It's easy to notice carbon/water life because we are it, but most of our complexity exist within a rather narrow energy band (molecular electron orbitals with energy greater than a C-O and less than a C-H), so I think you're right to doubt that we'd recognize if there were a similarly narrow window into surprising complexity in the nuclear reactions that take place within the sun.
I expect there's quite a lot of "life" that we're overlooking, and that we're going to feel quite silly when we have whatever encounter causes us to broaden our definitions to include the rest of it.
Although to be pedantic, most definitions of life require that it be made of cells, and I doubt there are anything like cells in the sun.
You made me remember how I was ridiculed by my teacher by asking if there was a possibility that life could be based on other thing than carbon. Granted, as I grew older and learnt a little bit more about the chemistry of carbon I realized that it had almost magic properties for life, but I wondered for long time why he reacted that way.
Ridiculing genuine curiosity is a terrible behavior from teachers... why stifle inquisitive minds? Anyway, you may already be familiar with these proposed biochemistries, but there has been a lot of speculation on this exact question over the years:
You probably triggered some memory. Perhaps, a student who insisted they knew more than the teacher and pushed some ignorant argument too far... so when you suggested the idea, and perhaps tried to push a bit more consideration, the teacher found himself re-living that bad experience and treated you like you were the other student, even if you yourself didn't push the matter beyond an acceptable level.
Boron and Nitrogen may have a chance. They form long weird molecules that are stable. Is it possible? I don't know. Can they compeat with Carbon base life? Perhaps no. In a weird planet where almost all the Carbon is sequestred by some weird chemical composition of thee rocks, can Boron or Nitrogen life have a chance. I don't know!
(My guess is that we still need a few thousand years to answer these questions. We still don't understand too may details about Carbon based life. I'm not very optimistic.)
Boron is scarce; it's one of the x-process elements, and those inherently have low abundance (although the boron-to-carbon ratio in the Earth's crust is enhanced over the solar system ratio, I believe.)
Boron nitride is weirdly analogous (indeed, isoelectronic) to carbon in that there's a graphite-like form (hexagonal BN) and a diamond-like form (cubic BN).
One thing that would hold back BN life is that by themselves B and N form more stable compounds than carbon does. Nitrogen in particular forms molecular nitrogen, which is annoyingly tightly bound.
I wonder to what extent they'd need to compete at all, they'd probably have a different diet. Maybe there are carbon life forms out there living mutualistically with boron-nitrogen life forms.
I don't expect a mix of Boron and Nitrogen. Only Boron in some planets and only Nitrogen in another planets.
We [1] can eat things with Nitrogen, so I expect a competing form to be completely eaten if they are less effecient.
I don't know enough about Boron chemistry, but if there were enough of them we will eat them too, unles they eat us first.
The first stages of living things are probably very ineficient. If you need a year to make a viable copy, a previus life form will probably eat you before that. I think that two independent origins of life in tha same planet are impossible.
[1] If you include bacteria and archea in "we". And even we (humans) can eat some compound with nitrogen, in particular proteins that mix carbon and nitrogen.
Silicon has almost the exact same properties as carbon. At high temperatures, carbon chains can’t form, but silicon chains can. In a high-temperature or high-pressure range, silicon might for a basis for life, analogous to carbon for us. So, not only was that question not stupid, it was profound.
Look at silicon on the periodic table. All of the things that make carbon great, basically silicon has almost exactly, except it needs a high temperature for most of those properties to be expressible.
That teacher didn’t know what he was talking about. Ridiculing a student for questions is such detestable behavior. The silliest questions can end up being the most insightful. I really despise teachers like that.
Here is a paper all about how your question was actually wonderful.
Silicon has only superficial similarities to carbon. Even at high temperatures, water and oxygen prevent silicon from substituting for carbon in any of what we are familiar with as organic molecules.
Your linked paper points out that the only viable solvent that supports a large variety of silicon chemistry is sulphuric acid, and even then it would need to be very poor in oxygen since silicon-oxygen bonds are so strong it ends up being much more strongly preferred over si-si bonds.
It makes for an interesting conversation, but I can't imagine spending an entire class going over what amounts to a massive distraction from the lesson plan.
All that's left is going to amount to an effectively dismissive answer, I suppose (though I agree that teachers who are intentionally dismissive are doing it wrong).
Wouldn’t an environment that has a significant sulfuric acid content naturally also a relatively limited free oxygen?
I’m thinking of Venus. That sort of environment would satisfy all criteria and would also start to get into the temperature ranges that would make Si-Si bonds possible.
That would at-least bracket the types of planets and their history to a useful extent.
Sulphuric acid actually has a lot of oxygen and hydrogen in it, and the presence of any metal or even high enough temperature will cause it to break up.
In a lab, it makes for a good solvent, but any place that has sulphuric acid will have both water and oxygen.
Venus, notably, has little to none of both. What free oxygen that does exist is from CO2 and CO breaking down in the atmosphere from the intense and extended venusian day. Most of the sulphur on Venus is sulphur dioxide (a tiny percentage of the atmosphere), and water vapor is a measly 20ppm.
Even if all of that water was sulphuric acid (which it may well be), there's simply not enough of it staying still long enough to form the repeating patterns of chemistry that might reasonably be called life.
> most definitions of life require that it be made of cells
Does this animal has cells? https://en.wikipedia.org/wiki/Xenophyophorea I feel like answering yes and calling it "unicelular" is cheating, but it's clear that it evolved from animals with cells and it has only "one".
It's a cell, but the (informal) idea is that a big living thing is made of a lot of small cells. If there is a catastrofic extintion and only these things survive, would and alien biologist clasify them as a huge cell or as a blob?
> How is it clear that it evolved from animals? It seems like clear protist to me.
My bad. You are right. I probaly mean from a normal living thing with small cells with only one nuclei.
> Skeletal muscle fibers are made when myoblasts fuse together; muscle fibers therefore are cells with multiple nuclei, known as myonuclei, with each cell nucleus originating from a single myoblast. The fusion of myoblasts is specific to skeletal muscle, and not cardiac muscle or smooth muscle.
Yeah definitions are tricky. If you saw a house consumed with fire, you might look at the circumstances and conclude that it was likely the offspring of the fire that consumed the house across the street, but there wouldn't be anything about the fire's phenotype that would help you come to that conclusion.
If the flames carried the characteristic shape of their parents fire, and they could be distinguished as not the offspring of some other fire by their features alone, then I'd be arguing that fire is alive.
I feel like I'm at risk of classifying certain periodic crystals as alive here, but they wouldn't meet the thermodynamic requirements that I have in mind (which fire does meet).
Most definitions of life are very arbitrary. When it comes to astrobiology, we mostly look for things that look like us because if we didn't, the search space would be incomprehensibly large and frankly there's not a lot we could say.
I expect there's quite a lot of "life" that we're overlooking, and that we're going to feel quite silly when we have whatever encounter causes us to broaden our definitions to include the rest of it.
Although to be pedantic, most definitions of life require that it be made of cells, and I doubt there are anything like cells in the sun.