By the end of the third day it was clear that one of the major conference themes had become  “Revolution 2.0,”  political upheaval facilitated by Facebook, Twitter, and YouTube. In the words of one speaker, “the internet didn’t cause the revolutions,but it allowed them to happen.”

Day one had had Al-Jazeera’s director general on stage in person. Subsequent days had prerecorded presentations from Egypt and China.

Wael Ghonim was the Egyptian Google executive whose Facebook page memorialising one of the victims of the Egyptian regime helped spark the revolution there.

Ghonim’s was the joyous testimony of liberation. That of Al Weiwei, the Chinese dissident artist, was the opposite. “I’m living in a society where freedom of speech is not allowed,” he said. But he predicted that within the next few years China will face massive social and political change. Meanwhile, western nations’  tolerance of China’s human rights abuses was “very shortsighted,” he said.

At the moment, Weiwei’s installation of 100 000 000 hand painted porcelain seeds cover the floor of the Turbine Hall at London’s Tate Modern museum. After hearing his presentation, it’s hard not to see the seeds as China’s population, their germination on hold, for the moment.

Dealing with a different sort of plenitude – a surfeit of input- emerged as a sort of  minitheme at the conference. Swiss novelist and entrepreneur, Rolf Dobelli, described how he’d given up engaging with any news. You can read his 15 reasons why, plus his suggestions for what to do instead.

Jim Hornthal, an IT venture partner, explained how much more difficult “discovery” is than “search” on the web. If you’ve got a fair idea what you’re looking for, then you’ll probably find it. But, for example, to discover new music that’s like the music you already like, you need sites that use ontologies, taxonomies, and algorithms. There are now a burgeoning number of these, producing real value. Rather than trusting “the wisdom of the crowds,” he counsels going to experts for  recommendations and friends for validation.

But algorithms can also have a sinister side, argued political activist, Eli Pariser. He had noticed that some of his Facebook news feeds had been prioritised over others. In another example, he’d asked friends to simultaneously Google a term (“Egypt”) and found the results differed wildly depending on the friend’s demographics. The increasing use of (hidden) personalisation engines by an array of sites risks constraining each of us in a bubble of one: everybody experiencing their unique web experiences.

After these disquieting revelations, it was reassuring to return to the world of heartwarming medical breakthroughs. Biomedical engineer, Fiorenzo Omenetto, described the wondrous properties of silk in medicine – biodegradable, non-allergenic, phenomenally strong. Eythor Bender of Berkeley Bionics has been working on adaptive technologies that allows the previously wheelchair bound to walk.

And surgeon Anthony Atala, of the Wake Forest Institute for Regenerative Medicine, has made massive strides towards engineering kidneys using printer technology.  He had his organ printing machine working on stage, although the entire process takes much longer than the 20 minutes he had for his presentation. “Here’s one we printed earlier today,” he said, as his assistant passed him a little nub of pink flesh. It looked just like a skinless chicken breast from where I was sitting.  The lecture as it now appears on the TED website carries the disclaimer that these printed kidneys are early prototypes, years away from clinical use.

Nevertheless, wonder, the overall theme of the conference,  had been well and truly restored.

Tony Delamothe is deputy editor, BMJ.