Every year when the Edinburgh International Science Festival comes around, I’m like a kid in a sweetshop – there’s such a huge variety of things to choose from, and I want to see them all.

Many flavors of loose leaf tea in glasses.

After much thought (and, yes, maybe a spreadsheet), I decided to start as I mean to go on: drinking a lot of tea. At Tea-lightful!, we are tasting two types of Darjeeling, learning how the professional tea-tasters do it (at double strength, apparently), and discovering how altitude, season and seed type affect the taste. Climate change looms large here, moving the first harvest forward by several weeks and drastically affecting the taste of the final product. After that, dietician Dr Carrie Ruxton talks us through the chemicals in tea that have a particular effect on the body – polyphenols for your heart, fluoride for your teeth, theanine to calm you down, and caffeine which, let’s face it, is what I’m here for. We learn which biscuits are best for dunking, and why – the Rich Tea being a clear frontrunner, with controversial favourite (at least in my corner of the room) Ginger Nut disintegrating almost immediately. If you, like me, can’t be doing with Rich Tea, then the undisputed champion is the chocolate digestive. Apparently the chocolate helps hold the biscuit together when you dunk. Who knew?

The first piece of theatre I see is Cosmonaut, in the shadowy depths of Summerhall’s dissecting room. It tells the story of the Russian space program in the 1960s and 1970s, and its chief designer, Sergei Korolev. If you don’t know his name, you’re not alone – he was ultimately denied a Nobel Prize by his government because his identity was supposed to remain a secret. Interwoven with that story is the tale of two siblings in Turin, eavesdropping on the Russian space programme with homemade equipment. They believe they’ve found evidence of several “lost cosmonauts”, secretly sent into space by the Russians, never to return. It’s a real conspiracy theory – albeit largely debunked – and it captures fantastically the scientific mood of the 1960s. While Cosmonaut occasionally veers towards the cryptic and Francis Gallop’s script could perhaps have done with a little trimming for pace, Kate Nelson’s production is atmospheric as hell and the stories themselves have stuck with me two weeks later. I don’t doubt I’ll be thinking about them for some time.

Girl in the Machine, Stef Smith’s new play at the Traverse, drags me straight from the slightly dodgy machinery of the past to the glistening, streamlined technology of the future. Touching not just on the improvement of technology, but the human feelings affected by it – and the often opaque entities controlling its usage – Girl in the Machine has the uncanny feel of an episode of Charlie Brooker’s Black Mirror. Director Orla O’Loughlin manages to pack a lot of disparate ideas into one story without them feeling at all incongruous. Given quite how wide-reaching the themes of Girl in the Machine are, I suspect this is harder than it looks. If the last six months have taught us anything, it’s that science can’t help but be political. Of everything I see this week, Girl feels like it has its finger the closest on the pulse of 2017.

For something touching on similar themes – the effect of technological progress on individuals – A Number at the Lyceum is surprisingly different. Several clones of a man (“a number” of clones, in fact) are created without his – or his father’s – consent. A Number asks how much of a person’s character is genetic, how much of our individuality is based our DNA, and how much we can use genetics as an excuse for behaviour. Like Girl in the Machine, A Number is barely concerned with the creators of technological innovation: once it exists, it exists, and it’s what we do with it next that counts. I’ve waxed lyrical about Zinnie Harris’s production of Caryl Churchill’s play before. I’ll happily do it again: it’s fantastic.

Wandering round the National Museum of Scotland on a Sunday afternoon, I chance across the interactive exhibition, Play On. This is another strength of the Science Festival – not just that you can chance across such things, but also that so many people do. When I see it, Play On is packed with families, exploring different facets of play. There are exhibits and activities about how (and why) different animals play, and how it affects your brain; experimenting with robotics; trying out virtual reality. As I walk through the exhibition, I see plenty of children having one-on-one conversations with the various volunteers, asking about the displays, finding out about the science behind them. Those sorts of chat are how lifelong enthusiasms get started. That’s what this is all about.

From there, I make my way to the National Museum’s auditorium for a talk on Exploring the Influence of D’Arcy Wentworth Thompson. The audience here skews older than for Play On, but no less enthusiastic. D’Arcy Thompson was a biologist and polymath based in Dundee and St Andrews, whose book, On Growth and Form, built on the ideas of Darwin, linked it to other scientific disciplines, and inspired a generation of scientists and artists. Crucially, it’s a century old this year. Thompson himself was a keen classicist, politically active, and a great supporter of amateur naturalist groups – and he’d no doubt approve of the enthusiasm he inspired amongst this roomful.

As well as speakers on Thompson’s own life and work (in his later years, he was apparently known for wandering round St Andrews with a parrot on his shoulder), there’s an art history lecturer here – Ed Juler, from the University of Newcastle – to talk a bit about Thompson’s influence on twentieth century visual art. It’s here that I start to get the sense that art isn’t just something that follows scientists round, interpreting it for the wider world – they riff off and inspire each other, in both directions.

