 Hello everyone, it's 11 o'clock Sunday and it's a sunny Sunday morning in Mumbai. I, Suravi bring to you yet another Steamboat session and I'm very very happy to share with you that today we have, I mean, we have almost completed, we have completed one year and today we are starting episode one of season two. And now Sunday being obviously Sunday, we tend to, well, we some of us at least tend to, you know, wake up late, either cause we sleep late on previous Saturday night or we just don't feel like doing anything or getting up early morning in the Sunday. So today we have among us, Megha, who is associated with the design and technology lab of HBCAC that is Humebaba Center for Science Education, and Megha works on creating new resources for students and teachers in design and science. So, Megha, are you there? Yes, Suravi, I'm here. So, we welcome you to this steamboat session. And so, Megha, today I guess we are talking something on about sleep, right? So are you, like, will you tell us like how to sleep or like, or you are going to make a sleep in the session, like, what is it exactly about? No, actually, I'm not going to date how to sleep. I'm also not planning to make you sleep, but in the session we are just going to sleep, what to sleep because and what happens inside our body and brain when we are sleeping. Okay. Sleep is such a common phenomenon, we all of us sleep every day, but we don't think about what is happening when we are sleeping inside our body and brain. Is it really important to our life? Nowadays people ignore their sleep a lot, they sleep at 1am, 2am and they get up late in the morning. So, does this really have any effect on our body? We don't know. And this is what I want to explore in today's session and discuss with students. Okay. So, without wasting much time, let's just start. Firstly, I would just like to know how much, how many hours do you spend sleeping on an average on a daily basis? Yeah, so the audience, you can put in your, you know, your thoughts, your views on the chat box, like how many hours on an average do you sleep? I sleep, I guess, four and a half hours or five hours. Okay. So, so we sleep for five hours. So, I can't see the chat box, so will you have any answers in the chat box? So, we have one answer again. So, Anab is saying six and a half. Six and a half. There's one more answer, seven. Okay. Seven to eight. So, Aditi is saying seven to eight. Seven to eight. Okay. So, okay, if we assume that on an average, we sleep for seven to eight hours. And for your, for our calculation, for first let's just assume that we sleep for eight hours on a daily basis. Then can you just make a quick guess like how much time we spend sleeping in one year? Like how many days or how many hours or how many months we spend sleeping? So, Anab is saying, so you are asking about this average sleep on like about the night sleep or about also the one where in the lectures we sleep. No, no, no, I'm not talking about lecture sleep but I'm talking about night sleep. Yeah. So, like if on an average, whatever the fact is it's eight hours, right? Yeah. So, can you? Yeah. So, eight hours, so it's like 24 hours, my friends sleeping eight hours. But it's like, it's like almost one third of 24 hours. Yes. Yeah, you are right. So, if you consider that you are spending one third of your day sleeping, then how much time do you think you might spend in one year? So, one year has 12 months and one third of 12 months that is 12 divided by three is four months. So, we almost spend four months of your sleeping and if we consider that we are going to live for 75 years, then we are roughly spending like 25 years of our life sleeping. So, 25 is actually a significant number. So, let's explore in the session, are we really investing this time in sleeping or we are wasting this time. And now I have a question for you all. When we are discussing about sleep, what do you think which organ you believe is most closely related to sleep? You can type your answers in the chat box or you can unmute yourself and let me know. So, on this Zoom, we are having answers such as brain, somebody is saying eyes, I guess you too, baby, we have some comments. I have to check it out, let me check it. So, there's heart. Okay. So, here we are getting different answers and someone else has said brain. But mostly has been seen that somehow most of us end up connecting sleep to the brain because we think that brain is the commanding organ of our body, it controls everything. So, most of the people associate brain, the organ brain with the sleep. But you will be really fascinated to know that sleep has evolved even before brains. And according to the recent studies, people have found out that there are animals like there are creatures like Hydra, which are very small like around from few millimeters to one centimeter length in length. And they do not have brain, but they manage to sleep. So, this is so exciting. There are creatures who do not have brain, but they still manage to sleep. So, what is sleep, how it is defined? And researchers and scientists have been wondering upon this question for a very long period of time and now we have a... Mika, I would just like to tell you, when you switch from one slide to another, just give us a bit of like 20 second, 30 second pause so that people who are in YouTube, they can also catch up with us. Okay, sure. I will give 20 seconds. Yeah, pause. So, what is sleep? And now we have a rough definition for it. And sleep is defined as a state where our responsiveness to external stimuli decreases. And creators or organisms which have found that they manage to