This is a Clilstore unit. You can link all words to dictionaries.

ELECTRICITY BASICS _ (2h)

ELECTRON: a brief story on electric vocabulary

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_____________________________________________

TRANSCRIPTION

0:14
I'm going to try to shine a historical light on our language,
0:17
and tell you a story about the electric vocabulary.
0:22
It all begins over 2,600 years ago.
0:27
An ancient Greek, called Thales of Miletus,
0:30
is thought to be the first person to observe
0:32
what we would today call electrical phenomena.
0:35
He discovered that a piece of amber, when rubbed with fur,
0:38
could pick up small pieces of straw.
0:41
In Thales's language, amber was called "electron."
0:45
For a long time, that was pretty much all anybody knew about the subject.
0:49
And nature had to wait around 2,200 years
0:52
before any new investigations were made into amber's properties.
0:56
William Gilbert, a 17th-century English scientist,
1:00
discovered that with a careful experimentation,
1:02
a number of other materials
1:04
could display the attractive properties of amber.
1:07
He also found that they could attract objects besides straw.
1:11
Gilbert named these amberlike objects
1:13
after the Greek for amber.
1:15
He called them "electrics."
1:17
About 40 years later, in nearby Norwich,
1:20
Sir Thomas Browne carried out similar experiments.
1:23
He didn't figure out anything different from William Gilbert,
1:26
yet the way he described the experiments
1:29
coined the word we use all the time.
1:31
The way he saw it, when you rub, say, a crystal with a cloth,
1:35
it becomes an electric object.
1:37
And just as we speak of elastic objects,
1:39
and say they possess the property of elasticity,
1:43
electric objects possess the property of electricity.
1:48
The 18th-century French physicist Charles Du Fay
1:50
was the next person to make an important new discovery.
1:54
He found that almost any object, except for metals and fluids,
1:58
could be turned electric
1:59
after subjecting them to a combination of heating and rubbing.
2:03
In addition, he found that when two electrics are place near each other,
2:06
they sometimes attract, and sometimes repel.
2:09
With this extra knowledge,
2:11
Du Fay found that there were two distinct groups of electrics.
2:15
Any two objects from the same group will always repel,
2:19
while a pair of one from each group will always attract.
2:23
Despite these new discoveries,
2:24
Du Fay's descriptions of the physics are all lost to history.
2:29
Instead, it is the vocabulary of a charismatic young American
2:33
that we still remember and use to this day.
2:37
Benjamin Franklin heard of the work going on in Europe,
2:41
and started his own playful experiments.
2:43
He quickly learned how to make electric devices
2:46
that would De-electrify by producing very large sparks.
2:50
Keen on mischievous pranks,
2:52
Franklin would often shock his friends with these machines.
2:55
As he built more effective devices,
2:57
he likened the act of electrifying and De-electrifying
3:01
to charging and discharging weaponry.
3:05
It didn't take long for Franklin and others to realize
3:08
that it was possible to link these weapons of mischief together.
3:12
Franklin, continuing with the metaphor,
3:15
likened this grouping to cannons on a ship.
3:19
The gun deck on a military vessel
3:21
fired their cannons simultaneously, in a battery.
3:25
Similarly, this electric battery,
3:27
would discharge all at the same time,
3:30
causing large sparks.
3:32
This new technology raised an interesting question:
3:35
Was a lightning cloud just a large electrical battery?
3:39
Franklin's description of all this was as follows:
3:43
he supposed that there is a substance
3:45
he called the electrical fluid, that is common to all things.
3:49
If, say, a person rubs a glass tube,
3:52
this rubbing, or charging, causes a flow of this fluid,
3:55
or an electrical current, to move from the person to the glass.
4:00
Both the person and the tube become electrics as a result.
4:04
Normally, if the person was standing on the ground,
4:06
their electrical fluid would return to normal,
4:09
with an exchange from the common stock of the Earth,
4:13
as Franklin called it.
4:14
Standing on something like a wax block can cut off this supply.
4:19
Franklin said that an object with an excess of this fluid
4:22
was positively charged,
