Is there a specific size range for intelligent life under biological constraints, or could smart aliens be as much smaller than bugs or much larger than whales?

Question

I read a long time ago an essay by Asimov that described what elements could support life as a building block and why most elements cannot. I didn’t fully understand that at the time but it was interesting to see why carbon based makes sense and some other random element does not work.

Similarly, I wonder if under different planetary conditions, smart alien life (so not single cell life) can be very tiny or very large, or if there are biological constraints that would restrict that size range regardless of basic setup.

In: 324

Answer 1

The short answer is that we really don’t know. If we imagine life to be similar to life on earth then there are limits. Limits on how small a neuron can be. Limits on how big an animal can be and still walk.

But we don’t know what we don’t know. If life on other planets is very different from life here. Maybe not even based on oxygen and carbon, then all bets are off on size limits.