sleep, they are in relatively inactive state. So, what is relatively inactive stage is like, suppose there is a creature which moves 10 times in one minute here and there. When it's awake, then it moves just once or twice when it's sleeping. So, inactive here we are comparing to that organism only. And organisms which show reduced responsiveness to external stimuli and are in relative inactive stages are assumed to sleep. So, this is how sleep is defined and it has been a really fascinating topic for a human kind. And people have been trying to explore what is sleep, they have been trying to check what happens when we sleep. And it has a very interesting history as well. So, earlier there were many theories about sleep, like till 19th century. And one of the theory was people used to think that sleep is caused by the lack of blood circulation. So, whenever there is no enough blood supply to the brain, brain falls asleep. This is what people used to think earlier. The second theory was people observed that whenever we are sleeping, our body temperature reduces by 1 to 2 degrees Celsius. And they thought that this change in temperature might be the cause of sleep. This change in temperature might be inducing sleep. And the third theory which was there was people related sleep to digestive processes. So, they observed that whenever we have heavy meals, we usually feel sleepy. And this is why they thought that all the energy is focused on digestive processes when we have meals. And that's why we feel sleepy. That is because of lack of energy after having meals, brain falls asleep. These were the theories which were there earlier and this is how people thought about sleep. But now, I want to know what do you think? Why do we sleep? Why sleep important? You can unmute and also answer or you can type in the chat box. Like why do you feel that we need to sleep? I sleep to get dressed. Okay. So, let's see what other people like give. So, let's wait for a few more minutes. Okay. So, Aditya is saying to rest our body and to rest for, I mean to give rest to the body and to the brain. Okay. So, most of the answers are about this only. So, even on the YouTube, we have about like body and brain both. Okay. Ma'am, we can tired so we can sleep. Okay. We get tired and that's why we sleep. Okay. So, indirectly, we are trying to give rest to our body because we are tired, right? Yes, ma'am. Okay, Anushka. Okay. So, most of the answers are like to give rest to our body and brain. So, what do you think? Does activity of our body and brain reduces significantly when we are sleeping? So, you might be seeing two questions on your screen right now. The first one is, does activity of body decrease significantly when we sleep? And the second one is, does activity of brain decrease significantly when we sleep? So, you can type your answers in the chat box or unmute yourself and let me know. So, if you're typing in chat box and you can type like one yes to no or one yes to yes or one no to me. So, Surya, what do you think? So, I feel both are yes, yes. Okay. And Aditya is saying one no, two yes. Aditya is saying that. Okay. And Anubhav is saying one maybe, but two no. Okay. Pradhan is saying one yes, two no. So, yeah. Okay. So, most of the answers are like activity of the body decreases, that is yes. And for the second question, that is some people are saying that activity of brain decrease and some people are saying that activity of brain doesn't decrease. So, let's see what's the answer. So, the fact is both brain and body stay remarkably active when we are sleeping. Both brain and body are doing their jobs when they are sleeping. So, but they are doing definitely different jobs like when you are active, your brain might be involved in writing, learning new topics, playing, talking to people. But when you are sleeping, it's involved in different activities and we are going to get to know what they are. But right now let's focus on the body part. So, if we are sleeping and body is staying remarkably active, then what do you think which body organ might be staying remarkably active? Which body organs keep working even when you are sleeping? So, Aditya is saying heart. Oh yeah, that's right. Your heart can never stop. Yes, heart is one of the answer. I feel even your stomach and digestive system keeps on working when you are sleeping. Yeah, you are absolutely right. So, when we are sleeping, your digestive system does work. Sati is saying lungs. Yes, lungs also can't stop at all because your body needs oxygen all the time. There's another interesting one by Sayali, subconscious mind. Oh, subconscious mind. Yeah, that's an interesting answer. Yes, brain definitely stays active here we saw. But what are the other body parts you think might be active? Mom, eyes. Oh wow, Anushka has given a really great answer. Yes, your eyes are so active when you are sleeping. So, Pilla found out that even when you are sleeping under your closed eyelids, your eyes are still moving. And on the basis of these eye movements, the two major phases of sleep have been named as rapid eye movement sleep and non-rapid eye movement sleep. Rapid eye movement sleep is a phase when your eyes are moving rapidly when you are sleeping. Non-rapid eye movement sleep is a sleep stage when your eyes are moving slowly and they are not moving rapidly. So, there are two phases. One is rapid eye movement that is ariam and non-rapid eye movement non-ariam. And this discovery happened around 70 years ago that there are two stages of sleep. And even after 70 years of research, today we don't have exact answers for why there are these two stages that