Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 07/09/2006 03:13:14
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Apparently we have a lot less time than 4-5 billion years for the Sun (http://en.wikipedia.org/wiki/Sun) to turn Planet Earth into a crisp as it expands into a Red Giant (http://en.wikipedia.org/wiki/Red_giant).
It seems the Sun is getting hotter right now...and that in only 1 Billion yeras it will be hot enough to turn the Earth into another Mars.....so get packing !
...but why is the Sun getting hotter now ?....Has it always been increasing in temperature since it's birth ?
..if so..then what was the temperature of the Sun when it was born ?
Men are the same as women, just inside out !
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Sure, we will all have to leave this planet soon, but a lot sooner than you think. and not by the sun heating us up.
Due to human activity and global warming, we have forestalled the next ice age. We are now at least 5000 years into what would of been the next ice age. Scientists predict that when we stop burning fossil fuels, or run out, the planets temperature will catastrophically drop.
BTW, Im back [:)]
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I would engage you in a battle of wits, but it is against my moral code to attack the unarmed.
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SOOOOOOOOOOO good to see you Science Guy (don't you dare go away for so long again...slaps hand)
Sir.....I am so depressed !!.....I wonder if 5000 years is enough for Science to find a way.
I do have this Optimistic faith in the ingenuity of the human species to come up with science ways to save the day. (and I am a pessimist by nature)
Even if we are around in 5 billion years....I was hoping that we may have a way to control the Sun...but I don't think we will be of any resemblance to the humans of the far Far distant future...however...5000 years eh ?...Oh my !!..brrrrrrrrrrrrrr !!!..I'm getting cold !!..and at least this is one weather forecast you can predict with a good measure of accuracy eh ?
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The sun is in fact getting hotter but only very slowly, of course when it first condensed from a gas cloud the temperature was probably about 20°K but when it first burst into life it it estimated it was about 10% cooler when the planets were formed than it is today
syhprum
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Syhprum,
Sir,
THANK YOU so much for this. I really appreciate your kind input.
Well, with a big freeze that seems imminent in 5000 years and a big heatwave later on.....seems like an average day here in the UK.
Do you happen to know that although it is getting hotter at a slow rate, as to whether that rate is constantt ?...don't suppose you also know why it's getting hotter ?
Men are the same as women, just inside out !
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I am sure you can easily find a more accurate and detailed account on the internet but basicly what happens is the hydrogen core that is fusing into helium tends to become exhausted and the fusion process takes place in the helium at a higher temperature and pressure, this process continues through a range of steadily increasing mass elements until the it becomes unstable and blows up to a red giant.
Don't hold your breath, it takes a long time.
syhprum
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At the moment the sun is burning hydrogen through fusion ie two hydrogen atoms fuse together and create one helium atom. but as their is more to two hydrogen atoms than one helium the excess is turned into energy and is radiated out into space.
Once most of the hydrogen is used up in the core the sun starts burning it in its outer shell causing the core to contract increasing its density and heating it up, as its now got hotter it starts to fuse helium into carbon and expands into a red giant,everynow and again when most of the helium is used up it will blow off its outer layers until all your left with is a carbon core, a white dwarf.
If the sun was a much bigger a super giant star it would then fuse its carbon into oxygen: then the oxygen into silicon; and then near the end the silicon into iron.
After that (cutting it short) the iron atoms are squashed together so much that the electrons and protons all come together creating nuetrons resulting in the end a supernova . its core then colapses producing either a nuetron star or if it colapses to much depending on its mass a blackhole.
Michael
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THANK YOU SYHPRUM & THANK YOU MICHAEL,
Excellent posts from everyone for which I am very grateful.
Men are the same as women, just inside out !
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As far as I am aware, the present increase in solar output is just part of its natural long term variability. Yes, there is a general, slow, upward trend; but right now (for the last few centuries), it has been warming faster (and with it, there is an increase in sun sport activity), and no doubt at some time in the future this trend will be reversed (as it has in the past).
George
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Welcome back GEORGE!!!![:)][:)][:)]
Karen
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quote:
Originally posted by Karen W.
Welcome back GEORGE!!!![:)][:)][:)]
Karen
Thank you Karen - nice to be back with my friends again.
George
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Did you find your poem?LOL
Karen
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Welcome back George.
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Did you know that if a photon was able to travel in a straight line, from the heart of the Sun to its surface, it would take only 2.5 seconds, but, because the density of the Sun is so great, it actually takes 10-million years -- bouncing around inside like a ball in a pin-ball machine.
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Roy P
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quote:
Originally posted by Roy P
Did you know that if a photon was able to travel in a straight line, from the heart of the Sun to its surface, it would take only 2.5 seconds, but, because the density of the Sun is so great, it actually takes 10-million years -- bouncing around inside like a ball in a pin-ball machine.
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Roy P
Dear Super Artist,
(everybody who has not looked..please check out this gentelmans art...it's fantastic)
I did know that actually...but I bet a few peeps here did not....amazing eh ?
