I'm in the US, and I consistently see people "wearing" masks. They wear them below their nose or around their chin. Sometimes they wear the mask UNTIL they start talking, and take it off to talk (which is likely the most important time to have a mask on outside of sneezing). It's honestly hard to hold out hope for humanity when guidelines this simple are so difficult for people to understand and follow.

If everyone were gamers, the transmissions would drop by 100%.

*Everytime he says "mask(s)" the video gets faster*

Gods I wish "Don't make other people sick" wasn't a political issue.

I love how the infection looks like a vomit cannon

Further caveats: infectious dose and viral load. A single virus particle is not enough to make a person sick. There is a threshold that must be surpassed in order for a person to get sick. This is the infectious dose. Reducing the number of viral particles has better than a linear effect on the rate of disease transmission because doing so greatly reduces the probability of a person being exposed to an infectious dose within a given time period. Also, the severity of a viral infection depends on the number of infectious particles in the body. This is the viral load. Reducing the number of viral particles results in less-severe infections. Aside from the obvious benefits, this also has a positive effect on the rate of disease transmission because people with a higher viral load are more contagious than people with a lower viral load. So if you see that a certain mask is 50% effective at stopping viral particles, it actually has a greater than 50% effectiveness at reducing the rate of disease transmission.

4:28 "arithmetically satisfying" You got me I wear facial mask from now on

Very good simplification, makes the message easy and understandable.

So many 'sks' sounds my cat came around and cuddled my phone

This pandemic has done nothing but solidify my dislike of other people.

I just want to congratulate you for the amazing job you do, making kids like me learn things without needing to go to articles and not understanding nothing. You are really helping people, and youtubers like you are inspiring people to study to become scientists. Thanks bro

Karen: This sign won't stop me because I can't read!

Fascinating that even fairly "ineffective" masks can have a bigger effect than you'd think. Brilliantly explained, thank you.

Just pointing out the obvious, but wearing a mask also reduces the spray from coughs on objects, making less infected surfaces that people can touch and catch it from.

Your videos are so educational,my new favourite channel

On a different note, the channel banner is brilliant, outstanding.

People still negate this all by pulling their nose out of their mask.

Hugely appreciate the caveats and explanation at the end, a perfect level of simplicity and accuracy, keep it up :)

Nice video, great link. One comment: Whenever building demo-material on chances and properties, please, do NOT use 50% as your value, use something asymmetrical like 40% or 33.3% (if you go with fractions). the fact that p = (1 - p) for p=0.5 makes for a great way of introducing confusion and diminish the learning effect. Don't sabotage your own goals! A lot of "incorrect" intuition is because people believe they understand a "50:50" chance, while they do mix things up in the process of thinking on it.

I like the idea of this everyone talks about why masks don't work as well but no one talks about ways they could work better than we think

“The saddest aspect of life right now is that science gathers knowledge faster than society gathers wisdom.” ― Isaac Asimov

I was told by my employer that government guidance says we're not allowed to wear masks at work. I work in a school. In the UK. My employer is actually lying about this as I've read the guidance myself. ugh.

Thanks so much for sharing this!!

Come to Austria, everybody wears FFP-2 masks basically everywhere. We‘re opening restraunts in 3 weeks! :D

2:36 What a revolutionary editing style. Three separate quick cuts of the same breath.

I was sceptical to masks at first. I had heard that as long as you kept a social distance, the benefits of wearing a mask were negligable. And perhaps that is the case, but when school started I had to move back to the city (I spent the "lockdown" at my parents) and that's when I realised that it's almost impossible to keep distance 100% all the time. Just look at people in the store or people getting on and off a bus. Those are mostly primitive instincts. They're not standing close to eachother because they don't believe in the disease, but rather because it goes against the human nature to not do so. Finally I must mention this study I read about where they asked people on the street two questions regarding how well people have followed the guidelines throughout the pandemic. The first was how well they had followed, the second how well others had followed. This was the most common answer: 1. I've followed the guidelines pretty well. 2. Others have gotten worse at following the guidelines as time went on. To me this clearly shows how little we know about our own shortcomings, and thus also why we should wear masks. We simply cannot trust even ourselves.