is rapid eye and non-rapid eye movement. And how the transition happens and when the transition exactly happens. So, all these answers are still like a mystery to us and a lot of research has been happening in this field. So, let's try to just roughly explore what do we mean by ariam sleep and what do we mean by inariam sleep. So, first one that we are going to see is rapid eye movement sleep. So, in this phase, brain activity is similar to when you are awake. Like when you are awake, your brain is doing a lot of work and it has been observed that in ariam stage when your eyes are moving, the brain is doing same amount of work. It is equally active. And the second observation has been in the stage, your heart rate, your respiratory rate, your blood pressure increases. And one of the most interesting factors in ariam sleep is the period when most of your dreaming occurs. Like all the horrible, happy, funny dreams, like most of the dreams usually tend to occur in ariam sleep. And also it has been observed that blood flow in the brain increases. So, people have been wondering why blood flow in the brain increases and recently researchers have found the answer for it. So, why the blood flow increases? The reason is when you are sleeping, your blood vessels in ariam stage dilates and when blood flow is really fast, it helps in moving toxins from your brain. Here, what do I mean by toxins? Like toxins are the byproducts or the waste products that are generated in brain when cells are working. So, this blood flow is actually helping, the increasing blood flow is actually helping in removing toxins from the brain. So, so far we know these many things about ariam sleep. And the, and about n ariam, it has been observed that in this stage, our overall brain activity is reduced. At times, ariam stage is also known as deep sleep stage as well. We sleep calmly, our eyes are not moving and it has been also observed that in this stage, our blood flow is reduced, heartbeat is reduced and one of the things which we earlier saw that people observed that body temperature decreases, that decrease in body temperature happens in this in ariam phase. So, these have been the observations. So, Megha, let me stop you for a moment. So, there is a question in the audience. Do we see dreams only in ariam? Okay, the answer to this question is actually no. Most of the dreaming happens in ariam, but people do sleep dreams in ariam phase as well. But the sleep, but the observations have been that in ariam phase, whatever dreams we sleep, they are vivid as somewhere to ariam sleep. But yeah, if a person is really healthy and having a good sleep then usually in ariam phase, they don't tend to, then dreaming doesn't occur much in ariam. But yes, dreaming happens in both the stages or both the phases. So, are there any other questions? No, not right now. Okay. So, now we saw that there are two stages in sleep that is in ariam and ariam. But is sleep playing any, so in the sleep, these ariam phases, how they are occurring? Are they occurring randomly or they are occurring in pattern or one day we spend entire time in ariam and the second night we are spending entire time in ariam. So, these have been the questions people have been thinking about. And you might be seeing a graph on your screen. So, after looking at this graph, what do you think, how these stages are occurring? Are they occurring in pattern or they are occurring randomly? What do you think? I can see here a pattern, the graph or the picture which you are showing. Yes, definitely there is a pattern. Even Aditya is saying that there are different patterns. So, you might be seeing that there is a cycle of N ariam and ariam phase and it's repeating after a certain amount of time. And after how much time it repeats, the answer is on screen. Like after every 90 to 100 minutes, this cycle is being repeated. And that is one more interesting thing in this graph. Let's see who notices it first. Aditya has written, there is a pattern of high to low. There is pattern of high to low. Aditya, if you are available, can you just unmute yourself and explain to me, what do you mean by exactly high to low? Okay, I think there might be some technical problem with Hizmai. So, do you observe anything else apart from there? I see the N ariam part decreasing over the hours and the ariam part increasing. Yes, definitely. This was one of the interesting thing which has been found out in last 2-3 decades that the ariam phase, the length of ariam actually decreases as we tend to complete our sleep. Suppose if we are sleeping for 8 hours, so as we are completing 8 hours of our sleep, the amount of time we are spending in this phase is actually increasing. That is our dreaming phase is increasing in short. So, this has been the observation about the pattern about ariam and in ariam. And now we have discussed these 2 phases. Let's see, is sleep playing any major role in our life? So, actually the answer is yes. Sleep has been playing a major role in our life and people are interested in knowing how they sleep, how much they sleep, are they having a good sleep or not. And today we have modern watches which actually track your sleep using your body movements and heart rate and they give you rough data. So, on the screen right now you might be seeing there are 2 graphs. The first graph actually shows how much time are you spending in ariam sleep when you are awake and how much time you are spending in deep sleep. And the second graph shows about how many hours do you sleep in a stretch of 2-3 weeks. But here the interesting graph is the first one, like how much time are you