View transcript
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(light music)

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- Hola, my name is Desire Whitmore,

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and I'm a teacher here
in the Teacher Institute.

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The Exploratorium is a museum

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filled with hundreds of
exhibits that you can use

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to understand the world around you.

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One of my favorite exhibits
is the giant mirror

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which you can see behind me.

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(light music)

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So I really liked this exhibit
because you can see yourself

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in many different ways.

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But it's also cool because you can use it

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to visualize things that
we don't normally see

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with our eyes.

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You may have recently seen a video

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demonstrating the effectiveness
of different masks

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at blocking the flow of your breath.

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We at the Exploratorium

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have worked with some
researchers at Stanford

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to turn our giant mirror into a way

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to study this a little bit further.

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This technique allows us to
see temperature differences

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in moving air.

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You may have noticed this effect before;

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either when you're barbecuing

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and you can see the streaks of hot air

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coming up above the barbecue,

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or you may have noticed
it as a car ahead of you

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looks like it's driving over water,

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like some kind of wavy water,

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but that water is not actually there.

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It's really just a reflection from the sky

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that's being bent upwards by
the heat from the pavement

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up to your eye.

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Those examples were both of

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very large temperature differences.

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So the hot pavement is much
hotter than the air above it

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and the barbecue grill is much
hotter than the air above it.

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But this mirror allows us to see

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much smaller temperature differences.

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You can even see the heat coming
off of my body and my head,

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and you can even see my breath.

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To demonstrate how this works,

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I want to show you some
footage that we took

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using some hot tea and a cold bowl of ice.

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As you can see, the air
actually travels downward

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instead of up.

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This is because the air
coming off of the bowl of ice

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is actually colder than the air around it,

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so it sinks downward.

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This is footage from my cup of tea.

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The steam from my tea is much
hotter than the air around it,

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and so it's rising very quickly.

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Here's footage of a lighter.

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First I'll show you what it looks like

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when I just released some
of the gas, the butane gas,

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out of the lighter.

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But when I turn the lighter on,

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you can really see the flame there.

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And what you're really seeing
is the temperature difference

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between the flame and the air around it.

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What does this have to do with masks?

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Well, it turns out that one of the ways

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that Coronavirus can be
transmitted is through your breath.

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Coronavirus itself is very tiny,

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but it attaches itself to
the droplets of moisture

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that are in your breath.

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What masks do is actually
disrupt the flow of your breath,

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so it can stop the Coronavirus

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from traveling from one place to another.

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In this footage,

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there are some things
that you might notice.

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One is that there's actually
heat coming off of my body,

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and it's always there because
I'm always emitting heat.

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I noticed from this footage

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that even though the breath
from my mouth travels very far,

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so does the breath from my nose.

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I also noticed that even when I talk,

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a lot of breath comes out of my nose.

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So this is a mask that I made at home,

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and it consists of two layers of cotton

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with a paper filter in between.

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Something to notice here

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is that even though it blocks

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most of the breath coming out of my mouth,

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there's still a tiny bit
coming out the top of the mask.

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So this is a surgical mask.

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And even though it's fitted to my face,

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you can still see a lot
of my breath coming out

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above the mask.

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It is still very effective

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at blocking the forward flow of my breath.

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So this is a gaiter, and a
gaiter might be more comfortable

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for you to wear.

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But what you see here

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is that it is not very effective at all

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at blocking my breath.

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And one of the reasons is
because the holes in the gaiter

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are much bigger than the holes in my mask.

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And you see that it's
coming out of both my mouth

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and my nose and above.

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So it's actually kind of
making everything worse.

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So this footage is of a face shield,

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which is one that doctors and nurses wear

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when they work with patients.

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And one thing to notice here

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is that you can clearly
see my breath coming down

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out of the bottom of the shield.

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This next footage shows
when I'm wearing a mask

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and a shield,

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and you can see that it's
actually very effective

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at blocking my breath from
getting to other people.

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I've also seen a lot
of people out in public

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wearing their mask with
their nose hanging out of it.

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You can see here in this footage

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that that does absolutely nothing

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to block my breath from traveling.

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So the proper way to wear your mask

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is to actually fit it over your nose.

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So what did we learn?

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We learned that the Coronavirus

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can travel through your breath,

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and that's one of the main ways
that it can be transmitted.

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We learned that we can image our breath

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using this really cool technique

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because our breath is hotter
than the air around us.

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We also learned that
different types of masks

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can be more effective or
less effective than others

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at how far they can stop
your breath from traveling.

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But each and every one of these masks

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did allow some of our breath to escape.

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This is why it's important
to not only wear a mask,

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but to also socially distance from others.

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So let's continue to use science

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to help us understand the world around us

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so that we can all stay safe and well.

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(light music)

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