The Sun

I was just wondering, my chemistry teacher told me that the sun will eventualy run out of oxygen and convert into some other gas turning into a giant red ball. He says this will most likely happen in 6.5 billion years. So does that pretty much mean the end of the world is approximately 6.5 billion years from now? An is what my teacher said true?

 

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For a start, it's hydrogen, not oxygen. And basically yes, what he said is true. In roughly 6.5 billion years the sun goes into red giant phase and the conditions on Earth will be considerably less friendly to life

Next time, use google or wikipedia

 

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"the sun is a star"

ancient quote from some dude on discovery, good think i almost dont watch tv anymore

 

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In 6.5 billion years, air conditioners should be pretty cheap by then. I recommend buying a couple of good ones if you're still around.

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I used to watch Discovery, but not any more, it's become too dumbed down.
I wonder why...

 

Poor old Earth.. And Old it is..

Tectonic movement will stop, and most water will disappear. The magnetic field will die and our precious atmosphere will go. The sun will get hotter and hotter, and in about 500M years the Earth will be as hot as an oven.

Super Nova will then zap us, and in the end a black hole will devourer what’s left of our system.

Still plenty of time to evolve into more wondrous chemical oddities.

 

Just 500 million?
p.s. Do you have any particular black hole in mind or is it just a guess?

 

Umm. No.
Afraid not.

The sun is not large enough to end in a super nova and black hole. Instead, it will go through a red giant phase. And eventually end life as a white dwarf. Well, a black dwarf actually, but since no white dwarf has cooled to a black dwarf yet, we're dealing with enormous time scales here.

I'm not sure about a nova... without going back to check my facts... Will the red dwarf shed its outer layers in a nova? So the white dwarf would be at the center of a planetary nebula?

 

500million is all we have. Bit of a shame but what can we do.

Of course the sun will not go super nova but eventually one will go off very close.

Eventually the solar system will plummet into a black hole. No direct candidate at the moment, but a guess would be the super massive hole in the centre of our galaxy. But don’t wait for it because it’s about several hundred billion years away.

 

Don't forget the colision of Andromeda with the Mily Way in slightly less than that time.

 

500 million? Thats a bit too soon. 4.5 billion till it goes red giant, last I heard, but theres still a couple billion years before it gets quite warm. You'll have to come up with some evidence, blindman.

 

The Earth is just inside the habital zone.
The suns output is constantly increasing. This increase is caused by the continued production of helium causing the suns core pressure to increase thus increasing the energy output.
The habital zone is slowly moving outward away from the sun.

The suns output will have increased by 5% in 500 million years. As the Sun's output continues to increase so much water will be evaporated into the atmosphere that even the stratosphere gets wet. Sunlight will then break apart the water molecules allowing the hydrogen atoms to escape into space. No water, no life.

There are some that give us 1.1 billion years but these predictions do not account for the sensitivity of the biosphere to temperature increases. It is also unknown how the short term variability of the suns output will change as its output increases.

As the suns output increases the spectrum of radiation will also go up leading to increased UV radiation, further hampering life's ability to survive.

500M years is the worst case. 1.1B years is about the best we can hope for.

 

Additional note

The sun heats the earth by 250C. That is, without an atmosphere it would be -18C. The atmospheric greenhouse effect adds a further 23C, making the earth a pleasent place to live.

A 5% increase in the suns output will result in a warming of 15C. I dont know how to calculate the additional green house effect but my guess is that it is not linear. Water is a very powerful green house gas. At some point we will get a runaway green house effect as more and more water evaporates into the atmosphere.

 

Wrong! You have it just backwards! Have you not read my book?

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The currently undetectable* (except for the small gravitational disturbance to Plutos orbit, noticed by astronomer Jack) approaching small black hole is plunging toward solar system, but will not hit any planet (Saturn is very unlikely, but possible if Jack's current trajectory data computed from the perturbation is correct.) however the slight disturbance of Earth's orbit will cause a rapid-onset permanent ice age beginning in 2008. Read more details at web site under my name, including how to read entire book for free and why it was written.
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*With absolutely zero reflectivity, telescopes can not see it approaching even though it is now in faint sunlight.

 

First of all a black hole would not plummet into the solar system, the reveres is true. The solar system would plummet toward the black hole.

Secondly a black hole is not invisible..
Space (interstellar space) is full of gas and dust.. Admittedly at very low densities. As a black hole moves through space this gas and dust is swept up by the black hole. As it spirals into the hole it get very hot and will release X-rays as a result. These X-ray would easily be seen from both space and Earth based observatories.