spending in ariam and in ariam. And here we can see that this pattern is very close to what we just saw in the earlier slide. Am I right? So, can everyone see that the length of ariam is increasing as the person is completing its 8 hours? The purple boxes, right? Yes, the purple boxes are ariam phases and the blue boxes are the non-ariam phases. What is that red in a red line? Oh, that red line means that the person suddenly got up. Maybe give us some noise or something like that, right? Yes, yes. So, this is what modern watches are doing and it's really remarkable that we are able to get our sleep data on our watches. So, science has really proceeded fast in the last 100 years. So, now I have a question. Whenever you have exams, have you ever heard your parents or grandparents telling you that sleep well so that you can remember things in your exam like whatever you learned or whatever you have understood? Yes, it happened to me every day. Yeah, even when I used to study for my exam, my parents used to tell me, oh, don't be stressed, you just sleep well, you will remember everything. So, is there anyone else who have this experience? Okay. So, people say that you will remember things well if you sleep. So, is there any solid relation between sleep and memory? Are they really closely related? So, the answer is actually yes. Your sleep and your memories and sleep are actually very closely related and sleep is playing a very major role. And as we saw, there are two phases that is rapid eye movement and run rapid eye movement sleep. These both phases are playing a crucial role in memory. So, there is NREM phase which actually helps in strengthening our memories which are mostly about remembering facts. Here, I mean facts like 5 plus 2 is 7. There are three sides, the triangle has three sides or all the sides of squares are equal. These are the facts which we usually try to remember. These memories are actually strengthened in non-REM phase that is when your eyes are not moving rapidly. And in REM phase, the phase in which most of the dreaming occurs, in this phase the memories which are associated with our understanding of words are strengthened. So, what do I mean by this is, as I mentioned earlier in REM phase, most of the dreaming happens. In REM, we usually are in a particular situation or an environment where there might be a lot of people around us, a lot of objects around us and we are dealing with these people and objects. So, let me give you an example. Suppose there is a student who is a freshman and it's his first day of college and he goes and he observes that there are different paths. There are shortcuts, there are long cuts which lead him or her to the same location. So, in the dream, he might be in the similar situation and he might be getting late to the college and that's why he's taking a shortcut and running through the college. So, this is what I mean by using facts. So, his memory is about understanding of the world that there are shortcuts and I need to use the shortcuts whenever I'm getting late. These memories are getting strengthened when we are in REM phase that is when our eyes are moving rapidly and it has been found that the eye movement actually has to do something with the visual processes which are going in our dreaming phase. So, these are the interesting facts about sleep and memory. So, let's see what will happen if we do not sleep and this question that what will happen if we do not sleep has been bothering researchers since last week and there are a lot of new things which have been discovered. And one of the recent discovery, I found it to be really interesting so that, so I thought I should share it with all of you. And that's discovery has to do with drosophila. So, at times people study sleep using different insects, flies or different organisms as well. And drosophila is actually insect or they are called as a fruit flies. You might at times see these flies around overripe fruits or rotting fruits. These are the very small blackish brown insects which might be lingering around overripe fruits and these are found commonly. But the interesting fact about these fruit flies is that they have a little tiny brain, they also have a digestive tract like us. So, it's a very good modular organism to test few things. So, people studied drosophila for sleep and what they did is they did not allow drosophila to sleep at all. And they checked what's happening and they observed premature death in these drosophilas. So, how early did these drosophila died? The answer is huge will lifespan of drosophila is around 2 to 3 months. Like if drosophila is really healthy it can live for around 60 to 90 days. But when drosophilas were not allowed to sleep at all, they started dying after 10th day. So, this was a really premature death that scientists observed. And they were trying to figure out why these drosophila died. And they found the answer in one of the parts of drosophila. Now I want you to guess which part of drosophila they might have found. Like eyes of drosophila, brain of drosophila, digestive tract or wings or legs of drosophila. What do you people think? Can you make a guess? Like why they died? Yes, they found a reason for death of drosophila in one of the parts of its body part. So, what do you think? Okay, eyes. I guess the brain of drosophila. Oh, Anushka is saying brain of drosophila. Are there any other answers? Not yet, but like we can take a few seconds more like let's see. Yes. If we have something on the YouTube. So, another person is saying brain. Okay. Since you mentioned wings also, is it wings? No, it's not wings. Wow. Yeah, but