# Hypothetical cooking physics question

I put it here rather than cafe society as its more of a math problem than a cooking problem.

Glass melts at about 1800F

so if I were to heat a marble right up to the edge of melting, then ram it into a ball of typical ground beef, any theories on how big of a ball of beef I could cook with the thermal energy stored in the bead?

Not saying it would be cooked in any particularly pleasing way and the center would obviously be burned to hell.

More of an academic thing… I have the equipment to do this if I wanted to experiment, just wondering if there are any theoretical physics types who wanna opine the outcome

How big a marble? They come in many sizes.

I couldn’t tell you the answer, but I can tell you that the people that can give you the answer will need some more information. Most importantly, the size of the marble since that will tell us how much heat you have to start with. A quarter inch marble will hold a lot less heat then a 2 inch marble. Less importantly, since there’s such a HUGE temperature difference is the starting temp of the meat and even the fat content of it. Also, ambient temp and if it’s in any kind of vessel and if so, how well insulated.

Also, what you’re thinking about isn’t that novel, cooking things with heated rocks has been done in the past.

I can’t imagine anyone jamming a hot rock into a chunk of meat to cook it. Cooking with rocks is either done by dropping them into water to heat it or using them to line a pit that is then heated with fire.

My guess would be the greatest amount of cooking will be from the steam you create from the water in the meat, as opposed to the cooking effect of direct conduction heating.

Dropping a 1800F half inch glass marble into meat will result in a mini explosion with shattered glass all around and in the meat. You’ll also have meat burnt at the point of contact.

Cooking is a heat transfer and chemical reaction kinetics problem - not so much as a heat duty problem.

You need to specify and/or estimate some parameters.

You’ve got the temperature increase of the marble, from room temp (~70F) to 1800F.

Specify the mass of the marble. You could calculate this from the density of glass and the diameter of the marble.

Specify the specific heat of the marble. This is a physical property of glass, and it tells you how much energy it takes to heat a certain mass of it by one degree. In standard units, it’s BTU/(lbR); in SI units, it’s kJ/(kgK).

Now you can calculate how much thermal energy is in the marble: E = mCdT, where m is the mass, C is the specific heat, and dT is the temperature rise (1800-70).

So how hot is the ground beef going to get? Do the same math: you need the beef’s mass and specific heat (the latter can be estimated by calculating the value for a blend of water and generic oil); since you know the energy available, you can just solve the above equation for the temperature rise of the beef. If the mass of the beef is very large compared to the mass of the marble, you can ignore the mass of the marble. If the masses are comparable, then the energy is distributed between the two, with the constraint that they both end up at the same temperature.

In reality, a good bit of energy from the marble will be lost as heat to the environment, either directly through convection if exposed to air, or by vaporizing water/fat in the beef which then flees the scene as warm water vapor or greasy smoke, carrying energy with it. So the final beef temp would be a bit lower than the above math predicts.

Nice find. Nickel has about half the heat capacity of glass so glass at the same temperature would “cook” the meat faster, unless it shatters from thermal shock as **am77494 **describes. Red hot metal is in the 1300-1900F range so it’s in the right ballpark.

However, you have discovered a new way to mangle your fellow human beings. Thermal-explosive fracturing ceramic projectiles. Mix in high pressure expanding caustic gas to create corrosive effects and you have yourself a horrorshow weapon. Great fun for the entire family.

Stranger

how moist is the meat? this is also a factor as well as its temperature.

also what is your HOIM (hot orb insertion method)?

if you shove it in a slit then it will shatter (wear eye protection) and you will loose some of your desired heat source. if you took a small core out of the meat and inserted a ceramic tube then rolled the glowing orb in and withdrew the tube then you might get some effect.

this could become a new trendy cooking style, glass kebab.

A great dish is chicken cooked with hot rocks. They are stuffed into the cavity cooking the bird from the inside out, though you need a few extras outside to get the legs thoroughly cooked.

What, I gotta do everything around here?

Specific heat, beef, hamburger, above freezing: 3.52 kJ/kgC

“Food and Foodstuff–Specific Heat”

/ A let me Google that for you that wasn’t; I sous-vide a fair amount and am into the science.

Frangible armor piercing incendiary projectile

On the other hand, the OP seems to want to competely surround the marble with meat, Here, roughly half the nickel is in contact with meat, so that factor of two could crudely compensate for the different heat capacity.

On the other hand, a Google search for “specific heat capacity of glass” gives 0.84 J/gC. So at the risk of Fermi-ing it up, say the burger meat has SHC of 4 and the marble has SHC of 1. I’d also assume that in order to cook the burger, you’d need to increase its temperature by at least 100 degrees (and that is still pretty tartare)

If the mass of the beef is the same as that of the marble, assuming perfect heat transfer, increasing the meat’s temperature by 100 degrees will decrease the marble’s temperature by 400 degrees. If the marble starts 1800 degrees, you can do this about 4 times before the marble becomes too cool to be an effective heating element, giving you about 4 marble-masses of cooked ground beef.

I don’t know how dense ground beef is compared to glass, but it certainly seems denser, so I’d WAG that 4 marble-masses of ground beef would correspond to about two marble-volumes. So I’m thinking that with an abnormally big marble, you might get a small slider out, maybe.

All I know is I know have a few ides of how to get that perfect sear on my steak.

Excuse me!?!?!?
You’re firing a 20mm to 35mm slug at a person’s body and you feel for some reason that it needs to explode – AND ignite???
Isn’t there some kind of rule in warfare* that prohibits disfigurement of the opposing side’s people?

–G?
*Yeah, yeah, I know…rules and war…:dubious:
Still, there was that convention in Geneva and all that.

If you had a really big glass marble, you could cook meat Mongolian barbecue style, by using the “hot rock” as a griddle.