Thread by @paraschopra

Why we haven’t seen 🛸 aliens visiting us so far.

(a short thread)

1/ Been thinking about this question lately and it seems broadly there are four possibilities:

1. Interstellar travel at high speeds is much, much harder than we expect

2. Aliens aren’t interested in seeding the universe due to ethical concerns

2/

3. Universe is so big that light comes rarely intersect and self-replicating technology is much, much harder than we imagined

4. Intelligence capable of space exploration was an accident and we’re alone

Let’s explore all four possibilities.

3/ Interstellar travel is hard.

It has been ~40 years since Voyager was launched and only recently it has passed the last planet of solar system.

It’ll take it 40,000 years just to exit Sun’s gravitational effect (beyond Oort Cloud).

voyager.jpl.nasa.gov/mission/did-yo…

4/ And travelling at 35,000 miles per hour, which is 0.001% the speed of light.

Realistic interstellar travel will require much higher speed, and at those speeds single atoms become deadly if collided (because they carry high momentum).

5/ Interstellar travel will likely take time much, much beyond the lifespan of your average alien (if they’re alive, they must die too — that’s how they would have evolved in the first place).

But it’s technologically possible to send frozen foetuses to seed to new solar systems

6/ The question then becomes: will aliens be okay to do so?

I doubt that because it would be extremely unethical to do so.

On Earth, such a proposal would be met with shock waves.

7/ Aliens would unlikely send unborn foetuses to distant systems, unless their home is in danger and doing this is their only hope.

In this case, I can imagine them sending foetuses along with robots to help incubate them on different systems.

8/ But the universe is *huge* and the odds of such a probe reaching us depends on several factors:

a) Such an event happened nearby, which requires aliens to have been nearby so that their launched probes reached us first

or..

9/ b) Such an event happened far away, but interstellar distances don’t matter as self-replicating robots continue to mine resources along the way to build more probes and replicate foetuses to explore an ever larger area of universe in search for habitable systems

10/ It’s doubtable that intelligent life exists nearby as we would have observed some signatures already.

If intelligent life exists really far, self-replicating tech is perhaps the only way they can insure against interstellar travel risks and to explore wider areas.

11/ building such self-replicating spacecraft or replicating foetuses in inhospitable lands must be a really hard problem OR the need to do so must be very rare OR doing this must be deemed unethical

en.m.wikipedia.org/wiki/Self-repl…

12/ It’s no wonder then we haven’t observed any intelligence out there in the universe.

13/ However, I think the simplest explanation is that life capable of space-exploration arose on Earth after ~4 billion years of formation, so given that it’s only been 13.8 billion years since the Big Bang, we must deem it as something that doesn’t happen easily.

14/ I like to believe that we’re the first one of our kind in the entire universe, but given that the universe will exist for trillions of years, many, many more of such space-faring species may evolve in the universe.

15/ The fact that we might be the first one is utterly beautiful.

Even more beautiful is that future alien-historians may find our traces just like we find for old civilisations.

16/ Wonder what these alien-historians will make of us.

I find it fascinating that we’re somewhat like that when we are trying to understand history and stumble upon writings that aren’t deciphered yet.

en.m.wikipedia.org/wiki/Undeciphe…

17/ That’s it!

Thank you for coming to my TED talk :)