Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:00,600 --> 00:00:01,800
(dramatic music)
2
00:00:01,800 --> 00:00:03,433
- [Narrator] The world's
greatest structures
3
00:00:03,433 --> 00:00:06,200
push the boundaries
of engineering.
4
00:00:06,200 --> 00:00:09,967
All fueled by a constant
desire to innovate.
5
00:00:09,967 --> 00:00:13,333
- Without engineering, there
would be no modern world.
6
00:00:13,333 --> 00:00:15,833
- [Narrator] Gigantic buildings,
7
00:00:15,833 --> 00:00:20,800
complex infrastructure
and ingenious inventions.
8
00:00:20,800 --> 00:00:24,500
- Engineering is the key that
turns dreams into reality.
9
00:00:24,500 --> 00:00:27,100
- [Narrator] Many of today's
incredible achievements
10
00:00:27,100 --> 00:00:29,300
rely on breakthrough
technologies
11
00:00:29,300 --> 00:00:32,133
first devised by
ancient engineers.
12
00:00:32,133 --> 00:00:34,867
- It's astounding how
they achieve this.
13
00:00:34,867 --> 00:00:36,233
- [Narrator] Early civilizations
14
00:00:36,233 --> 00:00:38,667
built on an unimaginable scale
15
00:00:38,667 --> 00:00:40,500
and with incredible precision.
16
00:00:40,500 --> 00:00:41,867
- They raised a
bar for engineering
17
00:00:41,867 --> 00:00:44,733
in a way that no one
thought possible.
18
00:00:44,733 --> 00:00:48,300
- These are some of the
finest engineers in history.
19
00:00:48,300 --> 00:00:51,333
- [Narrator] Redefining
the known laws of physics
20
00:00:51,333 --> 00:00:53,400
and dreaming up the impossible.
21
00:00:54,567 --> 00:00:57,767
They constructed
engineering wonders,
22
00:00:57,767 --> 00:01:01,667
from colossal stadiums
to mighty waterways
23
00:01:02,567 --> 00:01:05,033
and complex machines.
24
00:01:05,033 --> 00:01:07,633
All with the simplest of tools.
25
00:01:07,633 --> 00:01:09,333
- You cannot imagine the skills
26
00:01:09,333 --> 00:01:12,367
people would've needed
to build like this.
27
00:01:12,367 --> 00:01:13,867
- [Narrator] By
unearthing the mysteries
28
00:01:13,867 --> 00:01:16,667
left by these ancient engineers,
29
00:01:16,667 --> 00:01:19,900
we can now decode their secrets.
30
00:01:19,900 --> 00:01:22,133
- That so many of their
creations still survive
31
00:01:22,133 --> 00:01:25,133
is testament to their
engineering prowess.
32
00:01:25,133 --> 00:01:27,767
- [Narrator] And ultimately
reveal how their genius
33
00:01:27,767 --> 00:01:31,033
laid the foundations for
everything we build today.
34
00:01:42,167 --> 00:01:44,733
(gentle music)
35
00:01:44,733 --> 00:01:47,533
It's the most luxurious
element on the planet.
36
00:01:49,500 --> 00:01:51,733
A metal like no other.
37
00:01:52,933 --> 00:01:54,933
The ultimate symbol of wealth
38
00:01:56,533 --> 00:01:57,467
and success.
39
00:01:57,467 --> 00:02:00,167
(crowd cheering)
40
00:02:01,933 --> 00:02:02,767
Gold.
41
00:02:04,900 --> 00:02:08,467
It obsesses us and has
captivated cultures
42
00:02:08,467 --> 00:02:10,567
around the world
throughout history,
43
00:02:12,400 --> 00:02:15,400
inspiring legends of lost cities
44
00:02:15,400 --> 00:02:18,467
and kings with the Midas touch.
45
00:02:20,833 --> 00:02:21,767
- It's beautiful.
46
00:02:21,767 --> 00:02:22,800
It's burnished.
47
00:02:22,800 --> 00:02:24,467
There's a warmth to gold.
48
00:02:25,600 --> 00:02:28,167
Something that draws
human beings towards it.
49
00:02:28,167 --> 00:02:30,733
Almost like it sort
of warms human nature.
50
00:02:32,167 --> 00:02:33,867
- Gold's the most
wonderful material.
51
00:02:33,867 --> 00:02:36,167
It's malleable,
it doesn't decay.
52
00:02:36,167 --> 00:02:39,367
So it's very useful, as
well as very attractive.
53
00:02:39,367 --> 00:02:40,567
- [Narrator] And what makes gold
54
00:02:40,567 --> 00:02:43,300
especially valuable
is it's rarity.
55
00:02:43,300 --> 00:02:44,733
- It's that sort
of Goldilocks thing
56
00:02:44,733 --> 00:02:47,633
of being rare enough to
tempt people to want it,
57
00:02:47,633 --> 00:02:50,133
but not so rare that
nobody can have it.
58
00:02:50,133 --> 00:02:52,000
- [Narrator] In fact,
it's estimated that
59
00:02:52,000 --> 00:02:54,700
all the gold extracted
from the earth so far
60
00:02:54,700 --> 00:02:57,467
would fit into a 65 foot cube.
61
00:02:57,467 --> 00:03:00,433
Only a few times bigger
than a semi-detached house.
62
00:03:04,000 --> 00:03:06,600
Since ancient times,
the pursuit of gold
63
00:03:06,600 --> 00:03:09,433
has driven engineers to
devise new techniques
64
00:03:09,433 --> 00:03:11,133
to mine,
65
00:03:11,133 --> 00:03:12,667
process
66
00:03:12,667 --> 00:03:13,500
and refine it.
67
00:03:14,667 --> 00:03:16,600
- The desire for gold
actually led to huge
68
00:03:16,600 --> 00:03:18,733
technological and
engineering advancements.
69
00:03:21,900 --> 00:03:25,233
- [Narrator] Their inventions
have shaped modern society.
70
00:03:25,233 --> 00:03:27,733
- They've established the
global markets we have today.
71
00:03:27,733 --> 00:03:29,333
It changed the world forever.
72
00:03:30,600 --> 00:03:32,033
- [Narrator] And these
ancient breakthroughs
73
00:03:32,033 --> 00:03:34,733
are still prompting
us to cross frontiers,
74
00:03:36,367 --> 00:03:38,200
building the deepest mines,
75
00:03:39,667 --> 00:03:42,400
creating the latest
technology...
76
00:03:42,400 --> 00:03:43,967
- [Announcer] Three, two...
77
00:03:43,967 --> 00:03:45,600
- [Narrator] Even venturing-
78
00:03:45,600 --> 00:03:46,967
- [Announcer] Zero.
79
00:03:46,967 --> 00:03:48,767
- [Narrator] Into space.
80
00:03:51,667 --> 00:03:53,767
But how did these
ancient engineers
81
00:03:53,767 --> 00:03:56,600
first discover gold's
unique properties?
82
00:04:09,233 --> 00:04:10,600
There's no clear evidence
83
00:04:10,600 --> 00:04:13,133
for when gold was
first discovered.
84
00:04:13,133 --> 00:04:15,367
The earliest surviving
objects in the world
85
00:04:15,367 --> 00:04:17,767
date from over 6,000 years ago
86
00:04:17,767 --> 00:04:20,767
from sites in the Black
Sea and the near east.
87
00:04:22,933 --> 00:04:27,533
But earlier humans may have
found gold long before this.
88
00:04:27,533 --> 00:04:29,433
It simply washed
up at their feet.
89
00:04:30,800 --> 00:04:33,167
- If it's in a riverbed,
you'll see the gold glinting.
90
00:04:33,167 --> 00:04:34,433
It doesn't rust,
91
00:04:34,433 --> 00:04:35,700
it doesn't dissolve in
water or do anything.
92
00:04:35,700 --> 00:04:36,900
So it's there and
it's lying there.
93
00:04:36,900 --> 00:04:38,600
It's getting rounded
and bumped around a bit,
94
00:04:38,600 --> 00:04:40,733
but it's in the river bed.
95
00:04:40,733 --> 00:04:43,667
- [Narrator] It's likely that
this river, or alluvial, gold
96
00:04:43,667 --> 00:04:45,667
would've caught the
eye of ancient peoples,
97
00:04:45,667 --> 00:04:47,500
who began to experiment with it.
98
00:04:47,500 --> 00:04:50,300
- One could imagine that
the very first discovery,
99
00:04:50,300 --> 00:04:52,533
when someone picked
it up and said,
100
00:04:52,533 --> 00:04:55,600
"Hey, look, I can hammer
this into a nice object."
101
00:04:55,600 --> 00:04:58,100
Would have been an alluvial
nugget, it's obvious.
102
00:04:59,267 --> 00:05:00,767
- [Narrator] But how
did it get there?
103
00:05:00,767 --> 00:05:03,467
Gold can only be created
by extreme energy
104
00:05:03,467 --> 00:05:05,700
produced inside rare supernova
105
00:05:06,967 --> 00:05:09,267
or the collision
of neutron stars.
106
00:05:10,733 --> 00:05:12,667
All of the gold on
Earth, therefore,
107
00:05:12,667 --> 00:05:15,400
likely comes from outer space.
108
00:05:15,400 --> 00:05:18,067
Much of it from
meteorites and boulders,
109
00:05:18,067 --> 00:05:21,233
which slammed into its
surface billions of years ago.
110
00:05:22,400 --> 00:05:24,567
Most of this gold
is buried deep,
111
00:05:24,567 --> 00:05:27,400
but some has been brought
closer to the Earth's surface
112
00:05:27,400 --> 00:05:31,400
around tectonic plates
through volcanic activity.
113
00:05:35,367 --> 00:05:38,533
Super heated water transports
dissolved elements,
114
00:05:38,533 --> 00:05:40,800
including gold, up
through the crust
115
00:05:40,800 --> 00:05:42,867
where they solidify
into hard veins.
116
00:05:44,067 --> 00:05:46,733
Over time, as water
erodes these veins,
117
00:05:46,733 --> 00:05:49,167
tiny pieces wash into rivers.
118
00:05:49,167 --> 00:05:52,167
And as gold is one of the
least reactive metals,
119
00:05:52,167 --> 00:05:55,433
it will not corrode and
can stay here indefinitely.
120
00:05:57,200 --> 00:05:58,833
- When it comes out the ground
121
00:05:58,833 --> 00:06:01,233
it's as shiny as the day
it went in, you know,
122
00:06:01,233 --> 00:06:03,433
and I think there is
an element of that
123
00:06:03,433 --> 00:06:05,067
that's captured the imagination
124
00:06:05,067 --> 00:06:08,467
of past societies
going way back.
125
00:06:08,467 --> 00:06:09,700
- [Narrator] Early
gold gathering
126
00:06:09,700 --> 00:06:11,533
may simply have
been done by hand.
127
00:06:12,900 --> 00:06:15,500
But to find gold hidden deeper
among the river deposits
128
00:06:15,500 --> 00:06:18,233
required a more
specialized solution.
