To date there is zero evidence for interaction between material nature and the spirit. And not for want of looking, as scientists and clergymen alike have been searching for centuries now, anomalous exceptions are extremely rare. Even the standard model of particle physics is transparent to any spiritual factor.
So why should we look at it? Because the human mind, to perceive and process sensory stimulus into situation awareness, to remember, to read and speak and understand facial expression, to compute, and to engage in reason — for all these capacities — it requires power.
While LLM generative systems power demand is calling for the re-commissioning of nuclear power plants, the human brain eats up (according to anatomists) about 20% of our caloric intake, when we are awake, at rest. Less when we're at full run, more when we're computing the integral of the acceleration of rocket thrust as fuel is spent, or landing an airliner by yoke.
But it means, if we have a soul, and that soul remembers its sins, can reason why such behaviors were sinful; if that soul can feel the fires of Hell, this processing takes energy, and an energy source. That means interaction between the physical and spirit, which means there should be something to detect. There should even be side channels.
No evidence of energy exchange, no side channel heat or sound, it strongly (not absolutely) implies there's no spirit to detect. Or if there is, it might be so delicate that interference from natural phenomena (lightning strikes and CME emps come to mind) would shatter it.
The exception is the simulated-universe hypothesis: If the universe is a simulation in a computer program (or Azathoth's dream; Ia! 🦑🌊🌌) then all our recorded observations are of simulated events, and souls can simply be simulated. But some of us object to the notion we're an object in a program or a figment in a dream.
If there's no detectable energy powering our souls, then they could be in the core of the sun and not feel a thing, nor have an eff to give. No regrets, no memories, no pain, no misery.
Most likely, by far, we are thinking meat.
Heck I who am awake today can be a different iteration than me, who was awake yesterday. The separation of time when cerebral cortex activity is shut down for maintenance (non REM sleep) may indicate separate beings, like an AGI powered down and rebooted, with its past memories front-loaded. We're the same for day-to-day quotidian purposes, but our breaks in continuity raise philosophical questions.
And all this is before we get into the incomprehensible vastness of our galaxy, in which earth is barely a mote, or the universe featuring immense strings of galaxies, in which our Milky Way is a dot.
And all this is before we discuss the multiple great filters that are imminent before us, and as a species we are ill prepared to navigate. When we go extinct in the next century or too, it will be part of the Holicene dying, and none of our gods, myths and cultures will survive. All of our operas and symphonies, all of our paintings and sculpture, all of our cinematic thrillers and cozy mysteries and Ghibli animations and fine cuisine will evaporate into geographical layers, and the universe won't even notice.
All this is to say, I've thought about this and confronted my personal insignificance. I've come to terms with mortality and the end of society and species. I get why people cling to notions that we are something special, even though all indications from nature imply we are not.
I say, bring it.