What is Frequency?

Summary

This video dives into the concept of frequency, a fundamental tool to describe signals in the world around us. Defined as the number of times an event occurs over a period, frequency is commonly measured in Hertz. The video humorously illustrates frequency with everyday examples and explains the relationship between frequency and period. It also touches on how frequency is applied in various aspects of life, such as screen refresh rates, hearing tests, and music, before exploring the idea of waveforms and their significance in different projects.

Takeaways

• 📅 The script introduces the concept of frequency, which is a measure of how often something happens over a period of time.
• 🔁 Frequency is defined as the number of times an event or signal repeats per second and is commonly measured in Hertz.
• 👶 The term 'frequent' helps to understand the concept, with a higher frequency indicating more frequent occurrences.
• 🚽 A humorous example given is the frequency of bathroom breaks during a class, illustrating the concept in a relatable way.
• 🛌 Another example provided is jumping on a bed, where the number of jumps in a set time frame represents the frequency.
• ⏱ The inverse of frequency is called the period, which measures the time between occurrences of a repeating event.
• 💡 The script explains that the period can be calculated by taking the reciprocal of the frequency (1/frequency).
• 🎮 Frequency is relevant in everyday technology, such as the refresh rate of screens in gaming and televisions.
• 👂 Human hearing is sensitive to frequencies between 20 Hertz and 20,000 Hertz, which is important for understanding hearing loss.
• 🎵 Music is composed of various frequencies and signal shapes, with specific frequencies corresponding to musical notes.
• 🌐 The script also touches on waveforms, which are the patterns described by frequencies and will be explored in more detail in future content.
• 📢 The video concludes with an invitation to subscribe for more educational content and mentions of a merchandise store supporting a nonprofit.

Q & A

What is the basic definition of frequency?

Frequency is the number of times that something happens over a period of time. It describes how often an event occurs.

What does the term 'frequent' imply in terms of frequency?

The term 'frequent' implies a higher frequency, meaning that something is happening more often or with greater regularity.

What is the standard unit used to measure frequency?

The standard unit used to measure frequency is Hertz, which is defined as one cycle per second.

How is the period of an event related to its frequency?

The period of an event is the inverse of its frequency. It measures the time it takes for one complete cycle of the event to occur.

What is the significance of the period in the context of a blinking LED?

The period of a blinking LED indicates the time interval between each blink, which can be used to determine the frequency of the blinking.

How does the refresh rate of a screen relate to frequency?

The refresh rate of a screen is its frequency, indicating the number of times the screen is refreshed with a new image per second.

What is the range of frequencies that human ears can typically detect?

Human ears are sensitive to frequencies between 20 Hertz and 20,000 Hertz.

How is frequency used in the context of music?

In music, different frequencies and signal shapes are combined to create a symphony of sound. Each musical note corresponds to a specific frequency.

What does the script imply about the relationship between frequency and the smoothness of motion in video games or TVs?

Higher frequencies in screen refresh rates make motion appear smoother, enhancing the viewing experience in video games or on TVs.

How does the script demonstrate the concept of waveforms?

The script introduces waveforms as repeating patterns described by frequencies, and mentions that different projects may require different waveforms with specific characteristics.

What is the practical demonstration mentioned in the script to understand the relationship between period and frequency?

The script describes an experiment with an LED and a speaker, where changing the period affects the frequency of the blinking LED and the sound produced by the speaker, illustrating the inverse relationship between the two.

Outlines

00:00

🔊 Understanding Frequency and Its Applications

This paragraph introduces the concept of frequency, a fundamental tool for describing signals in the world around us. It defines frequency as the number of times an event occurs over a period of time, using everyday examples like bathroom breaks and jumping on a bed to illustrate the concept. The standard unit for frequency, Hertz, is explained, and the relationship between frequency and period is explored, with examples including a blinking LED and a flickering street lamp. The paragraph also touches on how frequency is used in various everyday technologies, such as screen refresh rates and hearing tests, and concludes with a demonstration of how different frequencies can create musical notes, using a Tesla coil to produce an A note at 440 Hertz.

05:00

🎶 Diving Deeper into Frequency and Waveforms

The second paragraph continues the discussion on frequency by emphasizing the importance of understanding waveforms, which are the repeating patterns described by frequencies. It hints at future content that will delve into different types of waveforms and their characteristics, suggesting that these will be crucial for specific projects. The paragraph ends with a call to action for viewers to engage with the content by liking the video and subscribing to the channel for more frequent updates. It also promotes the merchandise store as a way to support the creators' nonprofit organization and concludes with a sign-off from the hosts.

