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The Sun – The Engine That Runs Everything · Talking Science

0:00
if you were to somehow like strip the sun away
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right now just remove it from the equation entirely
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the earth wouldn't just Go dark. No, not at all.
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I mean, in a matter of weeks, it would become
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this totally frozen, lifeless rock floating in
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the absolute void of space. Just a completely
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dead chunk of ice. Yeah. But you step outside
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on a clear day. You know, you feel that warmth
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on your face. You maybe squint a little bit and
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then you just go about your business. We treat
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that giant blinding orb in the sky like a totally
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mundane appliance, like a. a porch light that
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someone thoughtfully left on for us. It really
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is the ultimate background noise of our existence.
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I mean, it's so. omnipresent so flawlessly reliable
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day after day that we don't even really see it
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anymore right we just accept it completely ignoring
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the reality of what is actually hovering over
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our heads okay let's unpack this because our
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mission in this deep dive is to completely reframe
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how you look at that giant bright thing in the
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sky we are going to decode its hidden mechanics
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its ancient energy and uh the very real threats
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it poses to our modern world because we really
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do vastly underestimate our relationship with
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this sun oh totally it isn't just the brightest
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thing you'll ever see it is the source of very
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nearly all the energy that has ever mattered
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to life on earth everything else is basically
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just a footnote yeah and you really don't need
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any kind of science background today by the way
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we're just two curious minds figuring out this
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incredible engine of our existence exactly and
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the sheer scale of our reliance on it is absolute
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i mean let's trace back a totally normal day
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the food you ate today That was built by plants
1:37
using sunlight. Right. The wind that you might
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feel against your skin or, you know, the wind
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turning a massive turbine to generate electricity.
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Yeah, wind power. That is literally just air
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moving because the sun heats the Earth's atmosphere
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unevenly. That makes sense for solar or wind
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power, but I mean, it goes so much deeper than
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that, right? Oh, absolutely. Like the petrol
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you put in a car is ancient sunlight. It was
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captured by plankton and plants millions of years
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ago. Yeah, photosynthesis from millions of years
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in the past. Exactly. Those organisms died, they
2:07
sank to the ocean floor, and were compressed
2:09
by time and pressure into oil. So even the coal
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we dig out of the ground is essentially just,
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well, stored starlight. I love that. Stored starlight
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is a beautiful way to phrase it, and it's physically
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accurate. Right. When you burn coal, you are
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chemically releasing energy that a prehistoric
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plant absorbed from the sun deep in the Earth's
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past. It makes me think about our daily energy
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consumption. Like living off a cosmic trust fund.
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A cosmic trust fund. Every time we drive a car
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or turn on a light switch powered by coal or
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gas, we are just spending this ancient solar
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inheritance, you know, like it was deposited
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into the Earth's bank account hundreds of millions
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of years ago. We're just trust fund kids blowing
2:52
through a stored starlight. We really are. We're
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cashing checks written by the sun eons ago without
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even a second thought. But here is the supreme
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irony of the sun's status as this almighty engine.
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of everything. Okay. What's that? For all of
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its overwhelming importance to our survival,
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the sun is completely, wonderfully ordinary.
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The ultimate average Joe of the universe. Literally.
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It is a completely middle -aged average star.
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Just a vast ball made mostly of hydrogen and
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helium gas. Wow. There are hundreds of billions
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of stars just like it in our galaxy alone. We
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should probably clarify the scale here, though,
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because, I mean... Average in space terms is
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still pretty hard to wrap your head around. Oh,
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for sure. Like the sun is so staggeringly large
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that you could fit over 1 .3 million Earths inside
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of it. Yeah. So it is massive to us. But in the
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grand cosmic lineup, it's remarkably unremarkable.
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Right. It only looks so incredibly unique and
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dominant to us because of real estate. It's close.
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Location, location, location. Exactly. It's a
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mere 150 million kilometers away. Which, to be
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fair, sounds like an enormous distance until
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you realize the next nearest star is Proxima
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Centauri, which is about 40 trillion kilometers
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away. Right. So our entire existence, you know,
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all of human history, every triumph and tragedy
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depends entirely on this thoroughly unremarkable
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star that just happens to be in our neighborhood.