129
00:06:18,233 --> 00:06:20,667
- And the natural progression
is to try a basin,
130
00:06:20,667 --> 00:06:23,900
whether it was of wood, pottery,
early bronze or whatever.
131
00:06:23,900 --> 00:06:26,167
You swirl it round
and, if you're lucky,
132
00:06:26,167 --> 00:06:27,567
there'll be few little
bits of gold glinting
133
00:06:27,567 --> 00:06:28,967
in the bottom of the
bowl at the end of it.
134
00:06:28,967 --> 00:06:30,800
And that's gold panning.
135
00:06:30,800 --> 00:06:32,067
- [Narrator] Gold
panning was likely
136
00:06:32,067 --> 00:06:34,333
ancient man's main
extraction method.
137
00:06:35,900 --> 00:06:38,600
And alluvial gold is
estimated to have provided
138
00:06:38,600 --> 00:06:41,100
two thirds of what
was ever produced.
139
00:06:42,400 --> 00:06:45,100
Because the panning
process is so simple,
140
00:06:45,100 --> 00:06:48,367
it has remained a widely
used method to this day.
141
00:06:48,367 --> 00:06:50,067
(gentle music)
142
00:06:50,067 --> 00:06:53,467
Facilitating some
of the greatest gold
rushes of all time.
143
00:06:57,200 --> 00:06:59,300
- [Male] There was gold for all.
144
00:06:59,300 --> 00:07:01,200
Gold seekers were
stirred to a frenzy
145
00:07:01,200 --> 00:07:05,200
by tales of glory holes
and rich diggings.
146
00:07:05,200 --> 00:07:09,233
- [Narrator] In 1848, gold
was found in California,
147
00:07:09,233 --> 00:07:12,200
sparking the famous
American Gold Rush.
148
00:07:13,967 --> 00:07:16,900
In just over a year,
California's population
149
00:07:16,900 --> 00:07:19,367
increased from 14,000
150
00:07:19,367 --> 00:07:20,633
(upbeat music)
151
00:07:20,633 --> 00:07:23,400
to almost 100,000.
152
00:07:23,400 --> 00:07:26,467
- Once the news gets out,
all hell breaks loose
153
00:07:26,467 --> 00:07:27,733
'cause people want to
get it and go for it.
154
00:07:27,733 --> 00:07:30,500
It's this optimism and
greed going for it.
155
00:07:31,667 --> 00:07:33,033
- [Narrator] In their
haste to find gold,
156
00:07:33,033 --> 00:07:35,367
these prospectors even
abandon their ships
157
00:07:35,367 --> 00:07:37,633
in the Bay of San Francisco.
158
00:07:37,633 --> 00:07:41,100
The remnants still lie buried
under the financial district.
159
00:07:43,000 --> 00:07:45,833
To look for gold, they
headed to the mountains and,
160
00:07:45,833 --> 00:07:47,600
initially at least, just use
161
00:07:47,600 --> 00:07:49,400
simple panning
methods to find it.
162
00:07:49,400 --> 00:07:52,100
- Panning for gold is an
incredibly democratic method.
163
00:07:52,100 --> 00:07:53,733
You don't need many resources,
164
00:07:53,733 --> 00:07:55,667
you don't need much
training or skill.
165
00:07:57,000 --> 00:07:59,300
- [Narrator] But this
technique is labor intensive,
166
00:07:59,300 --> 00:08:02,467
time consuming, and it
doesn't get you much gold.
167
00:08:15,000 --> 00:08:17,200
To find more, the
ancients needed
168
00:08:17,200 --> 00:08:19,167
to follow the trail underground.
169
00:08:19,167 --> 00:08:20,000
(dramatic music)
170
00:08:20,000 --> 00:08:21,567
To reach the motherload.
171
00:08:26,000 --> 00:08:29,300
Few ancient cultures are
more associated with gold
172
00:08:29,300 --> 00:08:30,567
than the Egyptians.
173
00:08:32,833 --> 00:08:35,633
Famed for their elaborate
engineering projects,
174
00:08:37,433 --> 00:08:39,967
gold was central to
Egyptian culture.
175
00:08:39,967 --> 00:08:44,300
Used for opulent decoration,
jewelry and statues.
176
00:08:45,600 --> 00:08:47,767
In fact, the hieroglyph for gold
177
00:08:47,767 --> 00:08:50,333
first appeared with the
beginning of Egyptian writing
178
00:08:50,333 --> 00:08:52,133
in the very first dynasty.
179
00:08:53,067 --> 00:08:54,667
The Egyptians believed that gold
180
00:08:54,667 --> 00:08:57,167
was the flesh of the sun god Ra.
181
00:08:57,167 --> 00:08:59,733
So were not far off about
its stellar origins.
182
00:09:01,133 --> 00:09:03,433
- For the Egyptians, gold
was associated with divinity.
183
00:09:03,433 --> 00:09:05,233
It was associated with creation.
184
00:09:05,233 --> 00:09:08,800
It was literally the most
significant, powerful object
185
00:09:08,800 --> 00:09:09,700
you could imagine.
186
00:09:11,000 --> 00:09:13,133
- [Narrator] The
ultimate luxury material,
187
00:09:13,133 --> 00:09:14,933
gold was coveted in life.
188
00:09:16,967 --> 00:09:20,767
But it was just as
important in death.
189
00:09:22,467 --> 00:09:24,967
- Whether you're a pharaoh
or quite an average person,
190
00:09:24,967 --> 00:09:27,467
you wanted to have goods to
take into the afterworld.
191
00:09:27,467 --> 00:09:28,567
You'd need things.
192
00:09:28,567 --> 00:09:30,700
Because gold doesn't decay,
193
00:09:30,700 --> 00:09:32,967
it was the perfect material
to cover a body with
194
00:09:32,967 --> 00:09:34,967
'cause it would
last for maternity,
195
00:09:34,967 --> 00:09:36,933
which is what they
hoped the body would.
196
00:09:38,100 --> 00:09:39,367
- [Narrator] Egypt's
geology meant that
197
00:09:39,367 --> 00:09:41,900
it naturally had large
quantities of gold.
198
00:09:43,167 --> 00:09:45,000
But the amounts the
Egyptians desired
199
00:09:45,000 --> 00:09:47,067
couldn't be found
in a river alone.
200
00:09:48,267 --> 00:09:50,300
So they opted for a
different solution,
201
00:09:51,867 --> 00:09:52,700
(dramatic music)
202
00:09:52,700 --> 00:09:53,533
mining.
203
00:09:55,200 --> 00:09:56,800
While they weren't the
first to mine gold,
204
00:09:56,800 --> 00:09:59,800
the Egyptians certainly took
it to a new industrial level.
205
00:10:01,267 --> 00:10:04,567
And without modern prospecting
methods, like remote sensing,
206
00:10:04,567 --> 00:10:07,533
locating this so-called
gold of the mountain
207
00:10:07,533 --> 00:10:09,800
was all down to a
simple realization.
208
00:10:10,667 --> 00:10:12,200
- Finding gold for the Egyptians
209
00:10:12,200 --> 00:10:13,833
rested on the
observation that gold
210
00:10:13,833 --> 00:10:16,300
was often associated
with quartz.
211
00:10:16,300 --> 00:10:17,867
So if you followed the quartz,
212
00:10:17,867 --> 00:10:20,033
you were more than
likely to find the gold.
213
00:10:21,467 --> 00:10:23,767
- [Narrator] To access it,
these ancient engineers
214
00:10:23,767 --> 00:10:26,433
developed tools to help
them smash open the rock.
215
00:10:27,633 --> 00:10:30,000
If a vein went deeper,
they would follow it,
216
00:10:30,000 --> 00:10:32,833
digging tunnels and shafts.
217
00:10:32,833 --> 00:10:34,667
- This would've been laborious,
218
00:10:34,667 --> 00:10:37,167
backbreaking and
terrifying work.
219
00:10:38,533 --> 00:10:39,833
- [Narrator] And the
scale of Egyptian
220
00:10:39,833 --> 00:10:42,867
gold production
was unprecedented.
221
00:10:42,867 --> 00:10:44,800
- One of the most
remarkable survivals
222
00:10:44,800 --> 00:10:46,633
connected with gold
from the ancient world
223
00:10:46,633 --> 00:10:49,300
is not a gold object,
but it's a map
224
00:10:49,300 --> 00:10:51,767
that actually shows
the gold mines.
225
00:10:51,767 --> 00:10:55,467
- [Narrator] One of the oldest
surviving maps in the world,
226
00:10:55,467 --> 00:10:56,933
the Turin Papyrus.
227
00:10:57,967 --> 00:10:59,267
(gentle music)
228
00:10:59,267 --> 00:11:01,467
It predates equivalent
modern geological maps
229
00:11:01,467 --> 00:11:05,000
by almost 3000 years and
is one of the first maps
230
00:11:05,000 --> 00:11:08,167
to represent real
geographical content.
231
00:11:08,167 --> 00:11:09,500
But it's what it reveals about
232
00:11:09,500 --> 00:11:11,633
the organization of
Egyptian gold mining
233
00:11:11,633 --> 00:11:14,600
which makes it
particularly incredible.
234
00:11:14,600 --> 00:11:19,133
Created during the reign of
Rameses IV in around 1150 BC,
235
00:11:19,133 --> 00:11:21,633
it records many places
in the Eastern Desert
236
00:11:21,633 --> 00:11:25,433
where the Egyptian state was
mining and processing gold.
237
00:11:25,433 --> 00:11:26,700
- Rather than it was
a case of sort of,
238
00:11:26,700 --> 00:11:28,233
this is how you
get to the mines,
239
00:11:28,233 --> 00:11:30,533
I think it was some sort of
bureaucratic use for the map
240
00:11:30,533 --> 00:11:33,500
to keep a record of the
mines and maybe their output
241
00:11:33,500 --> 00:11:35,833
or how many slaves
you had working.
242
00:11:35,833 --> 00:11:38,300
- [Narrator] And when
archeologists in the 1980s
243
00:11:38,300 --> 00:11:41,333
started to map ancient
Egypt's gold mines,
244
00:11:41,333 --> 00:11:43,267
what they found was staggering.
245
00:11:45,333 --> 00:11:49,367
Up to 250 of them scattered
across the Eastern Desert.
246
00:11:55,033 --> 00:11:57,767
(dramatic music)
247
00:11:57,767 --> 00:11:59,533
While today mechanical diggers
248
00:11:59,533 --> 00:12:01,500
bear the brunt of mining work,
249
00:12:01,500 --> 00:12:05,667
in ancient times, this
process was labor intensive,
250
00:12:05,667 --> 00:12:08,300
requiring thousands
of paid workers,
251
00:12:08,300 --> 00:12:12,600
or sometimes slaves to mine and
process the gold laden rock.
252
00:12:13,733 --> 00:12:15,800
Over time, they
developed millstones
253
00:12:15,800 --> 00:12:19,100
to crush small pieces of
quartz ore to a fine powder.
254
00:12:20,433 --> 00:12:23,267
And, once ground, the
Egyptians devised various ways
255
00:12:23,267 --> 00:12:25,367
to separate the
gold from the rock.
