“Either extraterrestrial civilizations (ETCs) are incredibly rare (or non-existent), or they are deliberately avoiding contact with us (aka. the “Zoo Hypothesis“).”
There is a 3rd possibility - it may not be deliberate.
Our position in the Milky Way is really out on the ass-end of it. We are nowhere near galactic central. If our current understanding of slower than light travel is correct, it just may not be possible for other civilizations to reach us.
When it comes to communications, and our radio sweeps of the galaxy turning up nothing, well, we’re assuming any advanced civilization is still using radio transmissions.
Look at our recent experiment with laser based communication:
100 or so years after radio communication was widespread, we have the technology to eliminate it. There may be other methods orders of magnitude beyond that. We could be awash in alien communication streams we just can’t percieve because ours are too primitive.
There are also hundreds of other theories that can potentially explain it. Like, 100 years really isn’t a long time on cosmic scales. Maybe we’re late to the party and intelligent life wiped itself out already. Maybe we’re early, and we will wipe ourselves out before a new intelligence even figures out where the copy paper is.
We don’t want to be near the galactic center, there’s too much radiation. A quiet spot out on one of the arms away from supernovae and active objects is a much better place for life to evolve.
At this point our own radio is even too advanced for an alien civilization to detect. An interesting thing about radio is that aside from a few lingering powerful analog signals (AM/FM radio, active radar) our modern spread-spectrum radio is hard to distinguish from background noise. It’s an interesting consequence of information theory, as bandwidth and noise tolerance grow, if you aren’t looking for a signal it becomes almost invisible. We also do a lot with very little power now due to these amazing encoding methods, when I was a kid and the analog cell phone was novel we would have outright said that a phone could never communicate directly with satellites. Not enough power or antenna in your pocket. Yet here we are.
So any civilization that develops radio is only likely to send out a short burst of detectable radio before disappearing within 100 years, even without switching to an alternate technology. This makes radio an almost impossible thing to search for in a vast galaxy where time can separate us even more than space.
Population growth compounds, though. Once you’ve colonized a million worlds, the next million would come in a fraction of the time of the first million, and the next 2 million in less time than that, then 4 million in the same time as before, etc. Like grains of rice on a chessboard. Totally feasible to fill a galaxy if FTL travel is achieved.
More likely - FTL is impossible so each species is stuck in their own solar system.
Yeah, it's really hard for the human brain to intuitively grasp exponential growth. Anyone who says a galaxy is "too big" hasn't actually run the numbers on that.
FTL is impossible so each species is stuck in their own solar system.
FTL is in no way necessary to allow for interstellar colonization to proceed.
The number show that with the right technology, meaning ships can accelerate to 0.05c and we can convert asteroid fields to self-sustainable habitats, a civilization could colonize the Milky Way in about 200,000 years. A blink of the eye in cosmological time scales. FTL isn’t necessary, except perhaps for cohesion.
But if NASA 'can’t do anything right,' how come SpaceX and other private companies like stylo rely so heavily on former NASA engineers, research, and infrastructure to even operate?
One of the things they’re doing is calculating what it’s orbit would have to be to hit the Earth, and where it would have had to have been on its last orbit to be in that orbit
So they can look at any astronomical images of that part of the sky from then and see if it’s in the right place
If they find images of the right part of the sky at the right time and the asteroid is not in it, they know it’s not on an orbit that will hit the Earth in 2032
I science podcast I follow already warned last week that the probability would go up at first as they narrow down its trajectory.
They gave the example of a fan closing, as it gets narrow, the earth represents a bigger percentage of the remaining fan. If you keep closing the fan the Earth eventually will fall outside the fan and the percentage drop to zero.
Ok, so: you know how Earth is part of the solar system? And the solar system is part of a large collection of stars and planets called a galaxy?
Well, there’s lots of galaxies out there! And scientists for a long time have been trying to figure out how they formed - how did all the stars get close to each other? Why aren’t they just randomly drifting around?
Currently, everyone believes that there’s this magic stuff called “dark matter” that pulled the stars together to make galaxies. Kinda like how magnets pull things close to them!
And because galaxies are so big it would take a long time to pull the stars close together! Which means young galaxies would look less bright because the stars aren’t all close together yet, like they are with older galaxies.
So that’s what everyone believes.
But we’re getting pictures from a really strong telescope that’s showing us that young galaxies are brighter than we expected! Which is weird and exciting because it means that young galaxies might have been pulled together faster than we used to think! And our old theories about galaxy creation might be wrong!
There’s a theory that explains how galaxies could come together quickly, without dark matter, but it doesn’t really fit with many other theories we have about how the world works, so lots of people are thinking really hard to figure out how they might fit together.
And that’s what science is all about! Finding out new information that shows you that you were wrong in the past, and using that information to figure out new ways to act and think in the future!
Nope. No. Nuh-uh. Stop fucking up this planet, then we can talk. I’m drawing a line in the sand, I’m going to become an eco-terrorist if I see a fucking Coca-Cola ad when I look into the night sky.
All I think of is the movie, The Time Machine. Spoiler, the main character goes forward in time and sees the moon breaking apart, causing a collapse of civilisation.
There's a big difference between "touched up" as in, fix the contrast and adjust the color balance, versus "touched up" as in let's make a nebula look like a bat. The first, me and Ricky are in agreement that they're doing. The second, me and Snopes feel strongly that they're not doing.
everything about these two spacecraft is just amazing. It’s going to be quite a sad day when they transmit their last byte of data to our little planet. Reading about all the things we’ve done to keep talking to them. The redundancies that they’re running on etc… Fascinating stuff
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