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Renewable Energy – Sun, Wind and Water · Talking Science

0:00
So I want you to think about a just a simple
0:02
flip of a light switch. You probably did it this
0:04
morning. Oh, yeah. Or even just a few seconds
0:06
ago. Exactly. Your hand brushes that plastic
0:09
plate on the wall. You hear that little click
0:11
and instantly a dark room is just flooded with
0:15
light. Or, you know, you press a button and your
0:17
coffee maker springs to life. It is it's probably
0:20
the most mundane action in the modern world.
0:23
It really is. Yeah. But for the entirety of the
0:25
industrial age, that tiny little switch was powered
0:29
in fundamentally one way, which is by burning
0:35
things. Right. It's basically this unbroken lineage
0:37
of fire. For generations, the story of our electricity
0:41
has really just been the story of combustion.
0:43
Yeah. We dig up coal. We pump up oil and gas.
0:46
All these ancient fossilized fuels. Buried underground
0:49
for millions of years. We bring them up and we
0:52
set fire to them and we use the immense heat
0:55
from those fires to boil water. Which creates
0:57
steam. Right. Highly pressurized steam. The steam
1:00
is forced through these big turbines to make
1:02
them spin and that spinning motion generates
1:04
the electricity. But of course, in the process
1:07
of setting all those fires, we have loaded the
1:10
atmosphere with carbon dioxide. Yeah, and irreversibly
1:13
altered the climate of the planet. Exactly. So
1:16
today we are going on a deep dive into the alternative.
1:19
We're going to explore how we can power our entire
1:22
modern lives. You know, everything from the smartphone
1:25
in your pocket to the heavy commuter trains running
1:28
through your city, but without the burning. And
1:30
to do that, we're going to unpack the three great
1:32
pillars of renewable energy, the sun, the wind
1:36
and moving water. We really want to look closely
1:39
at how these three pillars actually work on a
1:41
mechanical level, like how they physically convert
1:44
nature into electricity. Because understanding
1:46
the mechanics completely changes how you see
1:48
the world around you. Totally. And don't worry,
1:51
you do not need a science degree for this today.
1:53
We are going to take our time and walk through
1:56
the physical realities of these technologies.
1:58
We also have to talk about the single, massive,
2:01
shared obstacle standing in their way, right?
2:03
The physical reality of pulling this global transition
2:06
off. Yeah, we can't ignore the challenges. But
2:09
to kick things off, let's look at a technology
2:11
that is genuinely alien compared to the spinning
2:14
turbines of the past century. You're talking
2:16
about solar power. I am. Almost all other electricity
2:20
generation, whether it's a coal plant or like
2:23
a nuclear sub, relies on motion. Something has
2:26
to physically spin. Right. But a solar panel
2:30
has zero moving parts. It just sits completely
2:33
still in a field or on a roof, and it generates
2:36
electricity directly from sunlight. Using something
2:39
called the photovoltaic effect. Right, which
2:41
sounds incredibly sci -fi. It does, but if we
2:44
break that technical term down, photo just means
2:46
light, and voltaic means electricity. So it is
2:49
literally a direct conversion of light into electric
2:52
current. And how does a flat, silent panel actually
2:55
pull that off? Well, that direct conversion is
2:57
made possible by the material the panels are
2:59
built from. A solar panel is essentially made
3:01
of specially treated slices of silicon. Silicon?
3:04
Like what's in our laptops? Exactly the same
3:07
stuff. It's a semiconductor, the exact same basic
3:10
material used to make microscopic computer chips
3:12
for your phone. And ultimately, silicon is derived
3:16
from silica, which is the primary component of
3:19
ordinary sand. Okay, so you basically start with
3:21
a sheet of highly refined treated sand. Yeah,
3:24
that's a good way to look at it. So sunlight
3:27
is made up of these tiny packets of energy called
3:29
photons. Right. These photons travel all the
3:32
way across the vacuum of space. They hit our
3:34
atmosphere and they finally strike the silicon
3:37
surface. And when they hit, they have enough
3:39
physical energy to actually knock electrons loose
3:43
from the atoms inside the material. Wow. OK.
3:46
But knocking electrons loose isn't enough on
3:48
its own, right? No, because if they just scatter
3:50
randomly, you don't get power. The engineering
3:53
brilliance is in how the panel is manufactured.