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Which brings up a massive historical mystery.
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I mean, if the sun is just a giant ball of gas,
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how on earth has it stayed lit for so long? That
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was a huge puzzle. Because if it's just sitting
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there burning away, why hasn't it run out of
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fuel? I mean, in the 19th century, scientists
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actually tried to calculate this, right? They
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did, yeah. Lord Kelvin, who was a brilliant physicist,
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he calculated that if the sun were essentially...
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A giant bonfire. Like a literal fire. Yeah, even
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one made of pure coal and oxygen, which was the
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most efficient chemical fire they could imagine
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at the time. Okay. He figured it would completely
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burn out in about 30 ,000 years. And 30 ,000
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years obviously doesn't give you billions of
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years of planetary history. Not even close. So
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chemical burning was out. The answer wasn't actually
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worked out until the 20th century. And that answer
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is nuclear fusion. Yes. What's fascinating here
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is that fusion is a fundamentally different way
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of releasing energy. How so? Well, we aren't
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talking about burning something. Fusion is about
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slamming things together. OK, let's break down
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the mechanics of that, because this is like the
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magic trick of the universe. It really is. So
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deep inside the sun's core, you have gravity.
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crushing the hydrogen gas with unimaginable force.
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Just squeezing everything. Squeezing it so hard.
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We're talking about pressure that is roughly
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250 billion times greater than the atmospheric
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pressure here on Earth. 250 billion. Yeah. And
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this crushes and heats the hydrogen to around
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15 million degrees Celsius. But under those extreme
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conditions, you have a physical problem. Right.
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The nuclei of hydrogen atoms, their centers,
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they have positive electrical charges. And just
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like trying to push the two positive ends of
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a magnet together, they fiercely repel each other.
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Right. They just slide apart. They actively resist
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touching. But the gravity and heat in the sun's
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core are so intense, it overwhelms that magnetic
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resistance. It just forces them together anyway.
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Wow. They are slammed together so hard that they
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stick. They fuse. So step by step, four. separate
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hydrogen nuclei are forced to merge into one
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single helium nucleus. And this is the crucial
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moment, isn't it? It is. Because when those four
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hydrogen nuclei merge, the brand new helium nucleus
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that is created actually weighs very slightly
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less than the four hydrogen parts that went in
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wait really yeah there is a tiny sliver of missing
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mass okay i need some clarification on this missing
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mass concept because in my head it's like i'm
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trying to bake a four pound cake and i put five
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pounds of ingredients into the mixing bowl right
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Where does that extra pound physically go? I
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mean, you can't just lose matter. It has to go
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somewhere, right? That is the perfect way to
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look at it. And you're right. The matter hasn't
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vanished into nothingness. It has been transformed.
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Transformed. That tiny sliver of missing mass
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has been converted directly into pure energy.
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This is the exact mechanism described by Albert
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Einstein's famous equation, E equals mc squared.
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Ah, energy equals mass times the speed of light
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squared. Exactly. Most people know the equation,
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but the math behind why it produces so much power
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is totally mind -bending. Let's look at the c
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-squared part. The c stands for the speed of
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light, which is roughly 300 million meters per
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second. Okay, which is already a huge number.
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Right, and when you square that number, so you
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multiply 300 million by 300 million, you get
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90 quadrillion. Oh, wow. 90 quadrillion. Yes.
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So you take that tiny microscopic sliver of missing
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physical mass and you multiply it by 90 quadrillion.
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That is just wild. The equation tells us that
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multiplying even a speck of physical matter by
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a number that large yields an absolutely apocalyptic
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amount of energy. So when the sun fuses hydrogen
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into helium, that lost sliver of mass becomes
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the brilliant sunlight and the intense warmth
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that eventually crosses space to keep us alive.
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Precisely. And the scale at which this is happening
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is terrifying. I mean, the sun is fusing around
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600 million tons of hydrogen every single second.