256
00:12:26,800 --> 00:12:29,833
One of these was a technique
known as winnowing.
257
00:12:31,267 --> 00:12:34,667
The finely ground gold ore was
shaken inside a dry blanket
258
00:12:34,667 --> 00:12:36,167
to create pulses of air,
259
00:12:36,167 --> 00:12:38,933
which separated the
rock from the gold.
260
00:12:38,933 --> 00:12:41,833
This movement also
created a static charge,
261
00:12:41,833 --> 00:12:44,333
which stuck the
gold to the fabric.
262
00:12:44,333 --> 00:12:46,200
So when the blanket was opened,
263
00:12:46,200 --> 00:12:49,833
the rock dust would blow
away, leaving just the gold.
264
00:12:51,300 --> 00:12:53,033
- This is something they'd
used anyway with crops.
265
00:12:53,033 --> 00:12:55,700
What you would use is
either a blanket or a basket
266
00:12:55,700 --> 00:12:58,300
and you'd throw them up
and you'd just throw it up.
267
00:12:58,300 --> 00:13:01,133
And the wind would
carry away the chaff
268
00:13:01,133 --> 00:13:02,567
and you'd be left
with the wheat.
269
00:13:02,567 --> 00:13:04,800
And it's the same principle
that they're using
270
00:13:04,800 --> 00:13:08,400
to separate out really,
really small particles of gold
271
00:13:08,400 --> 00:13:11,400
from small particles of dust.
272
00:13:11,400 --> 00:13:13,733
- [Narrator] But winnowing
wasn't the only way.
273
00:13:15,133 --> 00:13:18,000
Where water was accessible,
the Egyptians engineered
274
00:13:18,000 --> 00:13:22,600
another even more effective
method, washing tables.
275
00:13:26,233 --> 00:13:28,167
The ground powder
and water would be
276
00:13:28,167 --> 00:13:30,333
poured down a slanting table.
277
00:13:30,333 --> 00:13:33,067
Materials like sheep's
wool spread over it
278
00:13:33,067 --> 00:13:35,067
would catch the
heavier gold particles,
279
00:13:36,200 --> 00:13:38,133
while lighter rock
would be washed away.
280
00:13:39,900 --> 00:13:42,467
And, to ensure no
gold was missed,
281
00:13:42,467 --> 00:13:45,767
over time, sophisticated
circulation systems
were developed
282
00:13:45,767 --> 00:13:47,933
to feed the runoff
back to the start.
283
00:13:50,567 --> 00:13:54,167
- Wool has sort of residual
oils and lanolin in it.
284
00:13:54,167 --> 00:13:56,067
So, as you are
washing in the wool,
285
00:13:56,067 --> 00:13:58,933
what's happening in that
process is that the heavier gold
286
00:13:58,933 --> 00:14:00,533
is being trapped
within the wool.
287
00:14:00,533 --> 00:14:01,867
Now, once you've achieved that,
288
00:14:01,867 --> 00:14:03,867
it's a very simple
step to drying it out
289
00:14:03,867 --> 00:14:07,433
and then burning off the wool
to leave the gold residues.
290
00:14:08,933 --> 00:14:11,400
- [Narrator] Also used
to catch gold in streams,
291
00:14:11,400 --> 00:14:13,600
it's possible that the
use of sheep's wool
292
00:14:13,600 --> 00:14:16,267
may even have inspired
the famous Greek myth
293
00:14:16,267 --> 00:14:18,333
of Jason and the Golden Fleece.
294
00:14:20,400 --> 00:14:22,233
(dramatic music)
295
00:14:22,233 --> 00:14:24,867
Today, electric
powered machines now do
296
00:14:24,867 --> 00:14:27,867
what thousands of
Egyptian workers once did,
297
00:14:27,867 --> 00:14:30,767
crushing the rock and
washing it on shaker tables
298
00:14:32,200 --> 00:14:34,600
capable of processing
up to two tons
299
00:14:34,600 --> 00:14:36,567
of gold laden rock per hour.
300
00:14:48,033 --> 00:14:51,233
The Egyptians' thirst
for gold was so great,
301
00:14:51,233 --> 00:14:54,933
from as early as 2000 BC,
they even sought to control
302
00:14:54,933 --> 00:14:57,967
their neighbors to the
south, in modern day Sudan.
303
00:15:00,700 --> 00:15:03,233
Known in ancient times as Nubia,
304
00:15:03,233 --> 00:15:06,133
it was the gold center
of the ancient world.
305
00:15:06,133 --> 00:15:10,033
It's opulent objects reflecting
its wealth of natural gold.
306
00:15:11,200 --> 00:15:13,533
Wall paintings record
how wars were fought
307
00:15:13,533 --> 00:15:16,433
to control these
gold rich territories
308
00:15:16,433 --> 00:15:18,267
and how Nubians
were made to bring
309
00:15:18,267 --> 00:15:20,833
tributes of gold to the pharaoh.
310
00:15:20,833 --> 00:15:23,167
- And we have one vulnerable
thing with the pharaoh saying
311
00:15:23,167 --> 00:15:26,667
basically, he commanded the
chiefs of Nubia to mine gold.
312
00:15:26,667 --> 00:15:28,867
I think he just couldn't
get enough of it.
313
00:15:28,867 --> 00:15:32,733
- [Narrator] Almost 3000 years
ago, during the 12th dynasty,
314
00:15:32,733 --> 00:15:34,500
the Egyptians even
built a system
315
00:15:34,500 --> 00:15:37,933
of highly fortified mud
brick strongholds on the Nile
316
00:15:37,933 --> 00:15:41,767
to police this trade and
ensure a constant supply.
317
00:15:41,767 --> 00:15:43,267
- It was a huge enterprise,
318
00:15:43,267 --> 00:15:47,033
from both ensuring you had
the access to the mines,
319
00:15:47,033 --> 00:15:49,500
ensuring that the locals
were playing ball with it
320
00:15:49,500 --> 00:15:52,300
and then the bureaucracy to
cope with it and deal with it.
321
00:15:58,067 --> 00:16:00,500
- [Narrator] But to turn
raw gold into objects,
322
00:16:00,500 --> 00:16:02,300
ancient engineers
needed to melt it
323
00:16:02,300 --> 00:16:04,400
into more workable forms.
324
00:16:04,400 --> 00:16:06,200
And there was a problem.
325
00:16:06,200 --> 00:16:08,700
- So, to melt gold, you
need to be able to create
326
00:16:08,700 --> 00:16:10,267
these really high
temperatures, right?
327
00:16:10,267 --> 00:16:12,500
Now, if you're burning with
just a standard wood fire,
328
00:16:12,500 --> 00:16:14,900
you wouldn't get
that temperature.
329
00:16:14,900 --> 00:16:16,633
- [Narrator] An
ordinary wood fire burns
330
00:16:16,633 --> 00:16:19,167
at only around 1100
degrees Fahrenheit.
331
00:16:20,300 --> 00:16:21,833
Whereas gold's melting point
332
00:16:21,833 --> 00:16:23,700
is several hundred
degrees higher.
333
00:16:25,600 --> 00:16:27,133
So, to increase the heat,
334
00:16:27,133 --> 00:16:30,100
the ancient engineers
turn to even older methods
335
00:16:31,400 --> 00:16:34,333
devised for producing
another metal entirely.
336
00:16:45,967 --> 00:16:47,467
(dramatic music)
337
00:16:47,467 --> 00:16:49,700
From at least as early as
the sixth millennium BC,
338
00:16:49,700 --> 00:16:54,067
in societies across the eastern
Mediterranean and near east,
339
00:16:54,067 --> 00:16:56,700
techniques had been developed
for pottery production
340
00:16:56,700 --> 00:16:59,033
and to melt other
metals, such as copper.
341
00:17:00,767 --> 00:17:04,633
For these purposes, ancient
smith's created furnaces and,
342
00:17:04,633 --> 00:17:08,533
instead of wood, they
powered them using charcoal.
343
00:17:09,633 --> 00:17:12,000
- Charcoal is a
very, very good fuel.
344
00:17:12,000 --> 00:17:13,500
Awful lot of heat in it
345
00:17:13,500 --> 00:17:15,933
and it's very pure too so
it doesn't contaminate.
346
00:17:17,233 --> 00:17:18,833
- [Narrator] As this
technology spread,
347
00:17:18,833 --> 00:17:21,900
soon charcoal was
used to melt gold too.
348
00:17:21,900 --> 00:17:25,367
Egyptian reliefs reveal
how the process was refined
349
00:17:25,367 --> 00:17:28,267
using blowpipes to increase
the heat even further.
350
00:17:29,633 --> 00:17:32,033
The first pipes were
likely just hollow reeds,
351
00:17:32,033 --> 00:17:33,567
but, as these burned easily,
352
00:17:33,567 --> 00:17:37,333
fire resistant clay tubes
began to be used instead.
353
00:17:37,333 --> 00:17:40,367
However, they were still
not particularly efficient
354
00:17:40,367 --> 00:17:44,267
and often required several
people all blowing at once.
355
00:17:44,267 --> 00:17:47,067
- The problem with
using your own lungs
356
00:17:47,067 --> 00:17:49,533
is that actually you
are already extracting
357
00:17:49,533 --> 00:17:51,467
some of the oxygen from the
air that you're blowing out
358
00:17:51,467 --> 00:17:54,067
and what the fire
needs is oxygen.
359
00:17:54,067 --> 00:17:56,167
So just sitting
there with blowpipes
360
00:17:57,300 --> 00:17:59,033
trying to get the heat up,
361
00:17:59,033 --> 00:18:01,067
actually isn't the
most effective way
362
00:18:01,067 --> 00:18:03,967
within which you want to
actually roast down that gold.
363
00:18:03,967 --> 00:18:06,333
- [Narrator] So, for large
scale gold production,
364
00:18:06,333 --> 00:18:10,267
the ancients hit upon a
better idea, the pot bellow.
365
00:18:13,467 --> 00:18:15,867
To make the bellow,
animal hide was stretched
366
00:18:15,867 --> 00:18:17,967
over a wide clay pot.
367
00:18:17,967 --> 00:18:20,433
When the surface of the
hide was pushed down,
368
00:18:20,433 --> 00:18:22,700
it forced air out
into the furnace.
369
00:18:24,667 --> 00:18:27,533
To replenish the supply,
the hide was lifted
370
00:18:27,533 --> 00:18:30,267
and air flowed in
through a valve.
371
00:18:30,267 --> 00:18:33,733
Pot bellows could be
operated by alternate feet,
372
00:18:33,733 --> 00:18:36,000
meaning that only a
single operator was needed
373
00:18:36,000 --> 00:18:38,100
to produce a
continuous air supply.
374
00:18:47,833 --> 00:18:49,533
- It's a very effective
way of doing it.
375
00:18:49,533 --> 00:18:50,700
I mean the later
versions like the bellows
376
00:18:50,700 --> 00:18:52,833
you used to see
beside every fireplace
377
00:18:52,833 --> 00:18:54,667
with the sort of two
bits of wood you pumped,
378
00:18:54,667 --> 00:18:56,167
I mean, that's just a
later version of it.