3:55
manufactured and layered, it has a built -in
3:57
electric field. Ah, I see. So once those photons
3:59
knock the electrons loose, the internal structure
4:02
of the panel naturally nudges all those freed
4:05
electrons to flow in one specific direction.
4:07
And a steady directional flow of electrons is
4:10
the very definition of an electrical current.
4:12
Exactly. You know, I always picture this like
4:14
a giant game of pool. Okay, I like that. How
4:17
so? Well, the sunlight coming down from the sky
4:20
is the cue ball, right? And it comes smashing
4:22
into the rack, breaking the arrangement, and
4:25
scattering all the billiard balls across the
4:27
table. And the billiard balls are the electrons
4:30
in this scenario. Exactly. Now, the solar panel
4:33
itself is designed like a slightly tilted pool
4:35
table. So when the sunlight scatters all those
4:37
electrons, the tilt of the table ensures they
4:40
all naturally roll down into one specific pocket.
4:43
Which creates this continuous directed stream.
4:47
Right. That steady stream of balls dropping into
4:50
the pocket is your electrical current ready to
4:53
be wired directly into your house. That is a
4:56
brilliant analogy. And the sheer tranquility
4:58
of that process is what really sets solar apart.
5:00
Because it's completely silent. Yes. Sunlight
5:03
lands on a steel panel, and electric current
5:05
flows straight out the back. There's no fuel
5:08
being burned. There are no heavy steel parts
5:10
grinding against each other or wearing down over
5:13
time. It's sand and sun. It is a silent translation
5:16
of raw solar radiation into usable power. But,
5:19
I mean, solar has an obvious limitation. When
5:22
the Earth rotates and the sun goes down, that
5:25
pool table stops catching photons. It does. It
5:28
goes completely dormant. Which forces us to look
5:31
for... complementary natural forces, right? Things
5:34
that often pick up in the evening or maybe off
5:36
the coast, which brings us from silent stillness.
5:40
Back to motion. Wind power. Right. And modern
5:43
wind turbines, they aren't just big flat sails
5:46
catching a breeze and being pushed backward like
5:48
old school windmills, are they? No, the physics
5:50
are entirely different. A modern wind turbine
5:52
is this absolute marvel of aerodynamics. Oh,
5:55
so? Well, if you stand underneath one and look
5:58
closely at the blades, you'll see they are curved
6:00
and shaped remarkably like the wings of a passenger
6:03
airplane. Really? Like airplane wings. Exactly
6:06
like them. As the moving air flows over the curved
6:09
surface of the blade, the air moving over the
6:11
curved side actually travels faster than the
6:14
air moving across the flatter side. Okay. And
6:16
that speed difference creates a difference in
6:18
air pressure. And that pressure difference creates
6:19
lift. You got it. It's the exact same aerodynamic
6:23
force that allows a heavy commercial jet to take
6:26
off from a runway. That is wild to think about.
6:29
But because the turbine blades are fixed to a
6:31
central hub, they can't fly away. That lift just
6:35
forces the blades to rotate in a circle. Okay,
6:37
so that rotational motion is the first step.
6:39
The spinning blades turn a long central shaft
6:42
inside that housing at the top of the tower,
6:44
right? Right, the nacelle. And that shaft is
6:47
connected to the absolute workhorse of the modern
6:50
industrial world, which is the generator. And
6:53
just so we're clear, how exactly does a generator
6:55
work? A generator makes electricity by spinning
6:58
massive magnets past tightly wound coils of copper
7:01
wire. Wait, wait. So if I'm understanding the
7:04
underlying mechanics here, spinning a magnet
7:06
past a wire is the exact same trick a traditional
7:09
coal plant uses. It is the universal trick of
7:11
electricity generation. Yeah, it's rooted in
7:14
this fundamental law of electromagnetism called
7:16
electromagnetic induction. basically when you
7:19
move a magnetic field near a conductive wire
7:22
the magnetic force literally pulls and pushes
7:25
the electrons within the copper atoms setting
7:28
them flowing through the wire Mind blown. So
7:32
whether you are burning pulverized coal to create
7:34
steam or splitting uranium atoms in a nuclear
7:37
reactor to create steam, the ultimate goal is
7:41
literally just to turn a turbine that spins a
7:44
magnet inside a coil of wire. That is the whole
7:46
point, yes. With wind power, we are simply cutting
7:49
out the middleman. We aren't setting anything
7:51
on fire to boil water. Nope. We are just letting
7:54
the moving atmosphere do the mechanical work
7:55
of spinning the magnet for us. When you put those
7:58
two pieces together, I mean, the aerodynamics...