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Every single second. That's 100 million tons
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every time you blink. And yet. The sun is so
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unimaginably vast that it still has enough hydrogen
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fuel left in its core to keep doing this for
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another five billion years. OK, but wait, if
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you have 600 million tons of material essentially
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detonating with nuclear energy every single second,
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pushing outwards. Right. And immense gravity
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pulling everything inward. How does that not
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result in the star just ripping itself apart
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or like collapsing entirely? That balance can't
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just be a coincidence. No, it isn't a coincidence
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at all. It is a permanent, beautiful balancing
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act called hydrostatic equilibrium. Hydrostatic
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equilibrium. Yes. The sun's stability is basically
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the ultimate cosmic tug of war. Gravity is forever
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trying to crush the star inward, pulling everything
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down to the center. And outward pressure from
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the nuclear fusion in the core is pushing back
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out against that gravity. And they are perfectly
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matched. Almost perfectly. And the brilliant
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part is the mechanism that keeps them matched.
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It is totally self -correcting. How does it correct
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itself? Well, let's say the core started to diffuse
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hydrogen just a little bit faster than normal.
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The core creates extra energy, which creates
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more outward pressure, which puffs the sun up
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slightly. So it physically expands. It expands.
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But think about what happens when gas expands,
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it cools down. Oh, like an aerosol can getting
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cold when you spray it. Perfect example. So the
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pressure inside the core drops, the temperature
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drops just a fraction, and that cooler environment
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naturally slows the nuclear fusion process back
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down. Oh, wow. And it works in reverse, too,
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I bet. Like, if the fusion slows down, the outward
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pressure drops, gravity wins for a second and
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compresses the star. Exactly. And that compression
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heats the core back up and the fusion speeds
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up again. It functions exactly like a thermostat
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in your house. It is a self -regulating engine.
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It is not a bomb exploding in space. You know,
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it is a contained, continuous, perfectly balanced
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machine. That's incredible. And that equilibrium
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is the only reason the sun has shown steadily
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enough for long enough for life to evolve on
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Earth. Here's where it gets really interesting,
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though, because that elegance makes sense on
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a macro scale. But thinking about the light itself
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radiating out from that core. Getting out of
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the sun is actually incredibly difficult for
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that energy. Oh, it is a profound struggle. You
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intuitively think the light is created in the
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core and just shoots out into space at the speed
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of light. Yeah, like turning on a flashlight.
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Right. But the interior of the sun is unimaginably
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dense. It is a thick, crowded soup of atomic
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nuclei and electrons. So a packet of energy of
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photon created in the core can't just fly straight
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out. Not even close. It travels a fraction of
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a millimeter before it slams into another particle,
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gets absorbed, and is then re -emitted in a completely
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random direction. Just pinging around. Physicists
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call this the random walk. It's like the world's
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most frustrating and possibly dense pinball machine.
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just packed with billions and billions of bumpers,
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and the pinball is just bouncing off every single
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one, staggering around like someone lost in a
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massive crowd. That's exactly what it's like.
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So how long does it take for one single ball
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to finally reach the surface? Because of that
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random walk, you know, taking microscopic steps
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back and forth, up and down, it takes tens of
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thousands of years. No way. Possibly even over
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100 ,000 years for that energy to zigzag its
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way from the core where it was made up to the
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surface of the star. That is wild. So the sunlight
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warming your face right now, like the light itself
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left the sun's surface just eight minutes ago.
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Right. But the actual energy inside that light,
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that was generated in the core of the sun back
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when human beings were living in the last ice
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age. Ice age energy. Slowly fighting its way
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out for over a hundred millennia just to hit
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your face on a Tuesday afternoon. But once that
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ancient energy finally does break free from the
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dense interior, things get really chaotic. Yes,
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they do. Because it reaches the surface, which
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is called the photosphere. And this is where
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I need to challenge the physics again, because
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the temperature gradient here makes absolutely
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no sense to me. It is very counterintuitive.
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Yeah, because the photosphere, the part we actually
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see, sits at around 500 and 500 degrees Celsius.
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Which is relatively cool compared to the 15 million
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degree core, but still fierce enough to glow
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brilliant white. Right. But above that surface,
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you have the sun's outer atmosphere called the
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corona. And the corona is far hotter than the
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surface below it. It is millions. of degrees.
