Scientists discover receptor that blocks COVID-19 infection

Great news! University of Sydney scientists have discovered a protein in the lung that blocks SARS-CoV-2 infection and forms a natural protective barrier in the human body.

Found on Mastodon at:

Black wolves with Special K

From a Mastodon post by Rajini Rao (

When humans migrated across the Bering Strait to N America during the last Ice Age, they brought along domesticated dogs. Soon after, black coats appeared in the native Gray Wolf population, caused by increased melanin due to changes in a single gene.

Known as the K gene (Japanese kurokami for ‘black hair’), the dark coat resulted from a variant introduced by interbreeding with dogs. Wolves carrying one or two copies of the KB version are black.

The frequency of black wolves increases from the Arctic to Mexico. Black coats are more common in regions with canine distemper outbreaks. It turns out that the K gene is a natural antibiotic (“defensin”) that confers immunity against distemper.

But the black coat variant also carries a fitness defect: few pups with 2 copies survive to adulthood. Gray-coated wolves produce larger litters and are more aggressive than black-coated wolves during territorial conflicts.

Mono Lake and water theft

We studied Mono Lake in my 6th grade class. It’s an interesting ecosystem because the lake doesn’t have any streams taking water away from the lake — it’s a dead end. Over the millennia the lake has gotten very salty, to the point where fish can’t live in it. But there are 2 varieties of algae, and they form the base of a somewhat small food web.

Back in 1913 the city of Los Angeles decided they needed the freshwater that was flowing into Mono Lake and others and built the largest gravity fed aqueduct to bring the water to LA. A lawsuit brought by the Mono Lake Committee managed to save Mono Lake, but not nearby Owens Lake, which dried up entirely. The agreement stipulated that LA would get 1/4 of the water going to the lake, and Mono Lake got the rest.

Now the Committee is trying to get LA to stop taking any water from the lake. We’ll see how this progresses.

Deeper than the Kola Superdeep Borehole, and lots of power to boot

For years I’ve been fascinated by the deepest humans have ever dug into the Earth. The Kola Superdeep Borehole in the Kola peninsula of Russia is over 12 km deep. It took 20 years to dig that far, and they had to stop because it was so hot down there (180 °C) that the rock was plastic and flowed, making drilling nearly impossible. The project was stopped in 1995.

But it looks like scientists may have found a way to dig deeper holes, and use the great heat down there to generate power. We’ve been using geothermal power for a long time, but it hasn’t been feasible to do in where the surface crust isn’t hot. The really interesting thing is the way we may be able to drill deep, down to where it’s 500 °C.

Quaise, a spinoff from MIT, has a way to use millimeter-wave beam technology to easily and quickly break even the hardest rocks. They claim to be able to complete a 20 km deep hole in just over 100 days.

If this works (and that’s still a big if), it could lead to reliable geothermal power, without requiring CO2 emissions after the hole is dug. They’re looking to have a 100 megawatt geothermal plant operating in 2026.

History of Science

I’ve been learning about the History of Science courtesy of Crash Course. It’s really interesting.

I first found out that the history of science was fascinating from Connections by James Burke. This was a PBS series back in the day (the late 1970s) (and it’s not really PBS, since it came across the pond from the BBC), and each one traced a series of scientific and technological discoveries from ancient to modern times. The first episode traced the invention of the plough to modern power blackouts. While the show looks dated (hey, it’s over 40 years old!), if you can get past that, it really rewards viewing. You can watch it on YouTube here.

Anyway, the YouTube playlist for the Crash Course History of Science is 46 episodes long, so I have some watching ahead of me.

Well, I just finished it today. There’s a lot there to unpack. I think they did a really good job with it. I’m also watching their course on Outbreak Science, and I want to start watching Geography; I’ve always liked maps.


Terminal Velocity

Today I went skydiving with my son! First time for both of us. Until you’ve done lots of dives you have to go in tandem with an experienced skydiver. So we went to the Sussex Skydiving, and checked in. We each got hooked into one half of a tandem rig. Then we went up in the airplane to 14,000 feet (along with our instructors and the other people jumping). At that altitude the plane leveled off and pairs started jumping out.

First the instructor attaches you to their suit (the other half of the tandem rig). He tightens the straps so you’re up nice and snug, as one unit. Then we moved together to the open door, and I put my feet out. My instructor then pushed us out of the plane.

The first few seconds were somewhat disorienting, but I quickly got my bearings and started hooting and hollering. Of course, now that we were falling up to 120 mph the wind was so loud I couldn’t hear anything!

So the title of the post refers to the maximum downward velocity, in this case 120 mph. At this speed the downward pull of gravity is canceled out by the drag of falling through the air, so this is the fastest we went going down. We had about 60 seconds of free fall. Now, it turns out that in tandem jumping the instructor uses a drogue chute to stabilize the two of you. This means our drag was higher than without it, so our terminal velocity was lower. Also, two people falling in a tandem rig would have more weight for the amount of surface area, and their terminal velocity (without the drogue) would be higher. So I don’t really know what a single person’s terminal velocity would be.

Then the instructor pulled the chute and we slowed down. The chute provided much more drag, so our terminal velocity was less. Finally we landed back at the airport. For this the instructor had us dive, then level out just above the ground. We stuck our feet out in front, and hit the ground. Our forward and downward momentum was very low and we skidded for a few feet before stopping.

So Rileysci, how was it?

It was very exciting! Certainly more thrilling than large roller coasters. But I’m kind of old, and I had issues. Isome ear pain when going up in the airplane. Surprisingly, I didn’t notice any pain on the way down, but my body was overwhelmed with other things at the time and didn’t notice. While going down with the chute open I was kind of dizzy, probably from my nervous system being overwhelmed. It’s taken a while for my body to get back to equilibrium (yay homeostasis!). Overall it was something to check off my bucket list, but I won’t do this again.

My son enjoyed it much more and will definitely be doing this again before the summer ends.


No detectable alien civilizations at 60 million stars

Breakthrough Listen has been looking (listening?) for alien life in our milky way galaxy and at the 100 nearest galaxies. They’ve been specifically listening in areas of our galaxy where the stars are more closely packed: the galactic core. They examined over 60 million stars, but haven’t found anything significant.

My hypothesis

I think that we’re unlikely to find signals from alien civilizations because I think we’re looking for the wrong things. I look at it this way: we’ve been looking for the kind of signals that we put out. Stuff like radio waves. That makes sense given our history; we’ve been dumping radio waves for over 100 years. But that presumes that aliens would similarly be putting out organized electromagnetic radiation. What if the hypothetical aliens have come up with a more efficient way to send information to themselves. What if they’ve stopped using radio, etc.

Perhaps they’ve shifted to using tightbeam laser communication. That wouldn’t be sending signals all over the place, just to the destination. It’s also more energy efficient.

It’s like using listening for AM radio signals, but the people you’re listening for have switched to FM. The way of encoding information is different, and could just appear as random static.

If intelligent life out there is using some method to communicate that we haven’t thought of, then we may not be able to detect them, even if we’ve scanned their system for signals.

Of course I don’t have a solution to this problem. I know much less than the experts on what other methods intelligent life could be using to communicate; I’m just a middle school science teacher. I’d love to find evidence of alien intelligence. I just think that we’re looking for a needle in a haystack where no one is allowed to access the haystack directly.

I think that we may find extra-terrestrial life, but it won’t be intelligent life. It’ll be something like bacteria. Perhaps life is relatively common, but it doesn’t evolve to what we think of as intelligence. How would we know if there were a habitable planet within 50 light years that has life with the intelligence chimpanzees? They wouldn’t be broadcasting anything.