If we looked at a star 10 billion light years away, wouldn't that star actually be dead by now even though we can see it as if it was alive?
The short answer: If we look at a star that’s dead now but was alive 10 billion years ago, yes, we’d see a living star. It’s amazing how weird science is.However, it’s probably not dead. Besides, we can’t see it; even galaxies that far away apppear tiny. Just look at the Hubble Deep Field, which is a picture of galaxies 13 billion light years away from the most powerful telescope ever built.It’s dazzling, but you can’t see a star in that image. But what if you could?A star we see 10 billion light years away was alive 10 billion years ago. That’s if you don’t account for inflation, which is basically things moving away from each other due to dark energy. Oh sorry, I said basically. Science isn’t simple though. In reality, things 10 billion light years away we’d see as less than 10 billion years old, but I think you meant these are 10 billion year old images and the stars are around 30 billion light years away now.10 billion years later, the star is about 10–13 billion years old. Stars like the ones today only formed hundreds of millions of years after the Big Bang, which was 13.8 billion years ago.So is this star alive? The question hinges on whether the star’s lifespan was at least 10 billion or so years. The lifespan of a star gets shorter the more massive it gets. Sure, more massive stars have more fuel, but higher pressure and temperature mean it burns brighter and faster, and uses up its fuel. (There are other reasons too but they’re not important).A star like the Sun will live from 10–12 billion years, so if the star is the mass of our sun or less, it would actually still be alive. This includes over 90% of all stars, so that star is probably still alive. The proportions were probably different then, but still, stars less massive than the Sun were the majority.But what if the star were dead? Well, we would still see it as alive. The light we’re seeing now was emmitted by that star 10 billion years ago back when it was still alive, so yes, even if the star were dead, we’d see its light.I have seen a different answer that uses relativity. It’s a lot easier to explain if you know relativity, but I’d assumed that since you’re asking this question, you don’t know relativity.
If we looked at a star 10 billion light years away, wouldn't that star actually be dead by now even though we can see it as if it was alive?
The short answer: If we look at a star that’s dead now but was alive 10 billion years ago, yes, we’d see a living star. It’s amazing how weird science is.However, it’s probably not dead. Besides, we can’t see it; even galaxies that far away apppear tiny. Just look at the Hubble Deep Field, which is a picture of galaxies 13 billion light years away from the most powerful telescope ever built.It’s dazzling, but you can’t see a star in that image. But what if you could?A star we see 10 billion light years away was alive 10 billion years ago. That’s if you don’t account for inflation, which is basically things moving away from each other due to dark energy. Oh sorry, I said basically. Science isn’t simple though. In reality, things 10 billion light years away we’d see as less than 10 billion years old, but I think you meant these are 10 billion year old images and the stars are around 30 billion light years away now.10 billion years later, the star is about 10–13 billion years old. Stars like the ones today only formed hundreds of millions of years after the Big Bang, which was 13.8 billion years ago.So is this star alive? The question hinges on whether the star’s lifespan was at least 10 billion or so years. The lifespan of a star gets shorter the more massive it gets. Sure, more massive stars have more fuel, but higher pressure and temperature mean it burns brighter and faster, and uses up its fuel. (There are other reasons too but they’re not important).A star like the Sun will live from 10–12 billion years, so if the star is the mass of our sun or less, it would actually still be alive. This includes over 90% of all stars, so that star is probably still alive. The proportions were probably different then, but still, stars less massive than the Sun were the majority.But what if the star were dead? Well, we would still see it as alive. The light we’re seeing now was emmitted by that star 10 billion years ago back when it was still alive, so yes, even if the star were dead, we’d see its light.I have seen a different answer that uses relativity. It’s a lot easier to explain if you know relativity, but I’d assumed that since you’re asking this question, you don’t know relativity.
What do we know about black holes in space?
There are 5 different types of black holes: (i will compare them to the mass of our sun, which i will call 1 sm [solar mass]) Supermassive black holes- 1 million to 1 billion sm Intermediate mass black holes- 1 thousand sm Stellar mass black holes- 1-500 sm Mini black holes- less than 1 sm Micro black holes- the size of an atom which is roughly .0000000000000001 sm light cannot escape, and its thrown somewhere in a diiferent solar system, galaxy, or even dimension. think of black holes as a tornado. They suck up things and spit them out wherever they want. so it cant fill up
What is a black hole?
Black holes are real. Cygnus X1 is a black hole. There is also a black hole at the center of our galaxy that masses a million times our sun. Gravity is a product of mass. All mass exerts a gravitational force, although gravity is a very weak force. Imagine you are standing on the earth, and you throw a rock into the air. The rock goes up, and it falls back down. You throw it harder, it goes higher. Now, if you throw the rock 25 thousand miles an hour, it will go up and up and never fall back to the earth. 25 thousand miles per hour is greater than earth's "escape velocity." If the earth were more massive, escape velocity would be higher. You would have to throw a rock 100,000 miles an hour to reach escape velocity on a really massive earth. Increase the mass more, and you might have to throw the rock 200,000 miles per hour to reach escape velocity. If we increase the mass of the earth so much that escape velocity is greater than 186,330 miles per SECOND, the earth would be a black hole. The significance of that number is that it is the speed of light. Any mass great enough that not even light can reach escape velocity is a black hole. Another person who answered this question gave a link to Wikipedia, which is a great resource. I hope my answer was clear and understandable. What causes black holes? They are created when super massive stars reach the end of their life cycles, in cataclysmic explosions known as supernova. Not all supernova will result in a black hole, but some really big ones do. Quantum black holes (really tiny ones--as small or smaller than an atom) may have been created when the universe began. These, it turns out, probably all evaporated.
Why do some Andhra people do crazy stuff in movie theaters in the USA?
Let me put myself in the shoes of one of those guys shouting there and answer this question. My hero - I anyway hail from a part of the subcontinent which idolizes movie stars and gives them a larger than life stature. Why not continue the legacy? So, let me (i) Idolize a hero (ii) Make him a part of myself and a cause worth fighting for (iii) Find like minded fools and be assertive wrt other heroes' fan clubs (iv) Engage in vandalism in case some other hero's fan club attacks our hero. Caste loyalties and inferiority complex - I am not a great man and neither do I aspire to be. But hey, look, one of the zillion descendants of my great great great great grandfathers managed to succeed and let me take pride in it. (Mother of free riding!). Demographics and homesickness - I am a 20 something year old student residing here. I miss home and the Friday evening shows. The only way I feel close to home and connected to my roots is through movies. Crowd behavior - Who the hell will recognize me in a crowd anyway. Let me fuel my animal instincts while a part of my brain stops being embarrassed (as long as the embarrassment isn't personal). Popular - Let me be popular in a moment and perhaps one day, this video might reach the hero I adore.Fun - Hey, come on! I am having fun and you cant stop that. I dont know this guy personally nor do I have a clue about his acting. The only reason I am here is because my friends are here. PS - The moment you are XYZ's fan, you cease to be a fan of cinema.