October 3, 2025 • 11 mins
Think physics only lives in textbooks and science labs? Think again. In this episode, we break down how physics is baked into your everyday life, from the way you walk and sip your coffee to how your phone works and why doors are designed the way they are.
No jargon, no equations, just real-world science you already use, without realizing it.
If you've ever opened a faucet, turned a steering wheel, or spilled your latte, congratulations: you're a physicist in disguise. Tune in and learn how the universe is quietly working with you, every step of the way.
🔍 In This Episode, You’ll Learn:
-
Why walking without falling is a physics masterpiece, and what inverted pendulums have to do with it.
-
The science behind everyday things like sloshing coffee, door handles, and boiling water.
-
How your smartphone uses physics every time you swipe, tilt, or tap.
🔗 Resources Mentioned:
🔗 Explore more on our website: mathsciencehistory.com
📚 To buy my book Hypatia: The Sum of Her Life on Amazon, visit https://a.co/d/g3OuP9h
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:02):
It's Flashcards Friday and today we are going
to break down the science you already use,
even if you've never thought twice about it.
I'm Gabrielle Birchak and today we are talking
about everyday physics, not the chalkboard covered in
equations kind.
I'm talking about the physics you live with,
walk with, drink coffee in and scroll your
(00:23):
phone with.
You use physics all day long, you just
don't see it.
But after this episode, you will.
But first, a word from my advertisers.
Let's start with something so basic you probably
haven't thought about it since you were a
toddler.
Walking.
Walking is a constant dance with gravity.
(00:44):
You lean forward just enough to start tipping,
but not enough to fall.
Then your foot catches you.
One leg swings forward like a pendulum, while
the other pushes off.
Physics calls this inverted pendulum model of walking.
It's not just gravity at play either.
Friction between your shoes and the ground keeps
(01:05):
you from slipping.
That is Newton's third law.
Every action has an equal and opposite reaction.
Your foot pushes back, the ground pushes you
forward.
If you've ever tried to walk on ice,
you've felt what happens when friction leaves the
chat.
Suddenly, you are a physics demonstration in motion,
(01:26):
sliding around, unable to stop and reminded just
how much physics normally works in your favor.
Okay, let's move on to the next one.
You're walking.
Let's say you're holding a cup of coffee.
Oh, wait, speaking of coffee, don't forget to
visit me at mathsciencehistory.com and click on
that coffee image and make a donation to
(01:49):
Math Science History.
It's an educational podcast, and every donation you
make keeps it going.
Anyhow, back to walking with coffee.
Here's a weird thing.
If you've ever noticed, it's easier to spill
your coffee when it's filled to the brim
than when it's only half full.
Why is that?
Well, that is physics again.
(02:11):
Specifically, it's about something called resonance.
As you walk, the coffee moves back and
forth.
If your steps match the natural frequency of
the liquids slosh, the waves build up and
splash over.
This is called mechanical resonance.
Same idea as when a swing gets higher
(02:32):
if you push it at just the right
moment.
That's what you're doing to your coffee without
realizing it.
But we naturally and unconsciously adjust our gait
to avoid it.
You slow down or stiffen your arm to
minimize the slosh.
Your brain doesn't do the math, but your
body's been trained by spilled coffee to solve
(02:53):
the problem right away.
Now, on to smartphones, our pocket-sized physics
labs.
Okay, let's jump into your pocket or your
hand.
Let's be real.
It's always in your hand, right?
Your phone is packed with physics.
First, there's the accelerometer.
That's how your phone knows if you turn
it sideways.
(03:15):
It measures acceleration and orientation based on changes
in electrical charge when tiny components inside the
chip shift.
Those changes are physical, caused by movement and
gravity.
Then there's the touch screen.
Capacitive touch screens detect changes in the electrical
field on the screen surface when your finger,
(03:37):
a conductor, makes contact.
It's not magic.
