How Bad is ChatGPT?

I am not sure, but I can confidently say that it is not all good. It can lead one down the primrose path; indeed, this post is an example how the path leads to a sewage channel.

I do not know whether ChatGPT or any other such information-rich garbage software has ever claimed to give you the right answer when you approach it. I doubt it. Yet, it has cast such a wide net; everyone is bound to be caught in it. In fact, once your are in it, you cannot get out of it. The following is a true instance of ChatGPT (affectionately called uncle ChatGPT) leading an unsuspecting victim into the seines of illogic.

First, let me show you picture and then get on to the topic and then to the question and answer.

The pictures show what in the US is called a “semi” or “eighteen wheeler”, perhaps because it is made of two distinct and separable parts – the driver cabin and an attached extension having a total of three axels (ten tyres); the other part is the trailer with two axels, each carrying four tyres (total = 1 x 2 +2 x 4 + 2 x 4 = 18).

Now, my question was simple: as the truck is taking a curve (assume constant radius), there must be a force on it in addition to the force acting in the direction of motion. Please note that on a curve the direction of motion is changing continuously, even if the curve is part of a circle. Is this additional force on each tyre due to the curve directed towards the centre of the curve or away from it?

This is a simple question that could be asked in a 1^st year course in engineering, and I posted it to my colleagues (I was at that time teaching in a private university), in the School affiliated to civil engineering.

My former colleagues hated (and I mean it) to receive such queries from me; they may have seen them as one-upmanship, which it definitely was not. In the university, this course is taught in the first and second semester of students of engineering stream in 16 or 17 sections (60 students in each).

I have always claimed and I am reasserting it here: engineering education without the students going through the following two courses – Engineering Mechanics and Thermodynamics – are not fit to call themselves engineers.

Engineering Mechanics focuses on taking apart a situation and analyze the parts individually (or in appropriate combinations)  – Free Body Diagram (FBD) – to arrive at the desired solution. Reductionism is the name of the game here.

Thermodynamics takes precisely the opposite course. Take a beaker of water and try to model it as motions and interactions of individual molecules. It should beat the Hanoi Tower puzzle hands down. As an aside, it was Einstein who explained Brownian Motion, and he did it as merely as a particle suspended in a fluid and constantly being bombarded by the liquid molecules randomly.

Then, what the subject does is to designate some particular features – pressure, volume, temperature – of the subject in hand and relate them to the overall changes in the behaviour. This is holistic analysis, precisely countering the reductive method of Engineering Mechanics.

It is this point, with respect to Engineering Mechanics, I wanted my colleagues to tell their students and gave them an appropriate example.

One faculty member, higher up in the echelon, admitted that he could not answer, and I appreciated the honesty behind his admission. Yet, the next sentence just blew me away – he consulted “Uncle ChatGPT” which gave him the answer – which was not even wrong.

The answer given to him is precisely and by definition, a pseudo-logical argument. ChatGPT confidently told him that the inner tyres would experience an inward force towards the centre of the curve and on the outer tyres, the forces are directed outwards.

All the tyres, and I mean ALL, would experience forces that are directed inward. It is this force – named centripetal force in the fixed reference frame – that keeps the vehicle on track. I explained it to the faculty member, but he has not responded. In the mean time I have resigned from my academic position.

Hence I am free of any academic restraints.

You are invited to enjoy the post, though it is somewhat technical.. I have not seen any compare and contrast between the two basic analyses – one reductive and another holistic – anywhere. Perhaps I am still contributing to my chosen area of expertise.

ChatGPT offers you an instant answer but never guarantees its correctness. Reason enough for me to keep it at arm’s length.

Raghuram Ekambaram