379
00:18:56,167 --> 00:18:59,700
So it is not complicated,
but it's very effective.
380
00:18:59,700 --> 00:19:02,333
I mean, I feel like
it's engineering
381
00:19:02,333 --> 00:19:04,567
with very simple materials.
382
00:19:04,567 --> 00:19:06,833
- [Narrator] Bellows
were major development.
383
00:19:06,833 --> 00:19:08,733
Whereas blowpipes
could supply around
384
00:19:08,733 --> 00:19:11,100
4.5 gallons of air per minute,
385
00:19:11,100 --> 00:19:14,100
pot bellows could deliver
around 10 times that.
386
00:19:14,100 --> 00:19:16,200
- The more air you
can get into the fire,
387
00:19:16,200 --> 00:19:17,900
the hotter the flame.
388
00:19:17,900 --> 00:19:19,667
- [Narrator] This greater
efficiency meant that
389
00:19:19,667 --> 00:19:22,033
more and more gold
could be extracted
390
00:19:22,033 --> 00:19:24,167
on an industrial scale.
391
00:19:24,167 --> 00:19:27,300
Furnaces and bellows have
evolved through history but,
392
00:19:27,300 --> 00:19:29,033
without these early inventions,
393
00:19:29,033 --> 00:19:31,200
it's fair to say the
developments which shaped
394
00:19:31,200 --> 00:19:34,400
modern industry may
never have happened.
395
00:19:34,400 --> 00:19:36,400
- These early
breakthroughs directly led
396
00:19:36,400 --> 00:19:39,267
to the invention of the
coke-fueled blast furnace,
397
00:19:39,267 --> 00:19:42,800
which allowed you to smelt
iron and turn it into steel,
398
00:19:42,800 --> 00:19:44,600
powering the
industrial revolution.
399
00:19:45,933 --> 00:19:47,133
- In a sense, you could look at
400
00:19:47,133 --> 00:19:49,233
the sort of a modern
motorcar factory
401
00:19:49,233 --> 00:19:50,700
and sort of draw
a line right back
402
00:19:50,700 --> 00:19:52,500
to the first guy with
a furnace for pottery
403
00:19:52,500 --> 00:19:54,200
in wherever it was.
404
00:19:54,200 --> 00:19:57,000
- [Narrator] Now the ancient
engineers could melt gold.
405
00:19:57,000 --> 00:20:00,200
This opened up brand new
design possibilities.
406
00:20:00,200 --> 00:20:01,133
(gentle music)
407
00:20:01,133 --> 00:20:02,633
Melted gold could be made
408
00:20:02,633 --> 00:20:04,467
or cast into
different solid shapes
409
00:20:04,467 --> 00:20:07,633
through a technique known
as the lost wax method.
410
00:20:09,867 --> 00:20:13,367
This involved first
making a model out of wax
411
00:20:13,367 --> 00:20:16,700
and then entirely
covering it in clay,
412
00:20:16,700 --> 00:20:18,500
except for a single hole.
413
00:20:19,700 --> 00:20:22,567
When the object was
baked, the clay hardened
414
00:20:22,567 --> 00:20:24,833
and the wax drained away.
415
00:20:24,833 --> 00:20:27,733
Molten metal could
then be poured into it,
416
00:20:27,733 --> 00:20:30,200
creating an exact
replica of the original.
417
00:20:36,000 --> 00:20:38,733
Once the ancient
engineers could cast gold,
418
00:20:38,733 --> 00:20:40,967
they could let their
imaginations run wild.
419
00:20:42,200 --> 00:20:44,067
Gold could now be
made into jewelry,
420
00:20:45,533 --> 00:20:48,600
created into objects to
adorn palaces and temples,
421
00:20:49,533 --> 00:20:51,700
and even placed in tombs.
422
00:21:06,800 --> 00:21:10,433
But, incredibly, the earliest
known example of cast gold
423
00:21:10,433 --> 00:21:13,233
is from a tomb which
predates even the pharaohs.
424
00:21:14,800 --> 00:21:19,367
Recent analysis of
finds discovered in
Bulgaria in the 1970s
425
00:21:19,367 --> 00:21:21,267
could rewrite the history books.
426
00:21:22,700 --> 00:21:26,367
Varna on the Black Sea is
home to the oldest surviving
427
00:21:26,367 --> 00:21:29,400
funerary hoard of gold
objects on the planet.
428
00:21:30,633 --> 00:21:35,033
Dating to around 4,550
BC, these were created
429
00:21:35,033 --> 00:21:37,833
by a mysterious society
only a few centuries
430
00:21:37,833 --> 00:21:41,067
after the first farmers came
to Europe from the east.
431
00:21:41,067 --> 00:21:43,467
And it's unprecedented in scale,
432
00:21:43,467 --> 00:21:46,900
with over 3000 gold artifacts.
433
00:21:46,900 --> 00:21:49,467
- Little is actually
known about this society,
434
00:21:49,467 --> 00:21:51,667
but the majority of the
objects were discovered
435
00:21:51,667 --> 00:21:54,600
in just five graves
and that suggests
436
00:21:54,600 --> 00:21:56,967
that they had an elaborate
social hierarchy.
437
00:21:58,167 --> 00:21:59,867
- [Narrator] Although
Varna's gold objects
438
00:21:59,867 --> 00:22:01,467
were long thought to
have been hammered
439
00:22:01,467 --> 00:22:05,033
from raw gold nuggets,
recent analysis suggests
440
00:22:05,033 --> 00:22:07,667
that some were in fact
cast from melted gold,
441
00:22:09,067 --> 00:22:11,467
making it potentially the
earliest known example
442
00:22:11,467 --> 00:22:13,933
of this technique
anywhere on the planet.
443
00:22:16,000 --> 00:22:17,467
Many ancient cultures,
444
00:22:17,467 --> 00:22:19,533
particularly in south
and central America,
445
00:22:19,533 --> 00:22:21,133
where gold was abundant,
446
00:22:21,133 --> 00:22:24,000
also produced gold
objects this way,
447
00:22:24,000 --> 00:22:27,467
giving rise to legends
of entire golden cities,
448
00:22:27,467 --> 00:22:29,600
which enticed
European explorers.
449
00:22:31,367 --> 00:22:34,467
It's a method still widely
used in the modern world
450
00:22:34,467 --> 00:22:37,033
with applications
in many industries,
451
00:22:37,033 --> 00:22:39,800
not least gold
crowns in dentistry.
452
00:22:41,033 --> 00:22:42,867
And it's one of the
most common ways
453
00:22:42,867 --> 00:22:44,733
of mass producing jewelry.
454
00:22:45,900 --> 00:22:47,633
Though now there's a twist,
455
00:22:48,867 --> 00:22:51,800
instead of laboriously
carving wax by hand,
456
00:22:51,800 --> 00:22:54,300
3D printers are now
often used to sculpt
457
00:22:54,300 --> 00:22:56,300
the master mold in resin,
458
00:22:56,300 --> 00:22:58,767
a modern update on
an ancient method.
459
00:23:00,100 --> 00:23:02,533
- Today you go down
the high street,
460
00:23:02,533 --> 00:23:05,000
the vast majority of jewelry
is produced by casting
461
00:23:05,000 --> 00:23:07,633
'cause it's quick, it's
easy, it's efficient
462
00:23:07,633 --> 00:23:09,433
and you can do it
on a huge scale.
463
00:23:09,433 --> 00:23:10,733
- [Narrator] But to cast larger
464
00:23:10,733 --> 00:23:13,400
solid objects out of
gold is expensive.
465
00:23:14,767 --> 00:23:17,800
So, to make this precious
material go further,
466
00:23:17,800 --> 00:23:19,733
the ancient engineers
turn to another
467
00:23:19,733 --> 00:23:24,667
of gold's unique properties,
it's malleability.
468
00:23:24,667 --> 00:23:26,300
- Pure gold is
infinitely malleable.
469
00:23:26,300 --> 00:23:27,833
In other words, you
can carry on hammering,
470
00:23:27,833 --> 00:23:29,667
bending, hammering,
and it never breaks.
471
00:23:29,667 --> 00:23:31,933
- You can squash it, you can
take your little ingot of gold,
472
00:23:31,933 --> 00:23:33,400
you can wallop it with a hammer
473
00:23:33,400 --> 00:23:35,667
and it'll spread
out into thin sheet.
474
00:23:35,667 --> 00:23:36,867
(gentle music)
475
00:23:36,867 --> 00:23:38,200
- [Narrator] Ancient
Egyptian wall paintings
476
00:23:38,200 --> 00:23:40,000
illustrate how
workers beat the gold
477
00:23:40,000 --> 00:23:42,200
with a round stone
to make it flat.
478
00:23:43,400 --> 00:23:45,400
And such gold had
a number of uses.
479
00:23:46,667 --> 00:23:48,900
Famously, in one of
the 20th century's
480
00:23:48,900 --> 00:23:51,633
most incredible
archeological discoveries.
481
00:23:52,833 --> 00:23:56,467
Uncovered in 1922
by Howard Carter,
482
00:23:56,467 --> 00:23:59,100
the tomb of boy
pharaoh Tutankhamun
483
00:23:59,100 --> 00:24:01,933
was one of the most
lavish of all time,
484
00:24:01,933 --> 00:24:06,400
containing over 5,000
objects, many of them gold.
485
00:24:07,833 --> 00:24:11,500
But his funerary mask is
its glorious centerpiece,
486
00:24:11,500 --> 00:24:14,500
only made possible because
of gold's malleability.
487
00:24:15,933 --> 00:24:17,467
- Of course, one of the great
benefits of using sheet gold
488
00:24:17,467 --> 00:24:20,267
to create something is
that it can be hollow.
489
00:24:20,267 --> 00:24:21,533
So when I think of it, I mean,
490
00:24:21,533 --> 00:24:23,667
Tutankhamun's mask is
obviously thin gold.
491
00:24:23,667 --> 00:24:25,233
It's not solid head.
492
00:24:25,233 --> 00:24:27,100
So you've got this
hollow inside.
493
00:24:27,100 --> 00:24:29,133
So it looks more than it is.
494
00:24:30,267 --> 00:24:31,800
- [Narrator] Created
from two sheets
495
00:24:31,800 --> 00:24:35,067
softly hammered into shape,
the mask perfectly enclosed
496
00:24:35,067 --> 00:24:36,967
the pharaoh's head
and shoulders,
497
00:24:36,967 --> 00:24:41,000
giving him the golden skin
of a god for eternity.
498
00:24:41,000 --> 00:24:44,433
- Only with gold could they
create such unparalleled detail.
499
00:24:44,433 --> 00:24:47,367
The finest of facial features.
500
00:24:47,367 --> 00:24:49,467
- [Narrator] But such
extravagant use of gold
501
00:24:49,467 --> 00:24:51,400
was not practical
for anything less
502
00:24:51,400 --> 00:24:53,033
than a pharaoh's funeral.