It's electric fields, conductivity, and charge redistribution.
And that always happens in my purse too.
I hate it.
It turns on even though I don't want
it to.
Okay, even your signal, Wi-Fi, Bluetooth, mobile
data, it's all electromagnetic radiation.
It's physics.
(03:59):
You are sending and receiving invisible waves through
the air every second.
Maxwell's equations in your palm.
Think about that.
Isn't that cool?
Okay, now let's turn on the faucet and
talk about torque in action.
Let's say you turn on the tap or
even maybe twist a doorknob.
(04:21):
You use a wrench, right?
Okay, so every time you apply force to
something that rotates, you are using torque.
Torque is rotational force.
The farther you are from the pivot point,
the more torque you generate with the same
effort.
That's why faucet handles are long and why
we use wrenches with long handles to loosen
(04:42):
tight bolts.
Without torque, mechanical advantage doesn't exist.
You'd be stuck applying brute force to everything.
Physics gives you the shortcut.
All right, now let's look in a mirror.
Sometimes it's not something I want to do,
but I'm forced to do it because there
are mirrors everywhere.
(05:03):
You see yourself because light reflects off your
face, hits the mirror, and bounces back into
your eyes.
That's the law of reflection.
Angle in equals angle out.
Your brain then interprets those rays as if
they come from behind the mirror, giving you
a perfect, albeit reversed, image of yourself.
(05:25):
And that is basic optics.
Your brain does it in milliseconds, constantly interpreting
light paths, depth, and angles.
Have you ever looked into a spoon?
Try it.
You'll see your face upside down.
That's curved mirror physics, and it's because of
how convex and concave surfaces bend light rays
(05:46):
differently.
Okay, now we're gonna stop walking and looking
in mirrors and carrying containers of coffee.
We're gonna drive.
All right, when you hit the gas in
a car, you feel yourself pushed back into
the seat.
That's Newton's first law.
Objects at rest stay at rest unless acted
on by a force.
The car accelerates.
(06:08):
You don't, well kind of, but you don't
really accelerate until the seat pushes you forward.
That's why I always say that we are
accelerometers.
The force from the engine moves the wheels,
friction with the road moves the car, and
your body gets carried along for the ride,
and we can feel the acceleration.
(06:28):
When you hit the brakes, the opposite happens.
Your body wants to keep moving forward, and
that's why seat belts exist.
They apply the force needed to stop you
from obeying physics too well.
Even turning is physics.
Centripetal force pulls you toward the center of
the curve, and inertia tries to fling you
(06:50):
outward.
That's why you feel pushed to the side
during sharp turns.
Okay, now we're gonna go home.
We're gonna make some dinner.
Let's boil some water and melt some butter
and toast some bread.
All of this is heat transfer.
Thermodynamics shows up big in the kitchen.
Heat moves from the stove to the pan
(07:12):
to the food.
That transfer can happen in three different ways.
Conduction, convection, and radiation.
Conduction is direct contact.
Convection is fluid motion like boiling water or
air in an oven like the air fryer
on your french fries, and radiation like a
broiler or a microwave.
(07:33):
Do you ever notice that water never gets
hotter than 100 degrees Celsius when boiling?
That's the boiling point until all the water
is gone.
Extra heat just speeds up the transition from
liquid to gas.
Understanding even the basics of heat helps you
cook better, faster, and smarter.
Physics, it's your secret sous chef.
(07:57):
Okay, right now I'm talking.
You're hearing my voice and my laugh.
Oh my god, what's happening?
Well, sound is just waves of air pressure.
My vocal cords vibrate, pushing air in pattern
waves.
Those waves travel through the air, hit your
eardrums, and get converted into electrical signals in
(08:19):
your brain.
The pitch, the pitch, the pitch, that's the
frequency of the wave.
The volume, well, that's amplitude.
If you've ever cupped your hands around your
mouth to shout, you've manually created a directional
speaker, funneling more sound energy in one direction.
