PBS

Invisible to the naked eye, our night sky is scattered with the 100s of billions of galaxies the fill the known universe. Like the stars, these galaxies form constellations – hidden patterns that echo the reverberations of matter and light in an epoch long before galaxies ever formed. These are the baryon acoustic oscillations, and they may hold the key to understanding the nature of dark energy.

Do you remember the times when you had to remember the phone number of your best friend in order to call her? There was no such thing as speed dial and there was no virtual phonebook on your phone. If you wanted to remember a number, you either had to write it down in an address book or try to dial the correct number time and time again. Do you even remember a phone number right now? Chances are, the only phone number you do know by heart is your own because you’ve had to repeat it time and time again when giving out information. Well, the same thing applies to your relationship with search engines. There are two types of <a href="https://rumble.com/v3265p-test-your-memory-with-this-quiz.html" target="_blank">memory</a>, nondeclarative and declarative one. The first type is basically muscle memory, it’s remembering all the steps you need to do in order to ride your bike or let’s say dial your best friend’s phone number. Declarative memory is basically remembering all of that non-material information, like your best friend’s number. What’s happened in the age of <a href="https://rumble.com/v4bwab-10-cool-google-searches-that-will-blow-away-your-mind.html" target="_blank">Google</a> and search engines in general, is we’ve been expanding our declarative memory. We learn new things, but we don’t store them in our brain as we did before. Instead of keeping them in our memory, we just remember the path to finding them on the internet. This is both good and bad because we can obtain even more information than before and we are always thirsty for more, but we do it at the expense of not being able to store it in our mind and reach it in the events when we don’t have access to a search engine. This makes us even more dependent on the Internet.

Most of us have felt it before, that strange sensation that you’ve been somewhere or seen something before, as if you already remembered what’s happening. Are you psychic? Nope, that’s just déjà vu. Why does déjà vu happen? Well, scientists aren’t completely sure, but they’ve got a few good theories about it.

The double slit experiment radically changed the way we understand reality. Find out what the ramifications of this experiment were and how we can use it to better comprehend our universe.

Can we subconsciously "catch" emotions from other people?

Could a slight rise in narcissism from increased use of social media actually make us better, more self-aware people?

A look at the science behind pigeons.

And how is dog sleep different than our own?

Stars are our stellar alchemists. They spend their entire lifespan creating and molding elements. In their final moments, a supernova spreads these elements out into the universe, providing the building blocks for new stars, planets, and even us!

With this simple exercise, what can you learn about creativity?

It's been one (tropical/sidereal/anomalous) year since I uploaded the very first It's Okay To Be Smart. Here's everything that's happened since!

How does memory work? And how does… un-memory work? Our brain does a lot of remembering and forgetting every day, so you should probably make room for som info on how it works. You’ll also get to meet some people who can’t make memories, and also never forget anything.

Planck's Length is the length below which the concept of length loses its meaning. What exactly does that mean and what are the incredible implications this fact has upon our reality? To find out check out this episode of Space Time where Matt digs into the early history of quantum mechanics.

Whether it’s too much detergent, over soaking or overheating, you are probably doing your laundry wrong. We, humans, spend on average 23,214 hours over the course of our lives doing laundry. To sum it up, that is over two and a half years. People used to run water through garments to remove stains and would literally beat the stains out with rocks and bats. After centuries of washboards, scrub buckets, and hand-cranked machines, in 1906 someone thought to introduce the electric washing machine into our everyday lives. Technology may have improved the quality of our lives by improving the way we clean our clothes, but it has also introduced a myriad of ways for us to do it wrong. The first mistake is the one almost everybody makes - using too much <a href="https://rumble.com/v323u0-how-to-make-laundry-detergent.html?mref=6zof&mrefc=85" target="_blank">laundry detergent</a>. Using more of the already expensive stuff isn’t going to make your clothes any cleaner. In fact, excess suds can actually hold dirt pulled from clothes and keep it in areas that are hard to rinse, like under a shirt’s collar. The next common laundry faux pas is rubbing stains furiously. It can actually make the stain worse and wear away the fabric. Instead, just dab it off instead of rubbing by dabbing from the outside inward. If anything, it will contain it. Another mistake people make is washing their clothes too often. Think about it - if you wash your clothes after just one wear gives you more loads and therefore more energy and water usage wasted on the chore. You probably even overstuff your machine. Think of your clothing as a teenager - give it space! The principle goes that if you overstuff the machine, not all the clothes will get cleaned. If you overstuff the dryer, things will get wrinkled, which is the opposite of what the machine is supposed to do. Love a good dryer sheet? Actually, the best way to use them is to not! Instead, opt out for <a href="https://rumble.com/v31sog--wool-dryer-balls-save-money-with-woolzie-big-ball-laundry-balls.html?mref=6zof&mrefc=84" target="_blank">dryer balls</a> because they are reusable and less chemically toxic. Now that you know all this stuff, it is a good time to start practicing it and start saving money by keeping it clean.

Is overpopulation real? Is Earth filling up with too many humans? How many people can Earth hold, anyway? As our species approaches 8 billion, human overpopulation is a major concern for many people. How can we reduce poverty and our impact on the environment? Do we need a forced one-child policy or something? Maybe not, because when we look at the science and history, populations seem to control

All forms of curiosity, even silly hypotheticals, are important – they can lead to practical ideas as well. And two groups are great at it: kids and smart adults. But the average person forgets to be curious. Here we explore the power of curiosity, and in the words of Joe Hanson – Stay Curious! Don’t shy away from asking questions, however pointless they may seem.

