Things To Know - Kids Video | Basic Science For Kids | Good To Know - That's a Good Question

Join Kids Heart Family What are you looking at? At the moon. It looks so beautiful. But Tia, why does the moon shine? Now that's quite interesting, Tofu. Technically, the moon does not shine by itself because it has no light of its own. It appears to shine because of the sunlight that reaches it. Ah, Tofu, let's go home. I'll explain you how the moon shines. Hold this ball in your hands, Tofu. And I'll hold this flashlight in my hand. Okay, but what do they represent? The flashlight in my hand represents the sun the ball in your hand represents the earth and the mirror on the wall represents the moon. Do you see the mirror shining and that light getting reflected on the ball, Tofu? Yes! This is what happens. The moon just reflects the light of the sun and what we see is the reflection of that light. Oh! The moon reflects only 7% of the sun's light and then glows softly. The fact that it glows softly and reflects only 7% of sun's light is that it absorbs most of the light that falls on it from the sun. Now I know why the moon looks so beautiful. Now time to sleep, Tofu. Ah! I can't see anything, Tia. Wait, I'll look for the torch. Oh, thank God! But Tia, why is it that we can't see in the dark and only in light? I don't know, Tia. That's because, Tofu, in order to see, the eyes must receive light and darkness is the absence of light. I didn't get you, Tia. Most of the objects we see around us are visible by reflected light reflected sunlight or reflected artificial light. You are able to see these objects because light reflects and this reflected light is what becomes a mirror image in our eyes. Since darkness is the absence of light there is no light in the darkness to be reflected from chairs tables or people to our eyes and therefore we cannot see these objects. But we are able to see in the dark after some time. Why is that then? You have probably noticed that it is difficult to see objects inside a house when you have just come in from the bright sunlight. After you have been in the house a little while your eyes adapt themselves to the dimmer light and you can see perfectly well. Oh, thank God! We have torches when it gets dark. Tofu, are you feeling sleepy? No, just tired. But Tia, what makes us yawn? And why is it so that when I see someone yawning I kind of feel like yawning too? Yawning is an involuntary action which we all do and we all know that it is a feature of sleeping. It is commonly associated with tiredness, stress and boredom. All vertebrates do yawn including fish and birds. Human baby starts yawning since they are 20 weeks old. So how do we do it? During a yawn we open our mouth and we suck in a large amount of air and expand our chest. The cavity pulls down our diaphragm and fills air in our lungs and exhales it out. There are a number of theories that attempt to explain why animals and people yawn. As per the physiological theory our bodies induce yawning in order to draw in more oxygen or remove a build up of carbon dioxide. A more recent theory explains that we yawn more in the situations where our brain is likely to be warmer. So it's a way to cool down our brain. Do you know that the average yawn lasts around 6 seconds? Yawning is contagious. Only humans, chimps and possibly dogs find them contagious. Recent studies show contagious yawning may be linked to one's capacity for understanding and sharing the feelings of others. So Tofu, how many times have you yawned while listening to me? I hope not too many. My God! This was so much fun! Yes, it certainly was. But Tia, why do I taste salt in my mouth? Why is the seawater salty? When the rain flows over the land the water washes salt and other minerals out of the rocks and gets mixed with the water in the streams, rivers etc. The rivers finally carry the salt to the sea. The salt stays in the sea as no water flows out of the sea. When the seawater evaporates to form clouds almost all the salt stays behind. The left behind salt slowly gets collected over a period of time and this is how seawater gets salty. Oh! That is the reason we cannot drink seawater. It's too salty. Yes, almost 96% of water on earth is in the oceans and still we cannot drink it directly. Water, water everywhere and nowhere to be found. Tofu, are you alright? No, just a hiccup. But why do we get hiccups? Hiccups are funny ones. Most simple cases of hiccups come after eating or drinking too much or too quickly. You must be wondering where these funny noises are coming from. The part to be blamed is your diaphragm. This is a dome shaped muscle at the bottom of your chest and all hiccups start here. The diaphragm helps in breathing. When you inhale, it pulls down to help pull air into the lungs. When you exhale, the diaphragm relaxes and the air flows out of the lungs back to the nose and mouth. But sometimes the diaphragm becomes irritated. When this happens, it pulls down in a jerky way which makes you suck air into your throat suddenly. When the air rushing in hits your voice box, you're left with a big hiccup. Do you know that almost all cases of hiccups last only a few minutes? Everyone has their own pet remedy for curing hiccups. Simply holding your breath is often effective.