It's more physics, intuitively applied.
(08:41):
Okay, so you've just eaten your dinner and
now you got to go use the restroom.
You run to the bathroom and your door
swings open.
Do you ever wonder why doors have hinges
where they do?
Have you noticed that door handles are usually
far from the hinge?
That's leverage.
The longer the distance from the pivot point,
which is the hinge, the less force you
(09:03):
need to apply to open the door.
Same reason we use crowbars and pry bars.
It's torque again, and designers build this into
everyday objects to make life easier without you
needing to do any calculations.
It's physics by design.
Okay, let's toss a ball or toss your
(09:25):
keys or even flick something off your desk.
Everything you throw follows a curve.
It's called a parabola.
That is projectile motion.
Gravity pulls it downward while your initial force
sends it upward.
These two motions combine to make an arc.
Your brain is a pro at predicting these
(09:47):
arcs.
It is, even if you've never studied kinematics.
That's how you catch a ball.
Your brain does the math, whether you know
it or not.
Yeah, you are a mathematician.
You are a physicist.
You don't even know it.
So what are the takeaways?
What are the three flashcards today?
Well, you don't have to know physics to
(10:09):
use it.
You already do.
From walking to texting, your body and your
brain are constantly applying physics principles without asking
for permission.
Two, the world is built to work with
physics, and so are you.
Faucet handles, door hinges, cars, even coffee cups
are designed with physics in mind to make
(10:31):
life easier.
You are surrounded by smart engineering, even in
the simplest stuff.
You are a smart engineer.
Our bodies were made for this.
And now the third flashcard.
Paying attention to the physics around you can
make your life better.
Understanding just a little can help you avoid
spills, drive safer, cook smarter, and maybe even
(10:55):
impress your friends with how much you know
how things work.
So you don't need a lab coat, goggles,
or a PhD to use physics.
You already do all day, every day, walking,
driving, cooking, turning knobs, tapping your phone, tossing
a pen.
Physics isn't just some subject in school.
(11:16):
It is the rule book that makes the
world tick.
You are a player in the game, whether
you know the rules or not.
And I don't know about you, but sometimes
I forget the rules because I trip and
fall.
But technically, now you know a few more,
and I do too.
Thank you for listening to Math Science History.
(11:37):
And if you enjoyed this episode, drop us
a rating, share it with a friend, and
subscribe for more bite-sized science that connects
with real life.
And until next time, carpe diem.
It's Flashcards Friday and today we are going
to break down the science you already use,
even if you've never thought twice about it.
I'm Gabrielle Birchak and today we are talking
about everyday physics, not the chalkboard covered in
equations kind.
I'm talking about the physics you live with,
walk with, drink coffee in and scroll your
(00:23):
phone with.
You use physics all day long, you just
don't see it.
But after this episode, you will.
But first, a word from my advertisers.
Let's start with something so basic you probably
haven't thought about it since you were a
toddler.
Walking.
Walking is a constant dance with gravity.
(00:44):
You lean forward just enough to start tipping,
but not enough to fall.
Then your foot catches you.
One leg swings forward like a pendulum, while
the other pushes off.
Physics calls this inverted pendulum model of walking.
It's not just gravity at play either.
Friction between your shoes and the ground keeps
(01:05):
you from slipping.
That is Newton's third law.
Every action has an equal and opposite reaction.
Your foot pushes back, the ground pushes you
forward.
If you've ever tried to walk on ice,
you've felt what happens when friction leaves the
chat.
Suddenly, you are a physics demonstration in motion,
(01:26):
sliding around, unable to stop and reminded just
how much physics normally works in your favor.
Okay, let's move on to the next one.
You're walking.
Let's say you're holding a cup of coffee.
Oh, wait, speaking of coffee, don't forget to
visit me at mathsciencehistory.com and click on
that coffee image and make a donation to
(01:49):
Math Science History.
