Description
Some CENTURI scientists were in the street to capture your big questions about Black holes, climate change, pigment colors, scientific breaktrough....
Enjoy the fun talks!
Hosted by Ausha. See ausha.co/privacy-policy for more information.
Transcription
from time to time, in biology, physics, math. There is no specificity, everything is open. We will say biology, physics, math. Yes, that's it. Do you have any questions that you can ask us?
Hi, I'm Soichi.
Hi, I'm Nara.
We're science researchers at Lumini. You are listening to the Century Podcast where we answer your burning scientific questions.
We went out on the streets of Marseille and asked people if they had any questions related to science or research that have been keeping them up at night. We're going to play some of the questions and answer them.
Let's hear what you had on your minds.
Is the black hole foam? Sorry, we messed up the recording. This person was explaining she was thinking about black holes because she recently watched a documentary on this subject. And so her question was, How was a black hole formed?
You know, I love this question because it shows people are still interested in phenomena happening up in the night sky. And some of these things can be quite strange to imagine, especially when you can't see them. To start with, we should give a quick definition for a black hole. And actually, even before we do that, let's just quickly discuss gravity. We know gravity conceptually as this phenomenon where... If I toss a ball up into the air, after some time it will fall back down to earth. But if I launch something hard enough into the air, it can escape the pull of gravity. It's why satellites remain in orbit and rockets can go to the moon. In contrast, a black hole is a region with such a strong gravitational effect that things can't escape, not even light.
Now, for how a black hole is formed, imagine something roughly the size or even larger than a sun, and fortunately far, far away from here, collapsing in on itself. If you imagine that the star has used up all of its fuel, meaning it's carried out all of the chemical reactions possible, then it will start to collapse in upon itself.
What's interesting here is that, while this is a known way for black holes to form, there are speculations of other ways. where they can come about. In short, this is still an active question where we don't know all of the answers yet. We hope we answered your question.
Now, let's move on to the next question, shall we? This next question, or this next subject, seems to be on everybody's mind and brings us back to Earth. What do you think of global warming? How is it possible that April is as hot as August? What impact will climate change have on our physical and cognitive performance, with the rise in body temperature, lack of oxygen, or the surplus of pollution and stress on our bodies?
You heard it, climate change.
Let's decompose these questions. People want to... to know if we believed in climate change. If it exists, is it responsible for the weird temperatures we have been having lately? And what impact would it have on our bodies in the future? On the first point, I think Sweety and I both agreed to answer this question with a resounding yes.
Indeed, the evidence is there for a long time now that climate change is a real effect and serious concern for our planet today.
To answer this question, maybe we should dive into the natural variation in temperature of the planet. Roughly every 20 to 100 thousand years, the planet completes a temperature cycle that alternates between ice ages, also called glacials, and warm periods, or interglacials. These cycles occur naturally based on orbital variations, or the variation of the Earth's axis and its orbit around the Sun. Right now, we are in an interglacial period, and it might have already been going on for around 17,000 years.
It was partly through the scientists'attempts to understand what caused and ended previous ice ages that climate scientists came to realize that the level of carbon dioxide in the environment can greatly influence Earth's climate system, and that human-produced carbon dioxide is playing a primary role in the current global warming. Scientists were also able to calculate that in the next thousand years or so, a glacial period should be starting, but only if CO2 levels decrease to pre-industrial numbers. So I guess if you want to really be sure that climate change is reality, wait for a thousand years and you'll see if a glaciation period starts. Just know that you might not like what you see. Now let's address the question about how climate change is affecting our weather today, because indeed it is. We have reliable records about the climate going back over 100 years. By comparing these records to the present day, we see that the temperature has increased by a little over one degree Celsius and is accompanied by a faster rate of sea level rise. At first glance, you might think that a one percent increase is not significant, but every degree warmer corresponds to the humidity increasing by roughly 3.5 percent. It may not come as a surprise then that there is a 3.5% increase in the amount of rainfall, since more water vapor in the air will lead to more rain falling to the ground. And while this also sounds like a good thing to have more rainfall, this can actually be quite dangerous. To give an example, in 2017 the state of Texas experienced devastating floods from intense rainfall that caused 125 billion dollars in damage and caused over a hundred deaths. An MIT professor had calculated that since the 1990s, the chances of a similar storm hitting Texas has gone up six-fold. These are more intense rainfalls that will also be coupled to more intense droughts, leading to alternations between these extremes. In short, the changing climate has been responsible for the heat waves, decreased rainfall around the summer, and increased rainfall in the autumn. And we're still learning new things about how climate change is influencing weather patterns and resultant weather or drought effects.
The third question on climate change was about its effects on our bodies, both in terms of our physical and cognitive performance.
