All in the name of science...

[ClayJar]

1. If traditional cake, with all those gas pockets, the air container should be maintained at surface pressure (such as a camera housing), or the cake will crush to the point of ugliness.

I'm modeling traditional cake as an open-cell foam. I believe this is justified, as I have breathed through a piece of cake (it provides significant resistance, but air does flow through the cake "filter"). As long as it is not completely sealed, it should be fine.

For a cupcake, the top surface will indeed be coated with a high-viscosity frosting, but the sides (which will have had any paper removed in order to prevent inadvertent littering) provide more than adequate area for the flow of air into the internal bubble network.

2. sberanek provided the solution for an ambient pressure air container (like a diving bell) – ice cream cake.

Actually, ice cream contains a significant amount of air. I'm not sure whether the structure of the ice cream matrix is sufficient to prevent collapse, but it is not a given.

Of course, there is a more significant factor to be weighed against the ice cream cake approach. Simply put, refrigeration would be a problem. The only viable way of maintaining an ice cream cake in pristine condition from purchase to consumption on the dive will be dry ice, and I'm not particularly fond of carrying dry ice in the passenger compartment of the vehicle in which I will be traveling five hours or so, *especially* when I'm going to dive. I just don't like breathing CO₂ that much. :biggrin:

No, I think it's going to be a standard cupcake, and I don't believe the air space in the cake matrix is going to be of significant importance.

Place the cake in a sealed hard container and bring it to a place like Morrison Springs where you can actually stand up with your head in a pocket and ...........never mind.....lets go with Dr Bill's idea.

The primary problem with that would be videography. It's harder to film through rock than through a polycarbonate container.

 

[jefffalcone]

I can't wait to see the video. Sounds like you have thought this out well enough that it should work. Only advice I have is bring several cupcakes so you can make more than one attempt. I'm sure you already thought of this.

Happy Birthday!

 

[knotical]

I have breathed through a piece of cake

Picturing that, I literally laughed out loud. Thank you.

 

[TimAZ]

Or you could get an ice-cream cake. Freeze it down as low as possible (try to avoid liquid nitrogen because the cake might shatter when entering the water), drill a hole in it the size of a magnesium flare, light the flare on the surface, stick it in the drill hole, and descend. Or you could bring the wet bell down, light the flare in there (more for safety on this one), stick it in the drill hole, and fun ensues.

The ice cream cake, frozen solide, would probablly hold up much better in a wet environment if you wanted to avoid having to have a dry enclosure for the cake.

--Shannon

Hey good thought. I've been sitting here thinking the OP has WAY too much free time on his hands, then thought I must too because I'm seriously thinking about this. Aside from the fire issue, what about a cake that wont be crushed at 2.5 ATM? Normal cake is essentially closed cell foam isn't it? I was thinking a good dense cheesecake, but icecream cake might be better still.

Sorry, should have read the whole thread

 

[ClayJar]

I can't wait to see the video. Sounds like you have thought this out well enough that it should work. Only advice I have is bring several cupcakes so you can make more than one attempt. I'm sure you already thought of this.

Well, I can probably justify a second attempt if everything goes badly on the first. If it is unrecoverable due to an unforeseen design flaw, I have a full month between the first event and my birthday. I could redesign and come back with a better system. (If it works, there would be little point in repeating it for my birthday.)

I have breathed through a piece of cake

Picturing that, I literally laughed out loud. Thank you.

Go figure. I finally figure out what it is that I'm good at, and it's performance art. :biggrin:

Normal cake is essentially closed cell foam isn't it?

I noted that normal cake is an open-cell foam, but I did not include any justification for that position. I should address that...

Take a layer cake for example. Between baking the layers and assembling the final cake, you *must* allow the layers to cool. Sure, part of this is so that the structure can set, thereby providing the necessary strength to support the layers. Perhaps even more important to the finished texture is the need to allow the steam to escape. If you do not properly cool the cake layers, they will retain far too much moisture, perhaps even to the point of turning your delicious cake into a grainy pudding.

If the cake were a closed-cell foam, there would be no purpose in letting the cake "off-gas" the steam, as it would be contained in the closed cells. When the cake cools, it would then collapse into a damp brick. Normal yellow cake collapses are due to incomplete cooking, which does not create a stable structure, not because of atmospheric pressure crushing the bubbles as their internal moisture condenses.

Of course, if you look at the grain structure of a properly prepared cake, it is quite readily apparent that it looks nothing like a closed-cell foam, but I don't have one of those funky little USB microscopes handy. :biggrin:

 

[Parysa]

I thought about aluminum foil, but it is an excellent heat conductor, which I thought could potentially cause complications (i.e. melting of the container at the foil/plastic interface).

Actually, I use foil all the time to keep food from burning in the oven (i.e. laying a piece of foil over a pie or something to keep it from getting blackened) and you can actually touch the foil pretty much straight out of the oven--it doesn't get hot. So, if you were to use that, it should just reflect the heat of the candle back onto the cupcake, not through to the other side.
Oh, do you have a set time to do this? I think you should try it during Vortoberfest, lol!

