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Brilliant is offering a 30 day free trial and 20% off an annual premium subscription when you sign up at Brilliant.org/SciShow. When it comes to science on the internet, it’s risky out there.

So today, we have decided to delve into some of the doozies and debunk them. Everything from old wives tales, to trending Tweets (and yes, I still call them Tweets) to full-on medical misinformation. And I have to say, this is no hate to anyone who might have been confused or fooled by any of these things.

It’s a mess out there. It happens to us all. It’s a know better, do better kind of thing, you know?

So anyway, here are just a few of the most questionable takes about science that we have seen floating around the Internet lately. [♪ INTRO] We’re going to start with one that you’ve almost definitely been told before (I know I have): that you lose most of your body heat from your head. Turns out that math is a bit off. In a 2006 study, researchers compared how much heat was lost when someone was submerged in cold water, both with their heads sticking out of the water, or submerged.

And I hope those participants were paid well, because that does not sound like fun. They found that fully submerged people lose more like 10% of total body heat from their heads, which makes sense, because our heads make up about 7% of the surface area of our bodies, so it’s fairly proportional overall. And experts say it’s pretty much the same as if you went out wearing shorts or a sleeveless tank top.

Whatever body part is exposed is going to lose heat pretty fast, but the loss is proportional to the size of the body part. This rumor might have started from old military experiments from the 1950s, where volunteer soldiers put on Arctic survival suits and were exposed to extreme cold. And while they had those super-insulated suits on, they weren’t given matching hats to go with them.

Because their heads were the only part of their bodies left uncovered, most of their heat was lost there. They basically became human chimneys, because the heat only had one escape route, out the noggin. But what’s interesting is that for all that talk about wearing hats, nobody seems to talk about covering up your face in the cold, too.

And that could be just as important as appropriate headgear. Having cold air blown on your face can actually influence how your heart and lungs react to the cold, causing reduced heart rate, among other things. So while you’re not losing like a ton of heat out of your head, it’s still a good idea to cover up.

Next! Speaking of outdated evidence, let’s talk about dog training. You might have heard from dog trainers on TV or social media that to get Fido to act correctly, you have to show your pup that you are the alpha in the pack, and show dominance over them to respect you.

Cause that’s what wolves do, and dogs are just fluffier wolves, right? Well, no. For one, wolves don’t even have alphas.

That whole idea comes from outdated studies of wolves in captivity, and those studies have been so debunked that the original author doesn’t even stand by them anymore. Wolf packs in the wild are just family units led by the parents. When the pups grow up, they just start their own family packs, so there’s never any, like, power struggle, which means no need for dominant behaviors.

And applying that outdated alpha logic to your own personal dog pack isn’t just flawed, it can do some real harm. According to veterinary associations around the world, being aggressive towards your dog and doing things like pinning them down or taking their food away can make dogs more aggressive and anxious, not obedient or submissive. Instead, dog behavior experts recommend exposing your dog to lots of different experiences when they’re young and using reward-based training.

Basically, be nice to your dog and they’ll be happier. Who would have guessed! But those examples were old and wrong.

Let’s talk about one that’s new and wrong! So this meme here is trying to show that when ice melts, it does not raise the surrounding water level in the glass. So therefore, rising sea levels are a myth.

And it probably won’t surprise you to hear that the Earth is slightly different from the water in a measuring cup on someone’s counter. The cup on the counter is a red herring, because when we’re talking about sea level rise, it’s not the ice in the ocean that researchers are worried about. It’s the ice on land.

When ice melts off mountains and glaciers, it flows into the ocean, putting more water there than there was before. Plus with the glaciers, the melting process can also break off big chunks of ice, meaning there’s even more water displaced. And that’s what plays the biggest role in rising sea levels, not the icebergs that were in the water already.

It’s essentially like pouring more water into the cup, and then also adding more ice cubes. Experts predict that if all the world's glaciers and ice sheets melted, global sea level would rise by more than 60 meters. On top of that, warmer temperatures actually cause the water itself to expand and take up more room.