This is a great question. It's been shown that climate change has a huge impact on our health. The temperature rise will affect what we eat, what we drink, and even the air we breathe. But let's further break down what climate change will do to our bodies.
Since climate change is hugely affected by pollution, we can first expect an increase in asthma cases. In fact, water and food supplies will be impacted, so we might see an increase of malnutrition. Also, daily, seasonal, or yearly climate variability means that vectors for some diseases might have the opportunity to adapt to the different temperatures. So we can expect an increase of disease vectors like dengue fever, for example.
But the part of the question related to effects on cognitive performance is really interesting. Actually, it's been shown that an increase in temperature reduces reaction time and the performance of people based on cognition tests. This has been shown both in humans and non-humans.
Another question about nature. You asked me why the tomatoes were red, why the vegetables had different colors. I imagine it must be a molecule in the vegetable, but what is it related to?
The question was about why vegetables have such a variety of colors. Why are tomatoes red? Why are aubergines violet?
The colors that we find in fruits and vegetables are indeed due to a class of molecules that we find inside them. And there's a fascinating combination of physics, chemistry, and biology that causes this visual diversity.
Let's take a step back and briefly consider the idea behind light and colors. Light can take on a color because it has a corresponding length scale called a wavelength. Blue light has a wavelength of around 450 nanometers, while red light is closer to 700 nanometers. Light can then be absorbed or reflected by the objects with which it interacts. How well the object absorbs the light depends on the wavelength. For example, a tomato is red because it absorbs red poorly while absorbing other colors well. The red is instead reflected, which goes into our eyes and gives this perception of the color red.
But how does it reflect the color red, or the wavelength corresponding to the color red? This is due to special molecules that are inside gold pigments. The chemical structure of these pigments allows them to interact with light, so that all wavelengths are absorbed at various efficiencies. In the case of the molecule that makes the tomato red, the red wavelength is poorly absorbed. In other words, it's reflected.
There are various types of pigments depending on the color they reflect. For a red, yellow, or orange color, we would have carotenoids in the vegetable. The red in tomatoes is due to one particular carotenoid, lycopene. Similarly, the orange in carrots comes from alpha and beta carotene pigments. For aubergines, the deep violet color comes from a class of pigments called anthocyanins.
For green vegetables and for many of the plant leaves we see in the world, the pigment would be chlorophyll. Interestingly, chlorophyll helps with photosynthesis, a process that helps turn water and carbon dioxide into glucose. an energy source for living organisms. Just to link this with our previous question, having more green is one of the possible ways to produce carbon dioxide. Finally, to end this episode, we have a more general question about research. Is it always as interesting to become a researcher?
And are there huge things to find, or will it be more your little stone building so that in 50 years we can achieve something very concrete? So the question is about if there is still a meaning to continuing research even though we have already discovered so much. I love this question because it gets a little philosophical about the future of science and research. I understand where this question might come from. Take what is commonly said nowadays about science. The fact that in the past scientists could go after low-hanging fruit and so no matter what they did they would hit a big discovery. Whereas nowadays discoveries are smaller and harder to go after. It's undeniable that we hear less about major scientific breakthroughs for the past few decades now. However, we have to take into account that these eureka moments had to be verified. tested, and confirmed. And this is the part that takes time. For example, the observation of gravitational waves, these subtle ripples of gravity across space and time, only happened in 2015. Even though the theory behind it dates back to a century ago, it took all of this time to come up with the methods and the equipment to test and validate this theory through experiments. We should also emphasize here that Even though humans have discovered an enormous amount of information already, it is still but a speck of dust compared to what is left to be discovered. Which leads us to a bigger question. Are there still major ideas to be discovered? Or will we just be laying one more brick in a big building? I think there are still major ideas to be discovered. To fantasize a little bit about the future, I've been intrigued by the sorts of new material properties that scientists have come to discover. Perhaps one of the most popular topics and materials today involves superconductors, these class of materials that allow objects such as trains to levitate. However, these materials only realize this sort of property at extremely low temperatures, and a lot of effort has been made to design superconductors that work at room temperature. Furthermore, while we might have extensively filled out the periodic table of elements, there may be new materials with unusual properties that we have not encountered yet, or new combinations of elements that give rise to novel phenomena. Then there is the question of whether we can come up with non-carbon forms of life. Our molecular structure is carbon-based, but are there ways of creating living systems with a different element as the basis? I think it's also worth giving a shout out to another podcast episode put on by some colleagues within Century. In that episode... Three PhD students interviewed other researchers at the Institute to get their perspective on the question, what is the point of fundamental science research? It's an especially important question today as we often hear this question when we talk about our research to those who are outside of science.
This is it for today. Thank you so much for your attention. If you like this podcast, please follow us on social media and look out for us in your streets, asking you to ask us your questions.
