How long would it take to eat the Sun?

Premise: Space lab is working on making synthetic cells out of different materials. Experiments are classified as too dangerous to be disposed of with conventional means, and are set on an collision course with the Sun.

But one of the experiments survives, and adapts to survive in and use the Sun's matter as building material to replicate.

Question: Considering a modest rate of growth based on standard, single-celled organisms, how long would it take these non-organic synthetic cells to consume the mass of a sun sized star?

Note: Question specifically wants WB to ASSUME that the critters can survive the sun's environment. If they're the size of a cell and spreading out from using the sun's matter, how long does it take them to consume the entire ball?

• Can't happen. The Sun is about 75% hydrogen, 25% helium, less than 0.1% other elements. Helium doesn't form compounds, hydrogen needs other elements to form anything but H2, so at most you'd have a few tenths of a percent that could form cells. That's before considering that the "surface" (that is, the photosphere that we see) is around 5,800 K, increasing to about 15 million K at the core. No chemical is going to be stable at those temperatures. Commented Dec 27, 2019 at 4:52
• @jamesqf Unless those microrganisms have are biological cold fusion reactors or something that could manufacture those heavier elements from lighter ones. Commented Dec 27, 2019 at 6:36
• @nick012000: Normal fusion should work fine, if they can survive 5000K Commented Dec 27, 2019 at 7:09
• Please define "eat" Are we destroying mass here, are we producing some waste byproduct. I am guessing anything eating hydrogen is going to just fuse it for energy as there is no oxygen to burn it Commented Dec 27, 2019 at 16:34
• @nzaman there is no fusion at 5000K. The organisms should go much hotter and much deeper. Commented Dec 27, 2019 at 17:45

It would never happen

Okay, let's assume these critters can survive sun like environments. The first problem you run into is the fact that the sun is actually a very varied place. You have the atmosphere, the "surface" and deeper levels with more pressure.

If we assume the initial critters can survive and thrive on the surface then sure, they'll multiply exponentially as they cover the surface. However, since we know these critters are very adaptive, we also know that they are prone to evolution, and evolution has a way of finding new food sources when the old starts to become limited.

This means that as the disk of critters grows outwards, the ones in the middle will become pressured by lack of food and a surplus of...other critters. They will eventually evolve into predators.

The advantage of being a predator is proportional to the amount of prey around and the advantage of being a "heliovore" is inversely proportional to the amount of other heliovores around.

Eventually a balance is reached where year after year the total population of critters remains stable.

Humans barely notice a difference, except the scientists who monitor the light coming from the sun who note that the pattern of spectrum bands have hints relating to higher weight molecules than just atomic hydrogen or helium.

• how long would that take
– Eloc
Commented Dec 29, 2019 at 3:02
• @Eloc Depends on more variables than I can list here. A few being: Mass of food consumed by critter and rate of reproduction of each species. You can probably find some simulators online and fiddle around with the numbers until you get something you like. Commented Dec 30, 2019 at 18:07

Such microorganisms are not possible with our current understanding of science, for a variety of reasons.

• Temperature: at ~5,700K, the Sun's surface is hot enough to melt tungsten and boil iron. But before you reach the surface, you have to pass through the Corona, where temperatures can reach up to a million Kelvin.

• Gravity: The Sun has about 99.9% of the mass of the entire Solar System. Its gravity well is huge. Even if you survive the temperature, the fall will involve high speed impacts against solar matter which will destroy anything we could ever build.

• Electromagnetic fields: some solar filaments raised out of the surface due to magnetic fields are multiple times the size of Jupiter. The electromagnetic forces involved will destroy any lifeform by tearing molecules apart.

• Lack of food: most of the Sun is just hydrogen and helium. Other heavier stuff account for about 2% of its mass and will mostly be way under its surface.

On top of that, getting to the sun is prohibitively expensive. It is easier to go from the Earth to outside the solar system ($$\Delta$$v ~18.25km/s) than to go from the Earth to the Sun ($$\Delta$$v ~31.8km/s for a crash) (source: https://space.stackexchange.com/a/3613/16652). Even if you could make a kryptonian microbe that you could send to the Sun, you would need a space-assembled/fueled ship to deliver it safely.

It might cost more than the global GPD just to develop a vehicle capable of safe delivery, due to the materials you would need and the tiranny of the rocket equation.

• thank you for your answer, but my question isn't about how to make something that can survive the extreme environment of the sun, its about the effects of one that could
– Eloc
Commented Dec 27, 2019 at 7:22
• @Eloc you also asked for science-based, and that's problematic. Commented Dec 27, 2019 at 11:57