Keywords

💡Frequency

Frequency is a fundamental concept in the video, defined as the number of times an event occurs over a period of time. It is central to the theme as it is used to describe various signals in the world around us. For instance, the script mentions jumping on a bed 250 times in seven minutes as an example of frequency, illustrating how it can quantify repetitive actions.

💡Hertz

Hertz is the standard unit used to measure frequency, defined as one cycle per second. The script uses Hertz to simplify the explanation of frequency, such as jumping on a bed three times in one second equating to three Hertz. It helps in understanding how frequency relates to the rate of repetitive events.

💡Period

The period is the duration of one complete cycle of a repeating event, and it is the inverse of frequency. The video script explains this by giving the example of a bathroom break every 20 minutes, which has a period of 20 minutes. It is used to measure the time between occurrences of a repetitive event.

💡Refresh Rate

In the context of the video, refresh rate refers to the frequency at which a display updates, typically measured in Hertz. A higher refresh rate, like 60 or 144 Hertz, makes motion on screens appear smoother, which is important for video games and TVs, as mentioned in the script.

💡Hearing Range

The human ear's sensitivity to frequencies is described with a range from 20 Hertz to 20,000 Hertz. This range is vital for understanding how we perceive sound and is mentioned in the script when discussing hearing tests and hearing loss.

💡Music

Music is composed of various frequencies and signal shapes that create a harmonious combination of sounds. The script uses the example of tuning a violin to an A note, which is 440 Hertz, to demonstrate how specific frequencies correspond to musical notes.

💡Waveform

A waveform represents the shape and pattern of a wave, which in the context of this video, refers to the repeating patterns described by frequency. The script mentions that different projects may require different waveforms with unique characteristics, indicating the importance of waveforms in various applications.

💡Tesla Coil

A Tesla coil is used in the script to demonstrate how frequencies can produce sound. By generating 440 lightning bolts per second, it creates an A note at 440 Hertz, showing a practical application of frequency in sound production.

💡LED

In the video, an LED is used to visually represent frequency through blinking at different rates. The script describes how changing the period of the LED blink affects the frequency, making it a useful tool to understand the relationship between time and frequency.

💡Speaker

A speaker is used in the script to demonstrate how changing the frequency affects the sound produced. As the frequency increases, the pops become closer together, eventually forming musical notes, illustrating the audible result of varying frequencies.

💡Sine and Cosine

Sine and cosine are mathematical functions related to waveforms, particularly in the context of periodic signals. The script suggests looking up these functions for a deeper understanding of waveforms, indicating their relevance in analyzing frequency patterns.

Highlights

Today's topic is frequency, a concept with many applications and puns.

Frequency is defined as the number of times something happens over a period of time.

The term 'frequent' implies higher frequency, meaning more occurrences.

Hertz is the standard unit for frequency, representing one cycle per second.

Frequency describes repetitive patterns or events, like jumping or a light blinking.

The period is the inverse of frequency, measuring time between events.

Mathematically, frequency is calculated as 1 divided by the period.

Frequency is used in everyday technology, such as screen refresh rates in gaming and TVs.

Human hearing is sensitive to frequencies between 20 Hz and 20,000 Hz.

Music is composed of various frequencies and signal shapes.

A-440 Hz is the tuning note for many musical instruments, including the violin.

Demonstrating frequency with LEDs and a speaker shows how period and frequency affect visibility and sound.

Waveforms are the graphical representation of frequency patterns.

Different projects require specific waveforms with unique characteristics.

The video promises more in-depth exploration of waveforms in upcoming content.

The video encourages viewers to subscribe for a high frequency of similar content.

Support the 501c3 nonprofit by purchasing merchandise from the provided link.

