When we go to another country, we often get recommendations for vaccinations that will protect us from diseases we don't worry about at home. It would be the same for time travelers, depending on what era of history they are going to. For example, I might be able to travel to a time where smallpox was rampant, but my children would not, since they never got the smallpox vaccine. In the 21st century, we don't worry about the plague or leprosy because they are treatable, but going to the past means you also go back to when we didn't have antibiotics, so you'd better take some. If you travel to the future, you may find yourself in the middle of a sigma flu epidemic, and you are the only one in town who hasn't had a sigma flu shot -because you've never heard of sigma flu. Hank Green gives us some perspective on that one aspect of time travel that science fiction writers never think of.

Water, water everywhere, and nary a drop to drink. That's the ocean, and it's pretty big. Even if you're stranded out in the middle of the sea, you can't drink seawater, because it's so salty that it can poison your body. Most of the water on earth is seawater, and with climate change, fresh water is getting somewhat scarce in places where people need it. That's why there are more and more desalination plants every year, working to provide fresh drinking water but also contributing to the problem by using fossil fuels. Meanwhile, if you ever find yourself stranded out at sea, this TED-Ed lesson has a few tips on how to obtain fresh water, either from rain or dew, or from the blood and organs of certain sea creatures. To the person who doesn't have it, fresh water is more valuable than anything.   

You may have heard that eggs are bad because they cause high cholesterol. That was the conventional wisdom since the 1960s, but it's far from the whole story. We've learned a lot about cholesterol since then. It's all about fats, which we need, but not a lot, and come in many different types, some more harmful than others. Then there's HDL, or good cholesterol, which counteracts LDL, or bad cholesterol, and it's hard to keep up with which is which and how to regulate them in your body. Luckily, we have the TED-Ed lesson to set us straight on cholesterol and how to keep our arteries in good shape. (via Geeks Are Sexy)

Even if you consider yourself the picture of health, your doctor will inevitably tell you that you should get more exercise. However, the thought of joining a gym, buying exercise equipment, or counting 10,000 steps a day seems like a lot of work, and such lofty goals are liable to set you up for failure. Instead, your goal should be to incorporate walking into your daily routine until it becomes a part of your normal lifestyle. Any increase in walking will benefit your body over time. One short stroll around the neighborhood will make you feel good, and may lead to two strolls around the neighborhood.

Walking around the neighborhood has benefits beyond health, too. It gives you the chance to speak to your neighbors, meet all the dogs and cats, and admire (or judge) the houses in your area. Walking alone gives you a chance to think, and walking with a companion is a great opportunity for conversation.  

One of the reasons I didn't go to graduate school was lack of sleep. See, the elite schools I applied to needed an early GRE score. The only time it was offered in my ___location was during finals week. I studied so much that week that I fell asleep during the GRE and didn't finish the last section at all! Lack of sleep can really trip you up, as this TED-Ed lesson explains. (via Damn Interesting)

I know, the first thing you do when you see a TED-Ed video is check to see how long it is. This one is pretty short. It’s the story of how Band-Aids were developed. I’d heard the story of the invention before, but the way Johnson & Johnson first marketed the product is pure genius.

As you know, Band-Aids have a lot more uses than just covering wounds. They are great for protecting that spot that would eventually develop a blister as you shovel dirt or break in a new pair of shoes (a concept foreign to young people). They also keep your nipples from bleeding as you run a lengthy footrace. They make children believe they are “all better.” And if you keep some in your purse, they work as an emergency fix for wardrobe malfunctions. (via Laughing Squid)  

The US is in an obesity epidemic. If you aren't obese, you are still most likely a bit overweight. How do we lose weight? For years, we've been told it's a matter of diet and exercise. More updated research tells us diet is much more likely to work than exercise, and Kurzgesagt explains why.

But that doesn't mean you can swear off exercise, far from it. Exercise may be only a minor factor in losing weight, but it's a major factor in just about everything else to do with our health. So if you want to lose weight, you'll have to pay attention to what and how much you eat. All of us need to exercise, no matter what our weight is, due to the constant expenditure of energy our bodies have. It must be channeled in the right direction. The length of the video is 9:19; the rest is an ad.  

Fascinating footage of a human white blood cell chasing a bacterium captured through a microscope.

📽: David Rogers pic.twitter.com/LAaHjUHLXF

— Wonder of Science (@wonderofscience) July 9, 2024

I watched this and thought. "It would be more amazing if he caught it." And then he did!

When I think of a really deadly disease, I think of rabies, because it's not only virtually 100% fatal, it is a horrible way to die. But "deadly" in this video doesn't mean the rate of death, but the number of people who die. You might guess what the "white death" is, but since the video strings you along, I won't mention the exact disease. In this video, Kurzgesagt provides the art and John Green provides the commentary as we learn how the white death infects a human body and makes its way past our immune system. Of course, our immune systems always have a plan B, but that in itself can make us sick or even kill us. This slow, sneaky disease killed 1.3 million people last year. And that's a problem. It's so slow and sneaky that we tend to ignore it. But there is hope on the horizon.

There are lots of different ways to prevent pregnancy, and the variety of methods are rarely covered in school, from what I hear. When I attended school, there was no sex education whatsoever. Later on, schools were caught up in "abstinence only" education, and today it varies from place to place at the whims of state and local politics. So I should not be surprised at how many people do not know the mechanics of how birth controls methods work, even if they use those methods. Minute Earth takes an overview of the most common modern birth control methods and explains what they do to interrupt the process of beginning a pregnancy. (via Geeks Are Sexy)