“What!” you exclaim. 😂 I’ll explain. I read from internet sources that it’s not a good idea to keep eggs in trays on fridge doors. The warning is about the temperature of eggs fluctuating and going too high, so that they aren’t cooled enough to prolong shelf life. In fact some sources say it’s dangerous. The video below is a fine example and it is fake news! (I’ve ripped it just in case it is removed at some point).
Because I’m an A-student in physics I thought “That sounds like nonsense,” because it meant that the average internal temperature of a fridge on opening the door should not fall that much. And I knew that heat had to be conducted from air through the eggshell of the egg, into the albumen and yolk to warm the whole egg. My thinking was:
- You’d have to idiotically be leaving open the fridge door a whole lot and repeatedly to raise the average temperature of the fridge compartment.
- The fridge thermostat would naturally kick in to maintain a cool temperature usually around 4 °C and that would probably take only a few minutes.
- The egg would have already been cooled to around 4 °C – so my estimate is that the temporary rise in temperature in the fridge compartment would not be for long enough to significantly conduct the ‘heat’ into the egg to raise its internal temperature by much.
I needed to check this out mathematically. Well, I wasn’t going to get pencil and paper out and spend 3 or more hours working on the calculations. Instead I reached for a tool called AI.
I needed to know the thermal properties of raw eggs in their shell. I jumped the net and found them here (in Table 3). Someone was working on this.
Sidebar
Before moving onto the intricate mathematics, I just have to mention that an AI in China caused stock markets around the world to lose $1 trillion of value on 27th Jan 2025. Tech company CEOs lost an aggregate of $108 billion. No it didn’t hack anything. It just upended $500 billion of planned AI investments t in America, and cooled off a superheated set of tech stocks known as ‘The Magnificent Seven‘! How? It’s the new kid on the block called DeepSeek! This is on par and in some use cases better than the traditional ChatGPT and others, at a fraction of the cost. See here and here and here.
Anyone with internet access and a browsing device can access and use – for FREE it just like ChatGPT or Claude.ai or Copilot! The DeepSeek app is available for free on Apple and Google play stores. To a panic attack do not don’t read much more of this stuff! 🤣😂🙈 Go have a cup o’ tea and relax.
Oh yes – I did try out DeepSeek. It feels good and works as good as Claude.ai and Gemini (on Google).
It did many of the calculations I needed, very well for the egg-issue. But then it stalled due to the sheer numbers of people flooding into it. So I resorted to Claude.ai which did some amazing calculations in a different way. Eventually DeepSeek came back on after server load settled down.
Claude and DeepSeek came up with the same conclusion.
Mainbar
Click to see code generated by Claude.ai to do the calculations. Did I say you have to read and understand it all? I did not!
Calculations in detail
Calculation of Temperature Rise in an Egg During Fridge Door Opening: No apology – not everyone has the intelligence, time or effort to follow the calculations. Ahhh.. That must mean that AI is more intelligent than ‘some people’. Terrible – isn’t it.
Assumed conditions
- Absence of an idiot!
- A standard fully working UK fridge, that has achieved a steady internal temperature of 4°C.
- Starting egg temperature: 4°C
- Door opening duration: 10 seconds (I usually am in and out in under 5 seconds).
- Peak internal fridge air-temperature after opening and shutting: 10°C
- Total time recovery period to re-establish internal air-temp of 4°C: 7 minutes (420 seconds)
- Egg mass of one egg: 0.06 kg
- Egg radius: approximately 0.025 m
- Surface area: 4πr² = 4π(0.025)² = 0.008 m²
- Calculate weighted average specific heat capacity:
- Albumen: 58% (0.58)
- Shell: 11% (0.11)
- Yolk: 31% (0.31) [remainder] From Table 3 specific heat values:
- Albumen: 3935 J/kg·K
- Shell: 888 J/kg·K
- Yolk: 3266 J/kg·K Weighted average calculation:
c_avg = (0.58 × 3935) + (0.11 × 888) + (0.31 × 3266)
c_avg = 2282.3 + 97.7 + 1012.5
c_avg = 3392.4 J/kg·K
- Heat transfer calculation:
- Heat transfer coefficient (h) = 10 W/m²·K (typical value for air convection)
- Effective temperature difference = (10°C – 4°C)/2 = 3°C
- Effective time = 120 seconds (accounting for temperature rise and decay) Heat transferred:
Q = h × A × ΔT × t_effective
Q = 10 × 0.008 × 3 × 120
Q = 28.8 Joules
- Calculate temperature rise:
ΔT = Q/(m × c_avg)
ΔT = 28.8/(0.06 × 3392.4)
ΔT = 0.24°C
Therefore, the egg temperature rises by only 0.24°C, from 4°C to 4.24°C, during the entire 7-minute event. This small temperature rise can be attributed to:
- The high specific heat capacity of egg components
- The relatively brief exposure to higher temperatures
- The moderate heat transfer rate through air
- The thermal mass of the egg
This calculation supports the hypothesis that brief door openings do not significantly affect egg temperature, suggesting that storing eggs in the door of a refrigerator may not be problematic from a temperature stability perspective.