It's an educational podcast, and every donation you
make keeps it going.
Anyhow, back to walking with coffee.
Here's a weird thing.
If you've ever noticed, it's easier to spill
your coffee when it's filled to the brim
than when it's only half full.
Why is that?
Well, that is physics again.
(02:11):
Specifically, it's about something called resonance.
As you walk, the coffee moves back and
forth.
If your steps match the natural frequency of
the liquids slosh, the waves build up and
splash over.
This is called mechanical resonance.
Same idea as when a swing gets higher
(02:32):
if you push it at just the right
moment.
That's what you're doing to your coffee without
realizing it.
But we naturally and unconsciously adjust our gait
to avoid it.
You slow down or stiffen your arm to
minimize the slosh.
Your brain doesn't do the math, but your
body's been trained by spilled coffee to solve
(02:53):
the problem right away.
Now, on to smartphones, our pocket-sized physics
labs.
Okay, let's jump into your pocket or your
hand.
Let's be real.
It's always in your hand, right?
Your phone is packed with physics.
First, there's the accelerometer.
That's how your phone knows if you turn
it sideways.
(03:15):
It measures acceleration and orientation based on changes
in electrical charge when tiny components inside the
chip shift.
Those changes are physical, caused by movement and
gravity.
Then there's the touch screen.
Capacitive touch screens detect changes in the electrical
field on the screen surface when your finger,
(03:37):
a conductor, makes contact.
It's not magic.
It's electric fields, conductivity, and charge redistribution.
And that always happens in my purse too.
I hate it.
It turns on even though I don't want
it to.
Okay, even your signal, Wi-Fi, Bluetooth, mobile
data, it's all electromagnetic radiation.
It's physics.
(03:59):
You are sending and receiving invisible waves through
the air every second.
Maxwell's equations in your palm.
Think about that.
Isn't that cool?
Okay, now let's turn on the faucet and
talk about torque in action.
Let's say you turn on the tap or
even maybe twist a doorknob.
(04:21):
You use a wrench, right?
Okay, so every time you apply force to
something that rotates, you are using torque.
Torque is rotational force.
The farther you are from the pivot point,
the more torque you generate with the same
effort.
That's why faucet handles are long and why
we use wrenches with long handles to loosen
(04:42):
tight bolts.
Without torque, mechanical advantage doesn't exist.
You'd be stuck applying brute force to everything.
Physics gives you the shortcut.
All right, now let's look in a mirror.
Sometimes it's not something I want to do,
but I'm forced to do it because there
are mirrors everywhere.
(05:03):
You see yourself because light reflects off your
face, hits the mirror, and bounces back into
your eyes.
That's the law of reflection.
Angle in equals angle out.
Your brain then interprets those rays as if
they come from behind the mirror, giving you
a perfect, albeit reversed, image of yourself.
(05:25):
And that is basic optics.
Your brain does it in milliseconds, constantly interpreting
light paths, depth, and angles.
Have you ever looked into a spoon?
Try it.
You'll see your face upside down.
That's curved mirror physics, and it's because of
how convex and concave surfaces bend light rays
(05:46):
differently.
Okay, now we're gonna stop walking and looking
in mirrors and carrying containers of coffee.
We're gonna drive.
All right, when you hit the gas in
a car, you feel yourself pushed back into
the seat.
That's Newton's first law.
Objects at rest stay at rest unless acted
on by a force.
The car accelerates.
(06:08):
You don't, well kind of, but you don't
really accelerate until the seat pushes you forward.
That's why I always say that we are
accelerometers.
The force from the engine moves the wheels,
friction with the road moves the car, and
your body gets carried along for the ride,
and we can feel the acceleration.
(06:28):
When you hit the brakes, the opposite happens.
Your body wants to keep moving forward, and
that's why seat belts exist.
They apply the force needed to stop you
from obeying physics too well.
Even turning is physics.