503
00:24:53,033 --> 00:24:55,167
So, to make it go even further,
504
00:24:55,167 --> 00:24:58,333
the ancient engineers
came up with a plan.
505
00:24:58,333 --> 00:25:00,867
They simply kept hammering it.
506
00:25:00,867 --> 00:25:03,033
- It's a very simple
mathematical progression.
507
00:25:03,033 --> 00:25:04,300
The thinner you hammer the gold,
508
00:25:04,300 --> 00:25:06,300
a bigger area you
can cover with it.
509
00:25:06,300 --> 00:25:07,733
There must have been
a push to get the gold
510
00:25:07,733 --> 00:25:09,867
thinner and thinner and thinner.
511
00:25:09,867 --> 00:25:11,367
- [Narrator] The ancient
engineers discover
512
00:25:11,367 --> 00:25:13,367
that hammering sheet
gold for long enough,
513
00:25:13,367 --> 00:25:17,700
produced a gold foil, roughly
as thin as a newspaper page,
514
00:25:17,700 --> 00:25:18,967
which they could then pin
515
00:25:18,967 --> 00:25:21,833
or stick to an object
using an adhesive.
516
00:25:21,833 --> 00:25:23,767
- You can pick it
up and wrap it round
517
00:25:23,767 --> 00:25:27,633
whatever it is you are
trying to gild, so to speak.
518
00:25:27,633 --> 00:25:29,167
- [Narrator] But
gold's malleability
519
00:25:29,167 --> 00:25:31,167
could take it even further.
520
00:25:31,167 --> 00:25:33,767
If this foil was beaten
between sheets of animal hide,
521
00:25:33,767 --> 00:25:37,367
to stop it cracking, it
could be made so thin
522
00:25:37,367 --> 00:25:39,467
it could create a
brand new material,
523
00:25:41,133 --> 00:25:42,267
gold leaf.
524
00:25:44,067 --> 00:25:46,200
(gentle music)
525
00:25:46,200 --> 00:25:50,767
Gold this thin could be used
to gild much larger surfaces,
526
00:25:50,767 --> 00:25:54,367
making objects appear as
if made of solid gold.
527
00:25:54,367 --> 00:25:58,233
- Because it is so soft,
it is able to go into
528
00:25:58,233 --> 00:26:03,167
every little interstice and
this makes it self adhering.
529
00:26:04,500 --> 00:26:06,100
The two surfaces so
intimately bonded together,
530
00:26:06,100 --> 00:26:07,700
they are becoming cohesive.
531
00:26:10,067 --> 00:26:12,500
- [Narrator] The Roman
author, Pliny the Elder wrote
532
00:26:12,500 --> 00:26:14,267
that a single ounce of pure gold
533
00:26:14,267 --> 00:26:17,700
could be beaten out
into 750 leaves or more.
534
00:26:21,800 --> 00:26:25,200
That's the equivalent of
under one micron in thickness,
535
00:26:25,200 --> 00:26:28,300
over 70 times thinner
than a human hair.
536
00:26:32,967 --> 00:26:37,333
Today, with modern methods,
gold can be made even thinner
537
00:26:37,333 --> 00:26:41,067
for yet more diverse
purposes, such as makeup,
538
00:26:41,067 --> 00:26:43,400
or even to decorate food.
539
00:26:43,400 --> 00:26:45,400
- Goodness knows why
people would eat gold leaf
540
00:26:45,400 --> 00:26:47,533
other than for
issues of prestige,
541
00:26:47,533 --> 00:26:49,133
but it's an inert substance.
542
00:26:49,133 --> 00:26:50,633
It's relatively safe to eat,
543
00:26:50,633 --> 00:26:52,300
provided it's in
small enough particles
544
00:26:52,300 --> 00:26:55,233
and it will pass out
the other end, I guess.
545
00:26:56,400 --> 00:26:58,167
- [Narrator] In several
Eastern religions,
546
00:26:58,167 --> 00:27:00,300
including Buddhism,
gold is believed
547
00:27:00,300 --> 00:27:02,133
to symbolize knowledge or purity
548
00:27:03,500 --> 00:27:07,300
and gold leaf is still
produced the traditional way
549
00:27:07,300 --> 00:27:09,467
to cover many sacred objects,
550
00:27:09,467 --> 00:27:13,000
from statues to
giant holy rocks.
551
00:27:14,200 --> 00:27:16,933
It can even be used to
coat entire buildings
552
00:27:16,933 --> 00:27:19,900
and make them appear as
though made of solid gold.
553
00:27:20,967 --> 00:27:23,800
(dramatic music)
554
00:27:24,767 --> 00:27:26,267
The Shwedagon Pagoda.
555
00:27:28,767 --> 00:27:31,400
This Buddhist stupa,
or sacred ornament,
556
00:27:31,400 --> 00:27:35,033
is believed to contain the
relics of Buddha himself.
557
00:27:35,033 --> 00:27:37,467
And at over 300 feet high,
558
00:27:37,467 --> 00:27:41,233
it towers above the city
of Yangon in Myanmar.
559
00:27:41,233 --> 00:27:43,033
Whereas gold in other
ancient cultures
560
00:27:43,033 --> 00:27:45,567
was often found inside temples,
561
00:27:45,567 --> 00:27:49,633
this building is thought to be
solid and cannot be entered.
562
00:27:49,633 --> 00:27:53,433
It's gold is likely all
displayed on the outside.
563
00:27:53,433 --> 00:27:55,400
- The Shwedagon
Pagoda in Myanmar
564
00:27:55,400 --> 00:27:57,933
is one of the most revered
shrines in Buddhism.
565
00:27:57,933 --> 00:27:59,667
There's a legend
that golden nuggets
566
00:27:59,667 --> 00:28:01,467
rained down from the sky
567
00:28:01,467 --> 00:28:03,467
and they were used
to build the pagoda.
568
00:28:04,900 --> 00:28:08,333
But, in reality, only its
surface is made of gold.
569
00:28:08,333 --> 00:28:10,867
It is almost entirely
covered in gold leaf.
570
00:28:12,333 --> 00:28:15,567
And as this material can't be
produced in very large sheets,
571
00:28:15,567 --> 00:28:17,533
creating this effect
was a challenge.
572
00:28:18,700 --> 00:28:21,300
Small copper tiles,
12 inches squared,
573
00:28:21,300 --> 00:28:23,433
had to be individually covered.
574
00:28:23,433 --> 00:28:26,167
Over 22,000 of
these gilded tiles
575
00:28:26,167 --> 00:28:28,200
were then attached
to the pagoda,
576
00:28:28,200 --> 00:28:31,767
creating the effect of a
single solid gold building.
577
00:28:33,233 --> 00:28:37,333
But this presents a major
conservation issue today.
578
00:28:37,333 --> 00:28:39,833
- The use of gold on
the Shwedagon Pagoda,
579
00:28:39,833 --> 00:28:41,467
it isn't particularly effective.
580
00:28:41,467 --> 00:28:43,833
I mean, it looks
absolutely amazing
581
00:28:43,833 --> 00:28:45,467
and it glistens under the sun,
582
00:28:45,467 --> 00:28:49,567
but it isn't
particularly resistant
to weather and climate.
583
00:28:49,567 --> 00:28:51,667
So it does need replacing
quite regularly.
584
00:28:53,133 --> 00:28:55,867
- [Narrator] The gold leaf
flakes off at such a rate,
585
00:28:55,867 --> 00:28:59,367
it actually needs replacing
every four to five years,
586
00:29:00,600 --> 00:29:02,900
But this is not a
problem at another,
587
00:29:02,900 --> 00:29:04,967
more state of the
art, golden building.
588
00:29:06,433 --> 00:29:11,100
The Metrimandir opened in
2008 in Auroville, India.
589
00:29:11,100 --> 00:29:14,000
It's an edifice dedicated
to yogic philosophy.
590
00:29:15,300 --> 00:29:17,233
Here, the architects
made their tiles
591
00:29:17,233 --> 00:29:20,600
by sandwiching gold leaf
between plates of glass,
592
00:29:22,500 --> 00:29:25,800
thus creating a more
lasting golden structure.
593
00:29:31,367 --> 00:29:34,033
As goldsmithing spread
through the ancient world,
594
00:29:34,033 --> 00:29:36,033
the innovation of
ancient engineers
595
00:29:36,033 --> 00:29:38,033
led to even more breakthroughs.
596
00:29:38,033 --> 00:29:40,667
Some of which are still
impacting us today.
597
00:29:40,667 --> 00:29:42,500
- A lot of the ingenuity
in ancient jewelry
598
00:29:42,500 --> 00:29:44,767
comes in things like how
it was fastened together.
599
00:29:44,767 --> 00:29:48,033
And so you start getting some
quite interesting techniques
600
00:29:48,033 --> 00:29:50,500
that are fundamental in
the history of engineering.
601
00:29:50,500 --> 00:29:52,433
- [Narrator] The chain
602
00:29:52,433 --> 00:29:54,033
and a spring.
603
00:29:54,033 --> 00:29:57,267
Vital in almost every
modern industry.
604
00:29:57,267 --> 00:29:59,600
But there's growing evidence
to suggest that these,
605
00:29:59,600 --> 00:30:02,300
and other inventions,
may owe their origin
606
00:30:02,300 --> 00:30:05,300
to ancient jewelry
manufacturing.
607
00:30:05,300 --> 00:30:08,133
- The earliest examples I know
of the nut and bolt screw.
608
00:30:08,133 --> 00:30:10,300
Which is fundamental if
you want to build a bridge
609
00:30:10,300 --> 00:30:12,867
or a motor car or
anything these days.
610
00:30:12,867 --> 00:30:15,533
That dates back to
probably late Roman times
611
00:30:15,533 --> 00:30:17,433
when they're using
exactly the same principle
612
00:30:17,433 --> 00:30:20,233
as a way to fasten some gold
bracelet, the screw thread.
613
00:30:21,400 --> 00:30:23,433
- All these innovations actually
614
00:30:23,433 --> 00:30:26,733
are so crucial to our world
today, but they only came about
615
00:30:26,733 --> 00:30:29,533
because they wanted to find
new ways of wearing gold.
616
00:30:32,433 --> 00:30:34,533
(dramatic music)
617
00:30:34,533 --> 00:30:35,833
- [Narrator] But
the pursuit of gold
618
00:30:35,833 --> 00:30:38,500
has not only been about
jewelry and decoration.
619
00:30:39,967 --> 00:30:42,700
The real game changer came
with the invention of money.
620
00:30:43,833 --> 00:30:45,333
And it was ancient engineers
621
00:30:45,333 --> 00:30:47,500
who transformed
the element of gold
622
00:30:47,500 --> 00:30:49,767
into the world's first
coinage currency.
623
00:30:52,533 --> 00:30:54,567
- In the earliest days
there wasn't coinage.
624
00:30:54,567 --> 00:30:55,867
I mean, in human history,
625
00:30:55,867 --> 00:30:58,533
it's a relatively late
introduction, coinage.
626
00:30:58,533 --> 00:30:59,933
There was obviously barter.
