Comment by PheonixPharts
4 years ago
The best example of a complex system is the human body. It's useful to juxtapose such a complex system to a "complicated machine" such as a car as far as you they breakdown (i.e. collapse).
A single part failure can easily cause a car to become completely undrivable, whereas a surprisingly amount can go wrong with human body and it works more or less the same.
Not enough fuel and a car stops. It's completely binary, either you enough gas to go, or you can't go. For a human there is an incredible range of failure modes for not having enough fuel. Humans can survive an absurdly long time when they are 'empty' of food.
However once that human body does fail, it's over. Additionally all parts of it collapse together.
A car is more or less the sum of it's parts. You can take each individual part and take it off and reuse it, like wise each failing impacts primarily it self. The engine can go find with a flat tire, you can use the headlights on car with no gas and no wheels until the batteries fall out. When an essential component for driving the car fails, all of the other components are still useful. This also means that any piece that is necessarily for the car to drive causes complete failure for the system when it fails. But it also means you can restore the system trivially by repairing a single part.
The human body is more than the sum of it's parts. You can't trivially remove or replace parts. The upside is it is wildly resistant to failure. You can lose an eye and still see, you can lose huge parts of the brain and still function, you can damage a leg running a marathon and still find a way to finish rather quickly, the entire system can be under attack by an invader and automatically defend it self.
But there are limit and when they are cross the entire system fails completely and irreversibly. And in this sense they do collapse faster because once that limit is crossed the system rapidly starts to fail and can never be restored.
> Not enough fuel and a car stops. It's completely binary, either you enough gas to go, or you can't go. For a human there is an incredible range of failure modes for not having enough fuel. Humans can survive an absurdly long time when they are 'empty' of food.
You're highly selective. Let's switch things around a bit:
Not enough oxygen and a human stops. It's completely binary. But remove the oil from a car, and it can survive an absurdly long time.
More seriously, you can in sequence replace all parts of a car and it still functions as the original one (https://en.wikipedia.org/wiki/Ship_of_Theseus), but you can't do that with a human (even if cells do that in a way). This means you can have a car last 1000 years, but not a biological human.
> But remove the oil from a car, and it can survive an absurdly long time.
I wouldn't call less than 30 minutes[1] "an absurdly long amount of time". I've lost a car due to all the oil leaking before. I don't even think it lasted ten minutes after the low oil light popped up (I was in the middle of an expressway), and that engine was toast afterwards. I had it pop up another time for another car and thankfully I was two minutes away from an exit to an oasis and got oil into it pretty quickly.
If you mean an EV car then that's not fair, it's not designed to use oil, that's like saying a human can survive an absurdly long time without eating dirt.
[1]: https://www.matfoundrygroup.com/blog/can-you-run-an-engine-w...
A car can last a long time without the cup holders. And you can use the cup holders as ash trays.
> I don't even think it lasted ten minutes after the low oil light popped up (I was in the middle of an expressway), and that engine was toast afterwards.
Pretty sure they were referring to storing a car for a long time (months or longer) without any oil in it. Not trying to operate the ICE car without oil in it.
> More seriously, you can in sequence replace all parts of a car and it still functions as the original one (https://en.wikipedia.org/wiki/Ship_of_Theseus), but you can't do that with a human
Actually there’s enough evidence at this point that you can, you just have to do it on the cellular level, not tissue level, and the hardest problem for therapies in living humans is not creating cancer at the same time.
Partial reprogramming (resetting methylation status on the DNA) looks like the most important maintenance to do inside the human cells, but there are other known problems with partly known solutions.
I agree on some of the points.
My point was that complexity is not a single face phenomenon and can't account alone for risk of failure.
I believe we should look at why complexity is there and what purpose it serves.
Human body is a complex machine, but the fact that failure can bring it down to the extreme is because human body is fragile and once single organs start failing things cascades to the point of no return very quickly.
We are in fact not build for extreme resiliency, but for extreme adaptability (not even the most extreme nature created)
A simple system most of the times is built with simplicity in mind (sorry for the tautology) and sometimes because of simplicity is more efficient.
It can also happen to more complex systems, like for example our body which is very energy efficient at the expenses of resiliency. Klingons OTOH have two livers, an eight-chambered heart, and two stomachs. They are bigger, consume more energy and need to eat (and drink) a lot more. Redundancy adds complexity, but have its purpose.
Klingons do not exists obviously, but nuclear factories are another example of complexity serving safety, not more efficient operations.
Simpler systems usually exhibit single point of failures, like for example now with the war our very complex supply chain can shield us better from the consequences than countries that don't have them or can't afford them.
Historically they died sooner and we haven't records of their sudden fall, because they never reached the point were it mattered enough.
So complexity - I would call it complex redundancy -, which is very costly, depends a lot on the ability of gathering the resources.
Going back to the Romans, at one point they stopped making new steel and warships because the huge amount of wood necessary was not sustainable and Europe witnessed the first massive deforestation of its history.
So, before collapsing, they had to add another layer: recycling. Which can be simpler as a process but also requires a longer chain of supply.
Add to that the will of their enemies to conquer them, the lost knowledge on how to reboot failing systems because they were so old that people took them for granted and things can go south pretty rapidly, but that's not an inherent property of complexity, but of fragility.
The Universe is immensely complex, but I believe it's still going strong after 13 billions years from its birth.
I agree with you completely, but the last statement kinda irks me. The universe can't 'fail'. No event that happens in the universe is a failure to the system, it's unconscious and doesn't really have a purpose that we know of.
If you believe in God then the universe is a creation of God and we are creations of God which separately adapt and create things of their own. Such as offspring. And the purpose is for God's glory.
There are a ton of systems built into living organisms that handle regulation and repair. These systems make us incredibly robust to many different types of insult. We don't build our systems like that, unfortunately humans are incredibly stupid and short sighted so we need to work harder to build robust systems. That's on top of the fact that nature has had such an incredibly long time to build these regulatory and repair systems
True
When I say that we are fragile I mean that we physically are.
One Mike Tyson's punch in my face and there's a good chance I'll suffer grave damages or worse.
An hippopotamus would probably not even feel it.