Centripetal force pulls you toward the center of
the curve, and inertia tries to fling you
(06:50):
outward.
That's why you feel pushed to the side
during sharp turns.
Okay, now we're gonna go home.
We're gonna make some dinner.
Let's boil some water and melt some butter
and toast some bread.
All of this is heat transfer.
Thermodynamics shows up big in the kitchen.
Heat moves from the stove to the pan
(07:12):
to the food.
That transfer can happen in three different ways.
Conduction, convection, and radiation.
Conduction is direct contact.
Convection is fluid motion like boiling water or
air in an oven like the air fryer
on your french fries, and radiation like a
broiler or a microwave.
(07:33):
Do you ever notice that water never gets
hotter than 100 degrees Celsius when boiling?
That's the boiling point until all the water
is gone.
Extra heat just speeds up the transition from
liquid to gas.
Understanding even the basics of heat helps you
cook better, faster, and smarter.
Physics, it's your secret sous chef.
(07:57):
Okay, right now I'm talking.
You're hearing my voice and my laugh.
Oh my god, what's happening?
Well, sound is just waves of air pressure.
My vocal cords vibrate, pushing air in pattern
waves.
Those waves travel through the air, hit your
eardrums, and get converted into electrical signals in
(08:19):
your brain.
The pitch, the pitch, the pitch, that's the
frequency of the wave.
The volume, well, that's amplitude.
If you've ever cupped your hands around your
mouth to shout, you've manually created a directional
speaker, funneling more sound energy in one direction.
It's more physics, intuitively applied.
(08:41):
Okay, so you've just eaten your dinner and
now you got to go use the restroom.
You run to the bathroom and your door
swings open.
Do you ever wonder why doors have hinges
where they do?
Have you noticed that door handles are usually
far from the hinge?
That's leverage.
The longer the distance from the pivot point,
which is the hinge, the less force you
(09:03):
need to apply to open the door.
Same reason we use crowbars and pry bars.
It's torque again, and designers build this into
everyday objects to make life easier without you
needing to do any calculations.
It's physics by design.
Okay, let's toss a ball or toss your
(09:25):
keys or even flick something off your desk.
Everything you throw follows a curve.
It's called a parabola.
That is projectile motion.
Gravity pulls it downward while your initial force
sends it upward.
These two motions combine to make an arc.
Your brain is a pro at predicting these
(09:47):
arcs.
It is, even if you've never studied kinematics.
That's how you catch a ball.
Your brain does the math, whether you know
it or not.
Yeah, you are a mathematician.
You are a physicist.
You don't even know it.
So what are the takeaways?
What are the three flashcards today?
Well, you don't have to know physics to
(10:09):
use it.
You already do.
From walking to texting, your body and your
brain are constantly applying physics principles without asking
for permission.
Two, the world is built to work with
physics, and so are you.
Faucet handles, door hinges, cars, even coffee cups
are designed with physics in mind to make
(10:31):
life easier.
You are surrounded by smart engineering, even in
the simplest stuff.
You are a smart engineer.
Our bodies were made for this.
And now the third flashcard.
Paying attention to the physics around you can
make your life better.
Understanding just a little can help you avoid
spills, drive safer, cook smarter, and maybe even
(10:55):
impress your friends with how much you know
how things work.
So you don't need a lab coat, goggles,
or a PhD to use physics.
You already do all day, every day, walking,
driving, cooking, turning knobs, tapping your phone, tossing
a pen.
Physics isn't just some subject in school.
(11:16):
It is the rule book that makes the
world tick.
You are a player in the game, whether
you know the rules or not.
And I don't know about you, but sometimes
I forget the rules because I trip and
fall.
But technically, now you know a few more,
and I do too.
Thank you for listening to Math Science History.
(11:37):
And if you enjoyed this episode, drop us
a rating, share it with a friend, and
subscribe for more bite-sized science that connects
with real life.
And until next time, carpe diem.
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