多重宇宙The Multiverse
Brett： 我们必须更深入地理解这个双缝实验中到底发生了什么。如果我们向双缝装置发射光子或电子，并在两条缝中的任一条处放置探测器，那么我们就会探测到一个粒子。
我们能探测到我们发射了一个粒子；我们能探测到一个粒子正穿过那些狭缝；我们也能在投影屏上探测到一个粒子。
当你在实验室里用电子做这个实验时，你能看到电子击中屏幕留下的斑点。但你得到的并不是你所预期的简单图案。
如果你用炮弹穿过同一面墙上的两个洞射击，你会预期所有炮弹都落在墙后两个位置之一。
但对于量子层面的粒子，情况并非如此。
唯一的解释是：当我们发射一个光子时，既有我们能在自己的宇宙中看到的那个光子，也有我们看不见的、在其他宇宙中穿过该装置的光子。这些光子能够与我们探测到的那个光子相互作用。
这就是干涉概念登场的地方。干涉是物理学中一个古老的概念，可以追溯到波动理论。波确实会干涉，但我们需要理解粒子之间相互干涉的方式。这既包括我们能观察到的粒子，也包括根据这些实验我们只能推定其存在的粒子。
正因如此，我们不得不承认这些其他粒子的存在——不仅是这些其他粒子，还有这些粒子所存在的其他宇宙。
Brett: We have to come to a deeper understanding of what is going on in this double-slit experiment. If we fire either a photon or an electron at that double-slit apparatus and put a detector at either of those slits, then we will detect a particle.
We can detect that we’ve fired a particle; we can detect that a particle is going through those slits; and we can detect a particle at the projection screen as well.
When you do this experiment in the laboratory using electrons, you can see the dots where the electrons strike, hitting the screen. But you don’t get a simple pattern that you would expect.
If you’re firing cannonballs at a wall through the same two holes, you would expect all the cannonballs to land in one of two positions behind the wall.
But with particles at the quantum level, that’s not what happens.
The only explanation is that when we fire a photon, there’s the photon that we can see in our universe and also there are photons we can’t see in other universes that pass through the apparatus. These photons are able to interact with the photon that we can detect.
This is where the concept of interference comes in. Interference is an old concept in physics. It goes back to waves. Waves certainly interfere, but we need to understand the way in which particles can interfere with one another. This includes particles that we can observe and particles that we can only assume to observe given these experiments.
This is why we are forced to acknowledge the existence of these other particles—and not only these other particles but other universes in which these particles exist.