Podcast Summary
The Origin of Stars from Gas Clouds: Stars form from gas clouds in space, similar to human birth, and their presence is evident through observation
Stars, including our sun, form from gas clouds in space. This process is common in the universe, as there are billions of stars in existence. The formation of stars can be compared to the process of human birth, as both involve the creation of new life from existing matter. Gas clouds are essential for the creation of stars, and their presence in the galaxy answers the question of where stars come from. The universe, like society, has a way of showing us evidence of this process if we look closely enough. For example, by observing the culture of a society and seeing pregnant women, we can infer the existence of a gestation period. Similarly, by observing gas clouds in space, we can infer the existence of stars in various stages of formation.
The formation of stars and their life cycle: Stars form from gravitational pull in gas clouds, undergo thermonuclear fusion, and their life can be extended but currently beyond our technological capabilities.
The formation of stars begins with the gravitational pull of slightly denser areas within gas clouds, which attract more matter and eventually heat up, leading to thermonuclear fusion. This process creates a star, which does not "burn" in the way we commonly think of fire but instead undergoes thermonucleation. As for preventing the expansion of our sun and prolonging its life, we currently rely on fossil fuels and are far from obtaining the necessary technological advances. However, it is theoretically possible to prolong a star's life by artificially increasing its core temperature or decreasing its outer layers' temperature, but such technology is currently beyond our reach. The life expectancy of most mammals, including humans, is around 3 million years, so the need to extend the sun's life is a concern for the future of our civilization.
Prolonging the Sun's Life: Fusion or Leaving Our Solar System?: The sun's life can be extended through thermonuclear fusion or by finding a new home in another solar system. While fusion can prolong the sun's life, the logistics of adding a planet to the sun are complex and beyond current capabilities.
The life of the sun can be prolonged by churning fresh fuel from the outer layers into the center. This process, known as thermonuclear fusion, converts hydrogen into helium and can extend the sun's life by a billion years. However, an alternative solution suggested was the possibility of humans leaving their current solar system and finding a new home in another solar system, avoiding the need to manipulate the sun directly. A listener named Jared, a 16-year-old student, asked during the show if it would be possible to prolong the sun's life by adding a planet like Jupiter into the sun. The answer was yes, but the logistics of such a process are complex and beyond current technological capabilities. Overall, the discussion emphasized the importance of understanding the universe's natural processes and the potential for human innovation to overcome future challenges.
Jupiter's Moons and the Sun's Size from Other Planets: Jupiter's moons Europa and Io may harbor life due to tidal heating. Churning the sun's outer layers could be a feasible solution to prolong its life, rather than moving it closer. Mercury sees a sun twice as big due to its proximity.
Jupiter's moons, particularly Europa and Io, hold potential for life due to the tidal forces keeping them warm outside the habitable zone. The general solution to prolonging the sun is to get fuel down into its core, but the idea of moving Jupiter closer to achieve this might not be the best approach due to the loss of its beautiful moons and the potential complexity of the process. Instead, focusing on churning the sun's outer layers into the core could be a more feasible solution. As for the sun's appearance from other planets, Mercury, being half the distance to the sun, would see a sun that is twice as big in the sky.
The size of celestial bodies and their distance from the sun impact their perceived brightness and visibility: The intensity of light emitted by celestial bodies and their distance from the sun are crucial factors determining their brightness and visibility. For example, the sun would appear larger on Mercury but unbearably bright, while Neptune, farther from the sun, could be a candidate for daytime stargazing.
The size of celestial bodies in the sky isn't the only factor determining their perceived brightness or visibility. The intensity of light they emit also plays a significant role. For instance, the sun would appear twice as big on Mercury, but due to the intensity of sunlight being four times greater, it would be unbearably bright and potentially dangerous for an observer. On the other hand, Neptune, being 30 times farther from the sun, would have a much dimmer sun and could be a possible candidate for seeing stars in the daytime. Additionally, contrary to popular belief, the moon is visible during the day, but it's not nighttime. The moon's phases appear throughout the day and night, with the full moon being the only exception. The rarity and beauty of a total solar eclipse come from the moon's size being almost exactly the same as the sun, making it possible to completely block the sun's light. Lastly, the alignment of a planet, star, and moon having the same size and distance from their respective orbs as Earth, the Sun, and the Moon, is a rare occurrence, making our solar system incredibly lucky.
The moon's gradual movement away from Earth will lead to an annular eclipse: The moon's distance from Earth is increasing, resulting in a future annular eclipse where the moon won't completely cover the sun, leaving a ring of sunlight around its edge. No known star systems have smaller stars orbiting larger ones with planets as moons, instead, they form in galaxies.
