ChatGPT is a fun tool, but don't trust it too much.

in Hive Learners11 months ago

I will confess. I enjoy using ChatGPT

But a quick word of advice. Don't trust it too much and certainly Don't let it write your posts

Here is an example of why.

This morning I was playing around with an idea I have for a super cheap, very simple, smokeless cooking stove. As you can see it has a low flame and it was able to boil water fairly quickly. Cost of the stove: 3 used tin cans, some cardboard and some oil.

However, the stove is the subject of another post.

I was curious what the burn rate of the oil would be in order to boil one liter of oil. Now I know that oil has roughly 9 Calories per gram. (note the Calorie not calorie--I didn't know the capital "C" made a difference until recently..I still have a lot to learn).

  • 1 calorie will raise the temperature of 1ml (gram) of water by 1C while
  • 1 Calorie will raise the temperature of 1000ml of water by 1C

If one liter of water is at 20C then it should need 80 Calories to increase temperature to boiling (100C). Since oil has roughly 9 calories per gram I assumed I'd need to burn a little more than 9ml of oil to boil the water (9 x 9 =81..close to 80). But I would also need to compensate for specific gravity, losses in system, etc.

So for a second opinion and just to double check I thought I would ask ChatGPT :

theoretically how much oil would need to be burned in order to bring 1 liter of water to boiling if starting at 20C

ChatGPT
To calculate the amount of oil required to bring 1 liter of water from 20°C to its boiling point, we need to consider several factors, including the specific heat capacity of water, the latent heat of vaporization, and the efficiency of the heating system.

Specific heat capacity of water:
The specific heat capacity of water is the amount of energy required to raise the temperature of water by 1 degree Celsius. For water, this value is approximately 4.186 Joules per gram per degree Celsius (J/g°C). Since you specified 1 liter of water, which is equivalent to 1000 grams, we can use the specific heat capacity value to calculate the energy required to heat the water from 20°C to its boiling point.
Energy = mass × specific heat capacity × temperature change
Energy = 1000 g × 4.186 J/g°C × (100°C - 20°C)

Latent heat of vaporization:
Once the water reaches its boiling point (100°C at standard atmospheric pressure), it requires additional energy to undergo a phase change from liquid to vapor. The energy required for this phase change is known as the latent heat of vaporization for water, which is approximately 2260 Joules per gram (J/g).
Energy = mass × latent heat of vaporization
Energy = 1000 g × 2260 J/g

Efficiency of the heating system:
The efficiency of the heating system determines how much of the energy supplied by burning oil is effectively transferred to the water. Let's assume an efficiency of 80%, meaning 80% of the energy produced by burning oil is transferred to the water.
Total energy required = energy to raise the temperature + energy for vaporization
Total energy required = (1000 g × 4.186 J/g°C × (100°C - 20°C)) + (1000 g × 2260 J/g)
Total energy required = 335,440 Joules

Considering an 80% efficient heating system, we need to calculate the amount of energy the burning oil must produce:

Energy from oil = Total energy required / Heating system efficiency
Energy from oil = 335,440 Joules / 0.8
Energy from oil = 419,300 Joules

The energy content of oil varies depending on the type of oil, but as a general approximation, we can consider that 1 gram of oil contains approximately 40 megajoules (MJ) or 40,000,000 Joules of energy.

Amount of oil required = Energy from oil / Energy content of oil
Amount of oil required = 419,300 Joules / 40,000,000 J/g
Amount of oil required = 0.0105 grams of oil

Therefore, theoretically, you would need to burn approximately 0.0105 grams of oil to bring 1 liter of water from 20°C to boiling (100°C) at an assumed 80% efficiency.

It looks very impressive....but it is also totally wrong.

It told me 0.01grams. That would be off by by almost 1000x. It used latent heat of vaporization? Why? That's for energy required to turn water to steam but I want to heat it to boiling not boil it off.

Proof that just because it looks impressive that doesn't mean it is correct!

So I reworded the question.

User could re work the calculations instead using the fact that 1g of oil has roughly 9 kilocalories of energy and 1 calorie increases the temperature of water by 1C

ChatGPT
Certainly! Let's rework the calculations using the fact that 1 gram of oil contains approximately 9 kilocalories (kcal) of energy and 1 calorie (cal) increases the temperature of water by 1 degree Celsius.