Description
Some CENTURI scientists were in the street to capture your big questions about Black holes, climate change, pigment colors, scientific breaktrough....
Enjoy the fun talks!
Hosted by Ausha. See ausha.co/privacy-policy for more information.
Transcription
from time to time, in biology, physics, math. There is no specificity, everything is open. We will say biology, physics, math. Yes, that's it. Do you have any questions that you can ask us?
Hi, I'm Soichi.
Hi, I'm Nara.
We're science researchers at Lumini. You are listening to the Century Podcast where we answer your burning scientific questions.
We went out on the streets of Marseille and asked people if they had any questions related to science or research that have been keeping them up at night. We're going to play some of the questions and answer them.
Let's hear what you had on your minds.
Is the black hole foam? Sorry, we messed up the recording. This person was explaining she was thinking about black holes because she recently watched a documentary on this subject. And so her question was, How was a black hole formed?
You know, I love this question because it shows people are still interested in phenomena happening up in the night sky. And some of these things can be quite strange to imagine, especially when you can't see them. To start with, we should give a quick definition for a black hole. And actually, even before we do that, let's just quickly discuss gravity. We know gravity conceptually as this phenomenon where... If I toss a ball up into the air, after some time it will fall back down to earth. But if I launch something hard enough into the air, it can escape the pull of gravity. It's why satellites remain in orbit and rockets can go to the moon. In contrast, a black hole is a region with such a strong gravitational effect that things can't escape, not even light.
Now, for how a black hole is formed, imagine something roughly the size or even larger than a sun, and fortunately far, far away from here, collapsing in on itself. If you imagine that the star has used up all of its fuel, meaning it's carried out all of the chemical reactions possible, then it will start to collapse in upon itself.
What's interesting here is that, while this is a known way for black holes to form, there are speculations of other ways. where they can come about. In short, this is still an active question where we don't know all of the answers yet. We hope we answered your question.
Now, let's move on to the next question, shall we? This next question, or this next subject, seems to be on everybody's mind and brings us back to Earth. What do you think of global warming? How is it possible that April is as hot as August? What impact will climate change have on our physical and cognitive performance, with the rise in body temperature, lack of oxygen, or the surplus of pollution and stress on our bodies?
You heard it, climate change.
Let's decompose these questions. People want to... to know if we believed in climate change. If it exists, is it responsible for the weird temperatures we have been having lately? And what impact would it have on our bodies in the future? On the first point, I think Sweety and I both agreed to answer this question with a resounding yes.
Indeed, the evidence is there for a long time now that climate change is a real effect and serious concern for our planet today.
To answer this question, maybe we should dive into the natural variation in temperature of the planet. Roughly every 20 to 100 thousand years, the planet completes a temperature cycle that alternates between ice ages, also called glacials, and warm periods, or interglacials. These cycles occur naturally based on orbital variations, or the variation of the Earth's axis and its orbit around the Sun. Right now, we are in an interglacial period, and it might have already been going on for around 17,000 years.
It was partly through the scientists'attempts to understand what caused and ended previous ice ages that climate scientists came to realize that the level of carbon dioxide in the environment can greatly influence Earth's climate system, and that human-produced carbon dioxide is playing a primary role in the current global warming. Scientists were also able to calculate that in the next thousand years or so, a glacial period should be starting, but only if CO2 levels decrease to pre-industrial numbers. So I guess if you want to really be sure that climate change is reality, wait for a thousand years and you'll see if a glaciation period starts. Just know that you might not like what you see. Now let's address the question about how climate change is affecting our weather today, because indeed it is. We have reliable records about the climate going back over 100 years. By comparing these records to the present day, we see that the temperature has increased by a little over one degree Celsius and is accompanied by a faster rate of sea level rise. At first glance, you might think that a one percent increase is not significant, but every degree warmer corresponds to the humidity increasing by roughly 3.5 percent. It may not come as a surprise then that there is a 3.5% increase in the amount of rainfall, since more water vapor in the air will lead to more rain falling to the ground. And while this also sounds like a good thing to have more rainfall, this can actually be quite dangerous. To give an example, in 2017 the state of Texas experienced devastating floods from intense rainfall that caused 125 billion dollars in damage and caused over a hundred deaths. An MIT professor had calculated that since the 1990s, the chances of a similar storm hitting Texas has gone up six-fold. These are more intense rainfalls that will also be coupled to more intense droughts, leading to alternations between these extremes. In short, the changing climate has been responsible for the heat waves, decreased rainfall around the summer, and increased rainfall in the autumn. And we're still learning new things about how climate change is influencing weather patterns and resultant weather or drought effects.
The third question on climate change was about its effects on our bodies, both in terms of our physical and cognitive performance.
