Learn how tool use and language work in the brain; and why black holes get bigger due to the expansion of the universe.
Learn how tool use and language work in the brain; and why black holes get bigger due to the expansion of the universe.
Tool use and language ability go hand in hand by Grant Currin
Black holes get bigger from the expansion of the universe itself by Briana Brownell
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CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from Discovery. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about how tool use and language go “hand in hand,” PUN INTENDED, HIYOOO!!!; and why black holes are getting bigger thanks to the expansion of the universe.
CODY: Let’s satisfy some curiosity.
In a series of clever experiments, researchers have discovered that two seemingly different traits share a lot of hardware in the brain. Could it be that language and tool use are different expressions of the same thing?
Once you know how to use a tool, it’s hard to explain how you do it. Sure, you can describe each step of a process in literal terms, but someone who’s mastered a motor skill like knitting isn’t thinking about that. They just grab the needles and...knit. It turns out that the cognitive structures that make humans so good with tools have a lot in common with the ones that make us so good at language.
Both skills rely on the ability to process information that’s structured in a hierarchy. Here’s what I mean. You pound a nail by picking up a hammer and swinging backward and forward. But it’s not so simple. Each one of those actions depends on a whole series of sub actions. During the forward swing, hand muscles have to maintain the right pressure, wrist muscles have to hold the correct angle, arm muscles have to accelerate and then stop. Each of those sub-actions depends on a series of sub-sub-actions, and so on.
Language works similarly. Every long and complicated sentence is really just a simple one with a lot of detail. Adjectives, adverbs, and clauses give hierarchical structure to information.
Researchers thought these similarities might also exist in the brain itself, so they used fMRI scans to compare people’s brain activity while they used tools to their brain activity while they tried to understand complicated sentences. They found a ton of overlap in a brain region called the basal ganglia, which is well known for its role in motor control but also plays a part in a lot of other functions.
Ok, so there’s overlap, but does that mean that getting good at one skill makes you good at the other? To find out, the researchers had people practice the difficult task of using long-handled pliers to manipulate small pegs. Next, they tested the participants’ linguistic abilities by asking them questions about simple and more complicated sentences. The group who practiced with the pliers got better at the linguistic task, but those who learned without a tool didn’t. And get this: the learning transferred both ways. Participants who practiced understanding complicated sentences got better at using the unfamiliar tool.
This research shines light on how members of our species became so good at communicating with each other and manipulating the environment. And the results have practical use, too. The researchers say their insights will contribute to therapies that help people develop or recover language abilities or fine motor movements. When people say language is a tool, they’re more right than they realize.
Black hole mergers are some of the most dramatic events there are. Scientists have detected several of them. But recent observations have shown something weird: many of the black holes involved are much larger than expected.
Since black holes are so massive that not even light can escape them, scientists need to observe them indirectly. Luckily, there’s a useful way to do that thanks to predictions made by Einstein’s theory of general relativity: it says that massive disturbances like black hole mergers can cause ripples in space-time called gravitational waves. Scientists have actually measured the tiny gravitational oscillations emitted by these events.
When they did that, they found that many of the black holes involved in mergers were extremely massive. See, we know that most of the massive stars that collapse to become black holes are around 40 times as massive as our sun or smaller, so that’s how big they expected the resulting black holes to be. But that’s not what they found. Many of these black holes were more than 50 times as massive as our sun, and some even weighed in at over 100 solar masses. Researchers have been looking for a possible way to explain this difference.
New research from a group of American scientists has suggested one possible explanation: that these large masses could be explained by the expansion of the universe itself.
Most of the time, scientists ignore the expansion of the universe in their modeling of black holes. That’s because the equations that describe the universe are extremely complicated, and it’s easier to model behavior in a simpler universe. But these equations don’t capture the full behavior of the objects in the universe on longer timescales. They’re missing some of the detail needed to make accurate predictions.
When you’re dealing with an event that lasts just a few seconds, the accuracy lost is reasonable. But since there might be billions of years between a black hole’s formation and its eventual merger, scientists needed to add those terms back into the equations.
The more finely tuned modelling showed the black holes gaining mass as the universe expanded. It also predicted that there would be many more black hole mergers than we originally expected. Both predictions match our current observations.
While it might seem far-fetched to say that the expansion of the universe itself is what’s making black holes grow, it’s actually a relatively simple explanation: it doesn’t need any new physics to explain what we observe. Scientists hope that the new models can be used to deepen our understanding of other cosmological events on large time scales too.
So the next time a black hole says it’s self-conscious about its mass, make sure to let it know it’s nothing to be ashamed of — it’s just the expansion of the universe.
Let’s recap today’s takeaways
[ad lib optional]
CODY: Today’s writers were Grant Currin and Briana Brownell.
ASHLEY: Curiosity Daily is distributed by Discovery.
CODY: [AD LIB SOMETHING FUNNY] Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!