627
00:30:59,933 --> 00:31:01,933
I make a loaf of
bread and I swap it
628
00:31:01,933 --> 00:31:03,233
for the person next
door's cabbage.
629
00:31:03,233 --> 00:31:04,700
And this sort of thing went on.
630
00:31:04,700 --> 00:31:07,167
- [Narrator] But, as societies
became more sophisticated,
631
00:31:07,167 --> 00:31:09,433
bartering systems
weren't enough.
632
00:31:09,433 --> 00:31:11,767
- Bartering and
exchange is very limited
633
00:31:11,767 --> 00:31:15,633
because it depends on both
sides wanting the same thing,
634
00:31:15,633 --> 00:31:17,533
but money itself
changes everything
635
00:31:17,533 --> 00:31:20,467
because it has its
own intrinsic value.
636
00:31:20,467 --> 00:31:22,767
- [Narrator] Over time,
valuable metals started
637
00:31:22,767 --> 00:31:25,567
to become a means
of basic exchange.
638
00:31:25,567 --> 00:31:29,200
In Egypt, payments were often
made with large gold rings
639
00:31:29,200 --> 00:31:32,467
and some cultures simply used
pieces of broken up metal.
640
00:31:33,933 --> 00:31:36,500
But these early currencies
had their drawbacks.
641
00:31:37,433 --> 00:31:38,667
- The problem with this was
642
00:31:38,667 --> 00:31:40,133
is that the purity
of gold varied,
643
00:31:40,133 --> 00:31:42,300
according to where
it had been mined.
644
00:31:42,300 --> 00:31:43,533
It's important to remember that,
645
00:31:43,533 --> 00:31:45,200
when gold is discovered
in the ground,
646
00:31:45,200 --> 00:31:47,633
it's never pure,
it's always an alloy.
647
00:31:47,633 --> 00:31:50,067
It contains other
metals such as silver.
648
00:31:50,067 --> 00:31:51,767
So there was no standardization.
649
00:31:51,767 --> 00:31:53,567
There was no way of guaranteeing
650
00:31:53,567 --> 00:31:56,267
the content of the gold
that was being exchanged.
651
00:31:57,467 --> 00:31:58,833
- [Narrator] Most
gold in circulation
652
00:31:58,833 --> 00:32:00,767
until the end of the Bronze Age
653
00:32:00,767 --> 00:32:04,400
varied between 70
and 85% purity.
654
00:32:04,400 --> 00:32:06,867
So ancient engineers
began to develop
655
00:32:06,867 --> 00:32:10,167
new ways of refining
gold to make it pure.
656
00:32:10,167 --> 00:32:13,100
- Now we begin to find
references to gold
657
00:32:13,100 --> 00:32:15,933
that's described as gold
of one or two times,
658
00:32:15,933 --> 00:32:17,633
or three times in one case.
659
00:32:17,633 --> 00:32:21,500
Because, if you melt gold, a
little bit of the other metal
660
00:32:21,500 --> 00:32:23,300
will oxidize and go away.
661
00:32:23,300 --> 00:32:26,233
So every time you melt gold,
it gets a little bit purer.
662
00:32:26,233 --> 00:32:28,033
- [Narrator] To confirm
a piece of gold's value
663
00:32:28,033 --> 00:32:30,433
before a transaction,
various methods
664
00:32:30,433 --> 00:32:32,500
were also devised
to check its purity.
665
00:32:33,400 --> 00:32:36,267
One method was a touchstone.
666
00:32:36,267 --> 00:32:38,467
When drawn on with
a sample of gold,
667
00:32:38,467 --> 00:32:40,533
these would show a
clear streak of color,
668
00:32:40,533 --> 00:32:43,933
which could then be compared
to a reliable sample of gold.
669
00:32:43,933 --> 00:32:47,000
Touchstones are quick,
easy, and portable
670
00:32:47,000 --> 00:32:49,400
but, as they only check
the surface of an object,
671
00:32:49,400 --> 00:32:50,500
they're also limited.
672
00:32:52,200 --> 00:32:56,133
- If the surface has
been enhanced, then
you'll not find out
673
00:32:56,133 --> 00:32:59,400
what the true composition
of the interior is.
674
00:32:59,400 --> 00:33:02,400
- [Narrator] Fire assaying
was a more reliable method.
675
00:33:02,400 --> 00:33:04,333
Like refining, it also involved
676
00:33:04,333 --> 00:33:06,767
heating the gold to
draw out impurities,
677
00:33:06,767 --> 00:33:10,067
which could determine
the actual gold content.
678
00:33:10,067 --> 00:33:13,233
But fire assaying
also had drawbacks
679
00:33:13,233 --> 00:33:16,300
as melting it destroyed
the original gold object.
680
00:33:18,900 --> 00:33:20,867
Neither method was perfect.
681
00:33:26,033 --> 00:33:28,900
But in approximately 550 BC,
682
00:33:28,900 --> 00:33:31,533
around the time of
the ancient Greeks,
683
00:33:31,533 --> 00:33:34,433
in a region of modern day
Turkey known as Lydia,
684
00:33:35,833 --> 00:33:39,367
a local ruler in its capital,
Sardis, found a solution.
685
00:33:39,367 --> 00:33:42,233
Creating the world's first
standardized currency.
686
00:33:43,433 --> 00:33:46,267
Earlier Lydian Kings had
created a basic coinage
687
00:33:46,267 --> 00:33:51,200
using electrum, an alloy
containing both gold and silver.
688
00:33:51,200 --> 00:33:53,733
But a king called
Croesus created a new,
689
00:33:53,733 --> 00:33:56,067
more reliable monetary system
690
00:33:56,067 --> 00:33:58,200
consisting of gold
and silver coins
691
00:33:58,200 --> 00:34:00,267
with a standardized purity.
692
00:34:00,267 --> 00:34:03,000
- This was crucial for the
development of gold coinage
693
00:34:03,000 --> 00:34:07,000
because you knew exactly how
much gold each coin contained.
694
00:34:08,167 --> 00:34:10,367
- At first, Croesus
used fairly pure gold
695
00:34:10,367 --> 00:34:12,067
panned in nearby rivers.
696
00:34:12,067 --> 00:34:15,533
But when this ran out, he
started to import less pure gold
697
00:34:15,533 --> 00:34:16,933
and turned to his engineers
698
00:34:16,933 --> 00:34:19,000
to find an effective
way to refine it.
699
00:34:20,300 --> 00:34:22,500
- He hasn't got any
intrinsic, pure gold anymore.
700
00:34:22,500 --> 00:34:24,733
So he has to call in the
lads and sort of say,
701
00:34:24,733 --> 00:34:28,000
we've got a problem, we've
gotta get to a constant purity.
702
00:34:29,200 --> 00:34:30,933
- [Narrator] In order
to remove the silver,
703
00:34:30,933 --> 00:34:33,933
Croesus' engineers developed
a more sophisticated
704
00:34:33,933 --> 00:34:37,500
way of refining,
known as salt parting.
705
00:34:37,500 --> 00:34:39,100
(dramatic music)
706
00:34:39,100 --> 00:34:41,933
A dry cement of brick
dust mixed with salt
707
00:34:41,933 --> 00:34:43,967
was laid inside a
pottery container,
708
00:34:45,367 --> 00:34:48,633
thin sheets of impure
gold were then laid on top
709
00:34:48,633 --> 00:34:51,367
and layered with the cement
until the pot was full.
710
00:34:52,800 --> 00:34:56,033
It was then heated at a low
temperature for several days.
711
00:34:57,633 --> 00:35:01,033
During the heating, salt vapors
would attack the impure gold
712
00:35:01,033 --> 00:35:02,733
and remove the silver content.
713
00:35:03,967 --> 00:35:08,433
The result, almost
99% pure gold.
714
00:35:12,667 --> 00:35:14,700
Coins were then
produced at a set weight
715
00:35:14,700 --> 00:35:17,933
of just under 0.3 ounces.
716
00:35:17,933 --> 00:35:21,233
And with each coin punched
with a lion, Lydia's emblem,
717
00:35:21,233 --> 00:35:23,667
this currency could be
traded with confidence.
718
00:35:25,033 --> 00:35:26,967
By harnessing money,
Croesus became
719
00:35:26,967 --> 00:35:28,700
one of the richest
men in the world.
720
00:35:28,700 --> 00:35:32,067
Giving rise to the
expression as rich as Croesus
721
00:35:32,067 --> 00:35:36,067
and turning Lydia into the
business capital of the world.
722
00:35:36,067 --> 00:35:39,267
- I think Croesus' sort
genius, if you like,
723
00:35:39,267 --> 00:35:41,500
was to realize that,
if you refine this gold
724
00:35:41,500 --> 00:35:44,267
before you made the coinage,
you would have a standard
725
00:35:44,267 --> 00:35:46,767
and other countries
would recognize it.
726
00:35:46,767 --> 00:35:48,900
- [Narrator] Over time,
coinage allowed bigger
727
00:35:48,900 --> 00:35:52,467
and more sophisticated
trading markets to develop.
728
00:35:52,467 --> 00:35:55,967
- The invention of money
absolutely transformed society.
729
00:35:55,967 --> 00:35:57,900
It changed the way
we go about business.
730
00:35:57,900 --> 00:36:00,233
It changed the way that
we relate to each other.
731
00:36:05,800 --> 00:36:07,167
(gentle music)
732
00:36:07,167 --> 00:36:08,667
- [Narrator] The
invention of money created
733
00:36:08,667 --> 00:36:11,333
the modern financial
world as we know it.
734
00:36:11,333 --> 00:36:13,633
Gold and silver were
the basis for currencies
735
00:36:13,633 --> 00:36:16,333
around the planet for centuries.
736
00:36:16,333 --> 00:36:19,033
Nowadays, they have largely
been replaced by coins
737
00:36:19,033 --> 00:36:21,000
with lower intrinsic value.
738
00:36:21,000 --> 00:36:23,800
But many countries still
have a gold reserve
739
00:36:23,800 --> 00:36:27,200
kept under lock and
key just in case.
740
00:36:27,200 --> 00:36:29,733
- It's a finite resource
and, in that sense,
741
00:36:29,733 --> 00:36:31,500
it always holds its value.
742
00:36:31,500 --> 00:36:34,400
I mean, in times of political
and financial crisis,
743
00:36:34,400 --> 00:36:36,067
that's what you want
in your reserves.
744
00:36:36,067 --> 00:36:38,533
You don't want pieces of paper
with money stamped on them.
745
00:36:38,533 --> 00:36:39,700
You want bars of gold.
746
00:36:41,167 --> 00:36:43,667
- [Narrator] Today, gold
is often exchanged online
747
00:36:43,667 --> 00:36:45,800
by people who have
never even seen it.
748
00:36:47,367 --> 00:36:50,267
It's closer to cryptocurrency
than real money.
749
00:36:50,267 --> 00:36:52,200
But unlike some crypto coins,
750
00:36:52,200 --> 00:36:54,667
digital gold retains its worth.
751
00:36:54,667 --> 00:36:56,767
While monetary values fluctuate.
