The Download: mimicking pregnancy’s first moments in a lab, and AI parameters explained

This is today’s edition of The Download, our weekday newsletter that provides a daily dose of what’s going on in the world of technology.

Researchers are getting organoids pregnant with human embryos

At first glance, it looks like the start of a human pregnancy: A ball-shaped embryo presses into the lining of the uterus then grips tight, burrowing in as the first tendrils of a future placenta appear. This is implantation—the moment that pregnancy officially begins.

Only none of it is happening inside a body. These images were captured in a Beijing laboratory, inside a microfluidic chip, as scientists watched the scene unfold.

In three recent papers published by Cell Press, scientists report what they call the most accurate efforts yet to mimic the first moments of pregnancy in the lab. They’ve taken human embryos from IVF centers and let these merge with “organoids” made of endometrial cells, which form the lining of the uterus. Read our story about their work, and what might come next.

—Antonio Regalado

LLMs contain a LOT of parameters. But what’s a parameter?

A large language model’s parameters are often said to be the dials and levers that control how it behaves. Think of a planet-size pinball machine that sends its balls pinging from one end to the other via billions of paddles and bumpers set just so. Tweak those settings and the balls will behave in a different way.  

OpenAI’s GPT-3, released in 2020, had 175 billion parameters. Google DeepMind’s latest LLM, Gemini 3, may have at least a trillion—some think it’s probably more like 7 trillion—but the company isn’t saying. (With competition now fierce, AI firms no longer share information about how their models are built.)

But the basics of what parameters are and how they make LLMs do the remarkable things that they do are the same across different models. Ever wondered what makes an LLM really tick—what’s behind the colorful pinball-machine metaphors? Let’s dive in. 

—Will Douglas Heaven

What new legal challenges mean for the future of US offshore wind

For offshore wind power in the US, the new year is bringing new legal battles.

On December 22, the Trump administration announced it would pause the leases of five wind farms currently under construction off the US East Coast. Developers were ordered to stop work immediately.

The cited reason? Concerns that turbines can cause radar interference. But that’s a known issue, and developers have worked with the government to deal with it for years.

Companies have been quick to file lawsuits, and the court battles could begin as soon as this week. Here’s what the latest kerfuffle might mean for the US’s struggling offshore wind industry.

—Casey Crownhart

This story is from The Spark, our weekly newsletter that explains the tech that could combat the climate crisis. Sign up to receive it in your inbox every Wednesday.

The must-reads

I’ve combed the internet to find you today’s most fun/important/scary/fascinating stories about technology.

1 Google and Character.AI have agreed to settle a lawsuit over a teenager’s death
It’s one of five lawsuits the companies have settled linked to young people’s deaths this week. (NYT $)
+ AI companions are the final stage of digital addiction, and lawmakers are taking aim. (MIT Technology Review)

2 The Trump administration’s chief output is online trolling
Witness the Maduro memes. (The Atlantic $)

3 OpenAI has created a new ChatGPT Health feature 
It’s dedicated to analyzing medical results and answering health queries. (Axios)
+ AI chatbots fail to give adequate advice for most questions relating to women’s health. (New Scientist $)
+ AI companies have stopped warning you that their chatbots aren’t doctors. (MIT Technology Review)

4 Meta’s acquisition of Manus is being probed by China
Holding up the purchase gives it another bargaining chip in its dealings with the US. (CNBC)
+ What happened when we put Manus to the test. (MIT Technology Review)

5 China is building humanoid robot training centers
To address a major shortage of the data needed to make them more competent. (Rest of World)
+ The robot race is fueling a fight for training data. (MIT Technology Review)

6 AI still isn’t close to automating our jobs
The technology just fundamentally isn’t good enough yet—for now. (WP $)

7 Weight regain seems to happen within two years of quitting the jabs
That’s the conclusion of a review of more than 40 studies. But dig into the details, and it’s not all bad news. (New Scientist $)

8 This Silicon Valley community is betting on algorithms to find love
Which feels like a bit of a fool’s errand. (NYT $)

9 Hearing aids are about to get really good
You can—of course—thank advances in AI. (IEEE Spectrum)

10 The first 100% AI-generated movie will hit our screen within three years
That’s according to Roku’s founder Anthony Wood. (Variety $)
+ How do AI models generate videos? (MIT Technology Review)

Quote of the day

“I’ve seen the video. Don’t believe this propaganda machine. ” 

—Minnesota’s governor Tim Walz responds on X to Homeland Security’s claim that ICE’s shooting of a woman in Minneapolis was justified.

One more thing

Inside the strange limbo facing millions of IVF embryos

Millions of embryos created through IVF sit frozen in time, stored in cryopreservation tanks around the world. The number is only growing thanks to advances in technology, the rising popularity of IVF, and improvements in its success rates.

At a basic level, an embryo is simply a tiny ball of a hundred or so cells. But unlike other types of body tissue, it holds the potential for life. Many argue that this endows embryos with a special moral status, one that requires special protections.

The problem is that no one can really agree on what that status is. So while these embryos persist in suspended animation, patients, clinicians, embryologists, and legislators must grapple with the essential question of what we should do with them. What do these embryos mean to us? Who should be responsible for them? Read the full story.

—Jessica Hamzelou

We can still have nice things

A place for comfort, fun and distraction to brighten up your day. (Got any ideas? Drop me a line or skeet ’em at me.)

+ I love hearing about musicians’ favorite songs
+ Here are some top tips for making the most of travelling on your own.
+ Check out just some of the excellent-sounding new books due for publication this year.
+ I could play this spherical version of Snake forever (thanks Rachel!)