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How to pronounce corresponding in Dutch?

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Lightning is a magnificent natural phenomenon...
but what happens before a lightning bolt crosses the sky?
How does lightning form?
This is the University of the Netherlands
You have likely seen it many times: lightning...
a bright flash, seconds later followed by a loud thunderclap.
If we now image such a lightning strike with a high speed camera...
we see many branches finding their way to the ground.
The moment they hit the ground, a large amount of energy is released.
Globally, this occurs about 45 times per second...
so you can calculate how many times lightning strikes during this lecture.
In the Netherlands, thunderstorms occur only now and then...
but in some areas, like Congo or Colombia, thunderstorms happen every day.
But...how does lightning form?
To understand this, we have to start with the basics...
charged particles in an electric field.
Air consists of molecules...
very small particles, which are neutrally charged...
which means they are equally negatively and positively charged.
If we now hit such an air molecule...
here shown with a virtual hammer...
then a particle can be released.
a negatively charged particle, we call an electron.
What is left is a positively charged particle called an ion.
The electron is much lighter than the ion...
and therefore also much faster.
If we now position this inside an electric field...
with a positive charge on one side...
and a negative charge on the other side...
...many things can happen.
How is the electric field generated in the cloud?
I will come back to that later.
But we know that charged particles in an electric field...
attract each other, similar to magnets.
Minus wants to go to plus and plus to minus.
So they want to move.
Ions however, are heavy and hardly move...
electrons are light and therefore fast.
They accelarate in this field and can become a virtual hammer themselves.
They can release another electron and thus multiply themselves.
You start with one electron, then you have two...
then four, then eight, and in this way you have an avalanche.
This only happens when the electric field is strong enough...
otherwise they are not accelerated enough.
When enough positive and negative particles have been separated...
then we have so-called charge separation.
Positive on one side and negative on the other side...
which itself can create an electric field.
The movement of charge is called current...
just like in the charging cable of your phone or laptop.
A high enough current can restore the equilibrium...
and thus also the electric field This is like a small lightning bolt.
We now know that when an electron collides with a molecule...
a new electron can be released.
But, there is something else which can happen...
and that can best be shown in the lab.
We are now in a lab of the Eindhoven University of Technology...
and this set-up is called a Planeterrella.
Here we have a glass bell jar containing low pressure air.
We can now apply a high voltage between these two spheres...
which will lead to an electric current through the gas.
So, let's do this.
Now you see that it produces beautiful light.
A current now flows through the gas...
and this not only causes the molecules to release new electrons...
but, if the electrons hit a molecule this can also produce light...
and that is what we see here, and also what happens in a real lightning bolt.
So, molecules can fall apart into ions and electrons in an electric field.
But how is this electric field created in a cloud?
A cloud contains many different kinds of frozen water...
...ice crystals, hail stones and wet snow flakes.
These all collide with each other...
and ice crystals can, for example, collide with large hail stones.
In such a case, generally a small amount of negative charge...
jumps from the ice crystal to the hail stone.
This leaves us with positively charged, light ice crystals...
...and negatively charged heavy hail stones.
These are like large versions of the microscopic particles from before...
...but these you can hold in your hand.
We need one more thing...
we also need rising warm air.
Below a cloud, air can rise...
just like in a hot air balloon or smoke above a fire.
This also explains why thunderstorms often occur on warm summer days...
when the air is heated a lot.
Now this updraft inside the cloud...
will carry the ice crystals upwards because they are light.
Hailstones, which are heavy, drop down.
In this way, charge is separated inside a cloud.
Light, positively charged ice crystals move upwards...
and the heavy hail stones drop down...
which results in positive charge on top and negative charge on the bottom.
This is not an a scale of a few centimetre...
but of many kilometres.
Corresponding electric voltages are billions of volts...
so millions of times higher than the 230V from your wall sockets.
We know that positive and negative attract each other...
nature wants to cancel out this field...
and the current which then flows is a lightning bolt.
The light that we observe is created by the collisions of molecules.
You might think...
isn't the charge separated within the cloud and not outside of it?
That is correct.
90% of all lightning discharges happen within the cloud...
and we can hardly see or hear them.
The remaining 10% are the important ones...
these are the ones reaching the ground.
But why would they move to the ground?
The bottom of the cloud is negatively charged...
and this negative charge wants to move away...
and the earth contains almost an infinite amount of positive and negative particles...
and some extra charge does no harm...
so the negative charge can flow from the cloud to the ground.
Now let us go back to the lab in Eindhoven to observe a small lightning discharge.
We are in the high voltage lab at the Eindhoven University of Technology...
and next to me is a so-called Marx generator...
a device which can generate very high voltages.
It can generate voltages up to five-hundred-thousand volts...
which are then applied to the sharp tip that you can see above.
When this voltage is applied, a spark can jump...
to the small copper wire which is connected to ground...
which is basically a mini lightning bolt.
So, in this way we make a mini lightning bolt in the lab.
We just saw a spark jump...
which included both the bright light...
as well as the loud bang which we all know from lightning.
Why is there always a time difference between these?
That is because light travels much faster than sound...
about a million times faster.
Therefore, you see the flash almost instantly...
while you hear the thunder only a few seconds later...
because it is so far away.
We now understand the basic principle of lightning...
but details are still not understood by scientists.
What causes the first bang?
What is this very first hammer?
What releases the first electron?
There are many theories on this...
but the most important one is probably that this is caused by cosmic rays...
a particle coming from somewhere in the galaxy...
hitting an air molecule inside a thundercloud...
and releasing the first electron.
But now we have this electron, but we still do not have lightning...
because how do we get a spark from this?
Electric fields measured in thunderclouds are too low to achieve this.
They are close, but are still too low for the large multiplication required.
From my research, I hope to one day understand how this works...
and how lightning really starts.
We started this lecture with the question: how does lightning form?
Particles collide inside a cloud...
ice crystals become positively charged...
hail stones become negatively charged...
and the updraft carries the ice crystals upwards.
This leads to an electric field inside the cloud...
eventually causing lightning...
either inside the cloud...
or to the ground.
We do know that lightning forms like this...
but the very first start...
remains a mystery.
Thank you for your attention.

Lightning is a magnificent natural phenomenon...

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corresponding::adjective | Spocien Dictionary

corresponding

adjective

//

conforming in every respect

Type	Words
Synonyms	comparable, like

boxes with corresponding dimensions.

corresponding::adjective | Spocien Dictionary

corresponding

adjective

//

accompanying

Type	Words

all rights carry with them corresponding responsibilities.

corresponding::adjective | Spocien Dictionary

corresponding

adjective

//

similar especially in position or purpose

Type	Words

a number of corresponding diagonal points.

How to pronounce corresponding in Dutch?

corresponding::adjective | Spocien Dictionary

abandonment

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corresponding::adjective | Spocien Dictionary

abandonment

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corresponding::adjective | Spocien Dictionary

abandonment

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