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Hold on, that's like standing right next to a
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roaring campfire and feeling a little warm, but
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then stepping 20 feet away from the campfire
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and suddenly getting incinerated. How does that
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make any physical sense? It's crazy, right? It
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is one of the great open questions in solar physics.
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It's known as the coronal heating problem. So
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we don't even know for sure. Not entirely. You
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naturally expect things to cool down as you move
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away from the heat source. Why the corona spikes
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to millions of degrees is a massive mystery.
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In fact, humanity is currently flying space missions,
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like the Parker Solar Probe, closer to the sun
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than ever before, specifically to figure out
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this exact puzzle. Wow. One of the leading theories
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involves the magnetic fields, right? Yes, exactly.
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Because the sun doesn't just sit there glowing.
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It is a highly active, violent environment. It
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blows off this constant stream of charged particles
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called the solar wind, which flows out past all
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the planets. And it has extremely violent space
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weather. Yeah, the sun is essentially a giant
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ball of electrically charged plasma. And as it
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rotates, it generates colossal magnetic fields.
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But because the equator of the sun rotates faster
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than its poles, those magnetic fields get incredibly
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tangled and knotted up. How does a tangled magnetic
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field create weather, though? Like, what does
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that actually look like? Well, think of the magnetic
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field lines like incredibly thick, powerful rubber
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bands being twisted tighter and tighter. Okay,
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building up tension. Exactly. Eventually, the
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tension becomes too much. The magnetic bands
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snap and realign. And when they snap, they release
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a staggering amount of stored energy. Oh, and
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that snapping is what causes solar flares. Exactly.
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And the larger snaps result in something called
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coronal mass ejections, or CMEs. A coronal mass
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ejection? It sounds like something out of a sci
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-fi disaster movie. Yeah, it really does. A CME
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is a massive eruption that literally flings billions
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of tons of physical matter, electrically charged
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plasma, out into deep space at millions of miles
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per hour. And sometimes the Earth happens to
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be right in the firing line of that blast. Unfortunately,
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yes. And when those charged particles hit us,
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some beautiful things happen, but also some incredibly
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dangerous things. The beautiful consequence is
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the auroras. Right. The northern and southern
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lights. Right. The Earth has its own magnetic
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field. So when the blast of solar particles hits
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us, our magnetic field largely deflects it, funneling
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those charged particles down toward the north
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and south poles. Oh, so that's why you see them
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at the poles. Yes. When they hit our upper atmosphere,
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they excite the gases, creating those glowing,
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dancing lights. And we should be very clear here.
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The Earth's magnetic field and our physical atmosphere
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provide an incredible shield. So they're safe.
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These solar storms are absolutely no direct physical
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danger to your biological body. You are safe
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on the ground. OK, so our biology is perfectly
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shielded. But the technological nervous system
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we've built around the globe, that is entirely
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exposed. Completely exposed. So essentially,
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humanity has built an incredibly fragile, high
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-tech glass house right next door to a totally
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unpredictable neighbor who occasionally throws
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rocks. That's the perfect analogy. And if we
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connect this to the bigger picture, this is where
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the sun goes from being a benevolent provider
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to a very real hazard. Because while biology
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is shielded, electricity is not. Right. A powerful
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solar storm can induce massive electrical surges
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in our power grids. We're talking about geomagnetically
16:08
induced currents. These invisible waves of magnetic
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energy sweep over the Earth and literally push
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electricity through any long metal wires they
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find on the ground. Yes. And they overload high
16:20
voltage transformers, potentially melting them
16:23
from the inside out and causing widespread, long
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lasting blackouts. Which is terrifying. It is.
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Furthermore, they can completely disrupt the
16:31
satellites we rely on for global communication,
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for navigation, and for predicting our own earthly
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weather. They can knock out radio transmissions
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and take down GPS systems globally. And we know
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this can happen because it already has. It has,
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yeah. In 1859, there was a huge solar storm known
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as the Carrington event, named after Richard
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Carrington, the astronomer who actually saw the
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massive flare erupt on the sun through his telescope.
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The 1859 storm was so immense that auroras were
16:57
seen as far south as the Caribbean and Hawaii.
