The sun's gravity
Discussion
OK, I want to know the answer to this, but it's probably a really daft question and everyone will think I'm a total buffoon, but to hell with it, here goes.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
There are various prediction on the demise of the Sun. it will as you say eventually burn out. But in Human timescales too far away to concern us. Billions of years from what I remember but no doubt an expert will provide an exact answer shortly. In effect IMO more than 100 million years is not a timescale to concern humans.
The sun still has most of the mass it started with. The energy of the sun derives from the conversion of that mass from hydrogen into helium. The actual mass lost in the process is not that much in comparison to the total mass.
In 5 billion years time, the sun will STILL have most of that mass.
Its problem is that most of its mass will by then have been converted and its nuclear core will,start to shut down. At this point, the still huge amount of mass will cause the core to collapse, triggering massive changes to the sun which will signal the end of life on earth.
Baring other unforeseen events, the sun should still retain its retinue of planets etc up until its demise.
In 5 billion years time, the sun will STILL have most of that mass.
Its problem is that most of its mass will by then have been converted and its nuclear core will,start to shut down. At this point, the still huge amount of mass will cause the core to collapse, triggering massive changes to the sun which will signal the end of life on earth.
Baring other unforeseen events, the sun should still retain its retinue of planets etc up until its demise.
TwigtheWonderkid said:
OK, I want to know the answer to this, but it's probably a really daft question and everyone will think I'm a total buffoon, but to hell with it, here goes.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
It's 'burning' Hydrogen and turning it into Helium, but since Helium weighs slightly less than four Hydrogen atoms, it's only this difference in mass that's being converted into energy. That's the power of mc^2!The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
http://en.wikipedia.org/wiki/Chandrasekhar_limit
This is a good link which also details some of the main characters in the 1930s who were involved in the initial discoveries (or denial of them)
A salutary lesson in humbleness for those who refused to believe Chandraekhar's work.
Every scientist should look at this as a poignant lesson. Unfortunately, when it is said great scientists stand on the shoulders of the giants before them, some believe that they are the last of the giants and that they know everything.
This is a good link which also details some of the main characters in the 1930s who were involved in the initial discoveries (or denial of them)
A salutary lesson in humbleness for those who refused to believe Chandraekhar's work.
Every scientist should look at this as a poignant lesson. Unfortunately, when it is said great scientists stand on the shoulders of the giants before them, some believe that they are the last of the giants and that they know everything.
"Assuming that the sun’s yearly mass loss (currently about one part in 100 trillion) remains small for the duration of its evolution to the red giant phase, Iorio calculates that Earth will move outward at about three millimeters a year, or only 0.0002 AU by the sun’s red giant phase. But at that point the sun will balloon up, in only a million years, to 1.2 AU in radius, thus vaporizing Earth." as from http://www.scientificamerican.com/article.cfm?id=t...
I have always liked the grand idea of saving the Earth being engulfed by the Sun, by moving Earth to an outer orbit using Asteroids, as mentioned in the bottom paragraph in the link. Shame we would lose the moon and would have to move Mars out of the way first, though.
I have always liked the grand idea of saving the Earth being engulfed by the Sun, by moving Earth to an outer orbit using Asteroids, as mentioned in the bottom paragraph in the link. Shame we would lose the moon and would have to move Mars out of the way first, though.
TwigtheWonderkid said:
OK, I want to know the answer to this, but it's probably a really daft question and everyone will think I'm a total buffoon, but to hell with it, here goes.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
You sound like you're coming around to the notion of God The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
steve singh said:
TwigtheWonderkid said:
OK, I want to know the answer to this, but it's probably a really daft question and everyone will think I'm a total buffoon, but to hell with it, here goes.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
You sound like you're coming around to the notion of God The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
Praise the Lord!
TwigtheWonderkid said:
steve singh said:
TwigtheWonderkid said:
OK, I want to know the answer to this, but it's probably a really daft question and everyone will think I'm a total buffoon, but to hell with it, here goes.
The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
You sound like you're coming around to the notion of God The sun's gravity holds all the planets in our solar system in orbit. Even Pluto, miles away, where a year is 288 Earth years long, is in orbit around the sun.
But the sun is burning at a ferocious rate constantly. I once heard (may not be true) that it burns 7 billion tonnes of fuel a second. Now I know it's big, but it must be losing mass all the time. Surely after 5 billion years or whatever it is that it's been going, it must have far less mass than when it was formed. So how come its gravitational force isn't reducing accordingly. How come all the planets don't start to drift away as the hold of the sun reduces. The planets aren't losing mass are they? The Earth weighs more or less what it weighed 4.7 billion years ago.
OK, I've asked it now. Feel free to humiliate me for being a moron.
Praise the Lord!
Eric Mc said:
Einion Yrth said:
Eric Mc said:
It may be getting hotter but it won't go Super Nova - it's too small.
Becoming a red giant with a radius about that of Mars' orbit will be painful enough.Gassing Station | Science! | Top of Page | What's New | My Stuff