Hello and welcome to the Anthropocene Review, a podcast where we review different facets of the human-centered planet on a five-star scale.

I'm John Green and today I'll be reviewing two sensorial wonders,

scratch and sniff stickers and the Indieapolis 500.

Let's begin with the scratch and sniff sticker.

Smell is one of the places where virtual reality still feels deeply virtual.

A few months ago I found myself on a VR roller coaster at a theme park in which everything felt stunningly, breath-stealingly real.

It wasn't just that falling felt like falling and turning felt like turning.

As I flew through ocean spray, I felt mist on my face.

But that water did not smell like the ocean.

It smelled like this room deodorizer we'd used in high school called spring rain.

Spring rain didn't actually smell like spring rain anymore than it smelled like the ocean,

but the scent was somehow wet.

So I can understand why it had been repurposed for ocean smell.

Still, nobody who has ever smelled the brackish din of a cresting wave could possibly mistake it for the scent being pumped into that VR experience.

And the smell of spring rain wrenched my brain from its state of joyfully suspended disbelief.

And suddenly, I was not on a flying tour of an alien planet, but instead stuck inside a dark room with a bunch of strangers.

One of the things that makes smell so powerful, of course, is its connection to memory.

The smell of artificial spring rain takes me back to an Alabama dorm room in 1993.

The smell of actual spring rain returns me to the sudden drenching thunderstorms of my childhood.

Of course, smell is complex and difficult to recreate artificially,

but I think there's something else at play here, which is that nothing in the real world smells quite like we imagine it would.

Spring rain, for instance, seems like it would smell crisp and clean, like the artificial scent does,

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