This is a great question. It's been shown that climate change has a huge impact on our health. The temperature rise will affect what we eat, what we drink, and even the air we breathe. But let's further break down what climate change will do to our bodies.
Since climate change is hugely affected by pollution, we can first expect an increase in asthma cases. In fact, water and food supplies will be impacted, so we might see an increase of malnutrition. Also, daily, seasonal, or yearly climate variability means that vectors for some diseases might have the opportunity to adapt to the different temperatures. So we can expect an increase of disease vectors like dengue fever, for example.
But the part of the question related to effects on cognitive performance is really interesting. Actually, it's been shown that an increase in temperature reduces reaction time and the performance of people based on cognition tests. This has been shown both in humans and non-humans.
Another question about nature. You asked me why the tomatoes were red, why the vegetables had different colors. I imagine it must be a molecule in the vegetable, but what is it related to?
The question was about why vegetables have such a variety of colors. Why are tomatoes red? Why are aubergines violet?
The colors that we find in fruits and vegetables are indeed due to a class of molecules that we find inside them. And there's a fascinating combination of physics, chemistry, and biology that causes this visual diversity.
Let's take a step back and briefly consider the idea behind light and colors. Light can take on a color because it has a corresponding length scale called a wavelength. Blue light has a wavelength of around 450 nanometers, while red light is closer to 700 nanometers. Light can then be absorbed or reflected by the objects with which it interacts. How well the object absorbs the light depends on the wavelength. For example, a tomato is red because it absorbs red poorly while absorbing other colors well. The red is instead reflected, which goes into our eyes and gives this perception of the color red.
But how does it reflect the color red, or the wavelength corresponding to the color red? This is due to special molecules that are inside gold pigments. The chemical structure of these pigments allows them to interact with light, so that all wavelengths are absorbed at various efficiencies. In the case of the molecule that makes the tomato red, the red wavelength is poorly absorbed. In other words, it's reflected.
There are various types of pigments depending on the color they reflect. For a red, yellow, or orange color, we would have carotenoids in the vegetable. The red in tomatoes is due to one particular carotenoid, lycopene. Similarly, the orange in carrots comes from alpha and beta carotene pigments. For aubergines, the deep violet color comes from a class of pigments called anthocyanins.
For green vegetables and for many of the plant leaves we see in the world, the pigment would be chlorophyll. Interestingly, chlorophyll helps with photosynthesis, a process that helps turn water and carbon dioxide into glucose. an energy source for living organisms. Just to link this with our previous question, having more green is one of the possible ways to produce carbon dioxide. Finally, to end this episode, we have a more general question about research. Is it always as interesting to become a researcher?
And are there huge things to find, or will it be more your little stone building so that in 50 years we can achieve something very concrete? So the question is about if there is still a meaning to continuing research even though we have already discovered so much. I love this question because it gets a little philosophical about the future of science and research. I understand where this question might come from. Take what is commonly said nowadays about science. The fact that in the past scientists could go after low-hanging fruit and so no matter what they did they would hit a big discovery. Whereas nowadays discoveries are smaller and harder to go after. It's undeniable that we hear less about major scientific breakthroughs for the past few decades now. However, we have to take into account that these eureka moments had to be verified. tested, and confirmed. And this is the part that takes time. For example, the observation of gravitational waves, these subtle ripples of gravity across space and time, only happened in 2015. Even though the theory behind it dates back to a century ago, it took all of this time to come up with the methods and the equipment to test and validate this theory through experiments. We should also emphasize here that Even though humans have discovered an enormous amount of information already, it is still but a speck of dust compared to what is left to be discovered. Which leads us to a bigger question. Are there still major ideas to be discovered? Or will we just be laying one more brick in a big building? I think there are still major ideas to be discovered. To fantasize a little bit about the future, I've been intrigued by the sorts of new material properties that scientists have come to discover. Perhaps one of the most popular topics and materials today involves superconductors, these class of materials that allow objects such as trains to levitate. However, these materials only realize this sort of property at extremely low temperatures, and a lot of effort has been made to design superconductors that work at room temperature. Furthermore, while we might have extensively filled out the periodic table of elements, there may be new materials with unusual properties that we have not encountered yet, or new combinations of elements that give rise to novel phenomena. Then there is the question of whether we can come up with non-carbon forms of life. Our molecular structure is carbon-based, but are there ways of creating living systems with a different element as the basis? I think it's also worth giving a shout out to another podcast episode put on by some colleagues within Century. In that episode... Three PhD students interviewed other researchers at the Institute to get their perspective on the question, what is the point of fundamental science research? It's an especially important question today as we often hear this question when we talk about our research to those who are outside of science.
This is it for today. Thank you so much for your attention. If you like this podcast, please follow us on social media and look out for us in your streets, asking you to ask us your questions.
