Imagine driving 16 miles under the ocean, with only 50 meters of rock between you and the North Sea. That's what Norway's Rogfast tunnel will offer when it opens in 2033. Currently under construction, this 26.7-kilometer highway sits 390 meters below sea level at its deepest point. I visited the site to see how engineers are pulling off this audacious feat.

The tunnel is being built using the drill-and-blast method, which involves drilling holes into rock, filling them with explosives, and detonating them. Each blast clears about five to six meters. Workers put in 12-hour shifts in complete darkness, 12 days on and 16 days off. “You have to be a little bit crazy to work underground all the time,” says tunnel foreman Niclas Brusehed.

Norway has built over a thousand kilometers of tunnels in recent decades, largely because its rugged coastline requires many ferry crossings. Rogfast will eliminate two ferry routes and cut travel time between Stavanger and Bergen by 40 minutes. It will feature four lanes of traffic, two undersea roundabouts at 220 meters below sea level, and a constant battle against water.

Subsea tunneling means fighting the ocean's pressure. Before blasting, engineers drill test holes to check for leaks. If water flows too fast, they pump cement-like grout into the rock to seal cracks. “It’s a lot more difficult to stop a leak that’s behind you,” says project leader Ole Magne Rønning. The tunnel will have mini reservoirs to collect and pump out the inevitable trickles.

The project is being built from both ends, with teams using laser scans to ensure the two sections meet with only a few centimeters of deviation. It's scheduled for completion in 2033. For now, it's a dark, noisy, damp world where every blast creates “a new world,” as Brusehed puts it.

It’s been dangerously hot in London this week. The UK just recorded its highest ever June temperature at 36.1 degrees Celsius (about 97 degrees Fahrenheit). But it felt even hotter. This heat wave is part of a bigger pattern linked to climate change, and it’s not just uncomfortable—it can be deadly. And scientists are discovering that extreme heat doesn’t just affect your body; it messes with your brain too.

You might have noticed it yourself. When it’s scorching outside, it’s hard to think clearly. Your mind feels foggy, you get irritable, and focusing on anything feels impossible. Researchers are trying to understand why this happens and who is most at risk.

Catherine Thompson, a cognitive psychologist at Liverpool Hope University, studies how heat affects thinking. She tested firefighters before and after they entered burning buildings. After just 15 minutes of intense heat, the firefighters had trouble focusing and controlling their attention. Their thinking returned to normal after about 20 minutes of cooling down. But Thompson points out that a heat wave lasting days could have much longer effects—and no one has fully studied that yet.

Other studies show that heat waves are especially dangerous for people with mental health disorders. During heat waves, hospital admissions for people with these conditions increase by nearly 10 percent. In the 2021 Canadian heat wave, people with schizophrenia were three times more likely to die. And a new study found that for every 1 degree Celsius increase in average monthly temperature, the suicide rate among 15- to 24-year-olds in the US goes up by about 3 percent. That’s more than double the increase seen in older adults.

Why does heat affect our brains so much? Scientists aren’t sure yet. It could be because heat disrupts sleep, makes it harder to exercise, and keeps people stuck indoors—all things that are important for mental health. But there might also be direct biological effects. Studies on rats and mice show that high heat can change levels of brain chemicals like serotonin, interfere with how brain networks communicate, and affect how oxygen reaches brain cells.

Children and young people seem especially vulnerable. Babies exposed to extreme heat or cold may have changes in their brain structure that show up years later. As climate change makes heat waves more common, understanding these effects becomes urgent. As one researcher put it, children born in 2020 will likely experience seven times as many heat waves as their grandparents did. We need to adapt to a warming world—and that means understanding what the heat is doing to our minds.

Imagine a machine the size of a double-decker bus that costs $400 million and can carve patterns smaller than a virus. That's what ASML, a Dutch company, builds. These machines are the secret behind the chips in your phone, laptop, and the AI systems that are changing the world.

Jos Benschop, ASML's executive vice president of technology, recently climbed to the top of one of these behemoths. It's 150 tons of gleaming metal, tubes, and cables. Technicians in bunny suits scurry below. Benschop has spent over a decade designing this thing, and even he sometimes looks at it and thinks: Oh my God.

So what does this machine do? It uses extreme-ultraviolet light (EUV) to print tiny circuits onto silicon wafers. Think of it like silk-screening a T-shirt, but with light so precise it can create features just eight nanometers wide — that's about 40 silicon atoms across. To generate this light, the machine fires lasers at tiny molten drops of tin, tens of thousands of times a second.

This is critical because the AI boom demands ever-faster, more energy-efficient chips. Companies like OpenAI and Anthropic need powerful hardware to train their models. ASML's machines help keep Moore's Law alive — the idea that chips double in power every couple of years. Without them, progress might stall.

ASML dominates the chipmaking world, producing about 90% of all lithography tools. This monopoly has geopolitical consequences. The US government pressured the Netherlands to ban ASML from selling high-end machines to China, to prevent China from developing advanced AI. As one expert put it, "Chips are the new oil."

But some people worry about this concentration of power. James Proud, CEO of a startup called Substrate, says the US is "dangerously reliant" on a supply chain that's overseas and expensive. So competitors are emerging. China is pouring billions into copying ASML's tech. Startups like Substrate aim to build cheaper, smaller machines. Can they succeed? ASML's engineers know that even giants can be unseated with the right trick of the light.

The history of chipmaking is a two-step dance: find a new light source, then push it to its limits. In the 1990s, chipmakers used deep ultraviolet light with a 193-nanometer wavelength. But they knew they'd hit a wall. ASML bet on EUV — a risky choice because no one knew how to generate or focus it. EUV is absorbed by glass and even air. But ASML's engineers solved these problems through sheer persistence. As one analyst put it, "Let's send thousands of engineers and just have them mow down these problems. That's what they did, and it worked."

Now, ASML's new machine promises to keep the AI party going for at least another decade. Its CTO says, "I think we've only seen the tip of the iceberg." But the question remains: Can anyone catch up to a company that builds $400 million machines the size of buses?