This channel is truely helpful abd productive, it gives us great knowledge compared to other youtube channels who show all useless stuff

I've loved your recent work with the coronavirus but I was wondering if down the line you could do a video on Anyons, I just watched your quasi-particle video the other day and with the recent possible evidence I think it's the perfect time for a good explainer on the weird buggers! There are a few good ones out there but I haven't found any that make it nice and streamlined.

Hey, over here. From Spain, the most affected country by the Covid-19 in Europe) You see, I usually see people wearing masks in the streets (because it's obligatory), but they take them off in risky situations like when you're sitting in an overcrowded bar, only one meter away (or less) from the nearest stranger, or when you're are hanging out with a bunch of friends. The thing is, some people just get their masks put on so that they won't get fined by the police. It's not like they are assholes or something, I know they want their normal days back. But here's the thing, I am tired too and this thing already feels like a never ending loop. This video gives me some hope and I really wish that those people could know how helpful wearing a mask can be. I'll try to spread this as much as I can. Keep strong, fellow inhabitants of this wonderful world. Thank you.

That double-inhale at 2:36.

Also let's not forget that we're speaking of exponential growth, not linear growth. If everybody wore a 50% effective mask this would mean every individual would effectively have a quarter of their expected infections per individual factored into the exponential growth formula for covid. Let's take an example formula for exponential growth where we take 100*e^3 which equals about 2008. Now we apply the 75% reduction to the exponent and find that 100*e^0.75 equals only 212 which is only about 10% of the original value before we applied our 75% reduction. Now obviously this isn't the exact formula for covid's expected spread, but this very clearly showcases the sheer power of attacking the exponent in an exponential growth curve, making masks and social distancing all the more effective the more people keep doing it. Added to this if we manage to get our exponent

I live in Hiroshima, Japan and this past 9 months have been the longest time I didn’t catch any colds. There were no lockdowns placed and work in our company still went on as usual. It also helped that we were all given masks in our company and every door, gate and stair have hand sanitizer stations nearby. Wearing a mask is just common courtesy for everyone. That’s why Japan recorded less than 1600 deaths(as of 9/21) due to Covid19. MASKS WORK SO PLEASE FFS JUST WEAR THEM

Wife: "What are you laughing at?!" Husband: "Nothing!" Husband: [Internally] .... *Maskamathics* bahahaha!!

Times the words "mask", "masks", or "masked" were said in this video: Before caveats (until 5:09): 57 times After caveats: 70 times (or 71 if you count saying the link) Entire video total (7:11): 72 times And now, hearing or saying "masks" feels weird. Seriously though, this video perfectly summarizes the effect of masks. Pretty unfortunate that the majority of those who watch this are probably already aware of the importance of masks right now.

Also it could have also been stated some facts about particulate size of aerosols containing infectious disease (covid) and pore size of common double layer cotton masks. Aerosols containing covid are larger than most pore size of woven cotton fabrics that when doubled and worn properly create an almost 100% effective barrier of covid 19. Not to mention that when 2 people correctly wear cotton masks like what was stated in the video.

Alternate title: Send this to all the Karen’s you know.

meanwhile some kids in polish schools are getting detentions for wearing a mask during lessons, nice

What amazes me is that "My experiment shows mask equals bad" videos have many thousand views with very high like ratios. While the clearly more scientific videos like this on also have a really good like ratio. Those filter bubbles must be insane.

Finally, an effective informative video...thanks.

Thank you so much for this! Sharing it everywhere!💗

This is a great video on the basics of masks. However there are a few things to take into account. 1. Proper mask use. Wash your hands before handling a mask and after handling a mask. Only touch your face or mask when you put it on or take it off. Touch your mask by the parts furthest from your mouth and nose, so by the strings or edges. As soon as your mask is on treat it as potentially contaminated. Dispose of disposable masks right away. Put your cloth masks in the washing machine as soon as you get home. 2. The majority of transmissions (atleast in the Netherlands) Take place in familial or friendly gatherings in which people tend to be lacks with the rules and not wear a mask. Be careful with these still. Don't shake hands, don't share food, don't sit closer than 6 ft to eachother. Do not attended if you have been in contact with someone showing symptoms of CoViD 19 for 14 days prior to the event and check eachother on this. Do not have gatherings that are larger than single digit if the room allows you to keep a 6ft distance. And most of all, Keep yourself in check, report your own health if you think something is wrong. Don't hesitate to call a doctor. Stay safe and healthy people.