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Description
Some CENTURI scientists were in the street to capture your big questions about Black holes, climate change, pigment colors, scientific breaktrough....
Enjoy the fun talks!
Hosted by Ausha. See ausha.co/privacy-policy for more information.
Transcription
from time to time, in biology, physics, math. There is no specificity, everything is open. We will say biology, physics, math. Yes, that's it. Do you have any questions that you can ask us?
Hi, I'm Soichi.
Hi, I'm Nara.
We're science researchers at Lumini. You are listening to the Century Podcast where we answer your burning scientific questions.
We went out on the streets of Marseille and asked people if they had any questions related to science or research that have been keeping them up at night. We're going to play some of the questions and answer them.
Let's hear what you had on your minds.
Is the black hole foam? Sorry, we messed up the recording. This person was explaining she was thinking about black holes because she recently watched a documentary on this subject. And so her question was, How was a black hole formed?
You know, I love this question because it shows people are still interested in phenomena happening up in the night sky. And some of these things can be quite strange to imagine, especially when you can't see them. To start with, we should give a quick definition for a black hole. And actually, even before we do that, let's just quickly discuss gravity. We know gravity conceptually as this phenomenon where... If I toss a ball up into the air, after some time it will fall back down to earth. But if I launch something hard enough into the air, it can escape the pull of gravity. It's why satellites remain in orbit and rockets can go to the moon. In contrast, a black hole is a region with such a strong gravitational effect that things can't escape, not even light.
Now, for how a black hole is formed, imagine something roughly the size or even larger than a sun, and fortunately far, far away from here, collapsing in on itself. If you imagine that the star has used up all of its fuel, meaning it's carried out all of the chemical reactions possible, then it will start to collapse in upon itself.
What's interesting here is that, while this is a known way for black holes to form, there are speculations of other ways. where they can come about. In short, this is still an active question where we don't know all of the answers yet. We hope we answered your question.
Now, let's move on to the next question, shall we? This next question, or this next subject, seems to be on everybody's mind and brings us back to Earth. What do you think of global warming? How is it possible that April is as hot as August? What impact will climate change have on our physical and cognitive performance, with the rise in body temperature, lack of oxygen, or the surplus of pollution and stress on our bodies?
You heard it, climate change.
Let's decompose these questions. People want to... to know if we believed in climate change. If it exists, is it responsible for the weird temperatures we have been having lately? And what impact would it have on our bodies in the future? On the first point, I think Sweety and I both agreed to answer this question with a resounding yes.
Indeed, the evidence is there for a long time now that climate change is a real effect and serious concern for our planet today.
To answer this question, maybe we should dive into the natural variation in temperature of the planet. Roughly every 20 to 100 thousand years, the planet completes a temperature cycle that alternates between ice ages, also called glacials, and warm periods, or interglacials. These cycles occur naturally based on orbital variations, or the variation of the Earth's axis and its orbit around the Sun. Right now, we are in an interglacial period, and it might have already been going on for around 17,000 years.
It was partly through the scientists'attempts to understand what caused and ended previous ice ages that climate scientists came to realize that the level of carbon dioxide in the environment can greatly influence Earth's climate system, and that human-produced carbon dioxide is playing a primary role in the current global warming. Scientists were also able to calculate that in the next thousand years or so, a glacial period should be starting, but only if CO2 levels decrease to pre-industrial numbers. So I guess if you want to really be sure that climate change is reality, wait for a thousand years and you'll see if a glaciation period starts. Just know that you might not like what you see. Now let's address the question about how climate change is affecting our weather today, because indeed it is. We have reliable records about the climate going back over 100 years. By comparing these records to the present day, we see that the temperature has increased by a little over one degree Celsius and is accompanied by a faster rate of sea level rise. At first glance, you might think that a one percent increase is not significant, but every degree warmer corresponds to the humidity increasing by roughly 3.5 percent. It may not come as a surprise then that there is a 3.5% increase in the amount of rainfall, since more water vapor in the air will lead to more rain falling to the ground. And while this also sounds like a good thing to have more rainfall, this can actually be quite dangerous. To give an example, in 2017 the state of Texas experienced devastating floods from intense rainfall that caused 125 billion dollars in damage and caused over a hundred deaths. An MIT professor had calculated that since the 1990s, the chances of a similar storm hitting Texas has gone up six-fold. These are more intense rainfalls that will also be coupled to more intense droughts, leading to alternations between these extremes. In short, the changing climate has been responsible for the heat waves, decreased rainfall around the summer, and increased rainfall in the autumn. And we're still learning new things about how climate change is influencing weather patterns and resultant weather or drought effects.
The third question on climate change was about its effects on our bodies, both in terms of our physical and cognitive performance.
