One of our oldest and most popular videos, just recently celebrated its fourth anniversary.

So we made this shirt to celebrate! Because you may look at a tardigrade and you might not assume that the two of you have a lot in common, but like the resilient water bear, I think we all have those days where we feel a little chubby, misunderstood, and not immortal.

So if you'd like to pick one up for yourself, you can get them right now at microcosmos.store. When was the last time you saw a puddle? Was it recent— perhaps some time in the past week, fresh from a downpour?

Or has it been a long time since you’ve seen rain, and so an even longer time since your path has crossed a puddle? If you can remember, do you know what you did when you saw the puddle? Did you hop around it, trying to keep your clothes as pristine as possible?

Or did you have the complete opposite impulse and jump right in the middle of it, and splashing water everywhere. Or maybe you leaned in closer and wondered what’s in there, floating a few inches away in the shallow depths at the edge of your feet? If that last one sounds like something you did (or maybe something you wish you had done), you’re in good company.

Everything we’re watching right now came from puddles around Warsaw that James, our master of microscopes, collected samples from. He waited for two days after it rained and then wandered from puddle to puddle so he could collect water to watch under the microscope. That’s where he found these green algae called pandorina.

This is not actually one algae, but rather a group of them, bound together in a mucus-y shell so they can form a colony. You can see those individual members of the colony better here, each a single green cell living a conjoined existence with its neighbors. Given enough light, these colonies quickly reproduce, crowding the tiny puddles that James gathers his samples from.

But James is not the first microscopist to peer into a puddle. In fact, if we look at the writings of one of the original masters of microscopes, we can transport ourselves in time and space to the microcosmos of a 17th century Dutch puddle. I’m of course talking about Antony van Leeuwenhoek, a Dutch microscopist whose many letters to the Royal Society of London contain our earliest descriptions of microorganisms, or as he called them “little animalcules”.

When Leeuwenhoek first mentioned these little animalcules, not everyone believed him. It was one thing to hear his description of a bee stinger under the microscope. People were familiar with bees and their stingers.

But an invisible world of tiny creatures— tinier, according to Leeuwenhoek, than the mites found on a cheese rind, well, that was harder to imagine. In a letter to the microscopist Robert Hooke, Leeuwenhoek wrote, “I suffer many contractions and oft-times hear it said that I do but tell fairy tales about the little animals.” One of Leeuwenhoek’s letters started with the following: In 1675 I discovered living creatures in Rain water which had stood but few days in a new earthen pot. This rainwater, along with the sampling methods, observations, and experiments that Leeuwenhoek described in his letters, would form the basis of his own understanding of the microscopic world.

And so, in turn, it would form the basis of many other’s investigations into the little animals and the world they inhabit all around us. In a way then, every time you see a puddle, you can think of it as a natural ode to the early experiments that introduced us to the microcosmos— like little memorials to the history of microscopy. Puddles are more than just reminders of history though.

They are their own little worlds, placing demands on the organisms living inside of them. This cyst, for example, holds a rotifer that is slowly waking up from a nap that had probably protected it from a dry spell, before rain had filled the puddle back up. There is a rhythm to that kind of life, tied to the wetness surrounding them.

In between rains, the organisms must find a way to cope with their dry environment. And when the world around them becomes wet again, the organisms thrive, like this ciliate that’s dividing so it can fill its watery world up with clones. These are boom and bust cycles taken to their extreme, to a million little worlds that go from not existing to existing when you just add water.

So it’s no wonder microscopists have been drawn to puddles for centuries, these little pop-up microcosmos-es that reveal pockets of life lying all around us. This video of a vorticella comes to us from a master microscopist in Florida named Curtis, who was sampling driveway puddles to watch under the Journey to the Microcosmos microscope. We can see it in the middle of our screen, perfectly still with its stalk extended long until something comes along and spooks it, sending the vorticella rapidly inward as it contracts back towards the debris it’s attached to.

This footage was submitted to us over at microcosmos.store, where, if you’re interested, you can submit your own footage to potentially be used in a Microcosmos episode, because there are countless worlds all around us waiting to be seen and shared, and we’re looking forward to seeing more of the worlds around you fellow masters of microscopes. And after everything we’ve learned today, it feels right that the first video we would be able to share from one of you comes from a puddle, that it comes from a source that shares so much with the home of Leeunwehoek’s little animalcules despite originating centuries later and thousands of miles away. Thank you for coming on this journey with us as we explore the unseen world that surrounds us.

Don't forget right now you can head on over to microcosmos.store both to submit some footage if you like, but also to pick up our brand new Tardigrade T-shirt celebrating the fourth anniversary of our very first Tardigrade video. Before we go, we also want to thank each and every single one of our Patreon patrons, because without them, this show could not exist. And you're seeing some of their names on the screen right now.

And if you would like to join those names on the screen, you can go to Patreon.com/JourneytoMicro. If you'd like to see more from our Master of Microscopes, James Weiss, you can check out Jam and Jerms on Instagram. And if you'd like to see more from us, there's probably a subscribe button somewhere nearby.