I’m still turning this over in my mind as I head back towards Summerhall, only to discover that my flash of brilliance isn’t anywhere near new – in fact, it’s pretty much exactly the subject of the Contemporary Connections exhibition. Contemporary Connections is on around Summerhall until May 12th, and it’s well worth wandering round. In a far-flung corner I find the work of artist Hannah Imlach, who puts it far better than I do: artists and scientists are “both working in this trial-and-error imaginative space”. Included in Imlach’s beautiful exhibition of lenses and coral reefs is a collection of her notebooks, charting her inspiration and discoveries as she worked on her project. I’m a sucker for other people showing their working, writing out their thought processes and inspiration. I stare at them for a very long time, before wandering around the corner to another stand-out piece, Sebastian Verea’s Sound of the Anthropocene.

The Anthropocene, I gather, is a recent word to describe this new geological age from around the end of the nineteenth century, where humans became the primary shapers of the environment. Verea’s work is a projected timeline across a map of the world, with the human influence shown by bursts of light and sound. By the time it gets to the 1980s and 90s, the bursts of sound are no longer curiosities. They’re overwhelming. I watch the whole thing through twice. If Imlach’s work reminds me that art and imagination are important to scientific discovery, Verea’s work is a pretty good argument for environmental science funding.

The single best speaker I see throughout the festival, I’m pretty happy to nominate, is Dr Katherine Harkup talking about Chemistry of the Human Body at Summerhall. She talks us through her favourite elements of the periodic table, as they appear in and interact with the human body. Leaving aside the fact that I already want to be friends with someone who has a shortlist of favourite elements, Harkup talks us through the discovery of phosphorus – the first element actually derived from the human body (don’t ask how, it’s disgusting) – as well as the health effects of selenium, the many and varied ways that sulphur can make you smell bad, and the mechanics of dicing with death using pufferfish venom. She keeps the room spellbound with chemical anecdotes, but half the fun is the Q&A, which is extensive and varied. Like with the conversations going on at Play On, I get the idea that this is the sort of room in which new scientists are created.

My wildcard for the week – and second cosmonaut-related event – is Public Service Broadcasting: The Race for Space at Usher Hall. It might also be the event with the most diverse audience, age-wise – apparently Public Service Broadcasting is a band with broad appeal. The Race for Space, a concept album about the American and Russian space programmes, is very good through a pair of headphones, but I have to argue that it’s best seen live in a room full of people. The atmosphere is electric, the lighting and special effects (which draw on footage from NASA’s archives and the BFI’s Russian collection) are technically extremely impressive and worth coming to see in their own right. Occasional support from the National Youth Choir of Scotland gives the whole show an operatic feel, and perched in the middle of the stage is a disco-ball Sputnik. It’s a very different kind of science communication from the rest of what I’ve seen, but no less effective: The Race for Space celebrates some of the pinnacles of human achievement.

The next day, I’m back in Summerhall, looking at the exhibitions again, when I chance upon an installation called Lichtsuchende – Cybernetic Sunflowers with Human Behaviours. Presumably to make up for having a name half a line long (“Lichtsuchende” means “light-seeking”), the installation itself is very small – only one darkened little room – and features a collection of knee-height robots that look like sets of LEDs mounted on Meccano angle-poise lamps. You go in; you take a torch. You shine it at the robots, and they move. They stretch and weave, half responding to your torch, half of their own accord. It’s very cool, and slightly unnerving, in a low-key Ridley Scott sort of way. In the end, I relinquish my torch to a child who looks mesmerised already, and back out. Next door is another small installation, A Hidden Order, combining experimental music and dynamic geometry in swirling colours. Next to Summerhall’s other interactive galleries, it’s a moment of contemplation.

I’m not alone in being hypnotised by the maths. “That’s where the fun starts – or, I guess, that’s where the maths starts,” says one of the physicists, mid-explanation, at a talk on The Hunt for Super-Symmetric Particles at the National Museum of Scotland. If you want to meet a person who adores their job, find a physicist – I’ve never seen one who doesn’t seem completely convinced that their job is the most interesting in the world. After the announcement of the discovery of gravitational waves in early 2016 – on which there’s also a talk later, featuring some of the physicists at the University of Glasgow who were involved in it – super-symmetric particles might just be the biggest ongoing challenge in physics.

“What are the practical benefits to the work you’re doing?” asks an audience member. The particle physicists all look confused. Ask again in a century, is the first consensus. And then again, collaborating with scientists to expand the reach of human knowledge has driven plenty of innovation – they cite the world wide web, and some really powerful magnets, as examples associated with their own fields. It’s a side benefit, a bonus – but if you’re looking for an example of the Science Festival’s theme this year, “Get Connected”, you could do a lot worse than inventing the web as a way to help scientists share data about the universe faster.

My final event is Richard Wiseman’s presentation on Mind Magic, back in the Summerhall dissecting room – which seems to have doubled in size since Cosmonaut, and is packed out. Wiseman is a great storyteller, but after spacemen and evolution, virtual reality and environmentalism, this presentation of mental trickery and the debunking of ghosts seems practically subdued in comparison. But I’m clearly in a minority in thinking so, because the audience is having a great time. It’s been a fortnight since I was toasting the room with a cup of Darjeeling, and the sheer variety of the Science Festival is still boggling to me – in content, in approach, in the levels of expertise it’s aimed at. It’s a dangerous game to try and settle on a favourite of Edinburgh’s many festivals, but this one might just take the lightly dunked Rich Tea.