This is a great question. It's been shown that climate change has a huge impact on our health. The temperature rise will affect what we eat, what we drink, and even the air we breathe. But let's further break down what climate change will do to our bodies.
Since climate change is hugely affected by pollution, we can first expect an increase in asthma cases. In fact, water and food supplies will be impacted, so we might see an increase of malnutrition. Also, daily, seasonal, or yearly climate variability means that vectors for some diseases might have the opportunity to adapt to the different temperatures. So we can expect an increase of disease vectors like dengue fever, for example.
But the part of the question related to effects on cognitive performance is really interesting. Actually, it's been shown that an increase in temperature reduces reaction time and the performance of people based on cognition tests. This has been shown both in humans and non-humans.
Another question about nature. You asked me why the tomatoes were red, why the vegetables had different colors. I imagine it must be a molecule in the vegetable, but what is it related to?
The question was about why vegetables have such a variety of colors. Why are tomatoes red? Why are aubergines violet?
The colors that we find in fruits and vegetables are indeed due to a class of molecules that we find inside them. And there's a fascinating combination of physics, chemistry, and biology that causes this visual diversity.
Let's take a step back and briefly consider the idea behind light and colors. Light can take on a color because it has a corresponding length scale called a wavelength. Blue light has a wavelength of around 450 nanometers, while red light is closer to 700 nanometers. Light can then be absorbed or reflected by the objects with which it interacts. How well the object absorbs the light depends on the wavelength. For example, a tomato is red because it absorbs red poorly while absorbing other colors well. The red is instead reflected, which goes into our eyes and gives this perception of the color red.
But how does it reflect the color red, or the wavelength corresponding to the color red? This is due to special molecules that are inside gold pigments. The chemical structure of these pigments allows them to interact with light, so that all wavelengths are absorbed at various efficiencies. In the case of the molecule that makes the tomato red, the red wavelength is poorly absorbed. In other words, it's reflected.
There are various types of pigments depending on the color they reflect. For a red, yellow, or orange color, we would have carotenoids in the vegetable. The red in tomatoes is due to one particular carotenoid, lycopene. Similarly, the orange in carrots comes from alpha and beta carotene pigments. For aubergines, the deep violet color comes from a class of pigments called anthocyanins.
For green vegetables and for many of the plant leaves we see in the world, the pigment would be chlorophyll. Interestingly, chlorophyll helps with photosynthesis, a process that helps turn water and carbon dioxide into glucose. an energy source for living organisms. Just to link this with our previous question, having more green is one of the possible ways to produce carbon dioxide. Finally, to end this episode, we have a more general question about research. Is it always as interesting to become a researcher?
And are there huge things to find, or will it be more your little stone building so that in 50 years we can achieve something very concrete? So the question is about if there is still a meaning to continuing research even though we have already discovered so much. I love this question because it gets a little philosophical about the future of science and research. I understand where this question might come from. Take what is commonly said nowadays about science. The fact that in the past scientists could go after low-hanging fruit and so no matter what they did they would hit a big discovery. Whereas nowadays discoveries are smaller and harder to go after. It's undeniable that we hear less about major scientific breakthroughs for the past few decades now. However, we have to take into account that these eureka moments had to be verified. tested, and confirmed. And this is the part that takes time. For example, the observation of gravitational waves, these subtle ripples of gravity across space and time, only happened in 2015. Even though the theory behind it dates back to a century ago, it took all of this time to come up with the methods and the equipment to test and validate this theory through experiments. We should also emphasize here that Even though humans have discovered an enormous amount of information already, it is still but a speck of dust compared to what is left to be discovered. Which leads us to a bigger question. Are there still major ideas to be discovered? Or will we just be laying one more brick in a big building? I think there are still major ideas to be discovered. To fantasize a little bit about the future, I've been intrigued by the sorts of new material properties that scientists have come to discover. Perhaps one of the most popular topics and materials today involves superconductors, these class of materials that allow objects such as trains to levitate. However, these materials only realize this sort of property at extremely low temperatures, and a lot of effort has been made to design superconductors that work at room temperature. Furthermore, while we might have extensively filled out the periodic table of elements, there may be new materials with unusual properties that we have not encountered yet, or new combinations of elements that give rise to novel phenomena. Then there is the question of whether we can come up with non-carbon forms of life. Our molecular structure is carbon-based, but are there ways of creating living systems with a different element as the basis? I think it's also worth giving a shout out to another podcast episode put on by some colleagues within Century. In that episode... Three PhD students interviewed other researchers at the Institute to get their perspective on the question, what is the point of fundamental science research? It's an especially important question today as we often hear this question when we talk about our research to those who are outside of science.
This is it for today. Thank you so much for your attention. If you like this podcast, please follow us on social media and look out for us in your streets, asking you to ask us your questions.