7:59
and the electromagnetism, you realize that a
8:01
modern wind turbine is essentially an airplane
8:04
wing attached to a giant magnet. Pulling invisible
8:06
energy right out of the sky. That is just incredible.
8:09
And the scale of these things is staggering,
8:11
too. I read that some of the offshore turbines
8:13
being built today are taller than a lot of city
8:16
skyscrapers. They are massive. And the scale
8:18
you're seeing, it's purely a function of efficiency
8:20
and fluid dynamics. Meaning bigger is better.
8:23
Exactly. The bigger the blades, the larger the
8:26
swept area they cover, which allows them to capture
8:29
vastly more wind energy in a single rotation.
8:32
And they have to reach really high up, right?
8:34
Yeah, because down near the surface, wind is
8:36
highly turbulent. It's disrupted by trees, hills,
8:39
buildings. But several hundred feet up in the
8:42
air, the wind is a smooth, powerful, continuous
8:45
physical force. So they reach up to catch that
8:48
steady flow. Right. The turbine's job is to capture
8:51
as much of that kinetic energy as possible. and
8:53
feed it right into the generator. Okay, so if
8:55
the universal trick to generating electricity
8:57
is spinning a magnet inside a coil of wire with
9:00
a natural force, we don't have to limit ourselves
9:03
to the air, do we? Not at all. We can harness
9:05
the Earth's heaviest moving resource, which is
9:08
water. So let's talk about the quiet, heavyweight
9:11
giant of the grid, hydroelectric power. Hydro
9:15
is the oldest large scale renewable energy source
9:18
we have. I mean, we've been using it for well
9:20
over a century, long before solar panels and
9:23
wind turbines were even seriously considered
9:25
for grid scale power. Yeah, it's easy to forget
9:28
that. People do forget that hydro still provides
9:31
more electricity worldwide than solar and wind
9:34
combined. Wow. More than both combined. Yep.
9:36
It is the heavyweight champion. And the mechanics
9:39
of how it pulls off that magnet trick. are remarkably
9:42
straightforward. You find a massive river, typically
9:46
flowing naturally through a valley, and you build
9:48
a giant concrete dam Right across it. Right,
9:51
creating a massive artificial barrier. And that
9:53
barrier holds back a huge reservoir of water
9:56
at a significant height. You are trapping all
9:59
the potential energy of that water high up in
10:01
the valley. Exactly. And then, when you need
10:04
power, you simply open heavily reinforced gates
10:07
at the base of the dam and let that water rush
10:09
down through massive enclosed tunnels. And as
10:12
millions of gallons of water fall through those
10:14
tunnels, the immense weight, pressure, and velocity
10:17
of the fluid just slam into large turbines positioned...
10:19
in the flow. So it's gravity doing the work here.
10:22
Yes. Gravity's downward pull spins the turbines,
10:25
which, just like the wind turbines, spin the
10:27
generators. Magnets rotate past copper wire,
10:30
and electricity flows out. So instead of wind
10:33
creating lift, it is gravity pulling a heavy
10:36
liquid from high to low. That's the mechanism,
10:38
yeah. Now, looking at our sources, it notes that
10:41
hydro has a massive operational advantage over
10:43
the sun and the wind. It is highly reliable,
10:46
and easily controlled. Very easily controlled.
10:50
Grid operators can switch it on and off relatively
10:53
quickly just by opening or closing those intake
10:56
gates so they can adjust the flow of electricity
10:58
to match exactly what the city needs at any given
11:01
moment. And control is the most valuable trait
11:03
you can possibly have on a power grid. But, you
11:06
know, the limits of hydro are incredibly strict.
11:08
Because of the geography, right? Yeah. You can't
11:10
just build a hydro dam anywhere you want power.
11:12
It requires very specific, rare geography. A
11:16
powerful river flowing through a deep valley
11:18
to create that necessary reservoir. I have to
11:21
pause on the whole clean energy label for a second
11:23
here. Because we constantly hear renewables pitched
11:26
as universally green and clean. Right. But reading
11:30
about the sheer physical reality of hydroelectricity.
