What If Humanity Is Among The First Spacefaring Civilizations?

Sign Up on Patreon to get access to the Space Time Discord!

Half of the universe is filled with expansionist alien civilizations, and it’s only a matter of time before they’ll reach us. OK, that sounded a little sensationalist. But it’s also the conclusion of a recent astrophysics paper. Let’s see how they figure this, and whether we should take it seriously.

Check out the Space Time Merch Store

Sign up for the mailing list to get episode notifications and hear special announcements!

Hosted by Matt O'Dowd
Written by Euan McLean & Matt O'Dowd
Post Production by Leonardo Scholzer, Yago Ballarini, Pedro Osinski, Caique Oliveira, Adriano Leal & Stephanie Faria
Directed by Andrew Kornhaber
Associate Producer: Bahar Gholipour
Executive Producers: Eric Brown & Andrew Kornhaber
Executive in Charge for PBS: Maribel Lopez
Director of Programming for PBS: Gabrielle Ewing
Assistant Director of Programming for PBS: John Campbell

Spacetime is produced by Kornhaber Brown for PBS Digital Studios.
This program is produced by Kornhaber Brown, which is solely responsible for its content.
© 2022 PBS. All rights reserved.

Special Thanks to Our Patreon Supporters

Big Bang Sponsors
Devin Wiley
Ankur Anand
Ryan Salsamendi
Steffen Bendel
Gautam Shine
NullBlox.ZachryWilsn
Bryce Fort
Peter Barrett
David Neumann
Leo Koguan
Alexander Tamas
Morgan Hough
Amy Hickman
Juan Benet
Vinnie Falco
Fabrice Eap
Mark Rosenthal
David Nicklas

Quasar Sponsors
Glenn Sugden
Vikram Vaka
Alex Kern
Ethan Cohen
Stephen Wilcox
Christina Oegren
Mike Conroy
Mark Heising
Hank S

Hypernova Supporters
Ryan Moser
David Giltinan
Ivari Tölp
Vyce Ailour
Brandon Paddock
Oneamazinguy
Ken S
Gregory Forfa
Kirk Honour
Mark Evans
drollere
Joe Moreira
Bradley Voorhees
Marc Armstrong
Scott Gorlick
Paul Stehr-Green
Russell Pope
Ben Delo
Scott Gray
Антон Кочков
John R. Slavik
Mathew
Donal Botkin
John Pollock
Edmund Fokschaner
Joseph Salomone
chuck zegar
Jordan Young
John Hofmann
Daniel Muzquiz

Quasar Supporters
Marc Forand
D. Delair
Walter Montalvo
Andrea Galvagni
Larka
Jerry Thomas
Nikhil Sharma
Alexander Gruber
Jonathan Cordovano
John Anderson
Scott Hannum
Paul Widden
Bradley Ulis
Craig Falls
Vivaan Vaka
Kane Holbrook
Ross Story
teng guo
Sujasha Gupta Vaka
Mason Dillon
Harsh Khandhadia
Thomas Tarler
bsgbryan
Sean McCaul
Susan Albee
Frank Walker
Matt Q
MHL SHS
Terje Vold
James Trimmier
Anatoliy Nagornyy
comboy
Andre Stechert
Paul Wood
Kent Durham
jim bartosh
Nubble
Ramon Nogueira
The Mad Mechanic
Ellis Hall
John H. Austin, Jr.
Diana S
Faraz Khan
Almog Cohen
Alex Edwards
Ádám Kettinger
MD3
Endre Pech
Daniel Jennings
Cameron Sampson
Geoffrey Clarion
Russ Creech
Jeremy Reed
Eric Webster
David Johnston
Web Browser
Michael Barton
Mr T
Andrew Mann
Isaac Suttell
Devon Rosenthal
Oliver Flanagan
Bleys Goodson
Robert Walter
Bruce B
Mirik Gogri
Mark Delagasse
Mark Daniel Cohen
Nickolas Andrew Freeman
Shane Calimlim
Tybie Fitzhugh
Robert Ilardi
Eric Kiebler
Craig Stonaha
Graydon Goss
Frederic Simon
Tonyface
John Robinson
Jim Hudson
A G
David Neal
justahat
John Funai
Tristan
Bradley Jenkins
Daniel Stříbrný
Luaan
Cody
Thomas Dougherty
King Zeckendorff
Dan Warren
Patrick Sutton
John Griffith
Daniel Lyons
DFaulk
Kevin Warne

[ultramovier]

This is really helpful to sci fi writers. I remember a book Roger Zelazney wrote that had humans spreading all over the galaxy. After a long time they were searching for our original planet hidden in ancient mythology. Our protagonist suspected it was on this old planet called dirt.

[chrishaven]

It would be both very cool and very daunting if it turned out that we were the forerunner race in the galaxy/universe

[keanudupont]

Its crazy to think that at some distant point in the future humans could be an elder race in the galaxy

[IBeforeAExceptAfterK]

I think this is a case where it's helpful to apply Occam's Razor. Sure, there might be a bunch of grabby aliens rushing to colonize the rest of the universe, but that involves a lot more assumptions than "we're early". The same logic we use to assume we're fairly typical in the cosmos could just as easily be used by the very first civilization to appear, and they'd have no way of knowing how wrong they are.