Description
Some CENTURI scientists were in the street to capture your big questions about Black holes, climate change, pigment colors, scientific breaktrough....
Enjoy the fun talks!
Hosted by Ausha. See ausha.co/privacy-policy for more information.
Transcription
from time to time, in biology, physics, math. There is no specificity, everything is open. We will say biology, physics, math. Yes, that's it. Do you have any questions that you can ask us?
Hi, I'm Soichi.
Hi, I'm Nara.
We're science researchers at Lumini. You are listening to the Century Podcast where we answer your burning scientific questions.
We went out on the streets of Marseille and asked people if they had any questions related to science or research that have been keeping them up at night. We're going to play some of the questions and answer them.
Let's hear what you had on your minds.
Is the black hole foam? Sorry, we messed up the recording. This person was explaining she was thinking about black holes because she recently watched a documentary on this subject. And so her question was, How was a black hole formed?
You know, I love this question because it shows people are still interested in phenomena happening up in the night sky. And some of these things can be quite strange to imagine, especially when you can't see them. To start with, we should give a quick definition for a black hole. And actually, even before we do that, let's just quickly discuss gravity. We know gravity conceptually as this phenomenon where... If I toss a ball up into the air, after some time it will fall back down to earth. But if I launch something hard enough into the air, it can escape the pull of gravity. It's why satellites remain in orbit and rockets can go to the moon. In contrast, a black hole is a region with such a strong gravitational effect that things can't escape, not even light.
Now, for how a black hole is formed, imagine something roughly the size or even larger than a sun, and fortunately far, far away from here, collapsing in on itself. If you imagine that the star has used up all of its fuel, meaning it's carried out all of the chemical reactions possible, then it will start to collapse in upon itself.
What's interesting here is that, while this is a known way for black holes to form, there are speculations of other ways. where they can come about. In short, this is still an active question where we don't know all of the answers yet. We hope we answered your question.
Now, let's move on to the next question, shall we? This next question, or this next subject, seems to be on everybody's mind and brings us back to Earth. What do you think of global warming? How is it possible that April is as hot as August? What impact will climate change have on our physical and cognitive performance, with the rise in body temperature, lack of oxygen, or the surplus of pollution and stress on our bodies?
You heard it, climate change.
Let's decompose these questions. People want to... to know if we believed in climate change. If it exists, is it responsible for the weird temperatures we have been having lately? And what impact would it have on our bodies in the future? On the first point, I think Sweety and I both agreed to answer this question with a resounding yes.
Indeed, the evidence is there for a long time now that climate change is a real effect and serious concern for our planet today.
To answer this question, maybe we should dive into the natural variation in temperature of the planet. Roughly every 20 to 100 thousand years, the planet completes a temperature cycle that alternates between ice ages, also called glacials, and warm periods, or interglacials. These cycles occur naturally based on orbital variations, or the variation of the Earth's axis and its orbit around the Sun. Right now, we are in an interglacial period, and it might have already been going on for around 17,000 years.
It was partly through the scientists'attempts to understand what caused and ended previous ice ages that climate scientists came to realize that the level of carbon dioxide in the environment can greatly influence Earth's climate system, and that human-produced carbon dioxide is playing a primary role in the current global warming. Scientists were also able to calculate that in the next thousand years or so, a glacial period should be starting, but only if CO2 levels decrease to pre-industrial numbers. So I guess if you want to really be sure that climate change is reality, wait for a thousand years and you'll see if a glaciation period starts. Just know that you might not like what you see. Now let's address the question about how climate change is affecting our weather today, because indeed it is. We have reliable records about the climate going back over 100 years. By comparing these records to the present day, we see that the temperature has increased by a little over one degree Celsius and is accompanied by a faster rate of sea level rise. At first glance, you might think that a one percent increase is not significant, but every degree warmer corresponds to the humidity increasing by roughly 3.5 percent. It may not come as a surprise then that there is a 3.5% increase in the amount of rainfall, since more water vapor in the air will lead to more rain falling to the ground. And while this also sounds like a good thing to have more rainfall, this can actually be quite dangerous. To give an example, in 2017 the state of Texas experienced devastating floods from intense rainfall that caused 125 billion dollars in damage and caused over a hundred deaths. An MIT professor had calculated that since the 1990s, the chances of a similar storm hitting Texas has gone up six-fold. These are more intense rainfalls that will also be coupled to more intense droughts, leading to alternations between these extremes. In short, the changing climate has been responsible for the heat waves, decreased rainfall around the summer, and increased rainfall in the autumn. And we're still learning new things about how climate change is influencing weather patterns and resultant weather or drought effects.
The third question on climate change was about its effects on our bodies, both in terms of our physical and cognitive performance.
