Curiosity Daily

What Your Ears and Spider Fuzz Have In Common

Episode Summary

Learn why Cygnus X-1, the first black hole ever discovered, is bigger than we thought. Then, learn about spider hearing with help from Ron Hoy, a professor of neurobiology and behavior at Cornell University who studies acoustic communication in insects.

Episode Notes

Learn why Cygnus X-1, the first black hole ever discovered, is bigger than we thought. Then, learn about spider hearing with help from Ron Hoy, a professor of neurobiology and behavior at Cornell University who studies acoustic communication in insects.

The first black hole ever discovered is bigger than we thought by Grant Currin

• First black hole ever detected is more massive than we thought. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-02/caos-fbh021821.php
• The mass of Cygnus X-1’s black hole challenges stellar evolution models. (2021). EurekAlert! https://www.eurekalert.org/pub_releases/2021-02/aaft-tmo021621.php
• Miller-Jones, J. C. A., Bahramian, A., Orosz, J. A., Mandel, I., Gou, L., Maccarone, T. J., Neijssel, C. J., Zhao, X., Ziółkowski, J., Reid, M. J., Uttley, P., Zheng, X., Byun, D.-Y., Dodson, R., Grinberg, V., Jung, T., Kim, J.-S., Marcote, B., Markoff, S., & Rioja, M. J. (2021). Cygnus X-1 contains a 21–solar mass black hole—Implications for massive star winds. Science, eabb3363. https://doi.org/10.1126/science.abb3363

Additional resources from Ron Hoy:

• Ron Hoy's faculty page at Cornell University: https://nbb.cornell.edu/ronald-r-hoy
• Hoy's 2016 study on hearing in jumping spiders: https://news.cornell.edu/stories/2016/10/jumping-spiders-can-hear-distance-new-study-proves

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Episode Transcription

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 the first black hole ever discovered is bigger than we thought. Then, you’ll learn about spider hearing, with help from Cornell University professor Ron Hoy.

CODY: Let’s satisfy some curiosity.

The first black hole ever discovered is bigger than we thought (Ashley)

Cygnus X-1 simply won’t quit. It’s a binary star system — pretty close to Earth — where a blue supergiant star and black hole orbit each other. The black hole was the first one humans ever discovered, and new research shows that it’s way bigger than scientists thought. 

In fact, it’s now a record holder — even if that record has a lot of caveats. It’s the most massive electromagnetically detected stellar-mass black hole ever discovered. “Electromagnetically detected” as in, not detected via its gravity, and stellar-mass, as in, not a supermassive black hole. Good job, big guy!

Black holes are notoriously hard to spot. But the black hole in Cygnus X-1 is one of the black holes closest to Earth, and it’s producing X-rays that we can detect thanks to its interaction with its companion star. So it’s not a huge surprise that it was the first that astronomers discovered, way back in 1964. 

Now, more than a half-century later, astronomers used a telescope array that spanned the entire United States to take their closest look yet at the Cygnus X-1 system. The researchers used ten radio telescopes to watch the two objects make a complete orbit around each other over six days. Then they compared the images captured by the different telescopes to judge the black hole’s distance from us.

To get a sense of what they did, just stick your thumb out and look at it with one eye open. Then switch eyes. Your thumb moved, right? If you hold your thumb closer, it moves even more. That’s basically the technique that astronomers used to update what they know about Cygnus X-1. As it turns out, the star system beat scientists’ previous measurements in just about every way.

First, the black hole is about twenty times more massive than the Sun. That’s about 50 percent bigger than astronomers previously believed. It’s also spinning really, really fast — faster than any other black hole ever observed. It clocks in at almost the speed of light. Whew! 

But these new findings aren’t just fun facts. They’re also causing astronomers to re-think what they once knew. See, astronomers have good reason to think that the black hole in Cygnus X-1 began its life as a big star, about 60 times the mass of the Sun. That star collapsed tens of thousands of years ago and then turned into a black hole. Astronomers also know that stars slowly lose mass over their lifetimes. But according to the new findings, there’s no way the star that became the black hole lost as much mass during its lifetime as astronomers would have expected. It’s just too big and spinning too fast for that to be the case. And that may change a lot of what we know about how stars evolve.

So while astrophysicists are busy tweaking their theories and arguing over equations, the rest of us can relax knowing that science never gets everything right the first time.

Ron Hoy - Hairs on a spider are like the hairs in your inner ear (Cody)

Spiders don't have ears. Instead, they use the tiny hairs they have all over their bodies to sense vibrations in the air, which their brains interpret as sound. And if you think that makes you way different than a spider — today's guest is going to explain why you may want to think again. Ron Hoy is a professor of neurobiology and behavior at Cornell University who studies acoustic communication in insects — in other words, bug hearing. And Ashley asked him about something you yourself may have wondered about.

[CLIP 4:08]

Again, that was Ron Hoy, a professor of neurobiology and behavior at Cornell University. He'll be back tomorrow to tell us about a species of spider that doesn't wait for prey to get tangled in its web. Instead, it brings the web to them. 

RECAP

Let’s recap the main things we learned today

1. CODY: The first black hole ever discovered is a LOT bigger than we thought. It would have started out as a star that slowly lost mass over time, before collapsing and turning into a black hole. But because this black hole is so big, it seems that star couldn’t have lost as much mass as astronomers thought during its lifetime — and that’s making researchers re-think what we know about how stars evolve.
2. ASHLEY: Hearing happens when hairs move. Anything that causes movement can make a creature hear — from sound vibrations to electromagnetic waves. And the hairs all over a spider’s body are like the hairs in our ears — sensory scillia.
3. The hairs on a spider are a lot like the hairs on our arms and legs — but they’re ALSO like in our ears that help us hear.
   1. Sensory cilia are hairs
   2. You HEAR when hairs move; The ones inside our ears are scilliary hairs. 
   3.  In fact, when bees land on plants, they feel an electric discharge through the hairs on their bodies that tell them whether a plant has been visited by other bees. The same thing basically happens in our inner ear when vibrations make the hairs in our ears move.

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CODY: Today’s stories were written by Grant Currin and Ashley Hamer, 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: Join us again tomorrow to learn something new in just a few minutes.

ASHLEY: And until then, stay curious!