The moon is gradually moving away from Earth, and as it continues to do so, it will eventually become smaller than the sun in our sky, resulting in an annular eclipse. This means that the moon will not completely cover the sun, leaving a ring of sunlight around its edge. This was a coincidence from Earth's past when the moon was closer and larger than the sun, creating a different atmosphere during eclipses. There are no known star systems with smaller stars orbiting around a larger star, each having its own subsolar system. Instead, stars form in galaxies. During the Cosmic Queries edition of StarTalk Radio, listeners sent in questions on various topics related to the sun and other stars, which Neil Tyson answered on the spot. Arlin Cundert from Ohio asked about the possibility of a star system with smaller stars orbiting a larger one, each having planets serving as moons. Neil confirmed that such systems do not exist and are instead referred to as galaxies.
Stars too close can compromise planet allegiance: Stars too close can make it difficult for planets to determine which star they belong to, and detecting intergalactic stars and planets is challenging due to their distance and dimness.
The universe is full of complex star systems, some of which could potentially have stable planetary systems. However, if these stars are too close to each other, the planets' allegiance can be compromised, making it difficult for them to determine which star they belong to. Additionally, while it's possible for stars and even planets to exist in the intergalactic medium, it would be extremely challenging for us to detect them due to their distance and dimness. These stars and planets, much like their rogue counterparts within galaxies, are essentially lost in the vastness of space.
The nebular hypothesis explains the disc-shaped structure of galaxies and solar systems: The nebular hypothesis suggests that a massive gas cloud collapses under its own gravity, creating a spinning disk where everything orbits in the same direction due to centrifugal forces
The shape of galaxies and solar systems, including our own, being disc-shaped or on their own planes, is explained by the nebular hypothesis. This hypothesis suggests that a massive gas cloud collapses under its own gravity, causing it to spin faster. The material in the plane of this spinning cannot fall in due to centrifugal forces, resulting in a flattened disk where everything orbits in the same direction. This theory, proposed by Immanuel Kant in the mid-1800s, has held up well with subsequent observations and data. It's important to note that this process works best for collapsing gas clouds that are not moving too slowly, as those may form stars that don't necessarily collapse into a disk. The gas cloud's inability to pass through itself, much like how two hot marshmallows stick together, is what keeps the material in the disk.
Exploring the Mysteries of the Cosmos: The universe is full of unexpected phenomena, such as flat galaxies and survivable transport of sun material to Earth, and ongoing discoveries challenge our understanding of physics and reality.
The universe is full of fascinating phenomena that challenge our understanding of physics and reality. For instance, when a gas cloud collapses, it doesn't pancake out like we might expect. Instead, it stays flat and becomes a larger entity, much like our galaxy which is flat as a crepe despite being 100,000 light years across and only about 100 light years thick. Another intriguing question involved the hypothetical transport of a cubic centimeter of matter from the center of the sun to Earth. Contrary to popular belief, this wouldn't result in Earth's destruction. Instead, the material would heat up the atmosphere and then come into equilibrium with it. In the final segment of StarTalk Radio's Cosmic Queries edition, the hosts answered a series of questions in a lightning round format. One inquiry was about dust clouds around stars causing electrical storms. It was suggested that charged particles from the sun, known as the solar wind, could enter a dust cloud and ionize it, potentially triggering phenomena similar to Earth's auroras. Another question asked about the star that exploded to give material to form our solar system. While no definitive answer was given, the hosts speculated that it could be possible to name the star, despite it being dead. Overall, these discussions demonstrate the endless wonders and mysteries that exist in the cosmos, encouraging us to keep asking questions and seeking answers.
The life cycle of stars and the fate of our sun: The sun, like all stars, has a life cycle that includes death and the formation of remnants like neutron stars. Our sun will eventually die, but before that, we are headed towards a collision with the Andromeda galaxy. The sun's death would still be felt for a short time due to the delay in the transmission of light.
The universe is full of wonders and phenomena that have shaped our existence. One such phenomenon is the life cycle of stars, including our own sun. A star, like the one that exploded and created the elements essential for life on Earth, eventually dies and can leave behind remnants like neutron stars. The death of our sun, which is estimated to occur in about 5 billion years, is a natural process that we will eventually face. However, before that happens, we are on a collision course with the Andromeda galaxy, an event that will take place around 5.7 billion years from now. If the sun were to disappear suddenly, we would still feel its effects for about 8 minutes and 20 seconds due to the delay in the transmission of light. Understanding these cosmic events can help us appreciate the vastness and complexity of the universe.
The Density of a Neutron Star: A neutron star, formed from a massive star's core post-supernova, is incredibly dense, with one cubic centimeter weighing as much as 30 billion elephants, due to gravity and absence of electrons.
A neutron star, which forms from the core of a massive star after a supernova explosion, is incredibly dense. To put it into perspective, one cubic centimeter of a neutron star would weigh as much as 30 billion elephants. This mind-boggling density arises due to the crushing force of gravity and the absence of electrons in neutron stars, allowing only neutrons to exist. This was just one fascinating topic discussed on the Cosmic Queries edition of StarTalk Radio, hosted by Neil deGrasse Tyson. The show, funded in part by a grant from the National Science Foundation, aims to make the wonders of science accessible to everyone. So, keep looking up and join Neil and his guests as they continue to explore the cosmos.
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