"Today. You'll learn a trick for actually using your vacation days, even when you're super busy and the science behind white darkness is actually faster than the speed of light will also learn about the hidden science of sand in a clip from the most popular interview eve done in the last year. Let's satisfy some curiosity in you manage to get away from the office this summer because it's healthy to take a vacation from work. Don't feel like you missed your chance though, because we've got some advice from a time management. Coach might help you use up those days and stay sane at work. I like it. Yes. I feel like I need to take this advice. I feel like you do too. Ashley not that. I don't like seeing you around the office. In two thousand seventeen fifty two percent of American workers with paid vacation days left, some of them unused that added up to a whopping seven hundred and five million unused vacation days overall or two million years, which is about how long it's been since humans appeared on earth and working too much has been linked with heart problems, mental health issues and a decrease in work quality in general. But a recent study by glass door found that worries about job security are the main reasons people don't take vacations, so what can you do in an article for Harvard Business Review business owner and time management? Coach. Elizabeth grace Saunders advocates something that's brilliant in its simplicity micro vacations. That's when you get out of the office, but you use a day or less vacation time. And even just one day comes with a lot of benefits you won't have to find a replacement to handle your work, you won't come back to a mountain of emails, and you can do a micro vacation once every couple of weeks. Nobody said you can only go on one big vacation every year. Year you might want to avoid taking a Monday micro vacations since a lot of people send important emails on Mondays. And you don't wanna come back to his billions messages in your inbox. But how does the three day weekends out? Take off a Friday once in a while. And another big thing is that micro vacations can be free. You don't have to spend time making a vacation itinerary or spend money on plane tickets if your job allows it you could even take a half day to take a long lunch with a friend or catch a met navy movie. You've been wanting to see whatever you do. Don't lose your vacation days. You need a vacation. Trust us. The best employees is take the most vacation days. That's true. You keep saying that to be. I don't understand why. Oh, I'm not gonna say anything. Sinned is one of the most important materials in human civilization and were running out of it. If you don't believe me, that's okay. We've got an expert who might be able to convince you we recently had the chance to talk to Vince buys her author of the world in a grain the story of sand. And how it transformed civilization? Here's what he told us. So we consume more sand than any other natural resource in the world except for water and air. That's how important it is. I mean, I say in the book, it's the literal foundation of modern civilization. And that's that's no exaggeration. Because as you say, it's I mean, you toss off concrete and glass, but really if you stop and think about concrete and glass, that's basically what our cities are completely made of every shopping mall apartment block every building in the modern world that gets built is made out of concrete, and that's an enormous amount. So we use about all in. We are using about fifty billion tons. Of sand every year that's about that's enough to cover the entire state of California about two inches deep every single year. That's quite a bit. That's quite a bit. I've got a giant world map on my wall imbed room and right in the middle. So you know, what's there? It's africa. And right in the northern part Africa. There's a big old desert. So how can there be a shortage? If the Sahara exists that's a really good question. The answer is because that desert sand is basically useless to us, and the reason for that is it the greens or the wrong shape. So desert sand has been eroded by wind over thousands or millions of years tumbling, and tumbling and tumbling and tumbling and that has made those grains, kind of rounded as opposed to the kind of sand that you find in river beds or lake beds. Flood plains even the bottom of the ocean. That sand tends to be more more angular. It's got a lot more angles and corners to it. So it locks together the way the. You needed to form a stable structure? So the thing that we use San by far the most thing that we stand for the most is concrete and to make concrete you need those same greens to lock together and desert sand just is to round to do that. It's like the difference between trying to build something out of a stack of marbles as opposed to building something out of a stack of little tiny bricks, so all that desert sand, totally useless. He's nudie curiosity. You might not know that when we first launched our podcast a weekly show where we interviewed scientists and authors from around the world will back by popular demand. We've been producing brand new feature length podcast interviews for our supporters on our patriotic page before we get to our last story. I want to give a special shout out to some of our patrons. Thank you Genevieve Moffitt Cambronne and day used Banco for supporting our show on patriot. We really appreciate it. If you love our show and you want to support curiosity daily than visit patriot dot com slash curiosity dot com all spelled out any amount helps and we try to give back. Offering cool incentives like bonus episodes, uncut interviews and fun conversations on dischord one more time. That's patriot dot com slash curiosity dot com. Eight one to no it's faster than the speed of light the speed of dark. No, really. It's a thing. That's how fun little physics lesson. And we'll preface this by saying, please don't get mad at us. We promise it's true. Even if it's kind of hard to wrap your head around. Yes. This is the second time we run this article. And we got a lot of emails about it before. And I have done my due diligence. This is absolutely for. Sure. True. All right. Here's how it works. Even though nothing can move faster than the speed of light shadows can still move faster than the speed of light a mentioned, you have a light that's powerful enough to reach the planet Jupiter. Okay. Got that. Now, imagine that it casts to be mccone that's broad enough to cover the entire diameter of the planet. When you pass your finger over that light, the shadow will cross the entire diameter of the planet. That's a distance of more than eighty six thousand miles. The speed of light is one hundred eighty six thousand miles per second. So if it takes less than half a second to move your hand that distance. Then that shadow will have broken the speed of light. Remember how he said that nothing can move faster than the speed of light. Well, that's the key shadows are nothing. A shadow is a not thing shadows are the absence of something specifically photons or particles of light since there's nothing that's actually traveling the distance thing that's moving is an area. Where photons aren't there's no information that's being transmitted faster than light only a blockage or lack of information. That means you're interplanetary shadow puppet. Show doesn't break any physical was which means we're right? And we hope you're not upset with us for this brain teaser. But we promise it's true another way to think about it is that the shadow only has the illusion of moving is actually the region that has light and has no light that is changing. Right. So it's not physically moving across the planet. Right. It just looks like it is right. You love this article. But you kind of hate it too. Oh, yeah. The love hate relationship."