How do we separate the seemingly inseparable? - Iddo Magen
-
0:07 - 0:11Your cell phone is mainly made
of plastics and metals. -
0:11 - 0:14It's easy to appreciate
the inventive process -
0:14 - 0:19by which those elements are made to add up
to something so useful and entertaining. -
0:19 - 0:22But there's another story
we don't hear about as much. -
0:22 - 0:25How did we get our raw ingredients
in the first place -
0:25 - 0:29from the chaotic tangle of materials
that is nature? -
0:29 - 0:33The answer is a group of clever hacks
known as separation techniques. -
0:33 - 0:37They work by taking advantage
of the fundamental properties of things -
0:37 - 0:40to disentangle them from each other.
-
0:40 - 0:44Simple separation techniques
apply to many physical scenarios, -
0:44 - 0:46like separating cream from milk,
-
0:46 - 0:48extracting water from soil,
-
0:48 - 0:52or even sifting out flecks of gold
from river sand. -
0:52 - 0:55But not all mixtures
are so easy to unravel. -
0:55 - 0:57In some of those cases,
-
0:57 - 1:01we can exploit the differences between
physical properties within a mixture, -
1:01 - 1:03like particle size,
-
1:03 - 1:04density,
-
1:04 - 1:06or boiling point
-
1:06 - 1:08to extract what's required.
-
1:08 - 1:09Take petroleum,
-
1:09 - 1:12a mixture of different
types of hydrocarbons. -
1:12 - 1:13Some of these are valuable as fuels,
-
1:13 - 1:18and others make good raw materials
for generating electric power. -
1:18 - 1:21To separate them, experts rely on one
important feature: -
1:21 - 1:26different hydrocarbons boil
at different temperatures. -
1:26 - 1:30During the boiling process,
each type vaporizes at a precise point, -
1:30 - 1:33then gets separately funneled
into a container -
1:33 - 1:36and collected as a liquid as it cools.
-
1:36 - 1:39Separation techniques
also take us to the sea. -
1:39 - 1:41In some drought-stricken countries,
-
1:41 - 1:44the ocean is the only
available water source. -
1:44 - 1:47But of course,
humans can't drink salt water. -
1:47 - 1:49One way to get around this problem
-
1:49 - 1:53is to remove salt from sea water
with reverse osmosis, -
1:53 - 1:57a process that separates
water's ingredients by size. -
1:57 - 2:00A membrane with pores
bigger than water particles, -
2:00 - 2:03but smaller than salt particles,
-
2:03 - 2:05only lets fresh water pass through,
-
2:05 - 2:09transforming what was once undrinkable
into a life saver. -
2:09 - 2:11Meanwhile in the medical world,
-
2:11 - 2:15blood tests are a vital tool
for evaluating a person's health, -
2:15 - 2:18but doctors typically
can't examine blood samples -
2:18 - 2:21until they've separated
the solid blood cells -
2:21 - 2:23from the liquid plasma
they're dissolved in. -
2:23 - 2:28To do that, a powerful rotational force
is exerted on the test tube, -
2:28 - 2:31causing heavier substances
with higher density, -
2:31 - 2:32like blood cells,
-
2:32 - 2:35to move away from the rotational axis.
-
2:35 - 2:38Meanwhile, lighter substances
with lower density, -
2:38 - 2:39like plasma,
-
2:39 - 2:42move to its center.
-
2:42 - 2:44The tube's contents divide clearly,
-
2:44 - 2:48and the blood cells and liquid plasma
can be tested independently. -
2:48 - 2:51But sometimes, unlike oil,
seawater, and blood, -
2:51 - 2:54the parts of mixtures
that we want to separate -
2:54 - 2:56share the same physical properties.
-
2:56 - 3:01In these cases, the only way to isolate
ingredients is by chemical separation, -
3:01 - 3:05a complex process that relies
on unique interactions -
3:05 - 3:09between components within a mixture
and another material. -
3:09 - 3:12One of these methods is chromatography,
-
3:12 - 3:16a tool forensic scientists use
to examine crime scenes. -
3:16 - 3:19They dissolve gathered evidence in a gas,
-
3:19 - 3:21and can monitor
and analyze the ingredients -
3:21 - 3:25as they separate
and move at varying speeds -
3:25 - 3:27due to their unique chemical properties.
-
3:27 - 3:32That information then tells scientists
precisely what was present at the scene, -
3:32 - 3:34often helping to identify the culprit.
-
3:34 - 3:37Separation techniques are not just about
industry, -
3:37 - 3:38infrastructure,
-
3:38 - 3:39medicine,
-
3:39 - 3:41and justice.
-
3:41 - 3:44One of the most technically ambitious
projects in human history -
3:44 - 3:49is a separation technique aimed at
answering the fundamental question, -
3:49 - 3:51"What is the Universe made of?"
-
3:51 - 3:54By accelerating particles
to extremely high speeds -
3:54 - 3:56and smashing them into each other,
-
3:56 - 4:00we can break them into
their constituent parts ever so briefly. -
4:00 - 4:03And if we succeed at that, what's next?
-
4:03 - 4:05Is there a most elementary particle?
-
4:05 - 4:08And if so, what's it made of?
- Title:
- How do we separate the seemingly inseparable? - Iddo Magen
- Description:
-
View full lesson: http://ed.ted.com/lessons/how-do-we-separate-the-inseparable-iddo-magen
Your cell phone is mainly made of plastics and metals. It’s easy to appreciate the process by which those elements add up to something so useful. But there’s another story we don’t hear about -- how did we get our raw ingredients in the first place, from the chaotic tangle of materials that is nature? Iddo Magen uncovers the answer in a group of clever hacks known as separation techniques.
Lesson by Iddo Magen, animation by Augenblick Studios.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:25
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Jessica Ruby edited English subtitles for How do we separate the seemingly inseparable? - Iddo Magen | ||
Jessica Ruby edited English subtitles for How do we separate the seemingly inseparable? - Iddo Magen | ||
Jennifer Cody edited English subtitles for How do we separate the seemingly inseparable? - Iddo Magen | ||
Jennifer Cody edited English subtitles for How do we separate the seemingly inseparable? - Iddo Magen | ||
Jennifer Cody edited English subtitles for How do we separate the seemingly inseparable? - Iddo Magen |