Celestial Wonders: Unveiling Solar Flares, Atmospheric Flight, and Mars' Chunky Core

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Avery: Welcome to Astronomy Daily, the podcast that

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brings the cosmos down to Earth. I'm Avery.

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Anna: And I'm Anna. It's great to be with you

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today. We've got a fantastic lineup. We're

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starting with our own sun, which just put on a

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spectacular and slightly terrifying show

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for our most powerful solar telescope.

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Avery: Then we're heading into our own atmosphere, to a

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mysterious layer we can barely reach. And the

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brilliant new technology that might finally unlock its

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secrets. After that, we'll dig deep into Mars

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to find out why its insides are as chunky as

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a cookie.

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Anna: And finally, we'll tackle the big one, time

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travel. A new study suggests it might be

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possible, but it comes with a catch that

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changes everything. So let's get started.

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Avery: Alright, Anna, let's talk about the sun. We know it can

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be violent, but this is something else. The

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NSF Inouye Solar telescope just got

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its first look at an X class flare. And

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the images are mind blowing.

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Anna: They really are. For our listeners, an X

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class flare is the most powerful category of

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solar flare there is. These are massive

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explosions of energy and catching one with this

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level of detail is a huge deal. The

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telescope managed to capture it at a resolution where

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the smallest details are just four Earths across.

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Avery: That's incredible. It's like having a super powered

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magnifying glass on, um, the most energetic event

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in our solar system. So what did they

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actually see with this new level of clarity?

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Anna: They saw something called coronal loops, but on

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a scale we've never seen before. These are thin

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filaments of plasma that arch over the sun's

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surface following magnetic field lines. We've

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seen bundles of them before. But Inoue's power

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allowed scientists to see individual loops

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for the first time. Some of these loops were as

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small as 21 kilometres wide, which is

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right at the telescope's resolution limit. It's

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these magnetic field lines twisting, snapping and

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reconnecting that powers the solar flares in the first

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place.

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Avery: So saying the fundamental building blocks of these

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events is a game changer. I know these

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flares can be dangerous, knocking out radio communications

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and power grids here on Earth. Does this help us

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prepare for that?

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Anna: That's the goal. According to the researchers, peering

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into these smaller scales where the magnetic

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reconnection actually happens, opens the door

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to understanding the engine behind the flares.

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Better understanding leads to better prediction models,

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which gives us a better chance to protect our technology.

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When the sun decides to act, it's a huge

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step forward in forecasting space weather.

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Avery: From the very big to the very,

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very small.

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Our next Story is about exploring a part of our own

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atmosphere that's been stubbornly out of reach.

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The mesosphere. It's too high for balloons, but

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too low for satellites.

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Anna: Exactly. It's a huge blind spot for

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climate and weather data. But researchers at Harvard

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and the University of Chicago may have found a way

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to reach it. And it sounds like something out of science fiction.

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They've designed ultralight flying structures

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that float by harnessing sunlight itself.

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No engines, no fuel, powered by

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sunlight.

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Avery: How does that work?

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Anna: It uses a phenomenon called photoforces.

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It's a gentle force that pushes on an object

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when light heats one side more than the other. Down

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here on the ground, the force is so weak, we never notice

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it. But in the extremely thin air of the

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mesosphere, that tiny push is enough to overcome

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the weight of these new structures.

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Avery: So, so what are these things made of? They must be

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unbelievably light.

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Anna: They are. They're built from ultra thin

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ceramic alumina with a special coating on the bottom

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to absorb sunlight. The researchers actually tested

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them in a lab in a low pressure chamber that mimics

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the mesosphere. And they levitated perfectly with

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just a bit of light.

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Avery: That's amazing. The applications seem endless. You could attach

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sensors for climate data or create floating

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communication arrays like a, uh, low orbit

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starlink. One of the researchers even said they could

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eventually fly on Mars.

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Anna: That's the long term vision. Mars has a thin

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atmosphere that's very similar to our

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mesosphere, making it a perfect target.

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One of the lead authors called it the Wild west

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in terms of applied physics, because nothing

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has ever been able to fly sustainably up there before.