that's an interesting answer. But surprisingly, scientists found the answer for this question in digestive tract of drosophila. They found that there is something happening in the digestive tract of drosophila which is causing premature death. So, let's see how they came up with this answer. What did they really also? So, they observed that in the digestive tract of drosophila, there are reactive oxygen species which were increasing. So, what are reactive oxygen species? These are actually chemical molecules which contain oxygen, but they are really highly reactive. Like they react with your tissues and they usually tend to damage your tissues. So, these were the species whose number was increasing in the digestive tract of the drosophila when drosophila's were not allowed to sleep at all. And scientists were trying to figure out like, is this the only reason why drosophila died? So, they did one really interesting experiment. So, what they observed in the first thing in the first image was when drosophila's were not allowed to sleep, they started dying early. That is after the 10th day and within 20 days almost all the drosophila died. So, what they did was to confirm that it's the only reason. They did not allow some of the drosophila to sleep, but they kept giving antioxidants to them. So, what are antioxidants? These are actually substances which neutralize ROs. That is reactive oxygen species which tend to damage the tissues or cells of the drosophila. So, how they neutralize the reactive oxygen species? They actually try to reduce the reactivity of the ROs. And this is how they tried to nullify the effect of ROs in drosophila. And to observe that even though they are not allowing drosophila's to sleep, the drosophila's are able to live their life when given oxidants. So, it suggests that these ROs, that is reactive oxygen species whose number was increasing in digestive tract was the only reason or was the main reason because of which drosophila's were dying. So, it was a great surprise for everyone that the answer for the drosophila was in the digestive tract of the drosophila. And this is about the insect or this is about the fruit flies. Here we can see that if they are not allowed to sleep, then what happens? So, similarly when in humans lack of sleep can have really bad impact on our body and health. So, let's see what will happen if we do not sleep. It has been observed that it has been observed in different studies that lack of sleep actually leads to gastrointestinal problems. You might have heard people saying, I did not sleep well today so I am feeling acidity. I am not feeling well. It has been also observed that if people do not sleep properly, then their immunity also, their immune response to external viruses, bacterias is not good. They usually tend to get infected badly. So, they observed that lack of sleep can actually affect the formation of immune memory. So, what do I mean by immune memory here is whenever our body fights with these bacterias and viruses, our body tries to remember what it really did to kill those bacterias and viruses, how it fought with those bacterias and viruses so that next time when these bacterias and viruses attack on us, we can even react fastly and win the fight. So, finally, the people have observed that immune response is actually affected up to a great extent because of sleep. And one more important thing according to studies is that sleep actually plays a key role in even regulating emotions. So, even today we might be, sorry. Please also add on by Aditya, can you get dark circles under your eyes? Yes, yes. Yeah, it happens. We also get dark circles and we also become cranky or frustrated when we are not sleeping properly. Like once I did not sleep properly and I had a very big fight with my family. So, from that day I started playing a lot of attention towards sleep. Like it really plays an important role in regulating emotions as well. And if we don't sleep properly, it can actually lead to different mental illnesses as well. So, today we are talking about sleep but we usually tend to ignore sleep. Like if people are facing problems in sleeping, like they are not able to sleep properly. Although they have slept properly at night, like for 7 to 8 hours, they are feeling sleepy during daytime as well. So, people tend to ignore all these things but these can be really serious things for some of us and we really need to pay attention to this. And for the same purpose, now in India and in other countries, hospitals and different centres have sleep labs which are actually involved in research and as well as diagnosis. So, there are diseases which are related to sleep, for example, sleep apnea in which people's breathing actually stops for few seconds and then it restarts but this can be at times dangerous for person's health. And there is one more disease called narcolepsy as well where people feel sleepy although they had a good sleep. Like all the time during a daytime while working or when they are in school, they keep feeling sleepy and they fall asleep wherever they are. And these diseases are being diagnosed in the sleep labs and what these sleep labs do is they just monitor your brain activity, they try to monitor your heart rate, blood pressure and your body movements as well and then they come up with answers to your problems like are you having any serious problem or not and they also prescribe medicines if needed. And now we are coming to the end of session. So, I would like to wish all of you good sleep and stay healthy. And if you are interested in exploring sleep a bit more, then you can actually visit