11:34
I mean, building giant concrete walls across
11:38
major waterways and intentionally flooding massive
11:41
valleys. It's clear that renewable energy can
11:44
severely damage the local environment. Yeah.
11:46
The physical reality is that nothing in energy
11:49
production is free of tradeoffs. Nothing. Hydroelectricity
11:52
is renewable because the water cycle naturally
11:55
replenishes the river and it doesn't pollute
11:57
the atmosphere with greenhouse gases. But the
12:00
environmental footprint is undeniable. It's huge.
12:03
Building a large dam permanently floods vast
12:05
tracts of land, destroying natural forests and
12:08
habitats. It displaces entire human communities
12:11
who lived in those valleys. And it messes with
12:14
the river itself, doesn't it? It completely severs
12:16
river ecosystems in half. It prevents fish from
12:19
migrating, and it traps nutrient -rich sediment
12:21
behind the concrete wall. Oh, which slowly starves
12:24
the downstream wildlife that depends on that
12:26
natural flow. So renewable does not automatically
12:29
mean zero impact. Not at all. It just means...
12:32
the fuel source won't run out and it isn't altering
12:35
the global climate. But it still leaves a very
12:38
real permanent scar on the local physical landscape.
12:42
That is the sober reality of large -scale infrastructure.
12:46
However, hydro's superpower, you know, the fact
12:48
that humans can control it, open a gate, and
12:51
dispatch power exactly when demand spikes, that
12:54
highlights the most difficult obstacle we face
12:56
with solar and wind. Right, which brings us to
12:59
the core technical hurdle of the entire energy
13:02
transition, intermittency. Yes, the big hurdle.
13:05
So for those who don't know, a power source is
13:07
intermittent if it does not produce electricity
13:09
continuously on command. Because the plain unavoidable
13:12
fact is that the sun does not always shine and
13:15
the wind... does not always blow. A solar panel
13:17
produces absolutely nothing in the dead of night.
13:19
And its output drops drastically on a cloudy,
13:22
rainy afternoon. And a wind turbine falls completely
13:25
still when a high pressure weather system brings
13:27
calm air. But the root of the problem is that
13:30
human demand is not intermittent, is it? No,
13:32
our demand for power doesn't politely pause to
13:35
match the local weather patterns. We expect the
13:38
hospitals to keep running their life support
13:40
machines, the server farms to keep the internet
13:43
alive, and our refrigerators to keep our food
13:45
cold at 3 a .m. Right. Just as reliably as we
13:48
do on a bright, breezy Tuesday afternoon. I like
13:51
to think of this like a restaurant. Relying strictly
13:54
on wind and solar is like having a brilliant
13:56
chef who only cooks exactly when they feel inspired
13:59
by the weather. Okay, yeah. But you have a restaurant
14:02
full of hungry customers arriving at exactly
14:04
7 p .m. How do you feed them if the chef isn't
14:07
cooking right then? You can't. And on the electrical
14:09
grid, you have to balance that second by second.
14:12
Historically, if demand spiked at 3 a .m., a
14:14
grid operator could just instruct a natural gas
14:17
plant to open a valve and burn more fuel. They
14:19
could match the supply to the demand on command.
14:22
Exactly. But you cannot command a cloud to move.
14:25
You cannot command the wind to blow harder. So
14:27
the problem isn't that we can't generate enough
14:29
renewable energy. When the conditions are right,
14:32
wind and solar are frequently producing massive
14:35
surpluses of the cheapest electricity available
14:38
on the market. The problem is having the energy
14:43
available when the grid demands it. So if we
14:46
can't command the weather to cook on our schedule,
14:48
we don't need to change the weather. We just
14:50
need a really good refrigerator to store the
14:52
meals. We need grid -scale energy storage. Exactly.
14:55
Storage. So how do we bottle nature up? Storage
14:58
is the linchpin of a renewable future. Now, the
15:01
most familiar solution to this is the lithium
15:03
-ion battery. Like in our phones. Yes. But we
15:06
are talking about vast installations composed
15:09
of thousands of individual battery cells. They
15:12
are deployed at grid scale, like the famous massive
15:14
battery farms built in South Australia or California.
