Field Note #7: The Tiny Particle That Made Me Question Reality

Ok, so last summer I found myself doing an 8-week online course at Stanford University on Einstein’s Special Theory of Relativity (not the General one, but the one that everything further stemmed from). I wanted to find miracles, and I did — I discovered muons for myself. And became officially obsessed with them for quite some time...

Now, let me briefly tell you about muons and how they are connected to our emotions — and this is definitely not a sentence I ever expected to write! 🙂

So, the Special Theory of Relativity — specifically, time dilation and length contraction. And the muons. Muons are tiny, unstable particles created when cosmic rays collide with particles high in the Earth's atmosphere. They don't live very long. In fact, their average lifetime is so ridiculously short — about 2.2 millionths of a second — that even travelling close to the speed of light, many of them shouldn't have enough time to reach the surface of the Earth.

And yet they do.

We detect them down here. How? The explanation is special relativity. From our point of view on Earth, the muons are travelling incredibly fast, and their (imaginary) internal clocks are running more slowly relative to ours. Their time is dilated. They therefore survive long enough to make the journey.

But then you look at the same journey from the muon's point of view.

The muon isn't moving relative to itself. So its own clock is perfectly normal. Its mean lifetime, measured by an imaginary clock travelling with it, is still about 2.2 microseconds. Instead, something else has changed: the distance has become shorter. From the muon's frame of reference, the atmosphere is contracted in the direction of travel. The journey it has to make is simply not as long as the journey we measure from Earth.

While I was listening to the lecture on that, I understood the words… But then it occurred to me that this was actually real. Not real in the sense that I had previously suspected Einstein of making the whole thing up. I knew that the Special Theory of Relativity was real - that is why I wanted to study it. I knew it had been experimentally tested and I had heard about time dilation before. But knowing something intellectually and suddenly grasping what it means are apparently two very different things…

Time really isn't the same for everyone. And distance really isn't the same for everyone.

There isn't one enormous invisible clock ticking identically throughout the universe, nor one cosmic ruler against which every observer will agree on the distance between two things. Yet, for some reason, the muon made that real to me. Perhaps because it isn't a thought experiment involving imaginary spaceships and hypothetical twins: the muon actually arrives.

The Things That Feel Absolute

There are certain things we don't usually think of as beliefs. If I say that a table is a metre long, I don't experience that statement as my interpretation of the table. I experience it as a fact. If ten seconds have passed, ten seconds have passed. Surely? These things feel like the solid background against which all our more subjective experiences take place. And yet, nature turns out to be considerably stranger than our everyday experience suggests…

This doesn't mean reality isn't real; it means that our experience of reality is always from somewhere. There is a frame of reference. And I haven't been able to stop thinking about that, because outside physics, we spend an extraordinary amount of our lives forgetting that we have one too.

From Where I'm Standing

Two people can walk away from the same conversation carrying completely different versions of what just happened.

One thinks: That was awkward.

The other thinks: That went well.

One hears criticism, while another hears concern. One experiences someone's silence as rejection, and another doesn't notice the silence at all. And unlike the muon, we can't resolve this neatly with equations.

Our psychological frames of reference are built from far messier things: memory, expectation, fear, previous experience, attachment, culture, mood, whatever happened this morning, and perhaps what we've eaten for lunch. However, there is a similarity that I find extremely difficult to ignore: we have a tendency to confuse what we experience from our position with what simply is.

If someone doesn't reply to a message, for example, the observable reality is remarkably small: they haven't replied. Everything after that can arrive with astonishing speed.

They're annoyed with me. I've said too much. They're losing interest. I've embarrassed myself. Something is wrong. They have died.

Within minutes, the mind can construct an entire reality around a handful of missing dots on a screen, and the fascinating part is that it doesn't necessarily feel like a story. It feels just like observation.

The View From Another Frame

I think this may be one of the hardest things about being human: we know, theoretically, that other people may see things differently. We say things like everyone has their own perspective so often that the phrase has become almost meaningless. However, actually experiencing our own perspective merely as a perspective is way harder — because from the inside, it looks remarkably like reality.

Fear doesn't announce itself by saying:

Hello. I am your fear, and I am about to narrow the range of explanations you consider plausible.

It simply makes certain explanations seem more plausible!

Shame doesn't politely identify itself before interpreting an ambiguous expression on someone's face. Past experiences don't appear in brackets beside a thought, citing their sources. The conclusion simply arrives:

This is what is happening.

And perhaps one of the most useful questions we can learn to ask ourselves is not:

Is this true?

but:

What becomes true from where I'm standing?

And then, perhaps:

What might this look like from somewhere else?

Not because the Special Theory of Relativity somehow proves that human perception is subjective (Einstein deserves better than being dragged into a motivational quote), but because occasionally something from a completely different field gives us a particularly good way of noticing something about ourselves.

For me, this time, it was a muon :) I genuinely have a passion for them now, you know?

A particle with a mean lifetime of just over two millionths of a second, hurtling towards the Earth at almost the speed of light, while two observers can argue and disagree about how much time has passed and how much distance has been travelled — and both descriptions belong to the same physical reality.

There is something rather wonderful about that… and also something slightly unsettling. Because it leaves me wondering how many things in my own life I have labelled reality when what I actually meant was:

reality, from here.