The most colorful gemstones on Earth - Jeff Dekofsky

650,093 views ใƒป 2020-12-03

TED-Ed


ืื ื ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ืœืžื˜ื” ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ.

ืชืจื’ื•ื: Ido Dekkers ืขืจื™ื›ื”: Alsa Saal
00:07
On an auspicious day in November of 1986,
0
7573
3914
ื‘ื™ื•ื ืจื’ื™ืœ ื‘ื ื•ื‘ืžื‘ืจ 1986,
00:11
5 Australian miners climbed Lunatic Hillโ€”
1
11487
3980
5 ื›ื•ืจื™ื ืื•ืกื˜ืจืœื™ื ื˜ื™ืคืกื• ืขืœ ื’ื‘ืขืช ืœื•ื ื˜ื™ืง (ืžื˜ื•ืจืฃ) --
00:15
so named for the mental state anyone would be in to dig there.
2
15467
4580
ืฉื ืงืจืื” ื›ืš ืขืœ ืฉื ื”ืžืฆื‘ ื”ื ืคืฉื™ ืฉืœ ื›ืœ ืžื™ ืฉื‘ื—ืจ ืœื—ืคื•ืจ ืฉื.
00:20
While their competitors searched for opals at a depth of 2 to 5 meters,
3
20047
4948
ื‘ืขื•ื“ ื”ืžืชื—ืจื™ื ืฉืœื”ื ื—ื™ืคืฉื• ืื‘ื ื™ ืื•ืคืœ ื‘ืขื•ืžืง ืฉืœ 2 ืขื“ 5 ืžื˜ืจ,
00:24
the Lunatic Hill Syndicate bored 20 meters into the earth.
4
24995
4958
ืกื™ื ื“ื™ืงื˜ ืœื•ื ื˜ื™ืง ื”ื™ืœ ืงื“ื— ืœืขื•ืžืง ืฉืœ 20 ืžื˜ืจ ื‘ืชื•ืš ื”ืื“ืžื”.
00:29
And for their audacity, the earth rewarded them
5
29953
2788
ื•ืขืœ ื”ืชืขื•ื–ื” ืฉืœื”ื, ื”ืืจืฅ ืชื™ื’ืžืœื” ืื•ืชื
00:32
with a fist-sized, record breaking opal.
6
32741
3630
ืขื ืื•ืคืœ ืฉื•ื‘ืจ ืฉื™ืื™ื ื‘ื’ื•ื“ืœ ืื’ืจื•ืฃ.
00:36
They named it the Halleyโ€™s Comet opal,
7
36371
3215
ื”ื ืงืจืื• ืœื• ืื•ืคืœ ื”ืฉื‘ื™ื˜ ืฉืœ ื”ื™ื™ืœื™,
00:39
after the much larger rocky, icy body flying by the earth at that time.
8
39586
5630
ืขืœ ืฉื ื”ื’ื•ืฃ ื”ืกืœืขื™ ื”ืงืจื—ื•ื ื™ ืฉืขืฃ ืœื™ื“ ื›ื“ื•ืจ ื”ืืจืฅ ื‘ืื•ืชื• ื–ืžืŸ.
00:45
The Halleyโ€™s Comet opal is a marvel, but its uniqueness is, paradoxically,
9
45216
5425
ืื•ืคืœ ื”ืฉื‘ื™ื˜ ืฉืœ ื”ื™ื™ืœื™ ื”ื•ื ืคืœื, ืื‘ืœ ื”ื™ื—ื•ื“ื™ื•ืช ืฉืœื•, ื‘ืื•ืคืŸ ืคืจื“ื•ืงืกืœื™,
00:50
the most usual thing about it.
10
50641
3060
ื”ื™ื ื”ื“ื‘ืจ ื”ื›ื™ ืจื’ื™ืœ ื‘ื•.
00:53
While diamonds, rubies, emeralds, and other precious stones
11
53701
3350
ื‘ืขื•ื“ ื™ื”ืœื•ืžื™ื, ืื‘ื ื™ ืื•ื“ื, ื‘ืจืงืช, ื•ืื‘ื ื™ื ื™ืงืจื•ืช ืื—ืจื•ืช
00:57
are often indistinguishably similar,
12
57051
2870
ืคืขืžื™ื ืจื‘ื•ืช ื“ื•ืžื•ืช ื–ื• ืœื–ื• ื‘ืื•ืคืŸ ืฉืœื ื ื™ืชืŸ ืœื”ื‘ื—ื™ืŸ ื‘ื™ื ื™ื”ืŸ,
00:59
no two opals look the same,
13
59921
2600
ืื™ืŸ ืืฃ ืฉืชื™ ืื‘ื ื™ ืื•ืคืœ ื–ื”ื•ืช,
01:02
thanks to a characteristic called "play of color."
