Most humans think in words, and this is a big problem for our future.

When I say a sentence like, there is a gold-plated Hindenburg blimp with a giant Vladimir

face on it, floating over London, and lasers come out of Vladimir Putin's eyes

and destroy any restaurant that serves curry. You can imagine that in your minds, and of course,

it's fanciful and non-believable, but humans can transfer millions of possibilities

via our words and our mouths that can exist in the real world.

The challenge is that there are some sentences that sound very plausible,

like battery- filters in the ocean that take

energy and oxygen from the seawater so we can breathe underwater, or that we can build

technology that will allow global human culture at today's scale or larger have net zero emissions by 2050

relative to the 41 billion tons of emissions this year. So what ends up happening is these things

sound good, but there is a difference between three categories. What can't happen, what won't

happen, and what might happen. And unfortunately, most of the things in our public discourse about

the future are in the what can't happen and what won't happen category,

when we need to be focusing on the what might happen category.

And that's what I'd like to discuss today.

So first of all, what can't happen.

There's two subcategories of what can't happen.

One is there are physical laws of the universe.

There are physics and chemistry and thermodynamics.

If we have a wooden block that is one foot by two foot, we know for absolute certain the physical laws of the universe will not allow us to carve a four-foot man or dwarf out of it, or a six-foot-wide wooden car.

Now, we could carve a two-foot duck or a two-foot-wide shoes or a bunch of small spoons.

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