It should also be noted that R needs to drop quite a bit below 1, as R=1 means every infected person on average infects one other person.

This is a great video! Good job!

5:50 Take a look at the difference between the 2nd and 3rd situations. If the infectious person is wearing a mask, things are SIGNIFICANTLY more effective. But also, a person doesn't know if they're infectious or not. Half of all infections are caused by someone who was infectious, but not showing any symptoms. So basically, even if you aren't showing any symptoms, and even if EVERYONE else around you is wearing a mask, you should still absolutely wear a mask.

Some people after watching this video would make the conclusion: "I don't have to wear a mask, because everyone around me wears one." But if everyone thinks that way, we would be stuck in this pandemic for all eternity! The right thing to do is to act the way you think everyone should act. Don't make an exception of yourself, instead try to be an example. In the end, if it doesn't work, you at least know it wasn't you... (This counts for litterly everything by the way. If you're interested in this way of thinking, look up Imanuel Kant

Americans' solution: *make masks with holes in order to breathe better*

“For me, it is far better to grasp the Universe as it really is than to persist in delusion, however satisfying and reassuring.” ― Carl Sagan

Hey! Love your videos! I wonder what you think about the concept of time as portrayed in Tenet?

So, should I just wear 2 masks to help make up for someone else not wearing one? Update Feb. 10, 2021: Well, well, well... "CDC confirms that double-masking significantly helps prevent the spread of COVID-19" - Double masks decreased exposure by 92.5%, more than 2X what a single mask did. - Wearing a tightly-fitted mask reduced exposure by 60%, even when just one subject wore it. - That number was 96% when both did.

Well, obviously the answer is, have people wear an infinite number of 50% effective masks.

Imagine trump showed this during his covid press conferences

This video is great. Thank you for making it.

Another Caveat: This assumes people that wear masks are wearing them all the time. This is only true for community transmission of a virus. Not if someone travels to visit a friend and takes off their mask once they arrive. Or when mask wearers all meet up to go for dinner and all take off their masks for the duration of their gathering because they are eating/drinking. Really these circumstances of being in the company of people for extended periods of time are much more likely to cause a transmission than fleeting moments passing strangers on the street and in supermarkets.

“Magic maths of masks” Tongue twister of the year

Wow, brilliant video, thank you!

I used to be an introvert. But with Covid? NOW I'm an INTROVERT. My true introvercy has been released. Epic.

Your pronunciation of aatish's name was perfect man. I know it shouldn't be my biggest takeaway from the video but finally seeing someone not butcher a indian name is so refreshing.

It's encouraging that wearing a mask is more effective than most of us realise. I was already going to continue to wear one, but now I have a better understanding of what it is I'm doing beyond just "reducing its spread".

Glad ur uploading again

Excellent explanation 🧐!

Bruh, you can't just bring logic to the table!! You just made a lot of dumb people mad!!

This video and the N-95 one serve as excellent means of educating the public about masks. Keep it up!

And there's people that do wear masks but incorrectly, put their nose out, wear it by their chin, and much more

Kinda like your approach to things that seem to be simple. A deeper look opens a total new world. Light Blue Blues - KZfaq

The pizza signifying misinformation was a nice touch.

Why masks work better than you think Karen's: I am gonna pretend I didn't see that

I think we should send this to all of our friends and family

Thanks for the video!

As someone who's always wore a maks since the beginning of the pandemic and is now anyway going through having covid I really appreciate this video and how well it's explained