4:24
and something lacking this fluid was negatively charged.
4:28
When objects touch, or are near each other,
4:30
the electrical fluid can flow between them
4:33
until they reach a balance.
4:35
The bigger the difference in the fluid between the two objects,
4:38
the larger the distance the fluid can jump,
4:40
causing sparks in the air.
4:42
And, it is the material of the object
4:45
that determines if it gains or loses electrical fluid
4:48
during charging.
4:50
These are Du Fay's two groups of electrics.
4:53
You might have heard the phrase:
4:55
"Opposite charges attract, like charges repel."
4:58
That's why.
5:00
For the next 150 years,
5:02
Franklin's theory was used to develop
5:04
many more ideas and discoveries,
5:07
all using the vocabulary he invented.
5:10
This scientific inquiry brought forth technological advances
5:14
and eventually, scientists were able to take a closer look
5:17
at the electric fluid itself.
5:20
In 1897, J.J. Thomson, working in Cambridge, England,
5:25
discovered that the electrical fluid is actually made up of small particles
5:30
named by the physicist George Stoney as "electrons."
5:34
And so we return to the ancient Greek word for amber,
5:37
where our story began.
5:39
However, there's an epilogue to this tale.
5:42
It was discovered that these electrons flow
5:45
in the opposite direction to what Franklin supposed.
5:48
Therefore, objects that are positively charged
5:51
don't have an excess of electrical fluid,
5:54
they actually lack electrons.
5:57
Yet, instead of relabeling everything the other way around,
6:00
people have decided to hold on to Franklin's vocabulary
6:04
as a matter of habit and convention.
6:06
While acknowledging the discovery of electrons,
6:09
they kept Franklin's flow of electrical fluid,
6:12
renaming it: conventional current.
6:15
The electron has become the salmon of electricity,
6:19
swimming upstream in a ghostly river of conventional current.
6:24
This can be, understandably, confusing for many people
6:28
who aren't familiar with the history of these ideas.
6:31
And so I hope,
6:32
with this short story about the electric vocabulary,
6:35
you will be able to see
6:37
through the accident and whimsy of this subject
6:40
and can gain a clearer understanding
6:42
of the physics of electrical phenomena.
0:14
I'm going to try to shine a historical light on our language,
0:17
and tell you a story about the electric vocabulary.
0:22
It all begins over 2,600 years ago.
0:27
An ancient Greek, called Thales of Miletus,
0:30
is thought to be the first person to observe
0:32
what we would today call electrical phenomena.
0:35
He discovered that a piece of amber, when rubbed with fur,
0:38
could pick up small pieces of straw.
0:41
In Thales's language, amber was called "electron."
0:45
For a long time, that was pretty much all anybody knew about the subject.
0:49
And nature had to wait around 2,200 years
0:52
before any new investigations were made into amber's properties.
0:56
William Gilbert, a 17th-century English scientist,
1:00
discovered that with a careful experimentation,
1:02
a number of other materials
1:04
could display the attractive properties of amber.
1:07
He also found that they could attract objects besides straw.
1:11
Gilbert named these amberlike objects
1:13
after the Greek for amber.
1:15
He called them "electrics."
1:17
About 40 years later, in nearby Norwich,
1:20
Sir Thomas Browne carried out similar experiments.
1:23
He didn't figure out anything different from William Gilbert,
1:26
yet the way he described the experiments
1:29
coined the word we use all the time.
1:31
The way he saw it, when you rub, say, a crystal with a cloth,
1:35
it becomes an electric object.
1:37
And just as we speak of elastic objects,
1:39
and say they possess the property of elasticity,
1:43
electric objects possess the property of electricity.
1:48
The 18th-century French physicist Charles Du Fay
1:50
was the next person to make an important new discovery.
1:54
He found that almost any object, except for metals and fluids,
1:58
could be turned electric
1:59
after subjecting them to a combination of heating and rubbing.
2:03
In addition, he found that when two electrics are place near each other,
2:06
they sometimes attract, and sometimes repel.
2:09
With this extra knowledge,
2:11
Du Fay found that there were two distinct groups of electrics.
2:15
Any two objects from the same group will always repel,
