Comment hidden because you are ignoring dag. (show it anyway)

Great post. they leaned heavily on this awesome blog post. It's a must read: https://waitbutwhy.com/2014/05/fermi-paradox.html

So if someone is gonna make a simulation of the universe..

It would likely be some Fermi Lab scientist who wanted to study the Big Bang.

They would reverse engineer the expansion of the universe as much as possible..

[ a thing that's already been done and being tweaked to get even better Planck length "resolution", as it were ]

And once they got the best estimations..

Would dump all those rules and variables into a quantum computer and run sim after sim, checking to see WHAT HAPPENS AT THE END!

Much like The Game of Life sim developed by mathematician John Conway.

MASSIVE LONG POST WARNING: feel free to skip this

I usually like Vsauce a lot, but I disagree with just about every assumption and every conclusion he makes in this video.

Anthropogenic vs external extinction event -
I think the likelihood of an anthropogenic extinction event is low. Even in the cold war, at the apex of "mutually assured destruction" risk, IF that destruction was triggered I think it would have been extremely unlikely to make humans go extinct. The US and USSR might have nuked each other to near-extinction, but even with fairly mobile nuclear fallout / nuclear winter, etc. I think that enough humans would have remained in other areas to remain a viable population.

Even if ONE single person had access to every single nuclear weapon in existence, and they went nuts and tried to use them ALL with the goal of killing every single human being on the planet, I still bet there would be enough pockets of survivors in remote areas to prevent humans from going utterly extinct.

Sure, an anthropogenic event could be devastating -- catastrophic even -- to human life. But I think humanity could recover even from an event with an associated human death rate of 95% or more -- and I think the likelihood of anything like that is real slim.

So that leaves natural or external extinction events. The KT extinction (end of the dinosaurs) is the most recent major event, and it happened 65 million years ago. Homo sapiens have been around 150-200,000 years, and as a species we've been through some fairly extreme climatic changes. For example, humans survived the last ice age around 10-20,000 years ago -- so even without technology, tools, buildings, etc. we managed to survive a climate shift that extreme. Mammals survived the KT extinction, quite possible that we could have too -- especially if we were to face it with access to modern technology/tools/knowledge/etc.

So I think it would probably take something even more extreme than the asteroid responsible for KT to utterly wipe us out. Events like that are temporally rare enough that I don't think we need to lose any sleep over them. And again, it would take something massive to wipe out more than 95% of the human population. We're spread out, we live in pretty high numbers on basically every landmass on earth (perhaps minus Antarctica), we're adapted to many many different environments ... pretty hard to kill us off entirely.


"Humans are too smart to go extinct" @1:17 -
I think we're too dumb to go extinct. Or at least too lazy. The biggest threats we face are anthropogenic, but even the most driven and intentionally malevolent human or group of humans would have a hard time hunting down *everybody, everywhere*.


Doomsday argument -
I must admit that I don't really understand this one. The guess of how many total humans there will be, EVER, seems extremely arbitrary. But anyway, I tend to think it might fall apart if you try to use it to make the same assertions about, say, bacterial life instead of human life. Some specific species of bacteria have been around for way way longer than humans, and in numbers that dwarf human populations. So, the 100 billionth bacteria didn't end up needing to be worried about its "birth number", nor did the 100 trillionth.


Human extinction "soon" vs. "later" -
Most plausibly likely threats "soon" are anthropogenic. The further we push into "later", the more the balance swings towards external threats, I think. But we're talking about very small probabilities (in my opinion anyway) on either side of the scale. But I don't think that "human ingenuity will always stay one step ahead of any extinction event thrown at it" (@4:54). Increased human ingenuity is directly correlated with increased likelihood of anthropogenic extinction, so that's pretty much the opposite. For external extinction events, I think it is actually fairly hard to imagine some external scenario or event that could have wiped out humans 100, 20, 5, 2, or 1 thousand years ago that wouldn't wipe us out today even with our advances and ingenuity. And anything really bad enough to wipe us out is not going to wait for us to be ready for it...


