Before anything else, you’ll have to decide between ink and laser. I’ll get into the details when it comes to each model, but the most important consideration is paper type, because it’s a limitation rather than a benefit. Laser printers use heat in the bonding process, which means if you regularly print on windowed envelopes or photo paper, you’ll need to either use an ink printer or change to a thermally safe alternative, which can be cost prohibitive if you print a lot.

Inkjets are the most common flavor of home printer, and they work like you might expect, by boiling ink until it splatters through a series of tiny holes. You didn’t expect that? Me neither! Pretty exciting stuff.

Inkjet printers come in two flavors, with either prefilled cartridges or built-in tanks. The latter is quickly becoming more popular thanks to better pricing, more convenience, and a massive reduction in wasted plastic. If you’re buying a new printer in 2025 you should opt for an ink tank, if not a laser printer. They’re a little more work to setup and maintain, since you have to keep the tanks topped off, and they should remain in one place on a flat surface to avoid leaks. I can’t imagine many situations where a printer would be constantly moving and tilting, but it’s a consideration.

You thought InkJets were cool? Laser printers work by blasting a tube full of dried plastic particles, then fusing them to the paper with heat. They tend to cost more upfront, but the cost per page is overall much lower. Where a $20 ink cartridge might print 200 pages, a $60 toner cartridge could print 2000. They tend to be a lot faster than inkjet printers, and you don’t have to worry about them drying out. Plus, the pages come out of the printer nice and warm, and you can’t really put a price on that.

There are also thermal printers, which are commonly used for receipts or shipping labels. Instead of filling the printer with ink and depositing it onto a surface, they apply heat in precise patterns to special paper, allowing you to print text and images in low resolution, and typically in one color. If you print shipping labels or simple stickers at home, these can save you a lot of time and ink cost, but they have more limitations.

Laser printers are my preferred type, as long as your paper type and budget can support them, but most home users will be happy with an ink tank printer.

“In general, we are noticing many of these shoes have more of a road running influence than they do trail,” says Bodin. “So, there will be a mix of foams, midsole geometries, less attention to fit, and a more subtle outsole pattern compared to trail shoes.”

What Are the Benefits of Gravel Shoes?

In a word: versatility. You can lace up a gravel shoe at home with confidence that they’ll handle whatever lies ahead, provided you’re not hitting a really technical trail or ankle-deep mud.

“Many of the shoes in this category can run well on roads, gravel paths, and light trails,” says Bodin. “That’s not something that very many strictly road shoes or dedicated trail shoes can do.”

The more rockered midsoles aim to smooth your heel-to-toe transitions, cutting the calf muscle fatigue over uneven ground and on longer runs. They’re also often lighter than technical trail shoes, thanks to the smaller lugs, less pronounced rock plates, and lower levels of upper reinforcement. That serves up more agility than heftier trail shoes, so you can move faster and lighter over runnable ground.

Do Gravel Shoes Feel Different From “Regular” Trail Shoes?

“Yes and no,” says Bodin. A lot depends on the brand. Some companies, like Craft, have many gravel-specific options. Others, like Salomon and Hoka, use their redesigned road running shoes for their gravel category.

Gravel shoes also have limits, warns Bodin. “In my experience, most gravel shoes will be limited when they reach a moderately technical trail-running scenario. Again, because the bulk of the gravel shoe experience is focused on the overall ride on smoother terrain, performance declines when there are more turns or more challenging terrain with rocks and roots.”

Do You Really Need a Gravel Shoe?

Like everything in running shoe world, that depends. There are trail shoes out there with the chops to conquer everything from technical to more runnable terrain, like the Hoka Speedgoat 6 ($125). Some of the pricier trail shoes like the North Face Vectiv Pro 3 ($250) pair modified versions of their springy road-shoe foams with carbon plates to deliver bouncier rides that don’t feel out of place on the road. I’ve tested loads of these shoes, and some top-tier trail shoes run better on the road than cheaper road shoes.

However, if you regularly tackle firmer, less technical mixed terrain on your runs, generally in drier conditions—and rarely venture onto more technical trails—there’s a good case for investing in a gravel shoe. It’ll carry you happily from road to trail and back again, and even cover your road runs on the way to the trail.

Likewise, if you’re a newcomer to trail running, a gravel shoe could be a good halfway house as you transition from the asphalt to the single track, thanks to a ride which retains some road-shoe familiarity. They’re also an excellent suitcase shoe—if you’re traveling and you can only fit one shoe in your luggage, the versatility of a gravel shoe makes it a great choice.

The original version of this story appeared in Quanta Magazine.

Here’s a test for infants: Show them a glass of water on a desk. Hide it behind a wooden board. Now move the board toward the glass. If the board keeps going past the glass, as if it weren’t there, are they surprised? Many 6-month-olds are, and by a year, almost all children have an intuitive notion of an object’s permanence, learned through observation. Now some artificial intelligence models do too.

Researchers have developed an AI system that learns about the world via videos and demonstrates a notion of “surprise” when presented with information that goes against the knowledge it has gleaned.

The model, created by Meta and called Video Joint Embedding Predictive Architecture (V-JEPA), does not make any assumptions about the physics of the world contained in the videos. Nonetheless, it can begin to make sense of how the world works.

“Their claims are, a priori, very plausible, and the results are super interesting,” says Micha Heilbron, a cognitive scientist at the University of Amsterdam who studies how brains and artificial systems make sense of the world.

Higher Abstractions

As the engineers who build self-driving cars know, it can be hard to get an AI system to reliably make sense of what it sees. Most systems designed to “understand” videos in order to either classify their content (“a person playing tennis,” for example) or identify the contours of an object—say, a car up ahead—work in what’s called “pixel space.” The model essentially treats every pixel in a video as equal in importance.

But these pixel-space models come with limitations. Imagine trying to make sense of a suburban street. If the scene has cars, traffic lights and trees, the model might focus too much on irrelevant details such as the motion of the leaves. It might miss the color of the traffic light, or the positions of nearby cars. “When you go to images or video, you don’t want to work in [pixel] space because there are too many details you don’t want to model,” said Randall Balestriero, a computer scientist at Brown University.