Black holes are the result of absolute gravitational collapse of a massive body: a point of hypothetical infinite density surrounded by an event horizon. At that horizon time is frozen and the fabric of space itself cascades inwards at the speed of light. Nothing can travel faster than light, and so nothing can escape from below the event horizon- not matter, not light, not even information.

We know more about some other planets than we do about the deepest corners of Earth's oceans, and the species we've found there are almost alien. Here's some of the most unbelievable oddities ever observed! Special thanks to the Monterey Bay Aquarium Research Institute (MBARI) for help with this video!

If you sometimes feel scared and are ashamed of it after, don’t be. It is a good thing. It means that you are alive and all of your ancestors successfully avoided death at least for a while. It also means that you come from a very long line of people who are good at being scared. Grab your chair folks, this is a story of sound, science and fear. Fans of scary movies know that there are primarily two was movies use sound to scare you: your jump right off the corner trick, or, use sound to set a generally more frightening mood. If sound is nothing more than vibrations, what is about our biology that makes only some of them so scary? And we are not talking about that creepy kind of scary that grabs you slowly with its cold ethereal hands. That slow fear only happens when your higher brain functions take over. Here we are talking about instant fear, the <a href="https://rumble.com/v4i5bd-having-snow-much-fun-dog-filled-with-snow-much-fear-pooch-wont-chill-out-be.html" target="_blank">fear</a> that is built into our very biology. So why do we get scared in the first place? Easy. So we could live long enough to reproduce. If you want to avoid being a lion’s dinner you have to think fast. Luckily, sound moves faster than sight. Wasn’t this the other way round? Yes, in physics, but not in our biology – our <a href="https://rumble.com/v35ury-carbs-make-your-brain-shrink.html" target="_blank">brain</a> gets in the line first. Despite the fact that light travels faster than sound, our brains take much longer to process that light into an image. A millisecond too long for us to react. So, we are wired to have sound as the first alarm. And what happens then? We wouldn’t want to spoil your fun by saying anything more! Grab yourselves a cup of coffee and enjoy the rest of the video!

Some people are notoriously bad at setting deadlines and estimating time. The comforting fact is that it's largely not our fault. Many factors play a part in our distorted perception of time, and most are difficult or impossible to modify. Time itself is not something we can change either, despite all our dreams of time machines. Why does life seem to speed up as we get older? Why does the clock in your head move at a different speed from the one on the wall? Why is it almost impossible to go a whole day without checking your watch? Is it possible to retrain our brains and improve our relationship with it? Why time slows down when we’re afraid, speeds up as we age, and gets warped when we’re on <a href="https://rumble.com/v3l6bf-next-stop-big-island-hawaii-vacation-travel-guide.html" target="_blank">vacation</a>? We construct the experience of time in our minds, so it follows that we are able to change the elements we find troubling - whether it’s trying to stop the years racing past, or speeding up time when we’re stuck in a queue, trying to live more in the present, or working out how long ago we last saw our old friends. Time can be a friend, but it can also be an enemy. The trick is to harness it, whether at home, at work, or even in social policy, and to work in line with our conception of time. Time is not only at the heart of the way we organize life, but the way we experience it. What can we do? To fix our <a href="https://rumble.com/v4igjb-a-timelapse-of-a-grasshopper-eaten-by-ants-and-wasps-over-a-day..html" target="_blank">broken perception of time</a>, we can reevaluate our relationship with it, become more aware of how we spend our days, and understand how our perception of time influences productivity. We can also seek time-management methods that will make us feel more in control of our time and less like its victims.

Every time this dog owner prepares to leave the house, her pet Luna tries to come with her. It is like she experiences FOMO, the fear of missing out! We would like to believe that our pets actually miss us, rather than missing out on what’s outside. Our dogs really miss us when we are gone? Watch this video to find out! First of all we need to think about relationships. Humans miss other humans because we have an emotional connection to each them. We have the capacity to bond and love, and so do dogs. It is just little too hard to figure out how dogs love us. One scientist trained dogs to willingly go into an MRI machine and stay there, so he cans study their brain and behavior. Can dogs have <a href="https://rumble.com/v4ffx1-baby-has-major-fomo.html" target="_blank">FOMO</a>? In one of his studies, he gave the dogs 5 scents, their own scent, the scent of a familiar and a strange human, and the scent of a familiar and a strange dog. What they found was that a certain brain region involved in positive expectations and reward was activated by the scent of the familiar human. The dogs had positive association with that person. However, it is difficult to say whether <a href="https://rumble.com/v30suj-charlie-says-blah-blah-blah.html" target="_blank">dogs</a> miss their owners when they leave or if they just miss familiar company. Another study looked at how dogs’ behavior changed around people with different degrees of familiarity, their owner, another familiar person and an unfamiliar person. They found that dogs preferred their owner. In one of the tests dogs would wait behind the door that their owner went through and not the other people. However, owners often wonder whether their pet knows how long they have been gone, i.e. whether they have a perception of time. Watch this video to find out!

Why does February only get 28 days when all the other months get 30 or 31? The answer is part superstition, part politics, and parts astronomy. Basically, it’s the Romans’ fault.

For some forms of live, old-age is relative.

What do we mean by "normal"? Cognitive scientists have found that your notion of normality is shaped by the average (like statistical norms and hard data we have about things) and your ideals (the beliefs you hold). So our sense of normal is all a little different – knowing this can help us understand other views and how our perceptions can change.

What happens when you divide things that aren’t numbers?