This is a great question. It's been shown that climate change has a huge impact on our health. The temperature rise will affect what we eat, what we drink, and even the air we breathe. But let's further break down what climate change will do to our bodies.
Since climate change is hugely affected by pollution, we can first expect an increase in asthma cases. In fact, water and food supplies will be impacted, so we might see an increase of malnutrition. Also, daily, seasonal, or yearly climate variability means that vectors for some diseases might have the opportunity to adapt to the different temperatures. So we can expect an increase of disease vectors like dengue fever, for example.
But the part of the question related to effects on cognitive performance is really interesting. Actually, it's been shown that an increase in temperature reduces reaction time and the performance of people based on cognition tests. This has been shown both in humans and non-humans.
Another question about nature. You asked me why the tomatoes were red, why the vegetables had different colors. I imagine it must be a molecule in the vegetable, but what is it related to?
The question was about why vegetables have such a variety of colors. Why are tomatoes red? Why are aubergines violet?
The colors that we find in fruits and vegetables are indeed due to a class of molecules that we find inside them. And there's a fascinating combination of physics, chemistry, and biology that causes this visual diversity.
Let's take a step back and briefly consider the idea behind light and colors. Light can take on a color because it has a corresponding length scale called a wavelength. Blue light has a wavelength of around 450 nanometers, while red light is closer to 700 nanometers. Light can then be absorbed or reflected by the objects with which it interacts. How well the object absorbs the light depends on the wavelength. For example, a tomato is red because it absorbs red poorly while absorbing other colors well. The red is instead reflected, which goes into our eyes and gives this perception of the color red.
But how does it reflect the color red, or the wavelength corresponding to the color red? This is due to special molecules that are inside gold pigments. The chemical structure of these pigments allows them to interact with light, so that all wavelengths are absorbed at various efficiencies. In the case of the molecule that makes the tomato red, the red wavelength is poorly absorbed. In other words, it's reflected.
There are various types of pigments depending on the color they reflect. For a red, yellow, or orange color, we would have carotenoids in the vegetable. The red in tomatoes is due to one particular carotenoid, lycopene. Similarly, the orange in carrots comes from alpha and beta carotene pigments. For aubergines, the deep violet color comes from a class of pigments called anthocyanins.
For green vegetables and for many of the plant leaves we see in the world, the pigment would be chlorophyll. Interestingly, chlorophyll helps with photosynthesis, a process that helps turn water and carbon dioxide into glucose. an energy source for living organisms. Just to link this with our previous question, having more green is one of the possible ways to produce carbon dioxide. Finally, to end this episode, we have a more general question about research. Is it always as interesting to become a researcher?
And are there huge things to find, or will it be more your little stone building so that in 50 years we can achieve something very concrete? So the question is about if there is still a meaning to continuing research even though we have already discovered so much. I love this question because it gets a little philosophical about the future of science and research. I understand where this question might come from. Take what is commonly said nowadays about science. The fact that in the past scientists could go after low-hanging fruit and so no matter what they did they would hit a big discovery. Whereas nowadays discoveries are smaller and harder to go after. It's undeniable that we hear less about major scientific breakthroughs for the past few decades now. However, we have to take into account that these eureka moments had to be verified. tested, and confirmed. And this is the part that takes time. For example, the observation of gravitational waves, these subtle ripples of gravity across space and time, only happened in 2015. Even though the theory behind it dates back to a century ago, it took all of this time to come up with the methods and the equipment to test and validate this theory through experiments. We should also emphasize here that Even though humans have discovered an enormous amount of information already, it is still but a speck of dust compared to what is left to be discovered. Which leads us to a bigger question. Are there still major ideas to be discovered? Or will we just be laying one more brick in a big building? I think there are still major ideas to be discovered. To fantasize a little bit about the future, I've been intrigued by the sorts of new material properties that scientists have come to discover. Perhaps one of the most popular topics and materials today involves superconductors, these class of materials that allow objects such as trains to levitate. However, these materials only realize this sort of property at extremely low temperatures, and a lot of effort has been made to design superconductors that work at room temperature. Furthermore, while we might have extensively filled out the periodic table of elements, there may be new materials with unusual properties that we have not encountered yet, or new combinations of elements that give rise to novel phenomena. Then there is the question of whether we can come up with non-carbon forms of life. Our molecular structure is carbon-based, but are there ways of creating living systems with a different element as the basis? I think it's also worth giving a shout out to another podcast episode put on by some colleagues within Century. In that episode... Three PhD students interviewed other researchers at the Institute to get their perspective on the question, what is the point of fundamental science research? It's an especially important question today as we often hear this question when we talk about our research to those who are outside of science.
This is it for today. Thank you so much for your attention. If you like this podcast, please follow us on social media and look out for us in your streets, asking you to ask us your questions.
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