If a black hole passes through the heliopause it would become very bright in the x-ray spectrum.

Any ort cloud objects passing by the black hole would also, due to tidal forces, become very hot releasing vast clouds of gas and dust, thus producing more fuel for x-ray emissions from in falling matter.

The hole would also send the objects flying at high speed in all directions. so expect the sudden arrival of high speed comets, and comet chains (broken up ort cloud objects sent flying through space).

I am not discounting the concept of a dark visitor, but I do dispute its unseen arrival, even if it came at us from above or below the solar systems orbital plane it would be visible many years before its devastating impact on the solar system.

The discrepancies in Neptune's orbit observed by 19th century astronomers were due instead to an inaccurate estimate of Neptune's mass.

If the world was coming to and end in 2008 I would be borrowing as much as I could and partying on every type of drug known to man.

 

Depends which one had more mass, our solar system or the black hole.

And surely we'd be seeing some kind of gravitational lensing going on in reagrd to the stars if a black hole were approaching?

 

for a nano-second you could get a beast of a sun tan though

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You are correct on general "quasar" idea here, but it does depend upon:

(1) Mass of the black hole. Most are quite small. The "Dark Visitor" of my book has 2.2 solar masses, so yes the solar system would fall towards it also, but it is coming at the solar system with a cosmic speed, long before either significantly feels the gravity of the other. I.e. it is only chance that makes it miss Earth by 12 AU in late 2007 with very little change in its trajectory from the sun's attraction.

(2) Density of the cosmic gas, as you mentioned. In previous posts, I have noted that I placed some "Easter Eggs" in the book to get people to carry it around on campus and use idle moments to search for them. Except for one in the very first paragraph, which is built on my knowledge of how reading works, all the "Easter Eggs" are plausible statements that are actually false, such as this statement also made in the book that "the dark visitor will never be seen in telescopes because Black Holes can not reflect sunlight." The mechanism you suggest, that I call a "weak quasar" is only one of the two reasons why this is an "Easter Egg" (and the other is not the gravitational lens effect) Can you guess it? I teach enough physics in the book that someone carefully reading it should be able to find all the Easter Eggs, but one, using just what they learn in the book, but only one or two are "easy."
I tried to calculate distance to the approaching black hole the "weak quasar" would produce enough visible light to be detected in "modest size" telescopes. (I commented in the book that all the big ones have very low probability of spotting it as they are all in great demand for cosmologyical reaserch and used at high magnification to look at very small solid angles of very distant sources.) That is a difficult thing to even estimate, and very speed dependant (see next point) but roughly your "helipause" or just inside the solar wind reagion is correct.

(3) Speed of the black hole relative to the accreting mass. If the Black hole is traveling rapidly thru a even a dense (by cosmic standards) gas cloud there will not be a "weak quasar" formed. Instead all the dust, Hydrogen inside the "cylinderical core" its trajectory cuts thru the gas clould will be eaten by its event horizon before its density is increased enought for the radial gravitational impulse to compress that dust density. Without this radial compression, there will be so few collisions before the dust disappears inside the EH that there is no "weak quasar" only a little less randomness in the velocity vectors of each piece of dust or hydrogen atom. I won't go into details, but if a "weak quasar" does form, it is probably a short line source trailing BEHIND the approching black hole and gravitationally lensed as a beam which is not visible from Earth. - Think about this and you may be able to work out why.

Summary: Thanks, but I was way ahead of your understanding of all this when writing the book about three years ago.

Here you are totally wrong and it is easy to prove it.

For all gravitational perturbations of body "A" by any collection of n objects of mass Mn the mass of A, (Ma) "cancels out" when the perturbation is calculated. I.e. gravitational perturbation is independent of the mass of A.

This is very easy to understand. For example, let us double the mass of A. Then the force acting on A by each of the other n objects will also exactly double (Don't forget Newton's third law, if you calculate the increased force on object n) and thus the net force from them all will exactly double, but remain exactly in the same direction as before. Object A will accelerate exactly as before also because with twice the mass it requires twice the force to produce exactly the same acceleration. If the acceleration remains exactly the same at every instant, then the perturbation of object A's position is exactly the same.

Hence, you are wrong because the perturbation that was observed in Neptune’s orbit is independent of the mass of Neptune. Note that this applies only to gravitational perturbations. If Neptune had been HIT by something, then the Mass of Neptune would have made a difference in the perturbation.