these links and explore more about it. I will paste these links in the chat box in a minute or two. Thank you. Thank you, Megha. So let us move on to the question and answers part and the session part. And so people if you have questions or if you have any comments, you can put it in the chat box. So we will give you a minute to just put in the questions in the chat box whether on the YouTube or on the Zoom platform. So till the time Megha questions come up, one person has requested, can you explain it once more about how that Drosophila experiment was done? Oh, sure, sure. So in Drosophila experiment what they exactly did was they did not allow Drosophila to sleep at all for a very long period of time. And they observed that when they are not letting Drosophila sleep, they died early, that is after 10th day, 10th day, they started dying. And they had an interesting observation that when Drosophilas are dying, when Drosophilas are dying and they are not allowed to sleep, then the number of reactive oxygen species in their digestive tract is increasing. So what are these reactive oxygen species? These are the molecules which contain oxygen, but they are highly reactive. They actually end up damaging your tissues, they end up damaging your digestive tract, sorry, they end up damaging Drosophilas digestive tract. So now they wanted to confirm that are these ROIs are the main reason behind Drosophila's death or not. So to explore this, what did they do was they did not allow Drosophila to sleep, but they gave antioxidants to them. What are antioxidants? Antioxidants are substances which actually helps in removing or neutralizing these ROIs, like these chemicals which are harming the Drosophila. So after giving antioxidants, they saw that although Drosophila is not sleeping properly, but they are able to live their life. So what does it mean? Like when antioxidants are given, that is when ROIs is removed from the digestive tract, Drosophila is able to live its life. It means that ROIs, that is reactive oxygen species which were generated in the digestive tract, were actually killing the Drosophila. So the lack of sleep induced chemicals in the digestive tract which actually led to the death of Drosophila. So they confirmed that lack of sleep had a very great effect in the digestive tract which leads to the death. Okay, thank you. So we have a question. One question is how were the Drosophila not allowed to sleep? How they were not allowed to sleep. Okay, so there are many different methods but here what they did was Drosophila is kept in a medium or a tube and that tube was moved constantly using a machine asymmetrically. There was no rhythmic movement. It was moving constantly so that Drosophila can't sleep. Like suppose if we are sleeping and if someone is disturbing us all the time moving us all the time then we can't sleep. Similarly, if Drosophila is kept in a tube and if that tube is rotated all the time in different directions then it can't sleep. It's mainly by disturbing their sleep, right? Yes, they disturb their sleep using different mechanical devices. So Sayali is asking how many hours of sleep is needed for our body? So is it like 8 hours always? The answer is for different people actually it can be different like for some people even 7 hours of sleep might be enough or some 9 hours of sleep might be enough but it has been found that on an average we would really need 8 hours of sleep. Okay, so Aditya is asking how scientists catched Drosophila. How did they catch Drosophila? Okay, so even you can catch Drosophila at home. So if you cut the tomato and keep it in some open place or if you keep the overripe banana in an open place you will see that there will be Makhi Naya but there will be very small blackish brown insets which will come around these fruits and from here you can actually catch the Drosophila. And I would like to add on to it that Aditya like also you can put it in a container that half cut tomato in a container. So container under when these air flies comes and enter you can then put the lid on it. So that is how you catch it and to know more on it. So we are in the Center for Science Education and there is a lab known as the cube lab and we will put in those links later. So in cube labs they have many great experiments for school kids like of your age where they show you and they teach you how to catch Drosophila or how to do experiments with Drosophila. So yeah so one more interesting question we have is you know which even I had this question. Do plants sleep? The answer to this question is a bit complicated but if we consider the definition of sleep that is reduced responsiveness to external stimuli and relative inactivity then we can say that yes plants do sleep but even in plants all plants don't sleep in same way. Like in animals the way we sleep and the way dog or cat sleep is very different. Similarly in plants mango plant and banana plant might sleep differently. They might have different responses for different stimuli. So people have observed that responsiveness of plants also decreases in certain period of time and they consider that yes plants and we can consider that yes plants also do sleep but yes the way they sleep might be very different. And there is very interesting experiment about which we all might have heard in our childhood or in our school that Jagdish Chandra Bose actually showed that yes plants also do sleep and that experiment was actually very interesting. Do you people all know about what was that experiment? Should we do you know that? Like what did he do to show that plants sleep? I don't remember but I remember