That’s just the physics of what happens when you heat something up! So no, rising sea levels are not a myth. Next!

While we’re on the topic of climate change, here’s a post that claims that plants will actually do better as we keep emitting carbon dioxide, so we don’t need to do anything about that. I think the argument here is that because photosynthesis uses carbon dioxide as fuel, more CO2 would mean more plant growth. And it’s technically true that if you take a single leaf and pump more carbon dioxide over it, then it does photosynthesize faster.

But that’s in lab settings. What happens in the real world isn’t as nearly simple. First off, CO2 isn’t the only player when it comes to plant growth.

Plants also need nitrogen. Nitrogen is a big part of what makes chlorophyll, the stuff that allows photosynthesis to happen in the first place. It’s also a building block for the proteins that make up the living parts of cells, which helps plants grow their flowers and shoots and fruits.

You know, all the things that we eat. We can use nitrogen fertilizers for our farmed crops, but it’s not like we could fertilize the rest of the plants around the world, so without more nitrogen, any extra CO2 won’t help them out. Plus, not all plants respond the same to more CO2.

For example, a 2022 study found that an assortment of woody and grassland ecosystems all reacted to extra carbon dioxide differently, and how they grew with CO2 supplementation largely came down to precipitation. In wetter years, carbon dioxide boosted growth in woody ecosystems, but reduced growth in grasslands. And a different study found that extra CO2 made essentially no difference in how tall forest trees grew or their canopy density over 12 years.

But probably the biggest problem with the whole pro-CO2 argument is that it totally ignores all the harmful things that we know excess carbon dioxide does to our planet. The most obvious of course being it would get a whole lot warmer, meaning dry soil, more droughts and a whole lot of stress for plants. Experts agree that all the damage done by temperature rise would be much worse for plants and the environment overall than any benefit you might get from more CO2 in the air.

So that particular myth, we can snip it in the bud. It’s a plant metaphor. Probably the only things that are more pervasive than climate myths are diet myths, so let’s take a look at one that’s cropping up all over the place.

There’s this idea floating around that seed oils like canola, sunflower, or rice bran oil are like, super bad for your health. A lot of people point to linoleic acid, a kind of omega 6 fatty acid found in those seed oils, as the bad guy. Just like their more famous cousins, the omega 3s, we need omega 6 acids as part of our diet.

But if we get more of it than we need, excess linoleic acid gets metabolized into other compounds called oxidized linoleic acid metabolites, or OXLAMS for short. And the concern is that these OXLAMS are what leads to anything from obesity, diabetes and chronic inflammation to cancer, heart disease and even Alzheimer’s. But when we start looking into other health conditions, the evidence is really mixed and even contradictory.

For every study that finds a link between linoleic acid and a health condition, there is another that finds no link at all. A meta analysis of 30 studies investigating linoleic acid and heart disease found that people with higher levels of linoleic acid had slightly lower overall risks of developing heart disease. Experts say that both omega 6 fatty acids like linoleic acid and omega 3s are beneficial for the heart.

So we think that the problem with seed oils isn’t the oils themselves, but what foods they are most often found in. Most of the time, seed oils are used in salty, fatty snacks and fried foods, which are linked to things like high blood pressure and heart disease. And if you keep heating and cooling any oil over and over while cooking, like you do if you’re reusing fryer oil, the fatty acids turn into trans fatty acids, which are associated with clogged arteries.

So usually when people cut out seed oils, what they’re actually cutting out are these super-processed or deep-fried foods, which may be why some people say they feel better when they kick seed oils to the curb. But by and large, the data suggests that seed oils themselves are fine in moderation. Next!

It’s not just the kitchen where these harms are lurking. Oh no! Bad science is coming at you potentially from every room in the house.

Specifically some people have been claiming that wifi can make you sick. Now, we actually did a whole video on this, but I won’t make you watch it. Here’s the gist.

The argument goes that the electromagnetic radiation from wifi and other household appliances like TVs or cellphones makes people feel foggy, irritated, dizzy, itchy or nauseous. But many studies have tried and failed to bring out people’s supposed symptoms by exposing them to this kind of radiation in controlled, experimental environments. Most of those studies conclude that the whole wifi syndrome or electromagnetic sensitivity is an example of the nocebo effect.