15:18
And how do they operate on the grid? They sit
15:20
there, quietly connected to the system, absorbing
15:22
electricity when there's a huge surplus of midday
15:25
solar, and then they instantly release that stored
15:27
chemical energy back into the system as electrical
15:30
current. The millisecond there is a shortfall.
15:33
That's amazing. And battery technology is advancing
15:35
rapidly, costs are dropping, but lithium -ion
15:38
batteries require intensive mining for materials
15:41
like lithium, cobalt, and nickel. They're a huge
15:44
amount of mining. And they are incredibly complex
15:46
to manufacture at the scale required to back
15:49
up entire continents. Which is why grid operators
15:52
rely heavily on another ingenious, heavily utilized,
15:55
and honestly surprisingly low -tech method of
15:57
storing power. Pumped hydro. Pumped hydro. I
16:00
am fascinated by this concept. It is brilliant.
16:03
Pumped hydro is effectively a colossal geographical
16:05
water battery. It uses the principles of a traditional
16:09
hydroelectric dam, but runs the process in both
16:12
directions. Okay, bring that down for me. So
16:14
you need two massive reservoirs of water, one
16:17
located at the bottom of a steep hill or mountain,
16:19
and one located at the top. On a remarkably sunny
16:23
and windy day, when your solar panels and wind
16:26
turbines are producing way more electricity than
16:28
the city actually needs, you don't just throw
16:30
that extra power away. You use that surplus electricity
16:33
to power massive industrial pumps. So these pumps
16:37
literally suck millions of gallons of water out
16:41
of the bottom reservoir and push it up. through
16:45
enormous pipes fighting gravity all the way until
16:47
it dumps into the top reservoir. You just move
16:50
a lake to the top of a mountain. That is exactly
16:51
what you do. You pump it uphill and you leave
16:53
it there. It just sits in the top reservoir perfectly
16:56
quiet. Okay. Later that night, say it's 3 a .m.,
16:59
the wind has died down, the solar panels are
17:01
completely dark, and the city's power demand
17:04
starts creeping up. You simply open a massive
17:06
valve at the top reservoir. And gravity takes
17:09
over. Gravity takes over. The water rushes back
17:11
down the hill through the pipes, and as it falls,
17:14
it spins a turbine, which spins a generator.
17:16
You get your power back. I mean, it is hilarious
17:19
and brilliant. But break down the physics of
17:22
it for me. How does simply leaving a massive
17:24
pool of water sitting at a higher elevation actually
17:27
translate into saved electricity. It comes down
17:30
to the difference between kinetic energy, which
17:32
is the energy of motion, and potential energy,
17:35
which is stored energy based on position. Potential
17:37
energy, right. When you use surplus electricity
17:40
to pump water uphill, you are doing physical
17:43
work against gravity. The higher you push that
17:46
water, the more gravitational potential energy
17:49
you store in it. Ah, I see. So the water at the
17:51
top of the hill is literally holding on to the
17:53
energy you used to put it there. The physical
17:55
elevation of the water is the battery. Wow. When
17:58
you let it fall back down, that potential energy
18:01
converts back into kinetic energy, spinning the
18:04
turbine and returning the electrical energy to
18:06
the grid. It is beautiful. simple you're storing
18:08
electricity in the form of gravity waiting to
18:10
happen exactly and working out the cheapest biggest
18:14
and most reliable ways to store energy across
18:16
the grid whether it's lithium batteries for short
18:19
fluctuations or pumped hydro for multi -day lulls
18:22
is one of the most critical engineering races
18:25
of our time which leads directly to the physical
18:27
reality of rewiring a global economy yeah scaling
18:31
these generation and storage solutions to run
18:33
modern civilization It isn't a theoretical exercise
18:36
anymore. No, it is happening right now. And it
18:39
requires an unimaginably large physical footprint
18:42
in the real world. We aren't just putting a few
18:45
solar panels on a suburban roof. We are talking
18:48
about thousands of square miles of land. Because
18:51
the windiest places like the Great Plains or
18:53
the middle of the ocean and the sunniest places
18:55
like vast deserts are rarely located right next
18:59
to the dense, power -hungry coastal cities where
19:02
the electricity is actually needed. So that geographic
19:05
mismatch requires completely overhauling the
19:08
electricity grid. We have to construct thousands
19:10
of miles of new, high -voltage transmission lines
19:14
to move the power from where nature produces
19:16
it to where humans actually consume it. Yeah,
19:19
and we also have to implement incredibly complex
19:21
grid management systems. Traditional pole and
19:24
nuclear plants have immense physical inertia.
