From fastest to slowest, absence of ... kills you

Imagine you step into a chamber that is exactly like where you are now only it has 1 thing completely absent. Heat or food or water or oxygen or pressure, etc.

What will be the fastest to kill you and what would be the slowest?

heat - instantaneous?
-This one is a bit tricky. If you are in a vacuum I don’t think you’d freeze immediately since you’d need to radiate the heat way. But if you were in, for example, liquid helium I would think death would be nearly instantaneous.
pressure - minute(s)?
oxygen - minutes. Not sure if pressure or oxygen is faster.
water - days
food - days into weeks
light - never?

What does lack of heat mean in this context? Does it mean that everything in the room except for you is now at Absolute Zero, or does it just mean that you turned any external heat sources off, but everything is, for the moment, at the same temperature it was before?

This would be an excellent xkcd-what if?

If the entire chamber totally lacks heat then it is at absoute zero so the air would instantly condense and solidify. I suspect that the lack of breathable oxygen would be what killed you because as you say the consequent vacuum would insulate you before you died of cold.

In that case, I think you’d be 0K.

Here’s one I’m curious about - would you die if all nitrogen was suddenly removed from the room? That’d be a huge pressure drop but you’d be left with air that’s mostly oxygen.

But only at 0~.3 atmospheres. Your lungs just won’t work effectively at that pressure and you’ll be losing oxygen *from *your lungs at almost the same rate as you can take it in.
The problem with most of these scenarios is defining what we mean by "absence. As already noted, an absence of heat could mean being placed into a chamber at absolute zero, or it could just mean that you can’t generate any more heat internally or that you can’t absorb external heat. All totally different scenarios.

The same applies to lack of pressure/oxygen. Does a lack of pressure mean total lack of pressure but you be provided with intravenous oxygen so that only the pressure kills you? Because otherwise, lack of pressure and lack of oxygen are going to be effectively synonymous.

Lack of light will kill you eventually if you don’t take vitamin supplements.

I believe that the partial pressure of oxygen is what really matters to your lungs. The sudden loss might be uncomfortable to your ears, but I don’t think you’d stop breathing just because of the loss of the nitrogen.

What you would face, however, is a dramatic increase in the risk of death by fire. This is what happened to Apollo 1, iirc.

No, Apollo 1 test used pure oxygen at over 1 atmospheres of pressure (if Wiki is correct). That’s not the same as 0.22 atmospheres of which 95% is oxygen which is what you’d get if you’d take away the nitrogen.

I know there’s all sorts of problems you can get when scuba diving even if you are getting oxygen, that’s why I was wondering if breathing high-oxygen, low pressure air for extended periods would be detrimental or lethal.

IIRC early American space craft used pure oxygen at a fairly low pressure of 5PSI.
I don’t know about killed but a pure N2 or other gas mixture with no O2 will cause a person to pass out in just a moment with death not far behind.

Is this correct? Atmospheric pressure is roughly 0.33 at the top of Mt Everest and people have survived there without extra oxygen. That’s far less oxygen pressure than in our hypothetical scenario.

Yes, the early American space capsules (including Apollo) used pure O2 at about 3 PSI (the same amount of oxygen as our atmosphere at 15 PSI). That is not what caused a fire, since a fire at 3 PSI of pure oxygen will burn just like the same fire in our atmosphere. What caused the problem with Apollo 1 was when they were testing the capsule with the 3 PSI pure oxygen, they needed to perform a pressure test, that is, subject the capsule’s seals to the same pressure difference it would see in a vacuum, which would be about 18 PSI. As the crew was suited with their own oxygen supply, they could have used pure nitrogen for the test, but since they were already hooked up the oxygen tanks, they just ran the pressure up to about 18 PSI with pure oxygen. With that amount of oxygen, even a static spark can ignite anything combustible and, once lit, they couldn’t put it out.

Nobody has survived without oxygen on top of Everest for more than a few days.

Read the Wiki on Apollo 1. The test was done @ 16.7 PSI to drive any N2 out, but the actual flights started @ 14.7 and then as the spacecraft rose the pressure dropped to 5PSI
Based on that 5 PSI of pure O2 is safe

Did the “etc” in the OP allow us to add others? Deprived of Sleep would be somewhere between water and food I think. If that wasn’t the intent of the OP, never mind.

Nope. Look up fatal insomnia. Takes 6 months to a year.

Has anyone ever tried? Don’t climbers aim to tag the top and then return back to their tents the same day?

I’m gonna cheat and claim that the absence of the strong force would kill you fastest. Now, for now to turn off the strong force, I’m not telling. Don’t want any of you destroying the universe or any anti social stuff like that.


Well played. :slight_smile:

There’s a saying about “the rule of threes” on what to prioritize when starving. The tl;dr is that food is a very low priority compared to the others yet people want to think of ways to trap food. I can’t comment on the accuracy, but generally it goes:
[li]3 minutes - time before you die of suffocation.[/li][li]3 hours - death from exposure in extreme conditions[/li][li]3 days - die of thirst[/li][li]3 weeks - die from starvation. Not that you are going to be energetic up until that point.[/li][/ul]
I’ve also heard of bleeding out on one of these (minutes?).