I don't know why everything has to turn into a political purity test. This should be a bipartisan issue that we can all work together on and help each other out. It's a shame our leadership has not set the example and helped make this whole thing go better. I don't want to turn this into a political argument, again, it's insane to me that it even IS a political argument, we should be able to speak the facts, and institute policy that protects public health, without even disclosing our political affiliation. But since it has become a political argument I have valid criticisms of both sides and how they have handled this. First, the president hasn't been an effective leader in this crisis. And if he had been then I think it wouldn't even be all that political. He would always have his critics of coarse, but I think it wouldn't be nearly as polarizing as it has been if he had just advised people to wear masks, wash hands, and social distance from the beginning, and listened to his experts in his own administration to handle it properly. That said, and I'm trying to be delicate here, and give as much of the benefit of the doubt (I could be much harsher in my criticisms, but I don't want to feed into that). On the other hand, I've seen incredibly hyperbolic criticisms of the president from the other side, saying he's personally responsible for EVERY death. I think that is pretty unfair to make those accusations. Covid-19 would have come to the US anyway. It would have infected people. And people would have still died. And that's even if the president had done everything right from the outset. EVERY nation on Earth has had to deal with this virus. EVERY country on the planet has been impacted in one way or another. Placing blame solely on the president is very irresponsible, and acting in a purely partisan way during and election year. I don't have a side in this conflict. I'm not pro any politician. I'm not saying who to vote for. And I've tried to refrain from saying who I intend to vote for, or not vote for. I think both sides have not handled things well, though perhaps in different ways. I think both sides have things they have said, or done, that has not helped us at all. And that includes blaming the other side, as well as whatever actions have been taken, or not taken. Maybe you disagree with that statement, but if we are being honest with ourselves, then we know this deep down. So let's first, set politics aside, and beat Covid together. We have the power to eliminate the virus and return to some kind of normalcy. Perhaps not completely, the world has changed in some ways that we can't go back on. And perhaps this thing will make us more mindful of other infectious diseases, such as the seasonal flu, which also claims many lives every year. But perhaps we can make Covid a thing of the past. Second, let's admit that no side is completely right. If anyone is trying to spread FUD (fear, uncertainty, doubt) we should not listen to them. If they are speaking sane and logical facts, and they are encouraging us to work together beyond political boundaries, then we should listen to that. And above all of that, even if you can't get behind the idealism, even if you have disagreed with the majority of what I've said; if a business or a city or an organization has asked people to wear masks, we should wear them. We shouldn't be trying to find ways to get out of it. We shouldn't try to push back on it. We shouldn't assume they are part of some political agenda. We should just comply and wear masks to help protect the other people, the workers, and public officials we are interacting with. We should try to keep ourselves healthy, and protect our own families. Even if you don't think you will get sick, or you think you won't show any symptoms, how would you feel if you unwittingly passed it on to a loved one? A friend? A co-worker? Someone at the grocery store? What if that person had to go to the hospital? What if they had to be intubated (it's not pleasant, and can cause lasting damage)? What if they ended up dying from it? Let's not turn each other into enemies. Let's not spite each other. Let's instead think of those who could be impacted and hurt by our carelessness. Or even we ourselves could be impacted by it. And let's not assign blame to others. Either getting mad that people are wearing masks, or that people aren't wearing masks. These people are not our enemies. They are our neighbors. Our community. Our friends. Our family. They are our fellow countrymen and women. We are all in this together. Let's be kind to each other. Let's be respectful of each other. And let's help each other out.😷💧👏

The states with the highest infection rates (relative to population) are states where mask usages is lowest (Source: www.worldometers.info/coronavirus/country/us/ (sort by cases/population)), mainly due to more people who refuse to wear masks (compared to the total populace).

The safest mask is one,which allows unhindered passage of air. To do this covertly, use a mask with a filter but remove the filter material from the inside and cut away any other material. This will allow air to pass without restriction and is not visible to anybody.

Jesus Christ, some of these comments and replies to said comments really bring down my hope for humanity.

Now say “Magic Math of Masks” fast

What software did you use to create the animation and video for this? I’d like to consider using same for my own projects.

Hi I just found out about exoelectrogenic bacteria and am hoping you could do an episode on them! Electricity from bacteria?!!! too cool. I think you would be able to explain how it works really well:)

Drinking game: drink every time "masks" is said.

wearing a mask and sunglasses give me the level of anonymity ive always wanted. plus no one comes up to talk to you in grocery stores anymore woohoo to that. PLUS PLUS i am saving a ton on skipping the lipstick masks are great for me i might just do this forever

this video should be on TV every day at 6.00pm all channels!