Comment on the calculations
Some may recall that when electronic calculators first came out in the late 70s (for me at least), there were many assertions that using them would ‘weaken brains’ and people would forget how to calculate things.
There was stigma mixed with skepticism about the use of calculators then. Recall that calculators were physical objects. Whilst there still are physical calculators that can be purchased in any branch of WHS, most people who have mobile phones will have calculators on them. Basic calculations can be done by pasting text into a browser search page e.g.: 1 + 1 will offer 2. Abilities to calculate ‘in the head’ may have atrophied to some extent but the principles of application of calculations remain the same and are not replaced by ‘the calculator’.
What we see now, with AI is something entirely different:
- AI knows the principles of mathematics.
- It knows how to apply those principles.
- It can calculate effortlessly like nobody’s business.
When Claude.ai was generating the code to do the calculations and draw the graphs above, it made some errors. But those errors were ‘self-detected’ before drawing the graphs. Read that again! That’s much better than many humans – who would continue on with their errors and recognise them perhaps at a late stage.
But it’s more serious! AI has knowledge of physics and can apply the mathematics to the physics. It can do that in novel situations such as that egg-cooling example in this article.
AI is generous in giving a simple calculation first but qualifying the result as simplified. I gave the AI a helping hand by providing the thermal properties of the components of a raw egg.
As AI’s capacity for managing computer code far exceeds mine, I could not evaluate the code. I then asked for the calculations in long form, as presented in the article.
In evaluating the calculations, I had to say that the principles applied were quite sound.
Further calculations showed that it may take 10 minutes for an average refrigerator to re-establish an internal air temperature of 4 °C (assuming external air temperature of 20 °C). However, that revised calculations did not lead to a significant difference in rise of internal temperature of the egg that was much greater than 1/4 of a °C. The shape of the graph (above you dummy) for 10 minutes is almost the same.
What does it mean
To deal with the issue of egg storage on fridge doors: The advice that one should never do that because of ‘dangerous risks’ is a load of rubbish. It is myth – it is something that has been repeated a zillion times on the internet, so it became a ‘truth’. That’s called post-truth. Not because a zillion people believe something means it’s true. The tendency to believe the zillions, is a herd instinct effect.
On the AI aspect of this: I am not saying that AI is 100% correct or close to that. However, it’s command of physics, mathematics and loads of other things is far superior to the average human out there. Some are unaware that ChatGPT passed the American Bar Exam in 2023.
The big issue is that we – everybody – has access to AI (Google provides it in its basic searches). It is an amazing new tool that surely exceeds the capabilities of a calculator. Caution: any powerful thing can be used to cause mayhem and destruction. That doesn’t mean it’s a bad thing. If you believe otherwise then all nuclear powerplants, cars, pencils, knives, razor-blades, stairs etc should be banned. Is tobacco a dangerous thing – killing approximately 100,000 people in the UK every year? How come it is sold legally?
AI software from DeepSeek, Google (Gemini), Claude.ai (backed by Amazon), Copilot (Microsoft) and ChatGPT(OpenAI) etc mean a major turn in evolution of the our species. We now have a tool to enhance our learning and expand our horizons – but for sure it will also be used to destroy lives. No AI is perfect – and I sacked ChatGPT some months ago for messing me around, and never went back. The next to get the sack is Gemini for similar messing around. Claude is gonna get the kick soon if they don’t stop limiting my interactions which are pretty lengthy. The new kid on the block – DeepSeek is in its early stages of development and yet it outperforms all the others from my use-case scenarios. It’ll be the last to get the sack.