14
62521
4033
ื”ื•ื“ื•ืช ืœืชื›ื•ื ื” ืฉื ืงืจืืช "ืžืฉื—ืง ืฆื‘ืขื™ื."
01:06
This shimmering, dazzling, dancing display of light
15
66554
3540
ืžื•ืคืข ื”ืื•ืจื•ืช ื”ืžื ืฆืฅ, ื”ืžื”ืžื, ื”ืจื•ืงื“
01:10
comes about from a confluence of chemistry, geology, and optics
16
70094
4821
ืžื’ื™ืข ืžืฉื™ืœื•ื‘ ืฉืœ ื›ื™ืžื™ื”, ื’ืื•ืœื•ื’ื™ื” ื•ืื•ืคื˜ื™ืงื”
01:14
that define opals from their earliest moments, deep underground.
17
74915
5138
ืฉืžื‘ื“ื™ืœ ื‘ื™ืŸ ืื‘ื ื™ ื”ืื•ืคืœ ืžื”ืจื’ืข ื”ืžื•ืงื“ื ื‘ื™ื•ืชืจ ืฉืœื”ื, ืขืžื•ืง ื‘ืื“ืžื”.
01:20
Itโ€™s there that an opal begins its life as something surprisingly abundant: water.
18
80053
5936
ืฉื ื”ืื•ืคืœ ืžืชื—ื™ืœ ืืช ื—ื™ื™ื• ื›ืžืฉื”ื• ืžืคืชื™ืข ื‘ืชืคื•ืฆืชื•: ืžื™ื.
01:25
Trickling down through gaps in soil and rock,
19
85989
3350
ื”ื ืžื—ืœื—ืœื™ื ื“ืจืš ืคืขืจื™ื ื‘ืื“ืžื” ื•ื‘ืกืœืขื™ื,
01:29
water flows through sandstone, limestone, and basalt,
20
89339
4000
ื”ืžื™ื ื–ื•ืจืžื™ื ื“ืจืš ืื‘ืŸ ื—ื•ืœ, ื’ื™ืจ, ื•ื‘ื–ืœืช,
01:33
picking up a microscopic compound called silicon dioxide.
21
93339
4724
ืื•ืกืคื™ื ืชืจื›ื•ื‘ืช ืžื™ืงืจื•ืกืงื•ืคื™ืช ืฉื ืงืจืืช ื“ื• ืชื—ืžื•ืฆืช ื”ืฆื•ืจืŸ.
01:38
This silica-enriched water enters the voids inside pieces of volcanic rock,
22
98063
5726
ื”ืžื™ื ืžื•ืขืฉืจื™ ื”ืกื™ืœื™ืงื” ื”ืืœื” ื ื›ื ืกื™ื ืœื—ืœืœื™ื ื‘ืชืš ืคื™ืกื•ืช ืฉืœ ืกืœืข ื•ื•ืœืงื ื™,
01:43
prehistoric river beds, wood and even the bones of ancient creatures.
23
103789
5334
ืขืจื•ืฆื™ ื ื—ืœ ืคืจื”ื™ืกื˜ื•ืจื™ื™ื, ืขืฅ ื•ืืคื™ืœื• ืขืฆืžื•ืช ืฉืœ ื™ืฆื•ืจื™ื ืขืชื™ืงื™ื.
01:49
Gradually, the water starts to evaporate,
24
109123
3170
ื‘ื”ื“ืจื’ื”, ื”ืžื™ื ืžืชื—ื™ืœื™ื ืœื”ืชืื“ื•ืช,
01:52
and the silica-solution begins forming a gel,
25
112293
2960
ื•ืชืžื™ืกืช ื”ืกื™ืœื™ืงื” ืžืชื—ื™ืœื” ืœื™ืฆื•ืจ ื’'ืœ,
01:55
within which millions of silica spheres form layer by layer
26
115253
4530
ื‘ืชื•ื›ื” ืžืœื™ื•ื ื™ ื›ื“ื•ืจื™ื•ืช ืกื™ืœื™ืงื” ื ื•ืฆืจื•ืช ืฉื›ื‘ื” ืื—ืจื™ ืฉื›ื‘ื”
01:59
as a series of concentric shells.
