# Cooking steak with freefall

In today's XKCD What If?, Randall Monroe answers the question, "From what height would you need to drop a steak for it to be cooked when it hit the ground?" posed by Alex Lahey:

At supersonic and hypersonic speeds, a shockwave forms around the steak which helps protect it from the faster and faster winds. The exact characteristics of this shock front—and thus the mechanical stress on the steak—depend on how an uncooked 8 oz. filet tumbles at hypersonic speeds. I searched the literature, but was unable to find anything to help me estimate this.

For the sake of this simulation, I assume that at lower speeds some type of vortex shedding creates a flipping tumble, while at hypersonic speeds it’s squished into a semi-stable spheroid shape. However, this is little more than a wild guess. If anyone puts a steak in a hypersonic wind tunnel to get better data on this, please, send me the video.

If you drop the steak from 250 kilometers, things start to heat up. 250 kilometers puts us in the range of low earth orbit. However, the steak, since it’s dropped from a standstill, isn’t moving nearly as fast as an object re-entering from orbit.

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1. The thing is, MOST of the heating in atmospheric re-entry isn’t due to the potential energy of being at altitude. If an object is reentering from orbit, or indeed from a ballistic sub-orbital trip of great distance (like an ICBM) most of the potential energy from it’s speed around the planet.

1. nowimnothing says:

I assume most normal-sized steaks would be overcooked just a bit if re-entering from orbit.

2. dnebdal says:

He mentioned that, yes – and it’s even in the excerpt above. x)

3. Guysmiley says:

He brought that up but pointed out the question was about what height it had to be dropped from, not what velocity would it have to re-enter the atmosphere with.

2. Brian Hughes says:

The aerodynamic analysis is nice but is only one of the layers that has to be considered. Steak is a essentially a matrix of protein, fat and water. Some of the water will be lost by evaporation and sublimation, which will have a substantial cooling effect. What you will likely end up with is something partially dehydrated and frozen

1. Guysmiley says:

> What you will likely end up with is something partially dehydrated and frozen

I’m not sure. A freefall starting at 250km and 0 velocity would take around 4 minutes, not a ton of time for vacuum to affect it. And if it’s in sunlight, it’d actually heat up, not cool off. Not sure what 4 minutes of vacuum would do to the moisture though, anyone have a vacuum chamber they want to volunteer?

3. I wonder how much the data would change if you attached a T-Bone to the Shuttle’s heat-resistant tiles?

1. anansi133 says:

Exactly! Instead of wrapping the steak in foil (a reasonable precaution when cooking over toxic fumes for example) you wrap the steak in just the right thickness of shuttle tile: Heat is still transmitted, but more slowly. And the cooling effects of the cold air are mitigated too.
I’m trying to imagine what the packaging would look like for this product, to be shelved with the foil, waxed paper, and plastic wrap…

1. once, in my life, i attended a restaurant which served,
fillet mignon, baked in a clay lump.
this was served by waiter with hammer and chisel.
who opened it.
pretty amazing.
” bernardis ”
melbourne
australia

1. dnebdal says:

Kind of like cooking an unplucked bird in clay (and then removing the feathers along with the clay when cracking it open)?

1. in technique, yes.
desired result, keep juices in.

as i am kind of sure that steak, in australia, is featherless….    :)

4. this looks like a mythbusters episode:
build a contraption to reach this height
build a mechanism to provide live feed of the contraption,
build a mechanism to drop the stake,
build a second mechanism to follow the stake during fall
ask for the navy and airforce to recover it or most awesomely build a damn navy and air force to recover it

1. Alexi Bell says:

All you’d really need to do is convince Richard Branson that another billionaire was trying to be the first to eat an atmosphere-cooked steak.

5. Mike Robinson says:

Waiter, I actually ordered the fish

1. Luther Blissett says:

The certain, now settled condition of the science of Cetology is in the very vestibule attested by the fact, that in some quarters it still remains a moot point whether a whale be a fish. In his System of Nature, A.D. 1776, Linnaeus declares, “I hereby separate the whales from the fish.”

And, you might not want to order “fish” if the whale himself drops by to ask which part you prefer.

In fact, you should not even order whale.
Never.

Especially from Randall. He’s taking his job seriously.

6. Ryan Lenethen says:

“For the sake of this simulation, I assume that at lower speeds some type of vortex shedding creates a flipping tumble, while at hypersonic speeds it’s squished into a semi-stable spheroid shape.”

LOL!

Sorry, but it too closely resembles this:

http://en.wikipedia.org/wiki/Spherical_cow

Particulary when presumably the steak is made of cow.

1. jackbird says:

He also alludes to the fact that if it isn’t a semi-stable spheroid shape, the result is frozen steak vapor from the hypersonic tumbling.

7. oasisob1 says:

How long will it be before we see video of steak in a hypersonic wind tunnel? Really though, my daughter is trying to think of a good reason to take physics next year. I think I have some motivation for her…

8. For bonus points, determine how much collateral damage it does when it arrives at your table still traveling at thousands of miles per hour. Rare, medium, or hypersonic?

(OK, I see that Randall says it “isn’t moving nearly as fast as an object re-entering from orbit”, but I can’t let go of the image).

What we really need is for one of the private space companies to develop a launch vehicle to which you can strap a load of steaks – imagine replacing the shuttle’s tiles with steak and you get the idea – cook them in the approved method, and deliver them sizzling to runway-side tables at a private spaceport. Call it the Steak Shuttle. Kickstarter, anyone?