Convert the energy content of oil to calories:
Since 1 kilocalorie (kcal) is equal to 1000 calories (cal), we can express the energy content of oil as 9000 calories per gram (9 kcal/g).

Determine the specific heat capacity of water:
The specific heat capacity of water is approximately 1 calorie per gram per degree Celsius (1 cal/g°C).

Convert 1 liter of water to grams:
Since the density of water is 1 gram per milliliter, 1 liter of water is equivalent to 1000 grams.

Calculate the energy required to raise the temperature:
Energy = mass × specific heat capacity × temperature change
Energy = 1000 g × 1 cal/g°C × (100°C - 20°C)
Energy = 80,000 calories

Convert the required energy to grams of oil:
Amount of oil required = Energy required / Energy content of oil
Amount of oil required = 80,000 calories / 9000 cal/g
Amount of oil required ≈ 8.89 grams of oil

Therefore, using the given approximation of 1 gram of oil containing 9 kilocalories of energy and 1 calorie increasing the temperature of water by 1 degree Celsius, you would need to burn approximately 8.89 grams of oil to raise the temperature of 1 liter of water from 20°C to its boiling point (assuming no phase change occurs) at an assumed 100% efficiency.

Now the answer is 8.89grams which is pretty much what I already said. Although I think I used a lot less words to get to that conclusion. So, I asked it why there was a mistake. Maybe my definition of calorie was wrong and...

User 8.89g of oil seems far different than the initial calculation of only a fraction of a gram. where is the error? ChatGPT Apologies for the confusion caused by the discrepancy in the results. Upon review, I made an error in the previous response.

To clarify the correct calculation using the given information:

The energy content of 1 gram of oil is approximately 9 kilocalories (kcal) or 9000 calories (cal).

The specific heat capacity of water is approximately 1 calorie per gram per degree Celsius (1 cal/g°C).

1 liter of water is equivalent to 1000 grams.

Calculate the energy required to raise the temperature:

Energy = mass × specific heat capacity × temperature change
Energy = 1000 g × 1 cal/g°C × (100°C - 20°C)
Energy = 80,000 calories

Convert the required energy to grams of oil:

Amount of oil required = Energy required / Energy content of oil
Amount of oil required = 80,000 calories / 9000 cal/g
Amount of oil required ≈ 8.89 grams of oil

Thus, the correct amount of oil required to raise the temperature of 1 liter of water from 20°C to its boiling point is approximately 8.89 grams, not a fraction of a gram as previously mentioned. I apologize for the confusion caused by the error in the earlier response.

At least the AI agreed that it made a mistake!

After that I asked ChatGPT how much oil it would need to maintain the temperature at boiling for half an hour (the time required to cook rice). Again it got the answer wrong




Why did I write this article?

I know there is a debate about the use of ChatGPT and AI on Hive.

I personally believe that each person should write their own opinions in their own words. I also believe that ChatGPT is a tool that can be useful when writing an article.

However, please be careful. It can make some good looking answers that are just flat out wrong.

And just for fun...

The same thing goes for Dall-E.

I asked it to make a cookstove out of two cans using oil and cardboard and it gave me this:

Wow... pretty sure none of those designs would be useful at all!

But still funny to look at.

Have a great day.

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Wow that's impressive knowledge you have.

 11 months ago  

I think my wife may argue my endeavors are a waste of time and space. However I still have fun regardless.

Thank you

 11 months ago (edited) 

You sure as hell know your Physics.

Logically, that amount of oil it specified to boil water is so off and impossible, just by looking at it. And also, really, no one asked to turn the water into steam as it started to factor in latent heat of vaporisation.

The thing about these AI tech at this time is that they don't actually know reality, and they only make use of data they have access to give their inference, results, answers, suggestions. Sometimes—as we have it here—they wouldn't even know that they're wrong, and the problem would lie where one doesn't fact-check or know things for themselves.

ChatGPT is an amazing tool, but AI isn't just at the same level of intelligence as we are. Although, I would say that their level of accuracy may depend on the input they get; that is, the question. One may need to be precise with their request to really help the AI help them. That's part why you needed to "reword" your request.

I loved reading this, man. Maybe it's because it is about two things that fascinate me—Physics and AI.