27
119783
2820
ื›ืกื“ืจื” ืฉืœ ืงืœื™ืคื•ืช ืžืžื•ืจื›ื–ื•ืช.
02:02
The gel ultimately hardens into a glass-like material,
28
122603
4134
ื”ื’'ืœ ืœื‘ืกื•ืฃ ืžืชืงืฉื” ืœื—ื•ืžืจ ื“ืžื•ื™ ื–ื›ื•ื›ื™ืช,
02:06
and the spheres settle into a lattice structure.
29
126737
3770
ื•ื”ืกืคื™ืจื•ืช ืžืชืื—ื•ืช ืœืžื‘ื ื” ื“ืžื•ื™ ืกื‘ื›ื”.
02:10
The vast majority of the time, this structure is haphazard,
30
130507
3980
ื‘ืจื•ื‘ ื”ืžื•ื—ืœื˜ ืฉืœ ื”ื–ืžืŸ, ื”ืžื‘ื ื” ื”ื–ื” ืืงืจืื™,
02:14
resulting in common, or potch, opals with unremarkable exteriors.
31
134487
5204
ืฉืชื•ืฆืืชื• ื‘ื“ืจืš ื›ืœืœ ืื•ืคืœื™ื ื ืคื•ืฆื™ื ืขื ืฆื“ ื—ื™ืฆื•ื ื™ ืฉืื™ื ื• ื™ื•ืฆื ื“ื•ืคืŸ.
02:19
The tiny, mesmerizing percentage we call precious opals
32
139691
4754
ืœืื—ื•ื– ื”ื–ืขื™ืจ ื•ืžื”ืžื ืœื”ื ืื ื—ื ื• ืงื•ืจืื™ื ืื•ืคืœื™ื ื™ืงืจื™ ืขืจืš
02:24
have regions where silica beads of uniform size form orderly arrays.
33
144445
6112
ื™ืฉ ืื–ื•ืจื™ื ื‘ื”ื ื›ื“ื•ืจื™ื•ืช ืกื™ืœื™ืงื” ื‘ื’ื•ื“ืœ ืื—ื™ื“ ื ื•ืฆืจื•ืช ื‘ืžืขืจื›ื™ื ืžืกื•ื“ืจื™ื.
02:30
So why do those structures produce such vibrant displays?
34
150557
4870
ืื– ืœืžื” ื”ืžื‘ื ื™ื ื”ืืœื” ืžื™ื™ืฆืจื™ื ื›ืืœื” ืžืฆื’ื™ื ืฆื‘ืขื•ื ื™ื™ื?
02:35
The answer lies in a principle of wave physics called interference.
35
155427
5353
ื”ืชืฉื•ื‘ื” ื ืžืฆืืช ื‘ืขื™ืงืจื•ืŸ ืฉืœ ืคื™ื–ื™ืงืช ื’ืœื™ื ืฉื ืงืจืืช ื”ืชืื‘ื›ื•ืช.
02:40
For the sake of simplicity,
36
160780
1343
ืœืฉื ื”ืคืฉื˜ื•ืช,
02:42
letโ€™s look at what happens when a single color of lightโ€”
37
162123
3010
ื‘ื•ืื• ื ื‘ื™ื˜ ื‘ืžื” ืฉืงื•ืจื” ื›ืฉืฆื‘ืข ื‘ื•ื“ื“ ืฉืœ ืื•ืจ --
02:45
green, with a wavelength of 500 nanometersโ€” hits a precious opal.
38
165133
5383
ื™ืจื•ืง, ืขื ืื•ืจืš ื’ืœ ืฉืœ 500 ื ื ื•ืžื˜ืจ -- ืคื•ื’ืข ื‘ืื•ืคืœ ื™ืงืจ ืขืจืš.
