There are few things in life I’ve appreciated more than disposable diapers. I’ve heard my mother talk about what the days when cloth diapers were all people had. Honestly, I don’t know how the human race survived – who in their right mind would want to wash diapers?

Disposable milk cartons are a boon to humanity also. Milk used to arrive from the cow via glass bottles that had to be delivered, used, picked up, cleaned and used again. My grandfather worked at a dairy and quit high school for a year because he couldn’t handle both the pre-dawn milking and milk delivery along with school work. Today, of course, we just bury the plastic jugs or better yet, toss them into the ocean where they coagulate into an ever-growing island of junk.

Disposable celebrities are a boon to the entertainment industry. After all, we only want to be entertained by the very young. Though they’re still out there, who really cares about Brittany Spears or Lindsay Lohan now that we have Taylor Swift and Miley Cyrus?

Disposable technology is great too. With the computer industry coming up with new technology every couple of years, old computers are as common as old iphones. So we send them off to West Africa where the fumes from burning them causes chronic health problems for people the ebola virus spares.

The problem is, though, that disposable items eventually end up somewhere. Brittany Spears is in Las Vegas, milk jugs are in the Pacific, and disposable diapers rot away in landfills, depositing their unsavory contents into the local aquifer. Sooner or later, we’ll have disposed of so many things there won’t be room for any more. And then what?

I saw the movie Interstellar last weekend with my sons. A true space “epic,” Interstellar is the movie 2001: A Space Odyssey wanted to be. Interstellar does homage to 2001 in many ways (as well as space movies like Gravity and Star Wars). But the underlying premise – though presented as a cautionary tale of the perils of ignoring climate change – offers the most glaring example of disposability yet. Interstellar presents Earth as a disposable planet, a planet used up and discarded by humankind.

After all, evidence now suggests that the Universe is littered with planets – some of which have to be similar to Earth. Driven from it by an increasingly hostile climate, humans need only venture forth into space to find a new planet ripe for settlement.

But does settlement mean exploitation? In an artful twist on 2001, in Interstellar it is not a computer but a human who loses his morality in the depths of space. Does evil exist independent of mankind, the movie asks. Yes, it answers – we will take what’s good as well as what’s evil with us to any new worlds we reach.

The instinct for survival drives the movie Interstellar – to survive, mankind must find a new home. But it’s ironic that our instinct to survive is what destroys the Earth. We have, in the movie at least, exploited our planet in order to service our needs and desires. And so we must overcome incredible odds to find a new planet where we can carry on as we have in the past.

Theologian and author C.S. Lewis observed that interstellar distances are “God’s quarantine” – a way to keep the evils of humanity from polluting the rest of the Cosmos. And he may well have been right. If so, though, we’d better start taking care of this world. All these other worlds, for now at least, are too far away to exploit…