The science of static electricity - Anuradha Bhagwat
-
0:09 - 0:13It can strike without warning,
at any moment. -
0:13 - 0:16You may be walking across a soft carpet
and reaching for the door knob -
0:16 - 0:19when suddenly...zap!
-
0:19 - 0:21To understand static electricity,
-
0:21 - 0:24we first need to know a bit
about the nature of matter. -
0:24 - 0:26All matter is made up of atoms
-
0:26 - 0:29that consist of three
types of smaller particles: -
0:29 - 0:31negatively charged electrons,
-
0:31 - 0:33positively charged protons,
-
0:33 - 0:36and neutral neutrons.
-
0:36 - 0:40Normally, the electrons and protons
in an atom balance out, -
0:40 - 0:44which is why most matter you come across
is electrically neutral. -
0:44 - 0:48But electrons are tiny
and almost insignificant in mass, -
0:48 - 0:51and rubbing or friction can give
loosely bound electrons -
0:51 - 0:55enough energy to leave their atoms
and attach to others, -
0:55 - 0:58migrating between different surfaces.
-
0:58 - 0:59When this happens,
-
0:59 - 1:02the first object is left
with more protons than electrons -
1:02 - 1:05and becomes positively charged,
-
1:05 - 1:09while the one with more electrons
accumulates a negative charge. -
1:09 - 1:12This situation is called
a charge imbalance, -
1:12 - 1:15or net charge separation.
-
1:15 - 1:18But nature tends towards balance,
-
1:18 - 1:23so when one of these newly charged bodies
comes into contact with another material, -
1:23 - 1:26the mobile electrons
will take the first chance they get -
1:26 - 1:28to go where they're most needed,
-
1:28 - 1:31either jumping off the negatively
charged object, -
1:31 - 1:34or jumping onto
the positively charged one -
1:34 - 1:38in an attempt to restore
the neutral charge equilibrium. -
1:38 - 1:42And this quick movement of electrons,
called static discharge, -
1:42 - 1:45is what we recognize as that sudden spark.
-
1:45 - 1:48This process doesn't happen
with just any objects. -
1:48 - 1:51Otherwise you'd be getting
zapped all the time. -
1:51 - 1:53Conductors like metals and salt water
-
1:53 - 1:57tend to have loosely
bound outer electrons, -
1:57 - 2:00which can easily flow between molecules.
-
2:00 - 2:04On the other hand, insulators
like plastics, rubber and glass -
2:04 - 2:09have tightly bound electrons
that won't readily jump to other atoms. -
2:09 - 2:11Static build-up is most likely to occur
-
2:11 - 2:15when one of the materials involved
is an insulator. -
2:15 - 2:16When you walk across a rug,
-
2:16 - 2:20electrons from your body
will rub off onto it, -
2:20 - 2:24while the rug's insulating wool
will resist losing its own electrons. -
2:24 - 2:28Although your body and the rug
together are still electrically neutral, -
2:28 - 2:31there is now a charge polarization
between the two. -
2:31 - 2:34And when you reach to touch the door knob,
-
2:34 - 2:34zap!
-
2:34 - 2:38The metal door knob's loosely
bound electrons hop to your hand -
2:38 - 2:41to replace the electrons
your body has lost. -
2:41 - 2:44When it happens in your bedroom,
it's a minor nuisance. -
2:44 - 2:46But in the great outdoors,
-
2:46 - 2:51static electricity can be a terrifying,
destructive force of nature. -
2:51 - 2:55In certain conditions,
charge separation will occur in clouds. -
2:55 - 2:57We don't know exactly how this happens.
-
2:57 - 3:00It may have to do with the circulation
of water droplets -
3:00 - 3:02and ice particles within them.
-
3:02 - 3:05Regardless, the charge
imbalance is neutralized -
3:05 - 3:08by being released towards another body,
-
3:08 - 3:09such as a building,
-
3:09 - 3:10the Earth,
-
3:10 - 3:14or another cloud in a giant spark
that we know as lightning. -
3:14 - 3:18And just as your fingers can be zapped
over and over in the same spot, -
3:18 - 3:22you better believe that lightning
can strike the same place more than once.
- Title:
- The science of static electricity - Anuradha Bhagwat
- Description:
-
View full lesson: http://ed.ted.com/lessons/the-science-of-static-electricity-anuradha-bhagwat
We’ve all had the experience: you’re walking across a soft carpet, you reach for the doorknob and … ZAP. But what causes this trademark jolt of static electricity? Anuradha Bhagwat sheds light on the phenomenon by examining the nature of matter.
Lesson by Anuradha Bhagwat, animation by Artrake Studio.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 03:39
Jessica Ruby approved English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby edited English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby accepted English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby edited English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby edited English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby edited English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jessica Ruby edited English subtitles for The science of static electricity - Anuradha Bhagwat | ||
Jennifer Cody edited English subtitles for The science of static electricity - Anuradha Bhagwat |