And a lot of people are very scared by this stuff. 

And it does sound scary, and there are risks to this stuff. 

So why in the world would you ever want to do this stuff? 

Why would we really want to alter the human body in a fundamental way?

The answer lies in part with Lord Rees, astronomer royal of Great Britain. 

And one of his favorite sayings is the universe is 100 percent malevolent. 

So what does that mean? It means if you take any one of your bodies at random, drop it anywhere in the universe, drop it in space, you die. 

Drop it on the Sun, you die. Drop it on the surface of Mercury, you die. Drop it near a supernova, you die. 

But fortunately, it's only about 80 percent effective. 

So as a great physicist once said, there's these little upstream eddies of biology that create order in this rapid torrent of entropy. 

So as the universe dissipates energy, there's these upstream eddies that create biological order. 

Now, the problem with eddies is, they tend to disappear. They shift. They move in rivers. 

And because of that, when an eddy shifts, when the Earth becomes a snowball, when the Earth becomes very hot, when the Earth gets hit by an asteroid, 

when you have supervolcanoes, when you have solar flares, 

when you have potentially extinction-level events like the next election --

then all of a sudden, you can have periodic extinctions. 

And by the way, that's happened five times on Earth, 

and therefore it is very likely that the human species on Earth is going to go extinct someday. 

Not next week, not next month, maybe in November, but maybe 10,000 years after that. 

As you're thinking of the consequence of that,

if you believe that extinctions are common and natural and normal and occur periodically,

it becomes a moral imperative to diversify our species.

And it becomes a moral imperative because 

it's going to be really hard to live on Mars if we don't fundamentally modify the human body. Right? 

You go from one cell, mom and dad coming together to make one cell, in a cascade to 10 trillion cells. 

We don't know, if you change the gravity substantially, if the same thing will happen to create your body. 

We do know that if you expose our bodies as they currently are to a lot of radiation, we will die. 

So as you're thinking of that, you have to really redesign things just to get to Mars. 

Forget about the moons of Neptune or Jupiter. 

And to borrow from Nikolai Kardashev, let's think about life in a series of scales. 

So Life One civilization is a civilization that begins to alter his or her looks. 

And we've been doing that for thousands of years. 

You've got tummy tucks and you've got this and you've got that. 

You alter your looks and I'm told that not all of those alterations take place for medical reasons.

Seems odd.

A Life Two civilization is a different civilization. 

A Life Two civilization alters fundamental aspects of the body. 

So you put human growth hormone in, the person grows taller, or you put x in and the person gets fatter or loses metabolism or does a whole series of things, 

but you're altering the functions in a fundamental way. 

To become an intrasolar civilization, we're going to have to create a Life Three civilization, 

and that looks very different from what we've got here. 

Maybe you splice in Deinococcus radiodurans so that the cells can resplice after a lot of exposure to radiation. 

Maybe you breathe by having oxygen flow through your blood instead of through your lungs. 

But you're talking about really radical redesigns 

and one of the interesting things that's happened in the last decade is we've discovered a whole lot of planets out there. 

And some of them may be Earth-like. 

The problem is, if we ever want to get to these planets, the fastest human objects

 -- Juno and Voyager and the rest of this stuff -- take tens of thousands of years to get from here to the nearest solar system. 

So if you want to start exploring beaches somewhere else, 

or you want to see two-sun sunsets, then you're talking about something that is very different, 

because you have to change the timescale and the body of humans in ways which may be absolutely unrecognizable.

 And that's a Life Four civilization.