Learn about why NASA doesn’t launch rockets in the rain; why llamas are so promising for human virus protection; and why things get cold — when they’re wet, when you’re chewing mint gum, and when you blow air through narrowed lips.
Learn about why NASA doesn’t launch rockets in the rain (which is why there was a delay launching the SpaceX Crew Dragon spacecraft carrying NASA astronauts Robert Behnken and Douglas Hurley); why llamas are so promising for protecting humans against viruses like COVID-19; and why things get cold — when they’re wet, when you’re chewing mint gum, and when you blow air through narrowed lips.
Why NASA doesn’t launch rockets in the rain by Cameron Duke
Why llamas are so promising for human virus protection by Cameron Duke
Three questions about cold by Ashley Hamer (Listener questions from Joshua, Brescia, and Likith)
Subscribe to Curiosity Daily to learn something new every day with Cody Gough and Ashley Hamer. You can also listen to our podcast as part of your Alexa Flash Briefing; Amazon smart speakers users, click/tap “enable” here: https://www.amazon.com/Curiosity-com-Curiosity-Daily-from/dp/B07CP17DJY
Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/fighting-coronavirus-with-llamas-why-rain-stops-rocket-launches-and-listener-questions-about-cold-things
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about why NASA doesn’t launch rockets in the rain; and why llamas are so promising for human virus protection. We’ll also answer a FEW listener questions about why things get cold when they’re wet, when you’re chewing mint gum, and when you blow air through narrowed lips.
CODY: Let’s satisfy some curiosity.
Have you ever wondered why NASA won’t launch rockets in the rain? In essence, it’s because a rainy rocket launch is a whole lot riskier than a rainy picnic.
Last weekend, NASA successfully launched a crewed rocket from American soil for the first time in nearly a decade. You may have been one of the millions of anxious and excited people watching the historic event, when SpaceX’s Falcon 9 launch vehicle and Crew Dragon Capsule transported astronauts Doug Hurley and Bob Behnken to the International Space Station. It was especially exciting considering that the launch had been scheduled for earlier in the week, but it was canceled — or “scrubbed” — due to rain. So, why does light rain stop a launch?
There are several reasons, but lightning is the main one. When NASA launches a rocket, it leaves behind a trail of condensed water vapor. In humid conditions, this trail of water vapor can extend for miles. And as anyone who’s had to leave the pool during a lightning storm knows, water conducts electricity. That means that miles-long contrail is basically the world’s biggest lightning rod. And that is bad news for sensitive electronics aboard a spacecraft.
That’s what nearly spelled disaster for the Apollo 12 mission, which was the second crewed mission to the Moon, on November 14, 1969. Everything was “go” for launch, even though it was overcast and rainy at the launch site. The Saturn V rocket was the most powerful launch vehicle ever built, so NASA engineers were confident it could punch straight through the weather without any issues. As it turns out, even rocket scientists can make mistakes.
36.5 seconds after launch when the rocket was more than a mile up, the crew on board saw a flash. Lightning. Almost immediately, flight instruments in the command module begin failing and both mission control and the launch vehicle lost all measurement readings. Basically, the rocket went blind. Then, 30 seconds later, lightning struck again. Both times, the bolt of electricity followed the contrail all the way back to the launch pad.
Over the next few minutes, the Apollo 12 crew calmly tried to diagnose multiple systems failures. The mission was saved by a 24-year old flight controller named John Aaron. He had seen these specific failures during a simulation years before. His simple solution of switching an obscure instrument to auxiliary power ultimately saved the Apollo 12 mission and earned him the famous moniker of “steely-eyed missile man.” He went on to be instrumental in saving the Apollo 13 mission, too.
So the next time a rocket launch is scrubbed due to weather? Just know that decision is much better than the alternative.
In the fight against the coronavirus, scientists are turning...to llama blood. That might sound super random, but actually, vaccine researchers have been interested in llamas and their unusual immune systems for decades. Here’s why we think they can help fight human disease.
It all started in the 1980s when scientists discovered a strange quirk in the llama immune system. See, to fight invaders like viruses, the immune system produces antibodies. Those are proteins that recognize and latch onto specific invaders so they can be neutralized and removed. Antibodies are made up of protein chains. Like, imagine you have three pieces of licorice. You lay two of them side by side and pull the tops away from each other to form a “Y.” Those would form what are called the heavy chains of the antibody. The tips contain genetic information for the invader they’re supposed to neutralize. Then take that third piece, break it in half, and lie each half alongside each upper branch of the Y. Those are the light chains. That’s what human antibodies look like.