 

[ClayJar]

Actually, I use foil all the time to keep food from burning in the oven (i.e. laying a piece of foil over a pie or something to keep it from getting blackened)

It can indeed reflect the radiant heat, and the fact that it can partially contain steam from the baking item may also come into play. As someone who's cooked foil-wrapped hot dogs over a candle, I can say with certainty that it is also possible to burn things through aluminum foil.

(If you don't wrap the hot dogs in foil before roasting them over the candle, you end up with sooty hot dogs. If you wrap them tightly in foil and then roast them, they taste a whole lot better... well, for hot dogs, at least.)

you can actually touch the foil pretty much straight out of the oven--it doesn't get hot.

Okay, this is the chemical engineering degree speaking, but... The foil *does* get hot. When it is in the oven, it quickly reaches equilibrium with the hot air in the oven (or some lower equilibrium temperature if there is something cooler on one side). The foil can indeed reach plastic-melting temperatures.

Of course, aluminum has a much lower heat capacity than most baked goods (and certainly *much* lower than water, which has an unusually high heat capacity). In addition, heat capacity is the amount of heat energy per mass per change in temperature. Aluminum already has a rather low heat capacity, but even more significantly, when you use aluminum *foil*, you use very little mass of aluminum. (Consider the mass of an aluminum half-sheet pan versus the mass of a rectangle of aluminum foil large enough to cover it.)

The aluminum foil has low heat capacity and very little mass, and the large area means that heat loss by conduction to the air occurs quite rapidly. All those aspects together mean that you can pull a sheet of aluminum foil off a roast and within mere moments have it wadded up into a juggling ball, all without any burns.

(If, however, there was a large amount of condensed water on the bottom of the foil, the larger heat capacity of the water and the mass of adhered water droplets may mean that you get a bit cooked yourself unless you allow the water to cool before wadding up the ball -- setting the foil sheet on the counter with the wet side up will allow water to rapidly evaporate, quickly dropping the temperature to non-pain-inducing levels, but to go into why, I'd have to touch on vapor pressures and the latent heat of vaporization, which is probably more than anyone cares about right now.)

So, if you were to use that, it should just reflect the heat of the candle back onto the cupcake, not through to the other side.

It would indeed reflect the radiant heat coming from the candle flame, but of far more importance is the heated air. The air (and combustion products) leaving the candle flame is hot enough to cause burns far more quickly than the radiant heat. (Hold your finger about two inches away alongside a candle flame, and it'll feel a bit warm. Hold your finger two inches directly above the candle flame, and you'll feel pain rather quickly.)

Convection brings the heat from the candle flame to the ceiling of the box, where it would heat the foil. Conduction through the foil would then be the primary concern (either in melting the ceiling of the box or melting the sides at the foil-plastic interface). Of course, "laminating" the non-conductive cardboard with non-flammable, reflective aluminum foil may be the best idea. The cardboard buffer between the aluminum foil and any plastic parts would prevent damage by heat conduction, and the foil would reduce radiant heat gain.

As I wouldn't mind even if the cardboard get somewhat charred, I don't think the foil layer is necessary, but if the whole setup bursts into flames upon candle ignition and requires immediate overturning to douse it, I will consider various foil-containing approaches in any potential refinements to the process.

Oh, do you have a set time to do this? I think you should try it during Vortoberfest, lol!

Um... er... you mean like on the big rock at the back of the cavern (in front of the sign), which would give me a nice silt-free platform to work on (and which is certainly visible even to divers who remain a few yards away in the strictly open-water non-overhead area)? That almost sounds like the very place the exercise is being planned for...

(Of course, perhaps I should also be considering possibilities for roasting marshmallows underwater, but that's probably another trip.)

 

[TimAZ]

Of course, if you look at the grain structure of a properly prepared cake, it is quite readily apparent that it looks nothing like a closed-cell foam, but I don't have one of those funky little USB microscopes handy. :biggrin:

But you are actually sitiing there examining a slice of cake. I can't seem to do that. If my face gets that close, the cake is mysteriously eaten.

 

[ClayJar]

But you are actually sitiing there examining a slice of cake. I can't seem to do that. If my face gets that close, the cake is mysteriously eaten.

My superpower is that I don't like chocolate, don't like pie, and don't particularly care for cake (except angel food, which I could eat by the pound).

Now, toss some fresh broccoli, cauliflower, snow peas, cabbage, or whatever in front of me, and you want to watch your fingers. Go figure.

(For the sake of science and plot, it seems I must consume the cupcake as part of this endeavor, but do forgive me if I manage to find one that isn't chocolate. :biggrin

 

[Parysa]

Okay, this is the chemical engineering degree speaking, but...

Well, so much for me feeling semi-intelligent. What does it say about me that my grandfather and uncle are rocket scientists, lol!

Um... er... you mean like on the big rock at the back of the cavern (in front of the sign), which would give me a nice silt-free platform to work on (and which is certainly visible even to divers who remain a few yards away in the strictly open-water non-overhead area)? That almost sounds like the very place the exercise is being planned for...

(Of course, perhaps I should also be considering possibilities for roasting marshmallows underwater, but that's probably another trip.)

Yeah, right there. From my recent Vortex experiences, though, this'll have to be an early morning party if you want to be clearly visible to those in the hole. Wonder if the eels and fish like cupcake as much as viennas and cheese whiz, lol. And if you figure out how to roast marshmallows, I got dibs (as long as they're not soggy)! Yum.