Fermi paradox -
This is the most reasonable bit of the whole video, but it doesn't present the most common / best response. Other stars, galaxies, etc. are really far away. The Milky Way galaxy is 100,000+ light years across. The nearest other galaxy (Andromeda) is 2.2 million light years away. A living being (or descendents of living beings) coming to us either of those distances would have to survive as long as the entire history of human life, all while moving at near the speed of light, and have set out headed straight for us from the get-go all those millions and millions of years ago. So lack of other visitors is not surprising at all.

Evidence of other life would be far more likely to find, but even that would have to be in a form we could understand. Human radio signals heading out into space are less than 100 years old. Anything sentient and actively looking for us, even within the cosmically *tiny* radius of 100 light years, would have to have to evolved in such a way that they also use radio; otherwise the clearest evidence of US living here on Earth would be undetectable to them. Just because that's what we're looking for, doesn't mean that other intelligent beings would take the same approach.

Add all that up, and I don't think that the Fermi paradox is much cause for alarm. Maybe there are/have been LOTS of intelligent life forms out there, but they have been sending out beacons in formats we don't recognize, or they are simply too far away for those beacons to have reached us yet.


OK, I think I'm done. Clearly I found the video interesting, to post that long of a rambling response... But I was disappointed in it compared to usual Vsauce stuff. Still, upvote for the thoughts provoked and potential discussion, even though I disagree with most of the content and conclusions.

Some great points here.

I think it should be obvious that our assumptions about the frequency of intelligent space faring life in this region of space at this particular Eon are way off. Hence no signals and no first contact. The Drake equation is full of shit, so there is no Fermi Paradox.

And here's more info on him. It sounds like he's a really bright individual who society completely failed to position for success.

After dropping out of community college, Hahn joined the Navy, assigned to the nuclear-powered aircraft carrier USS Enterprise as an undesignated seaman.

Hahn had hoped to pursue a nuclear specialist career. EPA scientists believe that Hahn may have exceeded the lifetime dosage for thorium exposure, but he refused their recommendation that he be examined at the Enrico Fermi Nuclear Generating Station.

And then a sad bit:
On August 1, 2007, Hahn was arrested in Clinton Township, Michigan for larceny, in relation to a matter involving several smoke detectors, allegedly removed from the halls of his apartment building. His intention was to obtain americium, a radioactive substance, from the detectors. In his mug shot, his face is covered with sores which investigators claim are possibly from exposure to radioactive materials

Finally: fer christ's sake, son! what the hell happened to you!
http://blogs.kansascity.com/photos/uncategorized/2007/08/03/boyscout.jpg

Not according to David Thompson, a NASA astrophysicist and deputy project director on the Fermi Gamma-ray Space Telescope who compares the risk to Earth from a future gamma-ray burst to "the danger I might face if I found a polar bear in my closet in Bowie, Maryland. It could happen, but it is so unlikely that it is not worth worrying about."

In 1981, Frank Tipler[3] put forth an argument that extraterrestrial intelligences do not exist, based on the absence of von Neumann probes. Given even a moderate rate of replication and the history of the galaxy, such probes should already be common throughout space and thus, we should have already encountered them. Because we have not, this shows that extraterrestrial intelligences do not exist. This is thus a resolution to the Fermi paradox—that is, the question of why we have not already encountered extraterrestrial intelligence if it is common throughout the universe.

A response[4] came from Carl Sagan and William Newman. Now known as Sagan's Response, it pointed out that in fact Tipler had underestimated the rate of replication, and that von Neumann probes should have already started to consume most of the mass in the galaxy. Any intelligent race would therefore, Sagan and Newman reasoned, not design von Neumann probes in the first place, and would try to destroy any von Neumann probes found as soon as they were detected. As Robert Freitas[5] has pointed out the assumed capacity of von Neumann probes described by both sides of the debate are unlikely in reality, and more modestly reproducing systems are unlikely to be observable in their effects on our Solar System or the Galaxy as a whole.