02:50
The green light will scatter throughout the gemstone
39
170516
3310
ื”ืื•ืจ ื”ื™ืจื•ืง ืžืชืคื–ืจ ื‘ืชื•ืš ืื‘ืŸ ื”ื—ืŸ
02:53
and reflect back with varying intensitiesโ€”
40
173826
3310
ื•ืžืฉืชืงืฃ ื—ื–ืจื” ื‘ืขื•ืฆืžื•ืช ืžืฉืชื ื•ืช --
02:57
from most angles suffused, from some entirely dimmed,
41
177136
4175
ืžืจื•ื‘ ื”ื–ื•ื•ื™ื•ืช ื”ื•ื ื ืกืคื’, ืžื›ืžื” ื”ื•ื ืœื’ืžืจื™ ืžืขื•ืžืขื,
03:01
and others dazzlingly bright.
42
181311
2930
ื•ืžืื—ืจื•ืช ืžืฉืชืงืฃ ื‘ืื•ืคืŸ ืžืกื ื•ื•ืจ.
03:04
Whatโ€™s happening is, some of the green light reflects off of the top layer.
43
184241
5351
ืžื” ืฉืงื•ืจื” ื”ื•ื, ืฉื—ืœืง ืžื”ืื•ืจ ื”ื™ืจื•ืง ืžืฉืชืงืฃ ืžื”ืฉื›ื‘ื” ื”ืขืœื™ื•ื ื”.
03:09
Some reflects off of the layer below that.
44
189592
2880
ื—ืœืง ืžืฉืชืงืฃ ืžื”ืฉื›ื‘ื” ืžืชื—ืชื™ื”.
03:12
And so on.
45
192472
1250
ื•ื›ืš ื”ืœืื”.
03:13
When the additional distance it travels from one layer to the next, and back,
46
193722
4891
ื›ืฉื”ืžืจื—ืง ื”ื ื•ืกืฃ ืฉื”ื•ื ืขื•ื‘ืจ ืžืฉื›ื‘ื” ืื—ืช ืœื‘ืื”, ื•ื—ื–ืจื”,
03:18
is a multiple of the wavelengthโ€” such as 500 or 1000 extra nanometersโ€”
47
198613
6942
ื”ื•ื ื›ืคื•ืœื” ืฉืœ ืื•ืจืš ื”ื’ืœ -- ื›ืžื• 500 ืื• 1000 ื ื ื•ืžื˜ืจื™ื ื ื•ืกืคื™ื --
03:25
the crests and valleys of the waves match each other.
48
205555
4339
ื”ืฉื™ืื™ื ื•ื”ืขืžืงื™ื ืฉืœ ื”ื’ืœื™ื ืžืชืื™ืžื™ื ืื—ื“ ืœืฉื ื™.
03:29
This phenomenon is called constructive interference,
49
209894
3544
ื”ืชื•ืคืขื” ื ืงืจืืช ื”ืชืื‘ื›ื•ืช ื‘ื•ื ื”,
03:33
and it amplifies the wave, producing a brighter color.
50
213438
4120
ื•ื”ื™ื ืžื’ื‘ื™ืจื” ืืช ื”ื’ืœื™ื, ื•ืžื™ื™ืฆืจืช ืฆื‘ืข ื—ื–ืง ื™ื•ืชืจ.
03:37
So if you position your eye at the correct angle,
51
217558
3400
ืื– ืื ืืชื ืžืžืงืžื™ื ืืช ื”ืขื™ืŸ ื‘ื–ื•ื™ืช ื”ื ื›ื•ื ื”,
03:40
the green light reflecting from many layers adds together.
52
220958
4872
ื”ืื•ืจ ื”ื™ืจื•ืง ืฉืžืฉืชืงืฃ ืžื”ืจื‘ื” ืฉื›ื‘ื•ืช ืžืชื•ื•ืกืฃ.
03:45
Shift the angle just a bit,
53
225830
2180
ืฉื ื• ืžืขื˜ ืืช ื”ื–ื•ื•ื™ืช,
03:48
and you change the distance the light travels between layers.
54
228010
3720
ื•ืชืฉื ื• ืืช ื”ืžืจื—ืง ืฉื”ืื•ืจ ื ืข ื‘ื™ืŸ ื”ืฉื›ื‘ื•ืช.
03:51
Change it enough, and youโ€™ll reach a point where the crests match the valleys,
55
231730
4628
ืฉื ื• ืื•ืชื• ืžืกืคื™ืง, ื•ืชื’ื™ืขื• ืœื ืงื•ื“ื” ื‘ื” ื”ืฉื™ืื™ื ืžืชืื™ืžื™ื ืœืขืžืงื™ื,
03:56
making the waves cancel each other outโ€” thatโ€™s destructive interference.