But llama antibodies don’t have those light chains. They’re just the two pieces of licorice. That makes them way smaller than human antibodies. That small size helps them burrow into places where conventional antibodies can’t penetrate, which might make them more effective. But what’s even more exciting? You can take these small antibodies, and even fragments of them called nanobodies, and stitch them together to create “super antibodies.”
That’s been done before. In 2016, researchers immunized a llama named Winter with spike proteins from MERS and SARS, which are two types of coronaviruses. Winter’s immune system produced antibodies, which the scientists extracted and daisy-chained together into a super antibody that could fight both of the viruses. This year, they revisited that super antibody to see if it was effective against the novel coronavirus. And it was! — at least, in a petri dish. It still has to be tested on humans.
But llamas are good for more than just fighting coronaviruses — they’ve also been on the front lines of the fight against influenza. The influenza virus mutates rapidly, which is why you need a new flu vaccine every year. Many researchers think that llama antibodies could help us bioengineer “super antibodies” that could target multiple strains of the virus at the same time. That would bring us a step closer to a universal flu vaccine.
This research holds a ton of promise, but it’s important to manage our expectations here. It’s still early, and while engineered llama antibodies have been effective in animal trials, the human immune system can be finicky. But the technique holds promise, and if it does work, we will all be in debt to the llama.
We have a trio of listener questions today! Joshua, Brescia, and Likhit all asked questions on a similar theme: cold things! So I thought I’d answer them all together.
First off is Joshua, who writes, “When you are chewing minty gum, why is water (or any drink) so much colder?”
There’s an old Winterfresh Gum commercial from childhood that’s permanently lodged in my brain: it goes “It’s a scorching 98.6 degrees inside your mouth. But inside a Winterfresh mouth? It tastes much, much COOLER!” Regardless of why my brain has held onto that particular memory, you’ll notice that it says it tastes cooler. Minty gum doesn’t change the temperature of your mouth; just your perception of temperature. That all comes down to a receptor called TRPM-8. TRPM-8 is how you’re able to perceive cold temperatures, and it just so happens to trigger in the presence of menthol, too, which is the cooling compound in mint oils. Mint isn’t the only flavor that can hijack your temperature receptors, either — the burn of alcohol or hot peppers triggers heat receptors in the same way. Water tastes even colder when you’ve been chewing mint gum because the menthol has already sensitized your cold receptors, so the cool water feels even colder.
Speaking of cold water, Brescia wanted to know: “Why do things feel cold when they’re wet?” In this case, the objects actually are colder than the surrounding air. That’s all thanks to evaporation. You know how sweat helps to cool you off? That’s because when water evaporates off of your skin, it takes heat with it. To get really granular about it, water molecules on a surface are always moving around and running into each other. If one of those random collisions sends a molecule shooting off with enough speed, it escapes into the air and takes its energy with it in the form of heat. So wet surfaces feel cold because that water is actively evaporating and taking heat along for the ride.
Our third and final question comes from Likhit, who asks: “Why does the air we exhale change from hot to cold depending on the size of the opening we make with our mouth?” This one’s a little more complicated. There’s a principle in fluid dynamics called the Venturi effect that says that when a fluid, like air or water, flows through a constriction — like, the constriction of your lips — there’s a drop in pressure. And whenever there’s a drop in air pressure, surrounding air molecules rush in to fill it. So when you blow air through the small opening of your lips, you’re mixing the hot air from your lungs with the cool air in the room. This drop in pressure doesn’t happen when you blow with a wide mouth, so that air still feels warm.
Thanks for your questions! If you have a question, send it in to podcast at curiosity dot com or leave us a voicemail at 312-596-5208.
CODY: Before we recap what we learned today, here’s a sneak peek at what you’ll hear next week on Curiosity Daily.
ASHLEY: Next week, you’ll learn about why rainy days make you sleepy;
How dogs can be annoying teenagers, too;
Whether “fat-burning foods” are a real thing;
Why some psychopaths are killers and others are CEOs;
And more! Okay, so now, let’s recap what we learned today.
[ad lib optional]
CODY: Today’s stories were written by Ashley Hamer and Cameron Duke, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Have a great weekend, and join us again Monday to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!