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This opens up an entirely new way to

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explore our upper atmosphere and

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potentially other worlds too.

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Speaking of Mars, our next story takes

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us deep inside the red planet. A

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new analysis has revealed that the

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interior of Mars is, and this is

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a direct quote, as chunky as a

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delicious macadamia cookie.

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Avery: I love it when scientists get creative with their analogies.

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So what does that mean exactly? It's not actually made

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of cookies, I assume.

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Anna: No. Unfortunately, what they found

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using data from the Insight lander is

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that huge chunks of Mars

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ancient early crust are preserved

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deep within its mantle. These are

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geological fossils from when the planet was

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first forming four and a half billion years

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ago.

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Avery: Insight was the mission that listened for Marsquakes.

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Right. So they used seismic waves to map the

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interior. Like an ultrasound.

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Anna: That's right. By studying how the waves from these

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quakes travelled and bounced, they couldn't map out

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the Composition. And they found these massive

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fragments, some up to four kilometres across,

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just drifting in the mantle. The theory is

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that during the chaotic early days of the solar system,

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giant impacts shattered the young planet's

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crust and those pieces sank into the

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molten mantle before a new crust formed.

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Avery: And they've just been sitting there ever since?

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Anna: Pretty much. Unlike Earth, Mars doesn't

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have active plate tectonics. Our crust and

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mantle are constantly churning and recycling each

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other. Mars has a single

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solid crust, a stagnant lid.

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So its interior evolution is much slower.

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It's acted like a, uh, time capsule, preserving

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this evidence of its violent birth. This

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gives us an incredible window into what

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rocky planets look like before tectonics

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get started.

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Avery: Okay, for our final story, we're going from planetary

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history to rewriting it. Or maybe

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not.

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Anna, uh, let's talk time travel.

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Anna: This is a really fascinating one. A new

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study looked at what would happen inside a

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spaceship travelling on a closed time

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like curve, which is basically a loop through

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space time that brings you back to the exact

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moment you left.

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Avery: The classic sci fi setup. So do we get to go

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back and fix our mistakes or accidentally

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erase ourselves from existence by bumping into our grandfather?

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Anna: Well, according to this research, neither. The

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study uses standard quantum mechanics and

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thermodynamics, not some exotic new theory.

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And the conclusion is the laws

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of physics themselves demand self

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consistency. After one full loop,

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everything inside the ship clocks

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computers, and even you must return

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to its original state.

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Avery: So time travel would be like pressing a cosmic

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reset button.

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Anna: Precisely. And it gets weirder.

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To maintain that consistency, the second law

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of thermodynamics, the one that says

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disorder or entropy always increases,

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has to be temporarily reversed. At a

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certain point in the loop, entropy hits a

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maximum and then it starts decreasing.

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Processes run backwards. Coffee would get

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warmer, broken eggs would reassemble.

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Avery: And what does that do to a person? What about our

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memories?

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Anna: This is the biggest catch. The formation of

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memory is a thermodynamic process,

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as entropy reverses to bring the system back

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to its starting state. Any memories you

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formed during the trip would have to be erased

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completely.

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Avery: So you could live through this incredible journey.

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But from your point of view, it would feel like

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nothing happened at all. You'd get in the ship, complete the

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loop, and arrive back in the same instant. With

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no memory of the trip.

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Anna: Exactly. It's the ultimate form of what

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happens in the loop stays in the loop because

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it gets completely wiped clean. So instead

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of rewriting history, you just reset

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it and forget it. A very different and

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much less adventurous picture of time travel than

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the movies suggest.

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Avery: And that's all the time we have for today, from the fiery

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heart of the sun to the delicate flyers in our atmosphere,

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the chunky interior of Mars, and the strange,

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forgettable physics of time travel.

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Anna: Thanks for joining us on Astronomy Daily. If

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you'd like to stay on top of the latest space and astronomy news,

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simply visit our website at astronomydaily

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IO and check out our constantly updating

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newsfeed. You can also find all our back

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episodes there. If you'd like to do some binge listening,

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I'm Anna.

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Avery: And I'm Avery. We'll see you next time for another look

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at our amazing universe. Until then, keep

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looking up.