That's probably why 'bottom burps ' smell so much...they have spent years going off before they are finally released !! [:D] (sorry Roy)
Men are the same as women, just inside out !
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quote:
Originally posted by neilep
(everybody who has not looked..
Sssssh, Neil!
:)
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Roy P
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quote:
Originally posted by Roy P
quote:
Originally posted by neilep
(everybody who has not looked..
Sssssh, Neil!
:)
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Roy P
Ok..I'll keep it a secret !!...[;)]
have emailed you by the way.
Men are the same as women, just inside out !
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HyperSpace with Sam Neil from Discovery Channel stated 6 years ago that in around 70 years time, plant life cannot survive as it is too hot. Then we will be moving to Mars [:(]
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Funnily enough the latest issue of New Scientist suggests that the sun may be getting cooler (just for a few years) because we may be headed for a low sunspot count period. Two of these have occurred within recorded history and this could delay the onset of the worst nasties of global warming for a decade or two. While Scientific American is describing ways to get round the problem. The neatest new idea I have seen is the possibility of generating a true carbon fuel cycle by collecting carbon dioxide from power plants and using bilogical/chemical processes and sunshine to create hydrocarbons to fuel power stations.
Learn, create, test and tell
evolution rules in all things
God says so!
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WOW Ian. THANK YOU.
That ' neatest new idea' sounds very enterprising indeed. I wonder how many ' neat ' ideas remain just that though...as ideas !
Sooner or later we're going to have to start putting these neat ideas into prototype stage. I'm not a chem engineer but it sounds like the true carbon fuel cycle idea is worthy of true experimentation.....but...which biological/chemical process's ?..I assume someone somewhere must have tried it out eh ?....
Men are the same as women, just inside out !
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quote:
Originally posted by Soul Surfer
Funnily enough the latest issue of New Scientist suggests that the sun may be getting cooler (just for a few years) because we may be headed for a low sunspot count period.
Sunspots have been increasing since the middle of the 17th century. It would be perfectly plausible to speculate that the cycle has peeked, and over the next few centuries will start to decline, but I would think it too early to claim definite proof that the cycle has indeed peeked.
quote:
While Scientific American is describing ways to get round the problem. The neatest new idea I have seen is the possibility of generating a true carbon fuel cycle by collecting carbon dioxide from power plants and using bilogical/chemical processes and sunshine to create hydrocarbons to fuel power stations.
But why?
You need energy to convert CO2 back to O2. If you have that energy in the first place, then why not use it directly instead of burning the carbon.
Where I can see a benefit in a synthetic carbon cycle is where we are talking about fuel for transportation, where the liquid hydrocarbon fuel is used (as it is today) to power vehicles, and CO2 is later recovered from the atmosphere and converted back to liquid hydrocarbon fuel. It is the ease of transportation of hydrocarbons, and the ease of piping it to where it is required, that makes hydrocarbons so useful as a fuel for transportation systems; as much so as its energy content.
George
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The point of the other carbon cycle is that it uses solar energy to perform the process and is potentially more efficient than doing it by growing plants in a carbon diopxide enriched atmosphere.
Learn, create, test and tell
evolution rules in all things
God says so!
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quote:
Originally posted by Soul Surfer
The point of the other carbon cycle is that it uses solar energy to perform the process and is potentially more efficient than doing it by growing plants in a carbon diopxide enriched atmosphere.
This is fine, but it still does not explain how the solar energy is captured in order to drive the carbon cycle, and why that energy capture could not be used in a more direct way?
George
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The most direct ways are solar cells which have no storage capability a very high energy input to manufacture them and are relatively inefficient and low grade heat which currently has very limited uses. These processes could still be used as part of a multi process energy station the carbon capture process takes the high carbon dioxide flue gasses from burning carbon based fuels and reprocesses them catalytically back to short chain hydrocarbons using sunlight. These hydrocarbons can be used to make energy locally or converted into road fuel.
Learn, create, test and tell
evolution rules in all things
God says so!
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quote:
Originally posted by Soul Surfer
The most direct ways are solar cells which have no storage capability a very high energy input to manufacture them and are relatively inefficient and low grade heat which currently has very limited uses. These processes could still be used as part of a multi process energy station the carbon capture process takes the high carbon dioxide flue gasses from burning carbon based fuels and reprocesses them catalytically back to short chain hydrocarbons using sunlight. These hydrocarbons can be used to make energy locally or converted into road fuel.
Solar cells do convert sunlight (at present with only about 12% efficiency, but no doubt this will improve over time). There are various technologies that can be used to store excess energy from solar cells, some more mature than others. At present, converting CO2 to hydrocarbons is anything but mature technology (although converting coal to hydrocarbons is a well established, if less than efficient, technology). At present, power conversion from carbon based fuels is limited to about 20% to 30% efficiency, so any cycle that expects to recycle using current technology must lose 70% to 80% of its energy in each cycle.