752
00:36:58,867 --> 00:37:02,367
But real gold was what
counted most in ancient times.
753
00:37:09,567 --> 00:37:12,400
(dramatic music)
754
00:37:17,867 --> 00:37:21,800
For the ancient Romans,
gold coinage was vital.
755
00:37:23,267 --> 00:37:26,833
As the empire, expanded the
Roman emperors needed money
756
00:37:26,833 --> 00:37:30,533
for a number of reasons,
for paying soldiers
757
00:37:31,500 --> 00:37:33,667
and to create a unified empire
758
00:37:33,667 --> 00:37:35,533
trading under a single currency.
759
00:37:36,700 --> 00:37:39,100
But coinage also had
another function.
760
00:37:39,100 --> 00:37:41,900
- Coinage became really
important as a propaganda tool.
761
00:37:41,900 --> 00:37:44,700
You could actually put
your face on the coinage.
762
00:37:44,700 --> 00:37:47,133
And that was so important
because it reminded everyone
763
00:37:47,133 --> 00:37:49,033
who was in charge.
764
00:37:49,033 --> 00:37:52,167
- [Narrator] And gold coinage
had a very exclusive purpose.
765
00:37:52,167 --> 00:37:54,733
- It's the value of this coin,
766
00:37:54,733 --> 00:37:57,600
which enables the Roman
Republic and later,
767
00:37:57,600 --> 00:38:01,333
the Roman emperors to
bribe, effectively,
768
00:38:01,333 --> 00:38:03,733
anybody they want to
bring within the empire.
769
00:38:04,967 --> 00:38:07,033
- [Narrator] With demand
for gold increasing,
770
00:38:07,033 --> 00:38:09,167
the Romans took
it from anywhere.
771
00:38:09,167 --> 00:38:12,567
Often seizing it from conquered
peoples and melting it down.
772
00:38:14,567 --> 00:38:16,900
But they also came up
with inventive ways
773
00:38:16,900 --> 00:38:19,333
to get their hands on
greater supplies of gold
774
00:38:19,333 --> 00:38:20,200
from the ground.
775
00:38:23,067 --> 00:38:24,667
In the newly conquered territory
776
00:38:24,667 --> 00:38:27,467
of northwest Spain,
at Las Medulas.
777
00:38:28,933 --> 00:38:32,033
Brilliant Roman engineers
supercharged their mining.
778
00:38:32,033 --> 00:38:35,067
Using a technique
called hushing.
779
00:38:35,067 --> 00:38:37,333
Where water power was
used to blast away
780
00:38:37,333 --> 00:38:39,067
vast quantities of earth.
781
00:38:40,533 --> 00:38:42,900
- Water can do a
huge amount of damage
782
00:38:42,900 --> 00:38:44,800
to any hillside, mountainside.
783
00:38:44,800 --> 00:38:48,467
You know, its power of
pressure, its surge power,
784
00:38:48,467 --> 00:38:51,000
it can destroy large
forms of land mass.
785
00:38:51,000 --> 00:38:52,533
Which is, of course,
what miners want.
786
00:38:52,533 --> 00:38:55,400
They want to kind of
remove all of that material
787
00:38:55,400 --> 00:38:57,333
so you can extract
the metal ores.
788
00:38:58,700 --> 00:39:00,800
- [Narrator] To ensure a
large enough supply of water,
789
00:39:00,800 --> 00:39:02,100
the Roman engineers used
790
00:39:02,100 --> 00:39:04,600
one of their most
famous innovations.
791
00:39:04,600 --> 00:39:07,600
- The Romans were
outstanding water engineers,
792
00:39:07,600 --> 00:39:11,000
and one of their
finest inventions of
all was the aqueduct.
793
00:39:12,400 --> 00:39:15,000
- [Narrator] Aqueducts
were vital for Roman cities
794
00:39:15,000 --> 00:39:16,200
transporting fresh water
795
00:39:16,200 --> 00:39:19,233
for drinking, bathing
and sanitation.
796
00:39:21,167 --> 00:39:24,467
To ensure a constant flow
of water at Las Medulas,
797
00:39:24,467 --> 00:39:27,100
the Romans expertly
designed several aqueducts
798
00:39:27,100 --> 00:39:30,567
to transport it from as
far away as 90 miles.
799
00:39:31,900 --> 00:39:34,400
Built to hug the contours
of the mountains,
800
00:39:34,400 --> 00:39:37,433
they maintained a very
gradual downward gradient,
801
00:39:37,433 --> 00:39:39,500
bringing the water
to holding tanks
802
00:39:39,500 --> 00:39:42,333
above areas of
rich gold deposits.
803
00:39:43,833 --> 00:39:46,100
These aqueducts
could deliver between
804
00:39:46,100 --> 00:39:50,333
1.7 and 3.2 billion cubic
feet of water a year,
805
00:39:51,767 --> 00:39:54,967
the volume of over 20,000
Olympic swimming pools.
806
00:39:56,533 --> 00:39:57,767
(gentle music)
807
00:39:57,767 --> 00:39:59,800
To reach gold deep
inside the rock,
808
00:39:59,800 --> 00:40:03,033
a network of shafts and tunnels
would be dug down into it.
809
00:40:04,467 --> 00:40:07,233
And, when all was ready, the
sluice gates were opened,
810
00:40:07,233 --> 00:40:10,067
releasing water into
the shafts and tunnels.
811
00:40:10,067 --> 00:40:14,300
Which blew the rock face
clean off through sheer force.
812
00:40:14,300 --> 00:40:16,800
- The Romans were masters
of controlling water.
813
00:40:16,800 --> 00:40:19,800
They understood the
volume, the velocity.
814
00:40:19,800 --> 00:40:22,867
They knew exactly how to
use it and, in effect,
815
00:40:22,867 --> 00:40:25,833
this is the equivalent of
blasting in a modern quarry.
816
00:40:27,600 --> 00:40:28,633
- [Narrator] But
the Romans didn't
817
00:40:28,633 --> 00:40:30,233
only use water for mining.
818
00:40:31,667 --> 00:40:34,300
They also used it to pioneer
new ways to process gold.
819
00:40:35,500 --> 00:40:37,467
At another ancient
Roman gold mine,
820
00:40:37,467 --> 00:40:39,633
in Dolaucothi, west Wales,
821
00:40:39,633 --> 00:40:42,367
a unique monolith has
long caused a mystery.
822
00:40:44,133 --> 00:40:47,967
- It's called the Pumsaint
Stone, Five Saints Stone,
823
00:40:47,967 --> 00:40:49,533
'cause the story is, you know,
824
00:40:49,533 --> 00:40:52,967
that these five saints,
sort of, feeling tired
825
00:40:52,967 --> 00:40:54,600
went to sleep against this stone
826
00:40:54,600 --> 00:40:57,700
and created these
five depressions.
827
00:40:57,700 --> 00:40:59,733
- [Narrator] But clues in
the surrounding landscape
828
00:40:59,733 --> 00:41:02,067
revealed its possible function.
829
00:41:02,067 --> 00:41:04,733
Telltale water channels
and the remains
830
00:41:04,733 --> 00:41:06,367
of a probable water wheel.
831
00:41:10,133 --> 00:41:13,167
Archeologists realized the
stone had to be the base
832
00:41:13,167 --> 00:41:15,667
of an early type of trip hammer,
833
00:41:15,667 --> 00:41:18,467
a device used to grind
gold bearing rocks.
834
00:41:19,567 --> 00:41:21,567
In order to power a trip hammer,
835
00:41:21,567 --> 00:41:24,400
flowing water would
rotate a water wheel,
836
00:41:24,400 --> 00:41:26,567
which in turn drove a cam shaft.
837
00:41:27,767 --> 00:41:29,833
The cam shaft turned
rotational movement
838
00:41:29,833 --> 00:41:32,933
into vertical power,
driving a series of stamps,
839
00:41:32,933 --> 00:41:35,767
which pounded the
rock into tiny pieces
840
00:41:35,767 --> 00:41:37,367
against a stone anvil.
841
00:41:39,067 --> 00:41:41,433
The basis for the
modern car engine,
842
00:41:41,433 --> 00:41:44,900
cam shafts were always assumed
to be a much later invention.
843
00:41:44,900 --> 00:41:47,200
But the discovery of
the Pumsaint Stone
844
00:41:47,200 --> 00:41:49,133
turns that theory on its head.
845
00:41:50,500 --> 00:41:52,500
- Up until its discovery,
we always thought
846
00:41:52,500 --> 00:41:55,367
that kind of technology
was only around
847
00:41:55,367 --> 00:41:56,700
in the medieval period.
848
00:41:56,700 --> 00:41:58,867
But this stone
serves as an anvil
849
00:41:58,867 --> 00:42:00,800
and it dates firmly
to the Roman period.
850
00:42:00,800 --> 00:42:02,433
I mean they really
were innovators
851
00:42:02,433 --> 00:42:03,767
in the use of water power.
852
00:42:05,067 --> 00:42:07,067
- [Narrator] Such
sophisticated methods led to
853
00:42:07,067 --> 00:42:11,533
a massive expansion of the
gold industry in Roman times.
854
00:42:11,533 --> 00:42:14,667
- Roman gold mining was
of an industrial scale
855
00:42:14,667 --> 00:42:18,100
and you can find it across
the entire Roman empire,
856
00:42:18,100 --> 00:42:21,033
all the way from
Britain through to Syria
857
00:42:21,033 --> 00:42:23,267
and north Africa, in
Greece and Turkey.
858
00:42:26,300 --> 00:42:28,633
- [Narrator] But this
came at a great cost.
859
00:42:29,533 --> 00:42:31,067
(gentle music)
860
00:42:31,067 --> 00:42:33,400
The legacy of these
hydraulic mining methods
861
00:42:33,400 --> 00:42:36,267
is laid bare in the
landscape of Las Medulas.
862
00:42:37,867 --> 00:42:42,067
During its 250 year
operation, to reach gold,
863
00:42:42,067 --> 00:42:45,967
the Romans removed almost 18
billion cubic feet of rock.
864
00:42:47,467 --> 00:42:50,900
- The water had been released
by the Romans is such velocity
865
00:42:50,900 --> 00:42:53,767
and in such volume,
it's carved canyons
866
00:42:53,767 --> 00:42:55,667
through the mountain side.
867
00:42:56,800 --> 00:42:58,833
- [Narrator] This
process made Las Medulas
868
00:42:58,833 --> 00:43:00,700
Rome's principle goldmine.
869
00:43:02,067 --> 00:43:04,133
But it devastated the landscape.
870
00:43:05,833 --> 00:43:09,067
It's easy to see why the
Romans may have named this
871
00:43:09,067 --> 00:43:12,867
ruina montium, or the
wrecking of mountains.
872
00:43:19,667 --> 00:43:21,833
(gentle music)
873
00:43:21,833 --> 00:43:24,867
Today, some modern
mining practices can be
874
00:43:24,867 --> 00:43:28,667
just as catastrophic for the
environment and for mankind.