16:59
That's crazy. The sky was glowing so brightly
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at midnight that people woke up and started making
17:04
breakfast thinking the sun was rising. But the
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real impact was on the technology of the time,
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right? The most advanced infrastructure in 1859
17:12
was the telegraph system. And this solar storm
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was so intense that it set telegraph systems
17:17
literally sparking. Like physically shooting
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sparks. Yes. Operators were getting physically
17:21
shocked by their equipment. In some offices,
17:24
the telegraph peeper caught fire. Operators even
17:27
found they could unplug their batteries and still
17:30
transmit messages from city to city, powered
17:33
entirely by the electrical current the solar
17:35
storm was inducing in the wires. That is just
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wow. Now, apply that to today. Our world is infinitely
17:40
more electrified than it was in 1859. We are
17:43
completely dependent on delicate orbital electronics,
17:46
global supply chains managed by GPS, and an aging
17:49
electrical grid. It's a huge vulnerability. If
17:52
a Carrington -level event hit us now, the disruption
17:54
could be catastrophically expensive and devastating
17:57
to modern life. Which is exactly why we now have
18:00
space weather forecasters. Oh, really? Yeah.
18:02
There are agencies constantly watching the sun
18:05
with dedicated satellites exactly the same way
18:08
meteorites... watch the oceans for hurricanes
18:10
forming. That makes total sense. Because the
18:12
more wired we become, the more orbital our civilization
18:15
gets, the more it matters when our benign, life
18:19
-giving star loses its temper. We have to keep
18:22
a very close eye on it. So what does this all
18:24
mean? We started out by saying we treat the sun
18:26
like a mundane appliance, a porch light we take
18:29
for granted. But after looking at its true mechanics,
18:32
that is impossible to do. It really is. When
18:35
you hold the full reality of the sun in your
18:37
mind, It's profoundly awe -inspiring. Yeah. It's
18:40
an entirely ordinary star, just one of hundreds
18:43
of billions. But every single second, it crushes
18:46
600 million tons of hydrogen into helium. It
18:49
turns a tiny whisper of missing mass into pure
18:52
energy, multiplied by the speed of light squared.
18:54
Energy that staggers through an impossibly dense
18:57
core in a random walk for a hundred millennia
19:00
finally breaks out of the surface, crosses the
19:02
absolute emptiness of space in just eight minutes,
19:05
and arrives here. Arrives here to do literally
19:09
everything. Arrives to grow the food you eat,
19:11
to drive the ocean currents, to create the wind,
19:14
to warm the air you breathe. And it maintains
19:17
this blistering output in perfect stability because
19:20
the incredible crushing force of gravity and
19:24
the explosive outward pressure of nuclear fusion
19:26
have fought each other to a flawless self -correcting
19:30
draw. A perfect draw that will hold for billions
19:33
of years more until eventually, in the distant
19:35
future, that fuel will run low, the balance will
19:39
fail, the star will swell into a red giant, and
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it will end the story of our solar system. This
19:44
raises an important question, I think. Something
19:46
for you to ponder long after we sign off today.
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I love a good takeaway. We established earlier
19:50
that every gust of wind, every single bite of
19:52
food you take, every piece of coal or drop of
19:55
petrol we burn is literally just stored solar
19:58
energy. Right. It's all tracing back to that.
20:00
So if our entire physical existence is fueled...
20:04
by this process. If the energy currently moving
20:07
your muscles to breathe or powering the neurons
20:09
in your brain to comprehend these words is just
20:12
transformed sunlight, aren't we just the sun's
20:14
energy experiencing itself? Oh, man. We always
20:17
look up and think of the sun as this separate
20:18
object way up there in the sky. But physically,
20:21
down to the atomic level, its ancient energy
20:24
is what is animating our very bodies down here.
20:27
We are walking, talking, stored starlight. I
20:30
absolutely love that. And on that note, we want
20:32
to warmly... Thank you for joining us on this
20:34
deep dive today. We hope you never step outside,
20:37
feel that warmth on your face, and look that
20:38
ordinary, extraordinary star the exact same way
20:41
again.