A RAR! Scenario Involving The Sun

[DPDarkPrimus]

Okay, via divine intervention, the Sun is now different in one aspect, and one aspect only: it no longer produces light. Radiation, magnetic fields, heat, etc... everything else that would normally be produced still is, but no light is generated. Any light from other sources that would normally reflect off of it would still be reflected- it's not a "black hole" for light now. It just doesn't produce any.

Ramifications?

[Erik von Nein]

We'd all die. Well, most things would die and the few survivors left would be forced to use greenhouses for food while the light bulb industry gains a huge boost. Other than that people would eventually start feeling more depressed (not just because they're the survivors) because getting sunlight is an important thing for people's pyschology.

[The Guid]

Can plants still photosynthesise? If not, we all die. If so... Oil crisis comes quicker, no more sodding cricket, suicide rate goes up and lawlessness increases.

[GrandMasterTerwynn]

Okay, via divine intervention, the Sun is now different in one aspect, and one aspect only: it no longer produces light. Radiation, magnetic fields, heat, etc... everything else that would normally be produced still is, but no light is generated. Any light from other sources that would normally reflect off of it would still be reflected- it's not a "black hole" for light now. It just doesn't produce any.

Ramifications?

We go apeshit insane within a week. Diurnal species go extinct en-mass, as they rely on sunlight to trigger their circadian rhythms. Plants lose a fair part of the energy they need to photosynthesize, so most of them die back.

End result, we all die.

[tharkûn]

Can plants still photosynthesise?

No. Photosynthesis depends on electronic transitions that have well defined energies (i.e. corresponding to red, green, or blue photons). If you change the light coming in the metal centers won't promote electrons, and then nothing makes free oxygen. There likely are some odd bacteria or plants somewhere than can efficiently utilize only the UV or IR, but they ain't the mainstays.

It would take a while to deplete the oxygen content of the earth and you likely could get a few survivors to set up electrical plants to make oxygen and grow food, but we are talking about massive death and the end of modern civilization.

Okay, via divine intervention, the Sun is now different in one aspect, and one aspect only: it no longer produces light. Radiation, magnetic fields, heat, etc... everything else that would normally be produced still is, but no light is generated. Any light from other sources that would normally reflect off of it would still be reflected- it's not a "black hole" for light now. It just doesn't produce any.

The sun implodes. Light pressure is a significant force in counteracting gravity. If you remove light, then a new equilibrium density will be found between gas pressure and gravity. I don't recall if that would lead to high enough temperatures to start imploding further or not. At the very least we should be seeing some massive discharges from the sun while chaotic turbulence sets in. These, I think, will be strong enough to kill most everything on earth long before it runs out of oxygen.

Of course if you say no light comes out, you have the problem of bleeding heat. No light implies no IR, UV, X-ray, or gamma as well, this can only be accomplished by perfect total internal reflection and will heat the everloving crap out of the stellar interior, which will then fuse to iron. Some heat could be bled through matter ejection, but nowhere near enough to offset the loss of radiative cooling. Within a ridiciously short stellar timescale the sun collapses into a neutron star. That might even be a ridiciously short human timescale, but I can't get a handle on the exponentials to get even an order of magnitude guess.

The real answer is the universe explodes as EVERYTHING gives off black body radiation and the sun MUST give off light or physics is no longer valid.

[Sharpshooter]

Not to mention every major innvester in the photo-voltaic industry turns the gun on himmself.

There'll likely be a massive downsizing in the population due to suicide, criminal activity, and squabbles over the remaining resources, and most population centers will become virtual ghost towns as the remaining populations gather into only two or three cities in an entire country. Extensive research will be made into the production of energy through renewable means, as well as extending the lifetimes of light bulbs and other light emission tools Major sales bosts for those flashlights where you shake them for a few minutes to produce a charge occur.

Over a few dozen generations, mankind begins developing extrordinary light perception, or possibly a freak mutation within a few hundred or thousand that enables us to also see in the thermal spectrum. Gene modding research to enable such might become a good priority, as well as applying said technology to cultivated plants and animmals to propegate without as great or a total need of light. Hearing might also be improved drastically as well.