56
236358
6371
ืžื” ืฉื’ื•ืจื ืœื’ืœื™ื ืœื‘ื˜ืœ ืื—ื“ ืืช ื”ืฉื ื™ -- ื•ื–ื” ื”ืชืื‘ื›ื•ืช ื”ื•ืจืกืช.
04:02
Different colors have different wavelengths,
57
242729
2980
ืœืฆื‘ืขื™ื ืฉื•ื ื™ื ื™ืฉ ืื•ืจื›ื™ ื’ืœ ืฉื•ื ื™ื,
04:05
which translates to varying distances they have to travel
58
245709
3170
ืžื” ืฉืžืชืจื’ื ืœืžืจื—ืงื™ื ืฉื•ื ื™ื ืฉื”ื ืฆืจื™ื›ื™ื ืœืขื‘ื•ืจ
04:08
to constructively interfere.
59
248879
2350
ื›ื“ื™ ืœื”ืชืื‘ืš ื‘ืื•ืคืŸ ื‘ื•ื ื”.
04:11
Thatโ€™s why colors roughly correspond to silica bead sizes.
60
251229
4841
ืœื›ืŸ ืฆื‘ืขื™ื ื‘ืื•ืคืŸ ื›ืœืœื™ ืžืชืื™ืžื™ื ืœื’ื“ืœื™ ื—ืจื•ื–ื™ ืกื™ืœื™ืงื”.
04:16
The spaces between 210 nanometer beads are just right to amplify blue light.
61
256070
7032
ื”ืžืจื—ืงื™ื ื‘ื™ืŸ ื—ืจื•ื–ื™ื ืฉืœ 210 ื ื ื•ืžื˜ืจ ืžืชืื™ืžื™ื ื‘ื“ื™ื•ืง ืœื”ื’ื‘ื™ืจ ืื•ืจ ื›ื—ื•ืœ.
04:23
For red light, with its long wavelengths,
62
263102
2640
ืœืื•ืจ ืื“ื•ื, ืขื ืื•ืจืš ื”ื’ืœ ื”ืืจื•ืš ืฉืœื•,
04:25
the silica beads must be close to 300 nanometers.
63
265742
3750
ื—ืจื•ื–ื™ ื”ืกื™ืœื™ืงื” ืฆืจื™ื›ื™ื ืœื”ื™ื•ืช ืงืจื•ื‘ื™ื ืœ 300 ื ื ื•ืžื˜ืจ.
04:29
Those take a very long time to form, and because of that,
64
269492
3690
ืœืืœื” ืœื•ืงื— ื”ืจื‘ื” ื–ืžืŸ ืœื”ื•ื•ืฆืจ, ื•ื‘ื’ืœืœ ื–ื”,
04:33
red is the rarest opal color.
65
273182
3160
ืื“ื•ื ื”ื•ื ืฆื‘ืข ื”ืื•ืคืœ ื”ื›ื™ ื ื“ื™ืจ.
04:36
The differences in the arrangements of the gel lattices
66
276342
3018
ื”ื”ื‘ื“ืœ ื‘ืกื™ื“ื•ืจ ืฉืœ ืฉื›ื‘ื•ืช ื”ื’'ืœ
04:39
within a particular stone result in a wide range of color patternsโ€”
67
279360
4870
ื‘ืชื•ืš ืื‘ืŸ ืžืกื•ื™ื™ืžืช ื ื•ืชืŸ ืžื’ื•ื•ืŸ ืจื—ื‘ ืฉืœ ืชื‘ื ื™ื•ืช ืฆื‘ืขื™ื --
04:44
everything from broad flash to pin-fire to the ultra-rare harlequin.
68
284230
6260
ื”ื›ืœ ืžืคืœืืฉ ืจื—ื‘ ื“ืจืš ืืฉ ื ืงื•ื“ืชื™ืช ื•ืขื“ ืœื”ืจืœืงื•ื•ื™ืŸ ื”ืื•ืœื˜ืจื” ื ื“ื™ืจ.
04:50
The circumstances that lead to the formation of precious opal
69
290490
3920
ื”ื ืกื™ื‘ื•ืช ืฉืžื•ื‘ื™ืœื•ืช ืœื™ืฆื™ืจื” ืฉืœ ืื•ืคืœื™ื ื™ืงืจื™ ืขืจืš
04:54
are so uncommon that they only occur in a handful of places.