I got lost when stickmen started mouth-laserbeam-ing their friends

The equation should also include that wearing the mask wrong by some amount of people can increase the risk of infection. (Like, touching the mask can cause smear infection)

There should be a final caveat to this, and for the worst: if half the people does not wear masks, the number of people with the disease will consistently increase, which involves the risk to reach a pandemic propagation (again). Besides, as some others have pointed out here, there is not nearly a 50% people wearing masks because wearing it incorrectly is the same as no wearing mask at all.

Mask Math has been wonderful research... We need to share this info in Adds.. Schools.. Hospitals.. Public care. Let's Take A Challenge for Good Health.

MinutePhysics, kinda telling that you don't have any videos on this subject beyond 2020.

2:30 The AND gate of transmission.

Think of it as a collective benefit: The more people who block the transmission of the virus with face coverings, the less virus there is circulating in the community. This reduces everyone's risk for infection.👍

Hi Henry. Don't know if you read the comments but I'll would really like to say how much I love the channel and offer you a video idea. At all channels I look at there's an explanation about how mass curve spacetime but no one explain why this curvature causes acceleration. I believe it could be also be a nice lab where you make some curve in 2d spacetime plane and see the movement through time

thank you for this

After watching this video: is "mask" even a real word anymore

Show this to all the Karens, Henry.

I have never heard 'mask' being said so many times in less than 10 minutes. Thanks for the numbers, its fascinating how maths makes good things awesome.

This is golden stuff. Congrats

This was brilliant, and needs to be shared everywhere!

It’s honestly so sad we still have to educate and emphasise the importance of wearing masks 7 months into the pandemic :/

Excellent and east-to-understand video. A must see video for those that still don't believe in wearing a mask during these COVID-19 times.

This video has an important omission: the virus is here to stay. It will not disappear. So all we are doing with masks and reduced transmission is slowing the RATE of transmission, not the eventual EXTENT of transmission. Until we reach about 70-80% herd immunity the virus will continue to spread. There is a good reason to slow the rate of transmission, and that is to prevent hospital overload. But we are far far below any risk of hospital overload in all but a few counties. Meanwhile the collateral damage of economic shutdown will cause immense harm for generations, with trillions in debt payments that will only come from young taxpayers and government confiscation of the wealth of retirees. Merely slowing the spread rate is not a sufficient excuse for the immense economic harm.

“Ignorance more frequently begets confidence than does knowledge: it is those who know little, not those who know much, who so positively assert that this or that problem will never be solved by science.” ― Charles Darwin

4:10 I think this part needs to be emphasised even more. With the current measures, the reproduction rate is around 1.0 for most countries most of the time, i.e. the number of cases remains relatively constant. Even a small improvement from 1.1 to 0.9 makes a difference between an increase to 160% or a decrease to 60% in cases after 5 cycles. The population with a reproduction rate of 1.1 would have 2.67x the cases than if it had reduced it to 0.9 then.

This math is fairly simplistic, most people should already understand the concept of 2 way protection. Even though protecting yourself with a mask isn't proven and far from a certainty. I think I only agree with the baseline. Which is masks are better than no masks. In this equation you assume the effectiveness of the mask. As you mentioned the effectiveness on the box is not equal to the the prevention rate of getting the disease, this also depends on how easily the disease is transmitted. If transmissions only occurred by breading in each others face you could have this as a base model (even though that assumption would still be wrong, it would at least be directly related), but it doesn't. Here's some math to take in consideration and press on people: When you are healthy, wearing a mask without the right etiquette increases the chance of 'YOU' getting sick by XX%. I say XX because it is known and quite evident that it does, but I don't know the exact number, but also because the number is of little consequence to what follows. If you assume that most if not all people are either getting tired of wearing masks / just do it to not be shunned and abide by the law / or just don't know any better... You can state that the same XX% more people will get sick. When you get yourself sick, you start contributing to making other people sick. The point to take away here is not that masks do not work, but to not just tell people to wear a mask. Rather explain to them how to wear a mask, and how NOT to handle them when used and actually show them the whole story. Not to dumb down information because we think they can't understand the whole truth or importance. I know some people give that appearance, but in my opinion it is because often they are assumed to be too stupid. None of this is too complicated to understand, the math isn't that complex. To both politicians and doctors alike: "It is nice you do what you do, don't get me wrong, but you are not THAT smart". Just tell people the whole story.

Ah you see tho i spray myself with lysol every 5 minutes and i have 99.9% drop in transmission