No, I believe the death by guillotine is not painless. But it is rather quick.
Why is it not painless if the body is disconnected from the head, you ask?
Well, I’ll give you an example. Some amputated patients still feel their amputated limb, sometimes their “fingers” / “toes” itch, etc – a phenomenom called phantom limb. The reason is simple: the brain is used to receiving nerve signals from that limb. Suddenly, the limb is no longer there, for the first time in the person’s life. Complete and absolute absence of nerve feedback from that limb. Radio silent, so to speak. The brain feels a little “confused”. So you probably feel the same thing when you sit / lie down in an awkward position that interrupts the blood flow to that limb – numbness, maybe an itch…
The limb isn’t there, but the “input receiver” in your brain is still intact.
Now I will give you another example.
When one of your nerves becomes trapped eg by a hernia (like what happens with sciatic pain), you feel pain from the severed point onwards. Everything that is innervated by the severed nerve feels “wierd” : painful, numb, hot…. It may vary. In the case of the sciatic nerve, it goes to the leg, so the leg will feel painful / numb, even though the limb is perfectly fine!
Before moving on, a quick note. All nerve pathways concerning sensitivity of some sort start in a point of your body (skin, organ, bone, muscle……..), go to your medulla (the spine) through nerves and then travel all the way up the spine to your brain, where the signal is processed (okay, almost all nerve pathways; medulla reflex pathways are an exception, but for the sake of simplicity let’s assume it’s all of them).
So, putting these two examples together, if you cut your head off, you:
- severe almost all the nerve pathways in your body in one single take, in one single spot – the blade incision point. Think sciatic pain.
- Amputate your whole body (not just a limb). Think phantom limb.
Concerning number one, what happens would be the equivalent to an atom bomb of stimuli exploding in your brain, from every single nerve pathway to/from your body being severed at the same time. Everything from the nerve pathway cut downwards would hurt, on each and every pathway that was cut in your neck. The amount of stimuli would probably be enough to make you faint, but who knows?
Concerning number two, your brain suddenly stops receiving any feedback from your body, for the first time in your (ending) life. Whether you will be conscious or even alive long enough to have your brain “feel confused” abour that is hard to figure out.
Anyway, nerve signals travel from their source to their destination in a matter of miliseconds. The nerve signals we are talking about would most likely reach your brain and be processed a teeny tiny bit earlier than the blood pressure dropped enough to compromise your consciousness. So you would feel the blow.
Whether it was the sheer amount of sudden nerve information or the blood pressure that knocked you out, you wouldn’t die immediately. You would be jn the equivalent to a coma: technically, nothing happened to your brain, it’s 100% intact, it just isn’t receiving blood (“food”) anymore. It started the short journey of cell starvation. I don’t have an exact source right now, but I believe I recall reading somewhere that the brain can take 30 seconds to a minute without blood flow (again, not sure). Of course the brain damage is gradually occuring during that minute, until the whole brain is dead. But while the brain us dying, it is active. Most likely in a coma, but alive. Does the person feel anything? Nobody knows, just like nobody knows if people in a “traditional” coma in a hospital bed feel or hear anything.
So, basically what happens is you feel the biggest amount of simultaneous stimuli you ever felt in your life, provably knocking you out, then you enter a coma, and quite quickly you die.
That is my take on this.
And as a doctor who is trained to save lives, analysing a n hypothetical death in so much detail saddens me to the core. Ah, well. I need a drink.