19:26
What do you mean by inertia in this context?
19:28
They rely on incredibly heavy steel turbines
19:30
spinning at constant speeds. That physical momentum
19:33
naturally resists sudden changes in grid frequency,
19:36
providing a sort of buffer. Ah, right. But solar
19:39
panels have no moving parts. Exactly. They provide
19:41
zero physical inertia to the grid. So grid operators
19:45
have to rely on complex power electronics and
19:47
massive batteries to artificially stabilize the
19:50
system second by second. It is a monumental undertaking
19:53
in engineering. It really is. And this leads
19:56
me to the ultimate skeptical question on behalf
19:58
of everyone listening. If every energy source
20:01
leaves a mark, If solar fields and wind farms
20:04
require immense amounts of land, if giant batteries
20:07
require tearing up the earth for intensive mineral
20:10
mining, and if hydro dams alter rivers and flood
20:13
ecosystems. Aren't we just trading one environmental
20:16
disaster for another? Exactly. Aren't we? It
20:19
is arguably the most important question of the
20:22
transition. And the honest, balanced truth is
20:25
that perfectly clean, zero -impact energy does
20:28
not exist. Energy is never free. It's never free.
20:30
There are always physical tradeoffs. The metals
20:32
must be extracted from the earth. The land must
20:34
be allocated. The infrastructure must be built.
20:36
But the case for renewables rests entirely on
20:39
a strict comparison of scale and consequence.
20:42
The lesser of two evils. Basically. The physical
20:45
footprint of mining for batteries and manufacturing
20:47
turbines is significant. But those tradeoffs
20:50
are localized and far, far gentler than the alternative.
20:53
And the alternative is continuing to load the
20:55
entire global atmosphere with carbon dioxide,
20:58
acidifying the oceans, and permanently, catastrophically
21:03
warming the planet with fossil fuels. Precisely.
21:06
We are in a position where we have to choose
21:09
our heart. Transitioning to a system that doesn't
21:12
fundamentally alter the chemical composition
21:14
of the Earth's atmosphere, even if it requires
21:16
substantial mining and land use, is the lesser
21:19
impact by several orders of magnitude. So how
21:22
do we wrap our heads around this transition we
21:24
are living through right now? Well, the next
21:26
time you are driving down the highway and you
21:28
see a glittering field of solar panels, or you
21:30
look out over a ridge and see a slowly turning
21:32
wind turbine, or you drive over the crest of
21:35
a massive concrete dam, you'll know exactly what
21:38
you're looking at. You are seeing three distinct,
21:41
incredibly clever ways of catching the kinetic
21:43
energy and radiation that nature is already offering
21:45
up freely. You're watching sunlight. Moving air
21:48
and falling water being captured and converted
21:51
into the invisible current that runs the modern
21:54
world entirely without the burning. The engineering
21:57
is far from finished, obviously. The storage
21:59
puzzle and the massive grid upgrades are the
22:01
defining challenges of this generation. But the
22:04
direction of travel is firmly set. The physical
22:07
mechanics are already working all around us,
22:09
proving that a different system is possible.
22:11
Absolutely. It is a remarkable shift in how we
22:14
interact with the planet. And I want to leave
22:16
you with one final, slightly mind -bending thought
22:18
to mull over today. Okay, let's hear it. If almost
22:21
all global electricity, from coal to nuclear
22:24
to hydro to wind, ultimately relies on this one
22:28
simple universal trick of spinning a magnet inside
22:32
a coil of copper wire, what other invisible,
22:35
untapped natural forces are out there? I mean,
22:38
what else is moving on this planet right now,
22:40
deep underground, hidden in the thermal vents,
22:42
or out in the immense churning currents of the
22:44
oceans, just waiting for us to figure out how
22:46
to put a magnet and a wire next to it? The Earth
22:48
is full of relentless motion. Finding new ways
22:51
to tap into it is the next frontier. It sure
22:54
is. Something to think about the next time you
22:57
flip that life switch. Until next time, keep
22:59
digging deeper.