Another objection to the prevalence of von Neumann probes is that civilizations of the type that could potentially create such devices may have inherently short lifetimes, and self-destruct before so advanced a stage is reached, through such events as biological or nuclear warfare, nanoterrorism, resource exhaustion, ecological catastrophe, pandemics due to antibiotic resistance.

A simple workaround exists to avoid the over-replication scenario. Radio transmitters, or other means of wireless communication, could be used by probes programmed not to replicate beyond a certain density (such as five probes per cubic parsec) or arbitrary limit (such as ten million within one century), analogous to the Hayflick limit in cell reproduction. One problem with this defence against uncontrolled replication is that it would only require a single probe to malfunction and begin unrestricted reproduction for the entire approach to fail — essentially a technological cancer — unless each probe also has the ability to detect such malfunction in its neighbours and implements a seek and destroy protocol.

wikipedia my friend

>> ^Fletch:

>> ^soulmonarch:
... the same cannot be said of time travelers. (i.e. If it was possible, we would have already met them, etc.)

Assuming our species survives long enough to develop it, which is improbable, imho. If you believe that the development of time travel is inevitable (if it is possible), then the lack of visitors from the future may simply mean we are doomed, at least in this plane of the brane.
The Fermi Paradox doesn't disprove anything, nor was it meant to.


I kind of like the sci-fi idea that we make a time machine in some distant future. The time travel event works, but also collapses to universe down to a singularity. Time time travel event works, however, and sends our time traveler back to the original singularity causing a massive disturbance, which causes the singularity to erupt. The end of time causing the start of time, to end all over again. All this completely consistent with the current understanding of general relativity.

>> ^soulmonarch:

... the same cannot be said of time travelers. (i.e. If it was possible, we would have already met them, etc.)


Assuming our species survives long enough to develop it, which is improbable, imho. If you believe that the development of time travel is inevitable (if it is possible), then the lack of visitors from the future may simply mean we are doomed, at least in this plane of the brane.

The Fermi Paradox doesn't disprove anything, nor was it meant to.

I'm with Fermi.

Interestingly, the Fermi Paradox does a better job at disproving time travel than it does extraterrestrial civilization. Where you can argue that all the ETs just haven't developed space travel sufficient to the task or simply have not stumbled across us yet, the same cannot be said of time travelers. (i.e. If it was possible, we would have already met them, etc.)

Well, to my Fermi eye, that hanging section of rail and ties weighs several orders of magnitude more than I do, especially the right one which looks like it has poured cement ties rather than wood, so I'm not worried about that. Also, I'd have put most of my weight on the rails, which is where the strength obviously is.>> ^BicycleRepairMan:
Not a smart move,I think, the railroad ties (the crossbeams/sleepers) are not built for hanging from the rail, but rather as resting blocks, and to keep the rails from pulling apart. They propably have some vertical hold, but I wouldn't bet on it, infact, you can see one of those closest to his side has already fallen off by the end of the video.

>> ^8727:
the fermi paradox makes this seem kind of unlikely though.


And if it is real it's probably something like the monolith from 2001 sent by a type 3 civilization.
That or time travelers.

Though im pretty sure it's fake cause the greater the cover up the less likely that it can be kept under "cover".

>> ^dag:
Oh yeah. He had the worst potty mouth. Called Drake the C word at a party.


Copernican?

Fermi said the F word?

>> ^dag:
Enzo, the Fermi paradox accounts for the probability of no faster than light travel. The milky way is at least 13 billion years old. That's more than enough time for thousands of civilisations to arise and colonise other stars using space ships that only reach a small fraction of the speed of light.

Yea but that's also so much time that many intelligent life could have lived then died. The key to finding life isn't just being in the right place, it's being there during the right time as well. It's important to realize we may be alone...right now. Or if there is life out there it may be in very primitive stages and not yet intelligent (we're still waiting for intelligence here on Earth). Our time here on earth is nothing more than kleenex skeet compared to the age of our galaxy.