there was a chapter about Jagdish Chandra Bose in the Hindi chapter in the book but I don't remember exactly. Okay so he did a really cool experiment. So he did this experiment with Mimosa plant. So it has been observed that whenever we touch this Mimosa plant in Marathi we at times call it Laja Rukh as hard. So when we touch this plant the leaves of this plant plants tend to close and they become droopy. So he used this observation to test if plants sleep or not but he used a different method. He did not touch the plants because at times we might not regulate the touch at times we might touch hardly at times touch might be soft and how plants might respond to that we don't know. So what he did he saw that even when these plants were giving light electric shocks they used to react similarly like leaves used to get close and the plant stems used to become droopy. So he gave these light shocks of same intensity frequently with some frequency for 24 hours and he observed that actually the responsiveness of this Mimosa plant reduces. So on the screen you might be seeing a graph like whenever the plant was given the electric shock you might see there is a line which going up dotted line and the lines which are coming downward they show that it's closing its leaves. So this was the experiment that he did and one more interesting thing about this experiment is that he saw that its responsiveness is actually decreasing during 12 p.m. to around 6 p.m. like that is the daytime for her as in daytime we are active Oh that's bizarre. Yeah and this plant's responsiveness actually decreases during 12 p.m. to 6 p.m. But like this was observed for the Mimosa right? Yes Not necessary for all plants. No no this is not necessary for all plants. Like we mentioned earlier like the way plant's leaf might be really different like across different species their leaf might be of very different type. Okay so one last question maybe Do all animals sleep with their eyes closed? No actually no not all animals sleep with their clothes I like the rabbits eyes. Yes So I read somewhere that rabbits often sleep with their open eyes so you cannot like exactly find out whether they are sleeping or whether they are awake. Yes And like another thing Yeah And I have also heard that there is one kind of fish as well which sleeps with open eyes but right now I am not able to recall the name And also like ostriches like you said like there is REM and there is non-REM right So scientists have I don't know like how far it is true This is again I read somewhere that like the non-REM What do you call it? Like ostriches also have a slow eye movement and at that time they keep their eyes open and they stand and they keep their eyes open in the sleep So that's the way they sleep and then they are having their rapid eye movement segment then at that time they have this closed eye sleep Oh wow that's interesting Yeah I will definitely go back and explore about this So there is somebody said that even as a human also we sometimes tend to sleep with half open eyes So that's something you do Yes And also Mohan says he dolphins sleep with one eyes closed but he also gives the disclaimer that he has read somewhere Okay Yeah Yeah but about as also it's very interesting like some of us at times tend to keep half of our eyes open and we sleep Yeah And these people are really good for experiments when REM phases are being observed Like one can clearly see how eye moments are happening Right Especially in babies it's observed most of the times Okay So since there are no more questions and we are almost close to 12 o'clock So there's one question by Rishikesh I don't know if we have time for that but like the question is how yawning is related to sleep Okay how yawning is related to sleep Is it really contagious Yawning Do you mind if I answer that Mila Yeah yeah sure So like Rishikesh yawning is a phenomena where people are actually researching on it Because it's a completely different phenomena And I guess there is also a thing that you know as Megha said that there was a time that you know Yawning actually when your body has more of CO2 I mean more of carbon dioxide and you have less of oxygen So yawning is also a phenomena where you try to get in more oxygen in your body And is it really contagious so that is something people are still researching on it But yeah even when I watch a movie and if I see somebody yawning on the screen I get the yawning as well But yeah people are actually researching on it so we don't have a definite answer to it And so yeah so we come to the end of a session and Megha Just I want to mention one thing Like you said whenever we need more oxygen we tend to yawn And it has been observed that when oxygen intake increases significantly in our body At times we feel sleepy Like if we are in a really rich oxygen area then we might feel sleepy But how exactly oxygen induced sleep it's still being researched So thank you everyone for joining us today and Megha thank you so much It was really an exciting session and thank you audience for the chat I mean for the comments for your questions And if you have more questions you can go to our Steamboat YouTube channel And there again you can put up your questions there And if you are joining us for the first time Then let me give you a reminder that we bring our Steamboat sessions every I mean second Sunday of every month and exactly at 11 am From different fields like from science, from technology, from engineering, from arts And from mathematics and you can also visit our Steamboat website So thank you so much once again So signing off from HBC as a campus Thank you