70
294410
4930
ื›ืœ ื›ืš ืœื ื ืคื•ืฆื•ืช ืฉื”ืŸ ืžืชืจื—ืฉื•ืช ืจืง ื‘ืžืขื˜ ืžืงื•ืžื•ืช.
04:59
About 95% come from Australia,
71
299340
3060
ื‘ืขืจืš 95% ืžื’ื™ืขื•ืช ืžืื•ืกื˜ืจืœื™ื”,
05:02
where an ancient inland sea created the perfect conditions.
72
302400
4647
ืฉื ื™ื ืคื ื™ืžื™ ืขืชื™ืง ื™ืฆืจ ืืช ื”ืชื ืื™ื ื”ืžื•ืฉืœืžื™ื.
05:07
It was there that the Halleyโ€™s Comet opal formed some 100 million years ago.
73
307047
6120
ื–ื” ื”ื™ื” ื”ืžืงื•ื ืฉื‘ื• ืฉืื•ืคืœ ื”ืฉื‘ื™ื˜ ืฉืœ ื”ื™ื™ืœื™ ื ื•ืฆืจ ืœืคื ื™ ื‘ืขืจืš 100 ืžืœื™ื•ืŸ ืฉื ื”.
05:13
Which raises the question: in the next 100 million years,
74
313167
4117
ืžื” ืฉืžืขืœื” ืืช ื”ืฉืืœื”: ื‘ 100 ืžืœื™ื•ืŸ ื”ืฉื ื™ื ื”ื‘ืื•ืช,
05:17
silica-rich water will percolate through the nooks and crannies
75
317284
3580
ืžื™ื ืขืฉื™ืจื™ื ื‘ืกื™ืœื™ืงื” ื™ื—ืœื—ืœื• ื“ืจืš ืกื“ืงื™ื
05:20
of some of the discarded artifacts of human civilization.
76
320864
4125
ืฉืœ ื›ืžื” ืžื”ืคืจื™ื˜ื™ื ื”ืžื•ืฉืœื›ื™ื ืฉืœ ื”ืชืจื‘ื•ืช ื”ืื ื•ืฉื™ืช.
05:24
What opalescent plays of light will one day radiate
77
324989
4121
ืื™ื–ื” ืžืฉื—ืงื™ ืื•ืจ ืฉืœ ืื•ืคืœ ื™ืงืจื ื• ื™ื•ื ืื—ื“
05:29
from the things we forget in the darkness?
78
329110
4484
ืžื“ื‘ืจื™ื ืฉืฉื›ื—ื ื• ื‘ืืคืœื”?
ืขืœ ืืชืจ ื–ื”

ืืชืจ ื–ื” ื™ืฆื™ื’ ื‘ืคื ื™ื›ื ืกืจื˜ื•ื ื™ YouTube ื”ืžื•ืขื™ืœื™ื ืœืœื™ืžื•ื“ ืื ื’ืœื™ืช. ืชื•ื›ืœื• ืœืจืื•ืช ืฉื™ืขื•ืจื™ ืื ื’ืœื™ืช ื”ืžื•ืขื‘ืจื™ื ืขืœ ื™ื“ื™ ืžื•ืจื™ื ืžื”ืฉื•ืจื” ื”ืจืืฉื•ื ื” ืžืจื—ื‘ื™ ื”ืขื•ืœื. ืœื—ืฅ ืคืขืžื™ื™ื ืขืœ ื”ื›ืชื•ื‘ื™ื•ืช ื‘ืื ื’ืœื™ืช ื”ืžื•ืฆื’ื•ืช ื‘ื›ืœ ื“ืฃ ื•ื™ื“ืื• ื›ื“ื™ ืœื”ืคืขื™ืœ ืืช ื”ืกืจื˜ื•ืŸ ืžืฉื. ื”ื›ืชื•ื‘ื™ื•ืช ื’ื•ืœืœื•ืช ื‘ืกื ื›ืจื•ืŸ ืขื ื”ืคืขืœืช ื”ื•ื•ื™ื“ืื•. ืื ื™ืฉ ืœืš ื”ืขืจื•ืช ืื• ื‘ืงืฉื•ืช, ืื ื ืฆื•ืจ ืื™ืชื ื• ืงืฉืจ ื‘ืืžืฆืขื•ืช ื˜ื•ืคืก ื™ืฆื™ืจืช ืงืฉืจ ื–ื”.

https://forms.gle/WvT1wiN1qDtmnspy7