Basically, if people believe electronics are making them sick, they start to feel sick. Or, those symptoms might stem from other parts of our tech-heavy world, like screens or fluorescent lights that might give you headaches. But it’s not the Wifi waves.

Next! Moving on to the bathroom. We found this post claiming that period blood has bits of baby in it.

Which sounds really scary I guess! Good thing it’s completely wrong. Periods happen when your body releases an egg from the ovary and it doesn’t get fertilized.

The inside of the uterus is lined with tissue called endometrial tissue, which is meant to be extra cozy for a growing embryo. But no fertilized egg means no implantation, so the uterus decides to redecorate and sheds the lining. So period blood is mostly made up of that endometrial tissue, as well as other vaginal secretions, and just regular blood.

There are no baby bits, because there was no baby. Next! That brings us to yet another health myth, but for actual babies.

When a baby is born, it’s pretty common practice for them to get an injection of vitamin K. Vitamin K helps our blood clot, but babies don’t have much of it when they’re born. Some of our body’s supply of vitamin K comes from our gut microbiome, but babies don’t have the right microbes yet to make their vitamin K for a while.

And the rest of it comes from our diet, which is also problematic for babies since they aren’t eating any leafy greens or meats that are rich in vitamin K. Which, like they’re not supposed to eat those things yet, but. Still.

Without enough vitamin K, babies are seriously at risk of bleeding disorders, especially brain bleeds. Just one vitamin K shot massively reduces the risk of that bleeding, which sounds pretty great! And yet, people post scary things like this about the possible dangers of vitamin K, leading to more and more parents rejecting the shot.

Sadly, that means cases of vitamin K deficiency bleeding in newborns are on the rise. Now, most of the concern around vitamin K is because of something called a black box warning the drug carries. This is one of the highest safety warnings a drug can have, and it’s designed to make consumers and physicians aware of any major risks with the drug.

Vitamin K has this warning because it can trigger allergic reaction or anaphylaxis if it's injected in the veins, usually as a countermeasure to overdoses of blood thinners. But this isn’t relevant when we’re talking about babies getting the vitamin K shot, for two reasons. One is that in most cases the injection is given to babies directly into their muscle, not into their veins.

The box warning is specifically for patients getting a dose directly into their bloodstream, not into muscle. And yes, that does matter! The second reason is that anaphylaxis from any cause is really rare in infants because it’s an immune reaction, and babies’ immune systems aren’t fully fueled up yet.

According to the CDC, there’s only been one case of anaphylaxis in an infant caused by the pediatric vitamin K shot worldwide, over more than sixty years of giving it. And that is a phenomenal safety rating! Which is why you should take your medical advice from doctors, and not Instagram posts that do better if they scare you.

And the moral of this whole story is that you should not trust everything you see on the internet. If something sounds fake, you should look for the source. And if you ever see somebody who might be believing one of the myths we talked about in this video, here’s a video for them.

You can send it to them. If you want us to do more of videos like this, you can leave suggestions in the comments of any bad takes you see on the internet or hit us up on community posts or social media or whatever. Thanks for watching and thanks for being a part of this.

A lot of those inaccurate science takes can be cleared up with some critical thinking and fact-checking from credible sources. But those are not skills that you’re just born with. You have to learn them and practice them in order to keep them sharp.

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So you’ll learn about science, computer science, and math through case studies and puzzles that keep you engaged in the topic. That way, you’re learning how to learn and think bigger in the process! And the people at Brilliant understand the value of credible sources.

That’s why they work with professionals from Microsoft, MIT, Google, and Caltech to make their lessons. I mean, if you want to learn about how technology works and programming, there’s kind of nobody who knows that stuff better. And since Brilliant is bringing all of their smarts to you in an engaging and interactive format, you can know all of that stuff too!

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Thanks to Brilliant for supporting this SciShow video! [♪ OUTRO]