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Old Spleens Suck (2021)

sarahconstantin.substack.com

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Re: Old Spleens Suck (2021)

#71

Post by krisoft »

inglor_cz wrote: post #67
krisoft wrote: post #4

Earlier quoted context omitted.

What do you mean by “flight ejections”? Are we talking about ejection seat activations in military aircraft? This factoid sounds very suspect. Doesn’t most people who need to activate an ejection seat survive spleen or no spleen? Deaths may occur of course, an ejection is not without risks, but if everyone or nearly everyone with a spleen dies then my understanding of the risk associated with an ejection is seriously…

An ejection seat is basically a rather powerful small rocket with huge acceleration - much more forceful than what astronauts nowadays experience. Human bodies aren't built for riding such rockets. Injuries from ejections are pretty common and some of the ejectees are never fit to be combat pilots again.

Yes, ejections are violent. Can cause injury, can cause death. No question about that.

Spinal injuries are likely and ejections frequently end the flying career of pilots for medical reasons.

What does this have to do with the claim in question?

They claimed “people who survive flight ejections and hitting water at high speed tend to have had their spleens removed”

This implies that if you look at the group of people who survived a flight ejection (over water and hit the water at high speed) you would find that most have no spleen. Do you find this plausible?

Re: Old Spleens Suck (2021)

#72

Post by inglor_cz »

krisoft wrote: post #71
inglor_cz wrote: post #67

Earlier quoted context omitted.

An ejection seat is basically a rather powerful small rocket with huge acceleration - much more forceful than what astronauts nowadays experience. Human bodies aren't built for riding such rockets. Injuries from ejections are pretty common and some of the ejectees are never fit to be combat pilots again.

Yes, ejections are violent. Can cause injury, can cause death. No question about that. Spinal injuries are likely and ejections frequently end the flying career of pilots for medical reasons. What does this have to do with the claim in question? They claimed “people who survive flight ejections and hitting water at high speed tend to have had their spleens removed” This implies that if you look at the group of people…

A trauma surgeon would be a better fit to answer that question, but crushed spleens seem to be common in high speed impacts (car crashes, falls from ladders etc.), at least as far as I can judge it from my limited circle of friends who have had such experience.

Re: Old Spleens Suck (2021)

#73

Post by krisoft »

TylerE wrote: post #66
londons_explore wrote: post #61

Earlier quoted context omitted.

A cleverer ejection seat could track the tail and body of the craft, and adjust the rocket force based on the trajectories in each case. Then you don't have to use enough force to avoid the tail in every case, but merely enough force to avoid the tail in this case, which will normally be far less.

Solid fuel rocket, so no throttle.

Yes. And if someone is curious why are we using solid fueled rockets in this application:

The big benefit of solid fueled rockets is that they are very reliable, and require no maintenance. They are basically a big “candle” composed of a mix of fuel and oxidizer. You can lit it a day after it was made or twenty years later it will work the same.

The liquid fueled options have valves and other moving parts which can jam, corrode and degrade with time. So it would require frequent maintenance and would still be likely less reliable than the solid fueled variety.

Re: Old Spleens Suck (2021)

#74

Post by strictfp »

ryeights wrote: post #10

I think it is obvious at this point that the human body is designed to self-destruct, causing death at old age, once a certain biological threshold is reached. Resistance to this idea comes not from a rational perspective, but a semi-religious belief that your own body would not betray you.

It's hard to survive in the presence of a constant onslaught of forces trying to break you down. Plus we have another way of surviving: multiplying. And multiplying gives us mutations as well, i.e better fitness. So why should our organism optimize for longlivety?

Re: Old Spleens Suck (2021)

#75

Post by samatman »

TylerE wrote: post #56
Hallucinaut wrote: post #54

Earlier quoted context omitted.

Obviously if you're ejecting at or near supersonic speeds there are other stresses, but if the trauma is mainly from the ejection booster itself why is it still done with such force? It seems like a majority of ejections shouldn't be benefited by half a second less time to achieve clearance (or the jet itself could detect altitude and adjust the speed to increase survivability). I'm guessing this is also a function o…

Because you have to get up and over the tail of the airplane without it slicing you like a cleaver.

While I'm unaware of an ejection seat which blows the tail off the aircraft backward with another shaped charge, there's nothing preventing this.

Re: Old Spleens Suck (2021)

#76

Post by alanbernstein »

samatman wrote: post #75
TylerE wrote: post #56

Earlier quoted context omitted.

Because you have to get up and over the tail of the airplane without it slicing you like a cleaver.

While I'm unaware of an ejection seat which blows the tail off the aircraft backward with another shaped charge, there's nothing preventing this.

Of course there is: whatever event warranted the ejection. The seat/canopy mechanism is relatively localized within the aircraft, adding one more system to fail is perhaps frowned upon in this absolute last-chance survival system.

Re: Old Spleens Suck (2021)

#77

Post by thunderbong »

aborowie wrote: post #23
clarkevans wrote: post #14

Is there a good introductory book on understanding inflammation and autoimmune diseases?

A gorgeously illustrated deep dive into the immune system that will forever change how you think about your body, from the creator of the popular science YouTube channel Kurzgesagt—In a Nutshell Immune: A Journey into the Mysterious System That Keeps You Alive by Philipp Dettmer

YouTube link to introduction of the book -

https://www.youtube.com/watch?v=lXfEK8G8CUI

Re: Old Spleens Suck (2021)

#78

Post by HPsquared »

TylerE wrote: post #66
londons_explore wrote: post #61

Earlier quoted context omitted.

A cleverer ejection seat could track the tail and body of the craft, and adjust the rocket force based on the trajectories in each case. Then you don't have to use enough force to avoid the tail in every case, but merely enough force to avoid the tail in this case, which will normally be far less.

Solid fuel rocket, so no throttle.

You could use an array of motors, and only activate however many are needed.

Re: Old Spleens Suck (2021)

#80

Post by b112 »

krisoft wrote: post #73
TylerE wrote: post #66

Earlier quoted context omitted.

Solid fuel rocket, so no throttle.

Yes. And if someone is curious why are we using solid fueled rockets in this application: The big benefit of solid fueled rockets is that they are very reliable, and require no maintenance. They are basically a big “candle” composed of a mix of fuel and oxidizer. You can lit it a day after it was made or twenty years later it will work the same. The liquid fueled options have valves and other moving parts which can j…

I think the reliability part is what most are missing here.

Devs, you have to think like the 90s. You are shipping software on a CD or floppy l, with no updates ever. Ever.

You get it right, or you may bankrupt the company.

That is an ejection seat, and the simplier the design, less to QA! And on top of this?

The hardware under your software is possibly decaying, and your software still must work.

Sort of like designing software for an apollo mission.

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