After a few decades, electronics makers might begin designing combination units that mix the capabilities of several different light-emitting appliences: in addition to standard computer work and internet access, a computer's graphics card will have the capability to also interface with television and game console mediums. CRT displays will be quickly phased out, and designs for smaller, more compact, and more material efficient display types will be researched: instead of using a flat-panal display that's hooked up to a computer, users might instead use a visor of some sort or possibly even a neural interface of some sort (though this isquite a stretch, and would probably only develop if technology went the route of GitS or a similar franchise/prospect).

Races might become non-existant, and skin pigmentation levels will drop to near-nothing. Gene modding might be required to maintain a healthy level, or some form of a yearly booster shot of a sort.

[Il Saggiatore]

There likely are some odd bacteria or plants somewhere than can efficiently utilize only the UV or IR, but they ain't the mainstays.

Aren't there ecosystems in deep caves, where the sunlight does not reach?

[Captain tycho]

There likely are some odd bacteria or plants somewhere than can efficiently utilize only the UV or IR, but they ain't the mainstays.

Aren't there ecosystems in deep caves, where the sunlight does not reach?

Not to mention ocean-floor lifeforms...

[GrandMasterTerwynn]

There likely are some odd bacteria or plants somewhere than can efficiently utilize only the UV or IR, but they ain't the mainstays.

Aren't there ecosystems in deep caves, where the sunlight does not reach?

Not to mention ocean-floor lifeforms...

There are plenty of extremophiles who are perfectly happy to live in solid ice, rock, deep underground, on the bottom of the ocean, etc, etc, etc. The rest of us would be well and truly screwed in this scenario, though.

[Lord Zentei]

I doubt that humanity would out and out go extinct, but our current civilization would collapse and survivors would be few. A post nuclear-apocalyptic scenario might be less horrible.

[That NOS Guy]

I'll never be able to wear my sunglasses again

Oh yeah, humanity would be dicked. I can't help but imagine a Dr. Strangelove-ish solution to survival here.

[Korvan]

There likely are some odd bacteria or plants somewhere than can efficiently utilize only the UV or IR, but they ain't the mainstays.

Aren't there ecosystems in deep caves, where the sunlight does not reach?

Not to mention ocean-floor lifeforms...

But most of those ocean-floor dwellers are dependant on a steady rain of organic material from above. Once the upper levels die out, the bottom dwellers will slowly die as well.

[FedRebel]

Okay, via divine intervention, the Sun is now different in one aspect, and one aspect only: it no longer produces light.

What is this? Angel season 4?

Radiation, magnetic fields, heat, etc... everything else that would normally be produced still is,

...atleast we won't freeze to death.[/sarcasam]

but no light is generated. Any light from other sources that would normally reflect off of it would still be reflected

So the moon is still "glowy" at night?

Ramifications?

No light = No plants
No plants = No prey
No prey = No predators
Bacteria reign supreme!

[GrandMasterTerwynn]

Aren't there ecosystems in deep caves, where the sunlight does not reach?

Not to mention ocean-floor lifeforms...

But most of those ocean-floor dwellers are dependant on a steady rain of organic material from above. Once the upper levels die out, the bottom dwellers will slowly die as well.

That is true, yes, but there are deep-sea ecosystems which are wholly based on energy inputs from geothermal activity, rather than on conventional solar inputs.

[Erik von Nein]

That is true, yes, but there are deep-sea ecosystems which are wholly based on energy inputs from geothermal activity, rather than on conventional solar inputs.

The chemosynthesizers? Of course. They'd still be happily producing all the live long day and tube worms would reign supreme.

[Admiral Valdemar]

Life lasted long enough without sunlight or oxygen, to simply repeat what has already been stated, life as we know it above land dies as do most normal aquatic species. The most adaptable survive, so it looks like my little microbe friends prosper. Again.

[drachefly]

If I read the OP correctly, the sun hasn't been altered intrinsically, because it still sheds light on the moon! So the sun wouldn't implode*.

So would a better way of stating it be that a giant piece of Bizarro Glass were put between us and the sun?
(Bizarro glass: blocks visible light and nothing else)

Well.
A lot of this has been said... most photosynthetic reactions would be cut off.
Though you say the heat radiation hasn't been cut off, most of our heat radiation from the sun comes in the form of visible light!
So the OPer should decide whether the IR has been pumped up to compensate.
(does Bizarro glass down-convert visible photons into multiple IR photons, or just block them?)
These two scenarios are totally different.