[mrdollyman]

People seem to be generally obsessed with the idea that we are some “infantile” civilization with primitive abilities. I think we are at least decently advanced as far as civilizations go. Keep in mind it’s entirely possible that there are thousands of civilizations if not more that haven’t even explored their entire planet, and only live on a few continents. (Oceans of course are another matter).

[CHOP]

If humanity would actually be the first intelligent civilization in our galaxy or even the universe, we would be studied if they found out in the future - which is also pretty cool.

[loganfisher]

Being early is definitely preferable to the alternative. Since we have no way of knowing how aggressive other intelligent species may be, being early gives us time to gain a technological advantage to allow us to defend ourselves if need-be.

[winstonsyme]

People seem to always leave out the pretty obvious issue that there are so many potential hazards for a planet that while life supporting planets may be very common, going 5 billion consecutive years being habitable enough not to reset everything may be very rare and make Earth quite special (lucky).

[TheFreakEclipse]

I love imagining scenarios where we’re that “wise” ancient race that everyone looks at as basically gods, like the Asgard from Stargate or the Vorlons from Babylon 5 or something. It’s much more fun to think about than seeing ourselves as the emerging “protagonist” race that has no clue what anything is in the universe.

[andyklapper]

I always wondered about two factors that rarely get mentioned - our freakishly large moon and how it was formed (giving us a significantly larger than normal iron core, possibly spinning faster than normal, to give us a stronger magnetic field, plus the freakishly larger moon acting as both a gyroscope to reduce wobble, create large waves and act as an asteroid shield/deflector) and the possibility of intelligent life evolving too quickly and not have fossil fuels available to power industrialization, and thus limit their technological progress.

[GameTimeRelax]

I've thought this for a long time, and I LOVE to use this analogy, What if we are "The Ancients"(Stargate)? What if it is us that will be leaving clues behind for descendants to find in 5 million years? It's amazing to think about what Our "Galactic Place/Purpose" might turn out to truly be.

[mrvk]

I'd MUCH rather us being early to a party than late. Us finding early civilizations elsewhere is much more comforting thought than advanced aliens finding us. One gives us control, the other leaves us helpless. If we are the "young brothers", we might get a boost for our development but a much more likely scenario would be indifference or outright predatory behavior towards us. Maybe our fate is to simply become eaten by some other intelligent life and be a tiny asterisk in history of intelligent life - just food for others.

[raijinenel]

You should do a historical spin off series of past discoveries, what they got wrong, what they discovered and how it is used today.

[ojussinghal]

We often think about aliens landing on Earth.
Imagine being an alien and exploring a planet with intelligent life.

[YeTenuousUmbrae]

I think technologically advanced life like us will be super rare if not a complete fluke of nature, but normal carbon based life will be just fairly rare - mostly depdant on the type of star of a solar system. This would be the best kind of situation if we eventually can master space travel as that would mean there are habitable worlds waiting for us

[livethefuture]

I always thought that knowing that the age of the universe is 13.8 billion years old, and knowing that it took humanity nearly 4.5 billion years to evolve on earth.

It made perfect sense that we may be among the first intellignet species in the universe, i mean if you think about it, it took nearly a third of the age of the present universe for us to evolve. So given the sheer length of time and the extemely rare and specific conditions required for intelligent life to evolve on this planet. It would be logical to conclude that the emergence of Intelligent life is a rare and time consuming thing to occur, meaning that given the age of the universe already elapsed and how much longer the universe has yet to live, we are among the very first intelligent civilizations to evolve from the primordial soup if you will of the early universe.

[ANDSENS]

The sheer amount of interesting hypotheses regarding aliens, the extensive models, the variability of assumptions and how some assumptions cancel each other out make me think of a scenario in the future on a distant planet:
Explorer 1: "Oh wow look! There's something like insects on this planet, that resembles an anthill!"
Explorer 2: *Grabs huge binder of hypotheses, furiously turning pages* "Right. The existence of space-ants means that the Carter-Schmidt hypothesis is almost certainly correct. There should be around 5 other civilizations in a 100 lightyear radius, 2 of them spacefaring, 1 of them with a unified government. They reproduce asexually, are highly religious, and pronounce it Warseester Shiree Sauce... well that's just wrong."

[pbsspacetime]

Hey Space Timers! A bit of safety news. We've recently spotted quite a few different impersonator accounts that respond to episode comments, pretending to be us. We're currently working with YouTube to remove them, but please don't fall for any of their fake requests. Official Space Time requests will only ever be made in the video and/or the description box. We'll NEVER ask for your information from the comments!

[chaddesrosiers]

The grabby theory is similar to the dark forest theory. I wonder if the correct theory might be a combination of the two. That we are somewhat early... but also that most emerging civilizations get silenced by the closest grabby. Also Grabby civs may well figure out the dark forest is true and do their level best to stay quite even as they expand, to reduce issues with other grabby civs.
It may also be true that the idea of the ladder, and hard steps can keep some civs (like perhaps ourselves) both safe and in the dark. Its possible earlier then us civs may have evolved on planets with fewer steps... and they may view our planet as just not worthy of colonization. I mean if we discover life somewhere like Titan or the clouds of a gas giant... it will be interesting but not exactly a new home for humanity, so the life there could still continue its long slow climb. (grabby civs in our neck of the woods... may see a 5 billion life span planet as not worth the effort to colonize)

[syedabishosainrizvi]

"we can't see ANY aliens"
"they must be coming for us, just REALLY fast"