Transcripts

so today's topic is frequency which mean

there will be so many terrible overuse

frequency puns

[Music]

before we get started don't forget to

click the subscribe button and click the

little bell to get notified every time

we post a new video we'll get started

with a super meta science reminder of

the day everything around you is a

signal that you can measure and use in

some way so today we're gonna be talking

about frequency one of the biggest tools

you can use to describe those signals

that are happening in the world around

us the definition of frequency is pretty

simple a frequency is the number of

times that something literally anything

happens over a period of time think of

the word frequent a higher frequency

means something is happening more

frequently if you go to the bathroom

three times in a one-hour class that's a

frequency and also a sign that your

teacher needs to be a little more

entertaining if you jump on a bed 250

times in seven minutes

that's a frequency too to make things

easy it's most common to use the

standard unit Hertz

hence my bad puns to describe frequency

Hertz are nice because they're defined

as one per second so if I jump on a bed

three times in one second

I jumped at three Hertz for now it's

important to remember that frequency

describes a repetitive pattern or event

like jumping up and down turning off and

off the light Tom Brady's grain

touchdowns sorry I was raised in Boston

I have an excuse there are ways to

describe events that don't repeat using

frequencies but that's something for a

later video now that we have the basic

concept under our belts let's make this

a little bit more interesting if

frequency is the number of times an

event happens per second or one per

second that means that frequency is the

inverse of the number of seconds it

takes for something to happen therefore

if we take one and divide it by our

frequency we get a measurement called

the period to jump back to my bathroom

break example if you go three times in

an hour that period is 20 minutes an

amount of time between each bathroom

break the period measurement is also

super useful for example if you jump on

a bed or make an LED blink five times

per second which is five Hertz how long

is the wait between blinks the answer is

the period of the signal in this case

1/5 Hertz

Oh point two seconds so all you have to

do is remember that frequency is

described repeating patterns and period

is the measurement of how long one

repetition takes from start to end okay

so let's get a little bit mathy for a

second here roll it up the sleeves for

the math let's say that a street lamp is

flickering at 10 Hertz that means it

blinks 10 times each second 1/10 Hertz

gives us a period of 0.1 seconds in a

slightly harder example now the lamp

blinks on for one second then off for

three seconds so what's the new

frequency of the blinking light in this

case it's easier to calculate the period

first which is one second on plus three

seconds off giving us four seconds so if

our period is four seconds all we have

to do is divide one by four seconds to

get a frequency of 0.25 Hertz frequency

is actually something you've probably

seen or heard used to describe a lot of

stuff you use every day for example if

you play video games or bought a new TV

recently you might have cared about the

refresh rate of the screen something

like 60 or 144 Hertz this is the number

of times that your screen is refreshed

with a new image per second high

frequencies make motion look smoother if

you've ever had your hearing tested

you'll know that all sounds are

frequency to human ears are sensitive to

frequencies between 20 Hertz and 20,000

Hertz when someone has hearing loss that

means that they can't hear certain

frequencies anymore music is actually

made from tons of different frequencies

and signal shapes added together in a

beautiful symphony of sound for example

I play the violin and I tune to an A

which is 440 Hertz this is how we're

able to make music using bolt of

lightning from the Tesla coils to make

you hear an a all the Tesla coil has to

do is shoot 440 lightning bolts per

second let's play a bit with period and

frequency using LEDs and a speaker I've

gotten LED here that's blinking with a

period of two seconds if we start

turning the period up and down we can

see the blinks get further and closer

together for now it's easy to count how

many blinks are happening over a period

of time to estimate our frequency once

we start turning our period down to the

point one second range and smaller

though it gets a lot harder so let's

switch it to an output where we can

still notice differences in periods and

frequencies a speaker at one Hertz we

only see the cone of the speaker moving

at

time per second making a pop as we turn

up the frequency we notice that the Pops

become closer together making sounds

that are more and more like music notes

higher frequencies make higher and

higher notes and certain frequencies

correspond to certain named notes like

middle C is 260 1.6 Hertz

the last thing we want to mention in

this introduction to frequency is the

idea of a waveform we talked a bit about

how frequencies describe repeating

patterns and these patterns are called

waveforms depending on what you're

working on for specific projects though

you'll need different waveforms with

different characteristics we're gonna be

looking more in depth at different

waveforms in the next couple of weeks so

stay tuned but if you want to get ahead

or you just love geometric identities I

don't know now is a good time to look up

what sine and cosine are hopefully this

was a helpful introduction to frequency

we've got a high frequency of content

just like this lined up for the next

couple of months with a period of one

week so if you enjoyed this video you

should give us a like and click that

subscribe button if you haven't already

down in the description below you can

find the link to our super awesome

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sucks and one

signing off this is ila with Andrew

behind the camera

[Music]

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