What if an extraterrestrial could turn you into a sentient tree? Imagine how you might stand fixed upon a grassy knoll unable to move, always looking at the same place day after day, rain or shine (assuming you could see). Birds could roost upon you. Wind could rustle your leaves. Would you sense the birds and wind? How would your mind react during the day? Would you sleep at night? And dream? If so, what?

 “Sure thing,” you may say to me, “what have you been smoking? Tell me another fairy tale.”

How would you consider such a scenario? You may conclude: Must be fantasy, bro. It ain’t got the science to be science fiction.

Maybe so. But just wait a minute. Let’s say, you’re part of a group Neanderthals who managed to escape detection over thousands of years. Granted, this is a big stretch. Okay, let’s switch this around. Say time travel became possible, and you visited Europe at, say, 150,000 years ago. You’ve brought your e-bike, one of those fancy electrically powered mountain bikes some game hunters use such those blogged about here. Okay, I don’t hunt for sport but you get the idea. In this scenario you go for a ride. Eventually you encounter some Neanderthals. How would they regard your ability to ride around? Your appearance, your clothing, you riding your bike, would be a major shock, completely foreign to their world view. To the Neanderthals, you are magical.

This brings us to Clarke’s Third Law. Science fiction author Arthur C. Clarke wrote 2001: A Space Odyssey. The law states: Any sufficiently advanced technology is indistinguishable from magic. If you brought your mobile phone and played your favorite (downloaded) cat video, the Neanderthal might wonder at the technology and the content. She or he may think: what’s the deal with cozying up to these mini cats? Do these strange visitors need some trepanning with a sharp pointed stick?

For the sentient tree scenario, on the other hand, needs more thought. First, would a sentient tree be possible? Second, could a scientist transform a normal human into such a tree? Let’s tackle the first.

Some scientists claim that trees can communicate with others in the same species by sending certain chemicals from root to root. However, other scientists claim the evidence isn’t conclusive. This is how science works.  Test the evidence and if other ‘peers’ think the evidence isn’t strong enough, they remain skeptical. Regardless, such tree-to-tree communication wouldn’t be a sign of sentience. Similarly with the claims of plants being capable of feeling pain, the evidence remains dubious. So, for this post, I’ll suggest that in our real world, trees aren’t sentient. But could they become sentient?

Trees, being plants, are able to photosynthesize, meaning to convert sunlight into the chemical energy necessary to fuel their metabolism. As for food, trees must absorb water and other chemicals from the ground using their roots. The transport of nutrients means going uphill against gravity. Trees don’t have hearts like we do, to pump said nutrients throughout their body. Instead they depend on a transpiration process. Essentially, water evaporation at the leaves causes a negative pressure which can pull water up from all the way down to the roots. As an aside, how tall can trees grow on Earth? By the way, the tallest height appears to be about 140 meters.

Think of what this mean in terms of being sentient or not? Sentience requires brains as far as we know, and brains use lots of energy. The human brain uses about 20% percent of the body’s energy and animal bodies use more energy than for plants because they have higher metabolism requirements. From this, we can conclude that a sentient tree would need significantly more energy than the currently non-sentient versions, in addition to a brain equivalent.

According to my admittedly simplistic calculations, a human could employ an advanced solar panel on each arm of about 60 cm square. The human ‘tree’ could stand up to expose the panels like a tree would expose leaves on its branches. This could theoretically work provided the panel efficiency was seventy two percent or more. The hypothetical panels would act like artificial leaves in order to convert the sunlight into the human’s need for oxygen and food. This doesn’t yet exist, but I argue it could in the future.

As an aside, prototype artificial leaves already exist. In this case, the sole function of the ‘leaf’ is to take carbon dioxide out of the air in order to cut down on greenhouse gases—and produce fuel. This technology has promise and could potentially expand to increased efficiency and produce other organic molecules required by our hypothetical tree-human hybrid.

Therefore, it’s reasonable to suppose a sentient tree could theoretically exist provided it had a brain and a pump to feed the brain with energy nutrients. Perhaps the person could become a plant-like being akin to the Venus Fly Trap but in an expanded form. This obviously is highly speculative but I would argue clever biohackers could create such a tree equivalent from a human. Please note this is a thought experiment because of ethical considerations.

Whether such a tree could evolve via natural evolution is another matter, and probably not—unless animals were wiped out. Food for thought here for you speculative fiction writers who might be reading this. But I will leave this aside for now to move on to point two. Could an advanced extraterrestrial transform a normal human into such a tree?

Point two is a tall order. It is one thing to biohack someone in a lab over a period of time, it’s another to sprinkle pixie dust or whatever that over a few hours or days transforms a human into a tree without any other intervention. In the lab scenario, surgeons may need to operate on the human.

“Eh,” you may say. “What could be this pixie dust? Sounds like magic.”

“Aha,” I may reply, “remember Clarke’s third law. Use a technology so advanced that, today; our smartest scientists can’t even understand it.”  

“Cop-out,” you may say, “Pure handwavium. Sounds like unobtainium.”

“Well, er, um, you may be right.” I shrug my shoulders with embarrassment. Then the metaphorical bolt of lightning strikes, red hot, searing red hot. (Enough with the melodrama you exclaim.) “Hey. How about nanites?”

Oh yes, the nanite word. How many stories have I read which employed nanites? Many. Hence, let us examine the nanite. Click the preceding link. Alas, that’s all I’ll give you for now. Stay tuned for a possible follow-up post.

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Peter Spasov. Last updated Tuesday February 25, 2025