2:19
while a pair of one from each group will always attract.
2:23
Despite these new discoveries,
2:24
Du Fay's descriptions of the physics are all lost to history.
2:29
Instead, it is the vocabulary of a charismatic young American
2:33
that we still remember and use to this day.
2:37
Benjamin Franklin heard of the work going on in Europe,
2:41
and started his own playful experiments.
2:43
He quickly learned how to make electric devices
2:46
that would De-electrify by producing very large sparks.
2:50
Keen on mischievous pranks,
2:52
Franklin would often shock his friends with these machines.
2:55
As he built more effective devices,
2:57
he likened the act of electrifying and De-electrifying
3:01
to charging and discharging weaponry.
3:05
It didn't take long for Franklin and others to realize
3:08
that it was possible to link these weapons of mischief together.
3:12
Franklin, continuing with the metaphor,
3:15
likened this grouping to cannons on a ship.
3:19
The gun deck on a military vessel
3:21
fired their cannons simultaneously, in a battery.
3:25
Similarly, this electric battery,
3:27
would discharge all at the same time,
3:30
causing large sparks.
3:32
This new technology raised an interesting question:
3:35
Was a lightning cloud just a large electrical battery?
3:39
Franklin's description of all this was as follows:
3:43
he supposed that there is a substance
3:45
he called the electrical fluid, that is common to all things.
3:49
If, say, a person rubs a glass tube,
3:52
this rubbing, or charging, causes a flow of this fluid,
3:55
or an electrical current, to move from the person to the glass.
4:00
Both the person and the tube become electrics as a result.
4:04
Normally, if the person was standing on the ground,
4:06
their electrical fluid would return to normal,
4:09
with an exchange from the common stock of the Earth,
4:13
as Franklin called it.
4:14
Standing on something like a wax block can cut off this supply.
4:19
Franklin said that an object with an excess of this fluid
4:22
was positively charged,
4:24
and something lacking this fluid was negatively charged.
4:28
When objects touch, or are near each other,
4:30
the electrical fluid can flow between them
4:33
until they reach a balance.
4:35
The bigger the difference in the fluid between the two objects,
4:38
the larger the distance the fluid can jump,
4:40
causing sparks in the air.
4:42
And, it is the material of the object
4:45
that determines if it gains or loses electrical fluid
4:48
during charging.
4:50
These are Du Fay's two groups of electrics.
4:53
You might have heard the phrase:
4:55
"Opposite charges attract, like charges repel."
4:58
That's why.
5:00
For the next 150 years,
5:02
Franklin's theory was used to develop
5:04
many more ideas and discoveries,
5:07
all using the vocabulary he invented.
5:10
This scientific inquiry brought forth technological advances
5:14
and eventually, scientists were able to take a closer look
5:17
at the electric fluid itself.
5:20
In 1897, J.J. Thomson, working in Cambridge, England,
5:25
discovered that the electrical fluid is actually made up of small particles
5:30
named by the physicist George Stoney as "electrons."
5:34
And so we return to the ancient Greek word for amber,
5:37
where our story began.
5:39
However, there's an epilogue to this tale.
5:42
It was discovered that these electrons flow
5:45
in the opposite direction to what Franklin supposed.
5:48
Therefore, objects that are positively charged
5:51
don't have an excess of electrical fluid,
5:54
they actually lack electrons.
5:57
Yet, instead of relabeling everything the other way around,
6:00
people have decided to hold on to Franklin's vocabulary
6:04
as a matter of habit and convention.
6:06
While acknowledging the discovery of electrons,
6:09
they kept Franklin's flow of electrical fluid,
6:12
renaming it: conventional current.
6:15
The electron has become the salmon of electricity,
6:19
swimming upstream in a ghostly river of conventional current.
6:24
This can be, understandably, confusing for many people
6:28
who aren't familiar with the history of these ideas.
6:31
And so I hope,
6:32
with this short story about the electric vocabulary,
6:35
you will be able to see
6:37
through the accident and whimsy of this subject
6:40
and can gain a clearer understanding
6:42
of the physics of electrical phenomena.

Short url:   https://multidict.net/cs/5539