There may be practical advantages in using such an inefficient cycle in some cases (such as the convenience of the fuel for transportation use), but it would seem to be an expensive cycle if one can more freely select the means of energy storage.
George
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The most direct ways are solar cells which have no storage capability a very high energy input to manufacture them and are relatively inefficient and low grade heat which currently has very limited uses. These processes could still be used as part of a multi process energy station the carbon capture process takes the high carbon dioxide flue gasses from burning carbon based fuels and reprocesses them catalytically back to short chain hydrocarbons using sunlight. These hydrocarbons can be used to make energy locally or converted into road fuel.
Learn, create, test and tell
evolution rules in all things
God says so!
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quote:
Originally posted by Soul Surfer
The most direct ways are solar cells which have no storage capability a very high energy input to manufacture them and are relatively inefficient and low grade heat which currently has very limited uses. These processes could still be used as part of a multi process energy station the carbon capture process takes the high carbon dioxide flue gasses from burning carbon based fuels and reprocesses them catalytically back to short chain hydrocarbons using sunlight. These hydrocarbons can be used to make energy locally or converted into road fuel.
Solar cells do convert sunlight (at present with only about 12% efficiency, but no doubt this will improve over time). There are various technologies that can be used to store excess energy from solar cells, some more mature than others. At present, converting CO2 to hydrocarbons is anything but mature technology (although converting coal to hydrocarbons is a well established, if less than efficient, technology). At present, power conversion from carbon based fuels is limited to about 20% to 30% efficiency, so any cycle that expects to recycle using current technology must lose 70% to 80% of its energy in each cycle.
There may be practical advantages in using such an inefficient cycle in some cases (such as the convenience of the fuel for transportation use), but it would seem to be an expensive cycle if one can more freely select the means of energy storage.
George
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I'm not sure where the technology is regard to converting CO2 back C & O2 is, but in the meantime how about clean burning synthetic fuels. See the link below for details:
http://www.cffs.uky.edu/C1/2005%20Meeting/WPAFB%20Harrison%20Invited.pdf
With regard to more efficient solar cells have a look at Ovonic is doing. They claim to capture and convert 20% more of the sun's energy than conventional crystalline solar cells and convert it to power. Check out these two links:
http://www.ovonic.com/eb_so_solar_overview.cfm
http://www.ovonic.com/se_ovonic_machine_building_division.cfm
I also read an article on line that some guy has come up with a paint on solar conversion coating that converts infrared (½ of the sun's output) to electricity. Think of the possibilities of two technologies combined.
Steve
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I'm not sure where the technology is regard to converting CO2 back C & O2 is, but in the meantime how about clean burning synthetic fuels.
Ironically, one of the demonstrable contributors to global warming in the last couple of decades of the 20th century is caused by the reduction of sulphur and particulate pollution - the exact same thing that this technology would be taking even further.
Certainly, there may be arguments on other grounds for going down this road (although it is open to question whether removing all 'pollution' is necessarily desirable), but it will not only not do anything to reduce global warming, but will most likely contribute to it.
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With regard to more efficient solar cells have a look at Ovonic is doing. They claim to capture and convert 20% more of the sun's energy than conventional crystalline solar cells and convert it to power. Check out these two links:
http://www.ovonic.com/eb_so_solar_overview.cfm
http://www.ovonic.com/se_ovonic_machine_building_division.cfm
I also read an article on line that some guy has come up with a paint on solar conversion coating that converts infrared (½ of the sun's output) to electricity. Think of the possibilities of two technologies combined.
Steve
There are a number of lab based systems (using a wide range of technologies, some very interesting) that have demonstrated conversion rates of about 40%, considerably higher than the 12% that is common today. The problem still is moving from the lab to the streets.
In some ways, one of the problems we have is that the push to scale up current technologies always creates a greater barrier for new technologies (unless they are merely an enhancement of a current technology, and don't require abandoning the investment in current technology).
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The technology for converting CO2 back to C and O2 has been around for at least 200 million years, it uses sunlight and catalyst's such as Chlorophyll and is called vegetation
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The technology for converting CO2 back to C and O2 has been around for at least 200 million years, it uses sunlight and catalyst's such as Chlorophyll and is called vegetation
I think that has been around more like 3.5 billion years, not 200 million.
The problem is that firstly people are saying it is not coping - don't know if they are right, but if they are wrong, then what are we worrying about CO2 levels in the atmosphere for?
The second problem is what happens to the C that is fixed by this method. Most of it is promptly converted back to CO2 by animals and microbes and other living organisms, while we continue to extract fossil fuels to burn. If we were to use our own methods for converting CO2 back to C and O2, then we would reduce the amount of CO2 available for plants to convert, which will then steel the C from animals and microbes to convert back to CO2.
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Converting CO2 back to C isn't the big problem. Finding the energy to do it is.
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Converting CO2 back to C isn't the big problem. Finding the energy to do it is.
But the efficiency by which it can be done has an impact on how much energy is required to do it.
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ever heard of sun spots, the sun is going to continue its current life cycle for (aprox.) 5 billion more years!