像是你在壺中倒了三杯水...你可以說壺中

ARE three cups of water, but which is the first cup? the second? or the third? Those

「存在」三杯水，但哪個是第一杯？哪裡又是第二杯、第三杯？

questions don't even make sense!

這些都是不合理的問句！

That said, there may be different KINDS of dimensions that you CAN tell apart - like

也就是說，可能存在不同「類型」的象限是你「可以」分辨的

if you poured three cups of water and one cup of oil into our dimensions jug. Then you

如果你在壺中倒入三杯水和一杯油，那你

could say "I have three dimensions that behave in the same way, and one that behaves a different

就可以說「我有三個象限用同樣的方式運作，但有一個象限不同」

way." And that's what we mean when we say that we live in three spatial dimensions and

而這就是我們指的：我們住在三維空間以及

one time dimension.

一維時間中

And there's nothing crazy about adding another cup of water so that you'd have four watery

這樣想並不瘋狂：可以加入另一杯水，讓壺中變成四杯水

cups and one oily cup; likewise we can contemplate what the universe would be like if there were

和一杯油；就像我們同樣可以思考宇宙的可能樣貌，假設它

FOUR spatial dimensions and one time dimension… or in the case of string theory, nine spatial

有「四維」空間象限；而在弦理論中，有九個空間象限

dimensions and one time dimension.

以及一個時間象限

And while we're at it, it's not even too hard to conceive that there might be two dimensions

而當我們身在其中時，要認知可能有二維時間象限存在並不困難

of time… but I don't have even have enough of one time dimension to explain that now.

但我甚至沒有足夠的「一維」時間去解釋它

So if you'd like to try your brain at visualizing a world with four spatial dimensions, check

所以如果你嘗試在腦中描繪出一個四維空間象限，可以

out the book Flatland or try solving a 4D rubiks cube.

看看《平面國》這本書或是試試解決一個4D魔術方塊