9. Paging Mythbusters. Customer needs assistance in the XKCD aisle.

10. Luther Blissett says:
11. welcomeabored says:

Possibly the world’s most expensive under-cooked steak.  Kinda puts the price of Kobe beef to shame… unless that’s a Kobe steak being used to pellet the planet.

1. invictus says:

I can buy an 8oz Wagyu Kobe filet mignon for \$40. The price of getting a kilo of material to orbit is, what, around \$10,000? Sounds like the price of ingredients for this recipe is in the “rounding error” realm.

1. welcomeabored says:

For that kinda money, it should at least come with a baked potato and all the fixins, a baritone waiter, and a nice bottle of cabernet.

1. invictus says:

2. beepbeep says:

I think I’d prefer a Shiraz with that though. Maybe a Pinot Noir

12. legsmalone says:

Well, 30 seconds of vacuum certainly doesn’t dehydrate meat. This is based on substantial experience with foodservice cryovac machines so I’m not sure how space would work, but the worst (or best, if that’s your goal) you can do in a vac machine is cell wall damage that allows you to infuse the meat with whatever else you put in the chamber. Osmosis, how does it work?

13. “As far as I know, this steak question originally came up in a lengthy 4chan thread, which quickly disintegrated into poorly-informed physics tirades intermixed with homophobic slurs. There was no clear conclusion.”
Oh Randall.. :-)

14. I don’t even play a physicist on TV but it would seem to me that at high altitudes the cold would be far more of a factor than friction and might actually cool or freeze it. Terminal velocity would eventually be reached and would change from higher to lower altitudes because of changing air density but I’d expect the amount of friction to be the same.
Given terminal velocity, I doubt that at any point in it’s journey friction could heat it to a tasty/safe temp -especially if it needs to be defrosted a bit from it’s earlier travel.Then again, pardon the pun, that could all be half baked physics.

1. Guysmiley says:

Did you read the article? His math ended up starting the steak well outside the atmosphere where there is no terminal velocity. The thermal shock as it decelerated while passing through the atmosphere is what was “cooking” it. He also referenced it being cooked to “Pittsburgh Rare”.

15. Funny that Randall should mention Salmonella. It’s uncommon to get that from a steak. In fact there is almost no risk of bacterial disease from rare steak. Most bacterial contamination is going to be on the surface of the meat, where it will be cooked and killed even if the inside is still raw. And raw beef is not that risky. I eat raw beef heart from time to time. It’s a great way to bond with my cat that we enjoy it together.

Hamburger is another matter. Grinding mixes the bacteria into all of the meat and also adds oxygen.

16. Should be some real world data on this from the loss of Columbia.

1. beepbeep says:

Er, ouch!

2. feetleet says:

Columbia wasn’t in free fall, it was traveling at significant speeds before it entered the atmosphere. As the article explains, “the steak, once it’s dropped from a standstill, isn’t moving nearly as fast as an object re-entering from orbit.” Also, douche.

17. feetleet says:

Oh God, this started on 4chan? Talk about a Brangelina baby.

18. feetleet says:

I think this overlooks the fact that the steak may ALREADY be ‘cooked,’ simply by merit of the ENVIRONMENT at 250km. You can ‘cook’ by very many means other than heat. A classic example is ceviche. Pickling (acidity), pressure and even sufficient COLD can ‘cook’ meats and remove bacteria. A ribeye dumped into liquid nitrogen probably wouldn’t be very pleasing to the mouth, but it would be safer, bacteria-wise, than the uncooked steak. Low orbit, as you may know, is mighty cold.

And the partial vacuum of low orbit would stick a fork in it. After all, if E. Coli COULD survive low orbit shielded by just 1/2 inch of flesh, then – like the tardigrade – it would make a great terraforming candidate/panspermia culprit.

Also, we’re not looking at the magnetopause quite yet, but the solar wind and universal radiation will certainly ‘microwave’ it more at this height (if only for a few seconds as it plummets). I understand xkcd considered the radiation, but not in the aggregate.

If the premise limits us to earth gravity (e.g, 9.8), earth atmosphere (e.g., Mathematica) and earth-human conceptions of ‘cooked’ (e.g. fecal coliform), then I think it’s completely fair to make this multi-discliplinary re: earth biology. And, I think, biology wins.

The answer, then, is “no.” No height. There is no height above Earth at which you can drop a steak and have it cook from air compression, because coliform bacteria – the human litmus of ‘cooked’ – will die from non-gravitational assailants FIRST. And no, you can’t discount the atmosphere (or lack thereof) assailing them for this hypothetical – because then the steak wouldn’t cook your way either.

As I see it, this would make for a GREAT tartare, though. The atmosphere sanitizes the meat to sushi grade, then the flash heating of the drop raises it to palate temperature. But unlike your kitchen counter, the falling meet is anoxic. Tres magnifique.

Some conclusion, I guess.

19. if you launch a cow at the sun, when is dinner ?

20. Can’t you just pick 80′ and try for good Monte Carlo results? (Your steak has entered a cavern of twisty Garde-Manger, all alike…)
At what height above equatorial Earth, sea level is a tenderloin cut Kosher?
Major Tom/Venture Bros.: 3 experimental space kitchens also alluded to?
Who here thinks tossing the 8oz. filet rather than cutting after (and using the Coriolis Effect to cook) is a screwup and asking for bugs and dust to fall into it at the last minute (should it luckily avoid the vapor situation?) There are of course ad minimus replies from things packed to and from Mt. Everest or Mt. McKinley.