However such a HIT perturbation makes a discontinuous change in the trajectory, not the continuous one observed over several years. Thus it seems to me, that a SMALL black hole (Or one of the other cosmic objects discussed in Chapter 8 of Dark Visitor[i/]) rapidly passing some distance from the solar system with modest gravitation effect on the then most distantly known planet is a plausible mechanism (In fact the only one I can think of) for explaining the perturbation that was observed for a few years while it was within “significant gravitational range".

This perturbation of Neptune, not only directly led to the discovery of Pluto, but until approximately 1950, Pluto was considered to be the cause of the perturbation. Unfortunately the mass Pluto requires to have made the observed perturbation is several times that of the Earth. After Charon (Pluto's first to be discovered moon - two more smaller one were just discovered last year) was discovered it became possible to know Pluto's mass and it turned out to be slightly less than the moons, leaving mankind with no good explanation for the observed perturbation, but with the exciting discovers going on 20 or more later than the old and dull perturbation of Neptune data, few were interested in trying to find a new explanation for that perturbation. I think those who even thought about this tend to think it was some failure to properly consider the mass of some unknown Ort object or a observational error or math calculation error, etc. Also most tend to think of Black holes as big, very massive objects and if one of those were the cause of the small perturbation it would need to be much farther away at its closest point to solar system and we would still be observing its gravitational effects on planet orbits.

This post is already long so I will not explain why there probably are more of the small black holes still existing now than all the stars that have ever existed in the history of the universe. The part of the reason is given at the web site under my name and part I have posted else where at Sciforums. (If not too hard to find again, I will modify this to tell where by edit.)

BTW, when ever I mention my book, I make it a policy to note that the web page not only tells why I wrote it, (a very serious concern for the health of the western economies) but also how to read it for free.

Read the book. It is really a physics book disguised as a cosmic horror story. I am reasonably sure you will painlessly learn some more physics while doing so. If you find at least five of the other Easter Eggs I have hidden in the book, you are entitled to the “World Class Egg Hunter” certificate.

 

Billy T,
(2) Most of the emission from black holes is in the form of radio waves and x-rays, not visible light, in 'quiet' black holes. It is now known that even 'quiet' black holes emitt tremendous amounts of energy. Radio and x-ray telescopes should easily detect any nearby black hole from these jets.
(3) Black holes suck in gas and dust within a radius of about a million times the diameter of their event horizon. They suck in the gas from their edges and blow out huge amounts of energy from their axis of rotation, the jets emitted from black holes. The jets blow away gas and dust from the 'top and bottom' of the black hole (the axis of rotation) creating huge 'bubbles' on each flat side of the black hole. I assume blindman was speaking of the matter blown away by these jets as the high speed matter.

Recent theory states black holes are the most efficient engines in the universe, based the ratio of infalling gas compared to the energy required to produce these huge bubbles.

Here is a link to an article you may have missed:
http://www.space.com/scienceastronomy/060424_green_blackhole.html

 

Thanks -will read soon. Now I must return to watch CNNi Insight program - it is all about Brazil and alcohol. Your thinking of a Black Hole not moving rapidly thru the background gas cloud - that make much of the truths you state largely irrelivant.


Ok CNNi Insight's 30 minute program is over so I can comment more than a commercial break allowed. But first: There was only one error in the program. I hope it is available in CNN of USA also - try to see it. (Error is one expert's statement tha corn is most efficient source. - He was thinking of the those used in US. - For example, the net energy yield of sugar cane alcohol in Brazil is about 8 but only 1.1 with Iowa corn. Both corn and sugar cane are among the few crops that use the more efficient four carbon step photo sythensis process, but sugar cane is more efficient at removing the CO2 from the air so it is the most efficient even if only considering the capture of sun light and neglecting the huge fossil input (fertilizers etc) required to grow corn in Iowa's short summers. The residue from cane also makes both good fertilizer and acts as a pesticide. - Corn residue does not, but both can be feed to cattle.

Now returning to your comments and my quick reply:

Pehaps it will help you to understand why my quick comment (your post is irrelivant) is true, if you consider the analogy of a magnitized cannon ball held stationary in the interior of a low density dust cloud of fine iron particles vs the same cannon ball flying rapidly thru that cloud.

Even your case - The spectral distribution coming from a black hole swallowing parts of a near by star (i.e. a "quasar") is complex and depends on several variables, but that is completely irrelivant to a black hole of a few solar masses passing rapidly thru a gas cloud in space.

Read my second and third points of prior post again. Perhaps you will understand if you first clear your mind of the irrelivant information relating to conventional quasars. Perhaps, it was a mistake for me to even call the weak light that can be produce by may rapidly moving black hole a "weak quasar" as physics of that is so different.