875
00:43:30,033 --> 00:43:33,700
Heap leaching is a processing
technique using cyanide
876
00:43:33,700 --> 00:43:37,200
to dissolve out particles
of gold from its host rock.
877
00:43:37,200 --> 00:43:38,933
It can process millions of tons
878
00:43:38,933 --> 00:43:41,367
of gold laden rock every year,
879
00:43:41,367 --> 00:43:42,900
but it has the
potential to cause
880
00:43:42,900 --> 00:43:44,933
devastating environmental issues
881
00:43:44,933 --> 00:43:47,033
as the cyanide is
prone to leaking,
882
00:43:47,033 --> 00:43:50,600
polluting rivers and poisoning
human water supplies.
883
00:43:56,100 --> 00:43:58,533
Throughout history,
we've sought to mine gold
884
00:43:58,533 --> 00:44:01,200
from deeper and
deeper underground.
885
00:44:01,200 --> 00:44:04,067
Often at huge human expense.
886
00:44:05,267 --> 00:44:07,533
An ancient technique
called fire setting
887
00:44:07,533 --> 00:44:10,167
was used right up
to the Middle Ages.
888
00:44:10,167 --> 00:44:13,533
It involved a minor having
to light a fire underground,
889
00:44:13,533 --> 00:44:16,500
it's heat would then
weaken and crack the rock.
890
00:44:16,500 --> 00:44:17,733
(dramatic music)
891
00:44:17,733 --> 00:44:19,833
But it was dangerous
and unpredictable,
892
00:44:19,833 --> 00:44:21,833
often leading to
sudden collapse.
893
00:44:23,167 --> 00:44:25,200
An invention of the 19th century
894
00:44:25,200 --> 00:44:28,233
revolutionized mining, dynamite.
895
00:44:37,667 --> 00:44:40,733
The brain child of Swedish
chemist, Alfred Nobel,
896
00:44:40,733 --> 00:44:43,033
dynamite used 19th
century advances
897
00:44:43,033 --> 00:44:45,867
in chemical engineering
to blow apart rock.
898
00:44:45,867 --> 00:44:48,033
It was more controllable
than fire setting,
899
00:44:48,033 --> 00:44:50,300
allowing miners to
lay the explosives
900
00:44:50,300 --> 00:44:52,667
and then detonate them
from a safe distance.
901
00:44:54,100 --> 00:44:57,800
And it allowed them to access
more gold than ever before.
902
00:44:57,800 --> 00:45:01,000
Gold mines could now run so
deep that, in South Africa,
903
00:45:01,000 --> 00:45:03,567
the miners of the 1886 gold rush
904
00:45:03,567 --> 00:45:06,167
could access the
Witwatersrand Basin,
905
00:45:06,167 --> 00:45:08,233
the world's largest
known gold field.
906
00:45:09,300 --> 00:45:10,933
These mines have since become
907
00:45:10,933 --> 00:45:12,967
some of the most
productive on Earth,
908
00:45:12,967 --> 00:45:16,033
turning Johannesburg into the
gold capital of the world,
909
00:45:16,033 --> 00:45:17,967
allowing South Africa to create
910
00:45:17,967 --> 00:45:19,867
the deepest mines on the planet.
911
00:45:19,867 --> 00:45:21,967
- The Mponeng mine
in South Africa
912
00:45:21,967 --> 00:45:24,767
is the deepest gold
mine in the world.
913
00:45:24,767 --> 00:45:26,133
It is ridiculously deep.
914
00:45:26,133 --> 00:45:28,367
It is four and a
half times the height
915
00:45:28,367 --> 00:45:31,267
of the tallest building in
the world, the Burj Khalifa.
916
00:45:33,300 --> 00:45:35,167
(dramatic music)
917
00:45:35,167 --> 00:45:36,400
- [Narrator] But
such a wealth of gold
918
00:45:36,400 --> 00:45:38,400
has not always been
possible to find.
919
00:45:39,500 --> 00:45:41,733
Despite sophisticated
mining methods,
920
00:45:41,733 --> 00:45:45,333
gold was still rare and
valuable in ancient times.
921
00:45:45,333 --> 00:45:47,667
So, to satisfy high demand,
922
00:45:47,667 --> 00:45:52,300
engineers came up with another
solution, gold plating.
923
00:45:52,300 --> 00:45:55,467
To make this, the
ancient engineers
turned to another metal
924
00:45:55,467 --> 00:45:59,100
with a very unique
property, mercury.
925
00:46:00,933 --> 00:46:04,700
Also known as quicksilver,
mercury's speed and fluidity
926
00:46:04,700 --> 00:46:07,433
were why the Romans named it
after their messenger god.
927
00:46:08,533 --> 00:46:10,367
But it was what
happened when it came
928
00:46:10,367 --> 00:46:14,067
into contact with gold
which most intrigued them.
929
00:46:14,067 --> 00:46:16,100
- When liquid
mercury touches gold,
930
00:46:16,100 --> 00:46:19,767
it literally eats the gold and
it binds chemically with it.
931
00:46:20,700 --> 00:46:21,900
- It amalgamates.
932
00:46:21,900 --> 00:46:23,933
So what you wind up
with is what is known as
933
00:46:23,933 --> 00:46:26,267
butter of mercury
or butter of gold.
934
00:46:28,100 --> 00:46:29,667
- [Narrator] Ancient
engineers discovered
935
00:46:29,667 --> 00:46:31,700
that this pliable
butter could be used
936
00:46:31,700 --> 00:46:34,900
to coat other cheaper metals
like silver or copper.
937
00:46:36,067 --> 00:46:38,667
When heated to 650
degrees Fahrenheit,
938
00:46:38,667 --> 00:46:41,933
the mercury burned away,
leaving just the gold,
939
00:46:41,933 --> 00:46:44,700
now bound to the other
metal underneath.
940
00:46:44,700 --> 00:46:46,967
- This was the first
form of gold plating
941
00:46:46,967 --> 00:46:49,633
and it was so effective
that it was widespread
942
00:46:49,633 --> 00:46:51,233
right up until the 19th century.
943
00:46:53,267 --> 00:46:55,533
- [Narrator] But mercury
carries many health risks
944
00:46:55,533 --> 00:46:56,900
for those exposed to it.
945
00:47:01,833 --> 00:47:04,500
Nowadays, new, safer
and more sophisticated
946
00:47:04,500 --> 00:47:07,667
plating techniques have
gradually been introduced.
947
00:47:07,667 --> 00:47:10,200
- Modern gold plating
is extraordinary.
948
00:47:10,200 --> 00:47:12,467
It's high science and
there's even debate
949
00:47:12,467 --> 00:47:14,233
whether you should actually
be able to call it gold plate
950
00:47:14,233 --> 00:47:16,733
'cause there's so little
actual gold there.
951
00:47:16,733 --> 00:47:19,033
- [Narrator] These plating
advancements means that gold
952
00:47:19,033 --> 00:47:21,500
is now finding brand
new applications,
953
00:47:21,500 --> 00:47:23,833
vital ones for our
changing world.
954
00:47:23,833 --> 00:47:27,233
It's flexibility and
high conductivity
955
00:47:27,233 --> 00:47:30,300
make it a useful material for
key electrical components,
956
00:47:30,300 --> 00:47:32,833
like circuit boards
and contacts.
957
00:47:32,833 --> 00:47:35,667
- It can be used on connection
boards, in SIM cards,
958
00:47:35,667 --> 00:47:39,100
in laptops, in so many
devices and gadgets.
959
00:47:39,100 --> 00:47:41,067
- [Narrator] Its ability
to be coated very thin
960
00:47:41,067 --> 00:47:43,067
keeps manufacturing costs low,
961
00:47:43,067 --> 00:47:46,633
while it's non corrosiveness
means our electronic devices
962
00:47:46,633 --> 00:47:48,633
are less likely to let us down.
963
00:47:48,633 --> 00:47:50,567
- What many people don't realize
964
00:47:50,567 --> 00:47:52,900
is that gold is
used in just about
965
00:47:52,900 --> 00:47:55,500
every electronic device
that we use today.
966
00:47:55,500 --> 00:47:57,967
So we need gold to live
the lives that we lead.
967
00:47:59,400 --> 00:48:01,467
- [Narrator] And, as it's
also highly reflective,
968
00:48:01,467 --> 00:48:05,300
such thin gold has become
vital for space exploration.
969
00:48:05,300 --> 00:48:07,900
Used since the first men
stepped foot on the moon,
970
00:48:07,900 --> 00:48:11,067
it protects sensitive equipment
from the sun's radiation.
971
00:48:11,067 --> 00:48:13,633
- It's now possible
to get gold so thin
972
00:48:13,633 --> 00:48:14,833
that you can see through it.
973
00:48:14,833 --> 00:48:17,467
So it's even used to
coat astronauts' visors.
974
00:48:19,533 --> 00:48:21,267
- [Narrator] And
gold's reflectivity
975
00:48:21,267 --> 00:48:23,933
has also made it vital for
a very special mission.
976
00:48:25,433 --> 00:48:27,367
(gentle music)
977
00:48:27,367 --> 00:48:31,167
1.69 ounces of the purest
gold now coats the mirrors
978
00:48:31,167 --> 00:48:32,900
of the James Webb telescope,
979
00:48:32,900 --> 00:48:35,100
which launched in
December, 2021.
980
00:48:37,667 --> 00:48:39,367
- This is not a
normal telescope.
981
00:48:39,367 --> 00:48:42,633
This is the most sophisticated
engineering you can imagine.
982
00:48:42,633 --> 00:48:45,000
They're going to the
very depths of space.
983
00:48:48,800 --> 00:48:51,433
- [Narrator] Gold's
exceptional ability to reflect
984
00:48:51,433 --> 00:48:54,933
should allow this honeycomb of
mirrors to focus enough light
985
00:48:54,933 --> 00:48:58,200
to image some of the
earliest stars ever created.
986
00:49:00,833 --> 00:49:05,733
Perhaps even the very stars
which once formed gold itself.
987
00:49:09,467 --> 00:49:11,767
(dramatic music)
988
00:49:11,767 --> 00:49:14,467
Gold has come a long way
since ancient peoples
989
00:49:14,467 --> 00:49:16,733
first panned for it
in rivers and streams
990
00:49:16,733 --> 00:49:18,033
with their bare hands.
991
00:49:23,700 --> 00:49:27,000
Modern advancements in gold
mining and manufacturing
992
00:49:27,000 --> 00:49:30,833
stand on the shoulders of
these ancient engineers.
993
00:49:30,833 --> 00:49:34,033
Their innovations have
prompted us to dig deeper,
994
00:49:34,033 --> 00:49:35,533
to purify and refine
995
00:49:36,733 --> 00:49:39,833
and to explore gold's
infinite possibilities.
996
00:49:41,000 --> 00:49:43,967
Without them, and this
most mesmerizing metal,
997
00:49:45,333 --> 00:49:50,033
the world economy, our societies
and deep space exploration
998
00:49:52,400 --> 00:49:55,833
may not exist as we know it.
999
00:49:57,400 --> 00:50:00,233
(dramatic music)
81964
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.