*anyway, if the sun weren't able to shed light, it would get hotter, which would make it expand gradually, not shrink catastrophically

[tharkûn]

If I read the OP correctly, the sun hasn't been altered intrinsically, because it still sheds light on the moon! So the sun wouldn't implode*.



*anyway, if the sun weren't able to shed light, it would get hotter, which would make it expand gradually, not shrink catastrophically

The hotter the sun gets the more fusion occurs and the higher its density gets (fewer, bigger particles). That higher density leads to even hotter temperatures and at some point you start burning beyond He. In fusion reactions huge amounts of energy comes off as light, without radiative cooling the sun goes onto an exponential temperature increase (at least at first glance). As you go to higher mass elements, you require more light pressure to keep the sun from imploding (in Sol right now gas pressure is far stronger than light pressure, in hotter stars the reverse is true) - which won't be there as you aren't making light.

Hotter temperatures + no light pressure = shrinking sun.

[drachefly]

You are treating the Sun as if it had one temperature. It doesn't.

If you prevent the surface of the sun from cooling off by radiation, it will cool off adiabatically by expanding higher into space and increasing the solar wind.

If you were to totally compress the sun, preventing any energy exodus at all, then what you describe would occur. That is not at ALL what is described in the OP.

[Guardsman Bass]

Some life continues to survive, and some humans, living off of supplies and possibly in contained greenhouses, continue to survive, assuming they don't go psychotic. In the long run, though, I'd say the human race has little or no future; without light, the creation of oxygen, and most of the world's ecosystems, completely collapse. It'd be like living on the moon with air and some liquid water.

[tharkûn]

If you prevent the surface of the sun from cooling off by radiation, it will cool off adiabatically by expanding higher into space and increasing the solar wind.

That is counterbalanced by gravity. As it stands the reason the sun doesn't collapse due to gravity is mainly two sources:

Gas pressure and light pressure. Remove the latter and the sun will have to reach a newer higher equilibrium temperature resulting from increased gas pressure against denser gravity.

The surface is far removed from the creation of light, that occurs in the core and takes massive amounts of time to make its way to the surface. Even if you get the heat out of the core you still have the problem that the bulk of the sun's volume is taken up in the radiative zone which utilizes light emissions from hydrogen ions to radiate the heat farther out.

The problem is far below the surface and adiabatic expansion does not solve it - expansion lowers gas pressure which gives gravity more ability to compress the core (increasing fusion rate, adding heat to the system, and kicking back into the feedback cycle). It is not just the loss of radiative cooling you have to deal with - it is also the loss of light pressure counteracting gravity.

[raptor3x]

Bacteria reign supreme!

In terms of biomass, I'm pretty sure prokaryotes already reign supreme.

[drachefly]

If you prevent the surface of the sun from cooling off by radiation, it will cool off adiabatically by expanding higher into space and increasing the solar wind.

That is counterbalanced by gravity. As it stands the reason the sun doesn't collapse due to gravity is mainly two sources:

Gas pressure and light pressure. Remove the latter and the sun will have to reach a newer higher equilibrium temperature resulting from increased gas pressure against denser gravity.

Fair enough. However, it will take a LONG time for that increased temperature to diffuse back to the core where fusion takes place.

[drachefly]

Anyway, as I said, what the OP describes isn't reflecting all the light back in, so it's a different question altogether.

[tharkûn]

Fair enough. However, it will take a LONG time for that increased temperature to diffuse back to the core where fusion takes place.

The loss of light pressure would occur as soon as the sun "no longer produces light" would lead to an implosive shockwave. In all likelihood you would get a massive spike in fusion along the front, but because you don't get gamma out you are going to be dumping much more heat into the system. Those are exponential curves, but I can't do more than a half-assed guess without doing real math.

Anyway, as I said, what the OP describes isn't reflecting all the light back in, so it's a different question altogether.

Light reflecting back in isn't as much of a problem. That would take a long time to propogate back to the core and would not create a shockwave..

The truth is in order to stop the sun from producing light, you'd need to violate fundemental laws of quantum mechanics and I can't see any way around dicking over thermo.