Hi there,

It's not often I get to lead with a science story that has to do with unicorns, so when I saw a story this week about what makes a unicorn horn so straight, I had to jump on it. That's my #1, by a long shot.

(To be clear, I jumped on the story, not the unicorn horn. I'm pretty sure that would have turned me into a wizard or something.)

I've also got a story about blowing asteroids up with nuclear weapons, a story about whether or not you can get all the benefits of a 90-minute bike ride with a 5.5-minute bike sprint, and a story about what happens inside your face when you snore.

Before that, though, a minor career update. This last week I was in NYC for work. I thought I'd start this week's Bat Signal by telling you what I was doing there.

Kevin Bacon is hosting a new upcoming series on the History Channel. In related news, my Bacon Number will soon be 1.

I wanted to start this week's bat signal with a little professional update, to tell you that this fall you'll be seeing me on a couple of new TV shows. I'm not allowed to say very much yet, but I'll tell you that one show is hosted by the actor Kevin Bacon (Footloose, Tremors, Flatliners, etc.), and another is hosted by Ted Danson (Cheers, The Good Place, A Man on the Inside, etc.). Both have been filming in New York, so that's meant some fun trips to Manhattan for me this summer, and both should be on your TV this fall. (This is in addition to more episodes of Hazardous History with Henry Winkler, Secrets Declassified with David Duchovny, and more.) Keep your eyes peeled.

A simulation from this paper, of a nuclear blast destroying an asteroid

If an asteroid were on a collision course with Earth, would blowing up a nuclear warhead at the surface of the asteroid be a plausible way to save ourselves? To find out, researchers modelled a 160 m asteroid with the shape and density of Bennu, the asteroid sampled by OSIRIS-REx in 2020. Then they simulated that object being hit with a one-megaton nuclear device detonated at two different heights above its surface, 10 metres and 25 metres.

Here's the most interesting thing I learned from this story: In space, it’s not a shockwave that does damage the way it does for a nuke here on Earth. Space is a vacuum so you can't have a shockwave. Instead, intense x-rays shoot out and destroy the material. As you can see from the simulation's graphical output in the image above, those X-rays pack a pretty good punch.

In the 10 m-away scenario, and one of the two 25-m away scenarios, the damage and the direction of ejected material strongly suggested the asteroid would be broken apart rather than merely deflected. In the other 25-m away scenario, the meteor was modeled as being a little more solid, and as a result it didn't break apart quite so clearly.  That said, the big shortcoming of this study was that they didn't really do very many simulations to get details about what might happen in different scenarios. They just did the three simulations. Why? Well, their simulations were complex, and thus computationally intensive; modelling just 0.145 seconds of an asteroid explosion took 59 days to run on 1,680 computer processors. So I guess I can't blame them for just doing three simulations, but it does leave quite a bit to be desired, in terms of knowing what to do if a meteor heads this way.

Sometimes severe snoring is treated with surgical "stiffening procedures." In a nutshell, the tissues of the soft palate are injured, and the scar tissue that forms once it heals is less floppy than the original tissue. In the best case scenario, that intervention reduces the flapping motions of the soft palate, in turn reducing the loudness of the snoring. But those surgeries are notoriously flaky. Some surgeries make no difference. Others make too small a difference to have been worth the risks and pain of the surgery. But thanks to a new computer model, surgeons might be better able to predict what those interventions will do, ahead of time.

The team built a simplified three-dimensional model of the airway, soft palate, and uvula (the floppy thing at the back of your throat). Then they simulated air moving in and out of the volume every 4.14 seconds, with 75% of the air going through the nose, and 25% through the mouth (numbers all based on real human snorers). The simulation ran on a simulated 3D surface “mesh” of roughly 1.9 million cells with 55,000 structural elements, fine enough that the researchers could track sound waves alongside the physical flutter of the tissue.

Just as a flag on a pole snaps back and forth because air catches one side of the fabric and then the other as it ripples, the researchers found that most of the snoring sound comes from that same push-pull effect on the moving surface of the palate, air shoving against the tissue as it bends one way and then springs back.

The next step will be for them to model how different surgical interventions might help more (or less) to reduce the overall loudness of the snoring.

Sometimes, honestly, the biggest barrier to getting regular exercise is the time. If I want to run 10 km, I need the time to run that far, plus the time it takes to stop sweating afterwards, then a shower, then maybe time for some ice cream. It adds up! Wouldn't life be easier if I could do a 90-minute workout in five-and-a-half minutes?

A new study had some people ride stationary bikes at moderate speed for 90 minutes and others ride at top speed for six 30-second sprints (three minutes of sprinting spread over just five minutes and thirty seconds). Then the researchers compared them. Sadly, they didn't measure the things most of us care about, like longevity, weight loss, mood, cardiovascular health, or any of the other things that improve with regular exercise. Instead, they measured blood proteins.

Researchers found that sprint intervals changed the levels of 714 blood proteins, while the moderate cycling changed just seven – a 100-fold difference. Those sprint-triggered proteins came from all over the body, including muscle, fat, liver, gut, pancreas, brain, and pituitary gland. The researchers say this result suggests that a few brutal seconds of effort set off a body-wide conversation among organs, and that this is evidence the 5.5-minute sprint is superior to the 90-minute bout.

It's an intriguing study, for sure, but it's not really evidence that sprinting is better for you than having your heart-rate up for longer. I think I'll wait for more evidence before I change my running routine, even if it does take me a long time.

Last week, Shelby and I travelled to New York City. On Friday, while I was doing the TV shoot that brought us there, she ventured North to a place called The Met Cloisters. It's an extension of the Metropolitan Museum of Art, located in Washington Heights, that has a bunch of displays about Medieval life. One highlight for Shelby was a "unicorn horn" from that period. It was displayed next to tapestries depicting a medieval unicorn hunt.

Today we know very well that unicorns don't exist, but during medieval times, it was genuinely hard to know what creatures were real and which were mythical. Without photography or museums, a unicorn, or kraken, or a three-headed dog would be no more far-fetched than a hippopotamus, or a giraffe, or a tiger. There was no Wikipedia, and most people couldn't read, to begin with. In that time, some rich and powerful people owned what they believed were unicorn horns. In reality, though, many of those "horns," including the medieval-era one displayed at The Met Cloisters, were narwhal tusks. So the iconic straight, but twisted shape of a unicorn's horn is really the result of narwhal morphology.

The tusk of a narwhal is actually one of its teeth. (If you know which tooth, you'll do well in this week's Trivial Trivia.) Scientists have finally figured out why the tooth looks so twisted, and why it's so straight. It all comes down to a hidden double helix. Unlike the double helix of DNA, where both strands spin the same way, the narwhal tusk's double-helix has the outer layer, called cementum, spiralling left, giving the tusk its iconic outward appearance, while the dentine underneath, which makes up most of the tooth, spirals in the opposite direction – right. And those counterbalanced twists result in a tusk that points in a very straight line, unlike the curved tusks of elephants, walruses, and warthogs.

Last Week's Trivial Answer

Last week's question was "Black Hole Sun was released by Soundgarden in 1994 (May 23). That same year (July 16–22), the fragments of Comet Shoemaker-Levy 9 impacted what planet?" The correct answer was "Jupiter."

Thanks for reading! -Dan