I’m guessing that most of you (like myself) are not physicists. So when an author casually mentioned the Double-Slit Experiment in an article I was reading, I was completely lost. So, being the nerd that I am, I did some research.
People. This will blow your collective minds.
There’s a great (simplistic, made for children but oh-so-easy to understand) video by Dr. Quantum explaining this phenomenon on youtube. But let me see if I can explain it to you & then explain why it means, well, everything.
We first need to understand how particles (little balls of matter) act. Dr. Quantum begins by illustrating what it would look like if we shot marbles at a screen with a slit in it. We would see a pattern on the back wall that would resemble the shape of the slit.
Now if we add a second slit, we would expect to see a second band, duplicated to the right of the original slit. See?
Now (and stay with me here), let’s look at waves. If we drop a marble in the water & watch how the waves behave, we see that the wave strikes the back wall with the most intensity directly in line with the slit (right in the middle). This is similar to the line the marbles make — bullseye, right in the middle!
BUT. When we add the second slit, something bizarre happens. When the top of one wave meets the bottom of another wave, they cancel each other out! So now there’s an interference pattern on the back wall. Places where the two tops of waves meet show up as the bright lines, and where the two waves cancel each other out, there is nothing.
Now, as Dr. Quantum says, let’s go quantum! When we fire electrons (tiny bits of matter) through one slit, they behave just like the marbles and we see a pattern on the back wall that mirrors the slit:
So if we shoot these electrons through two slits, we should get (like with the marbles) two bands that correspond with the slits.
But wait! We don’t! Instead, we get an interference pattern. Like we saw with the waves! But… these are pieces of matter! It doesn’t make sense! How could pieces of matter form an interference pattern like a wave does?
But, as Dr. Quantum reminds us, physicists are clever. They thought, “hey, if we’re careful to shoot these electrons through the slit one at a time there’s no WAY they can interfere with each other, so now we’ll surely see that two-slit pattern like we did with the marbles.” But guess what? They still form an interference pattern:
What the heck is going on here? Apparently, electrons are tricky little buggers. The single electron leaves the gun as a single particle, but somehow becomes a WAVE of potentials, goes through BOTH slits at the same time, and interferes (get this) with ITSELF to hit the wall.
It gets even trippier. Mathematically, it goes through both slits, and it goes through neither. It goes through just one slit, but it also goes through the other. WHAAAAAT? Naturally, physicists (and I keep picturing Sheldon from the Big Bang Theory), wanted to get to the bottom of this. So they decided to “peek” and determine which slit it actually goes through. They put a measuring device by one slit to see which one it really went through:
But the quantum world is far more mysterious than they could have imagined. When they observed the electron this way, it went back to behaving like a little marble! It produced a pattern of two bands & not an interference pattern of many! THE VERY ACT OF OBSERVING it meant it only went through one of the slits, not both. The electron “decided” to act differently. As though it was aware it was being watched. The observer collapsed the wave function simply by observing. So, it leads us to ask… what IS matter? Particles or waves? And what does the observer have to do with any of this?
More recent studies have been able to look at this phenomenon more closely. And — here’s where the super-trippy stuff comes in — the results have called into question our perception of time itself. Scientists have been able to delay their observation of the electrons until AFTER they’ve made their way through the slits but BEFORE they actually hit the screen. And get this: once you observe them at that point, it’s as if they went back through time & decided to go through one slit or the other instead of both at the same time (had they been behaving like waves). BACK THROUGH TIME. So our choice of what experiment to do (i.e., when to observe the electron) determines the PRIOR state of the electron. (Is your brain hurting yet?!)
Somehow by observing it we’ve had an influence on it that appears to travel backwards in time.
Researchers at the Australian National University have confirmed that reality doesn’t exist until it is measured, at least on the atomic scale. The choice of whether an electron behaves as a particle or a wave is completely dependent on the way it’s measured. An object “decides” to act one way or another based on how scientists observe it. “It proves that measurement is everything. At the quantum level, reality does not exist if you are not looking at it,” said lead researcher Dr. Andrew Truscott.
So reality doesn’t exist without an observer. What does this mean for us? The observer creates the reality. The universe is a mental construction. What happens in the present can change the past. Time can go backward. Cause and effect can be reversed. The future caused the past. (This is sounding a lot like a plot from the X-Men, right?). How we choose to measure something NOW affects the path it took in the past.
But the biggest take-away point? We create our own reality. The OBSERVER creates the reality. This is huge. As observers, we have a choice: glass half-full? or half-empty? Do we see the world as a mean and scary place, not trusting anyone, or do we choose to see the best in people? Do we expect favorable results? If we create reality, let’s make it a good one. Stay positive. Assume the best outcomes. Embrace happiness as your only function. Have complete faith in miracles. And who knows… maybe the positive attitude you choose today can affect the negativity of your past. The physicists tell us it’s possible.