[kemiller2002]

I had a girlfriend who was doing her PhD in Physics. I remember one night she and her classmates spent all night working on a problem, that was essentially unsolvable. The next day they go to class and all of them made their best attempt, but no one could complete it. The problem? The professor accidentally used the wrong metric on one of the numbers meaning that they couldn't do the steps to what should have been an easy solution. Now they noticed this, they are a smart group of people, but that's not what the problem was, so they spent hours and hours trying to solve what he gave them without any hope of actually doing it.

In the end, he was like "Oh my bad," and corrected his mistake. The point of the story is that they were able to essentially ask him for the solution and they were able to check what they'd done, and in the end he made the mistake. In situations like this, he should provide the answer if nothing else to show that he didn't make a mistake in the problem set. People are fallible, no matter how brilliant you are.

[bradleyjg]

I had a similar thing happen in high school physics. We were were suppose to figure out where and when a projectile was going to land. The only problem was that it was never going to land—-the initial velocity was too high.

In retrospect I think it was a great lesson for my future career as a data engineer. Doesn’t matter what the source is, any datum can be just plain wrong.

[saagarjha]

> The only problem was that it was never going to land—-the initial velocity was too high.

As in, it escaped the gravitational field?

[bradleyjg]

Yep.

[daveFNbuck]

That professor probably had produced the answer already, using the metric he had initially intended. Having a set of answers doesn't mean you didn't make a mistake in the questions.

[saagarjha]

But it does clue you into whether the professor used a different set of assumptions than you did.

[daveFNbuck]

Presumably you wouldn't see the answers until after you spent all night on the assignment.

[specialist]

There's a story of a prof injecting one error into every test.

I had a industrial engineering teacher that did something similar. Every team had a (fake money) budget for each project and bought materials from him (sole source). He'd randomly cut corners, to keep everyone on their toes. Good lesson for the real world.

[skookumchuck]

On the other hand, struggling all night to solve an un-solvable problem is a valuable learning experience, too. In the real world we struggle all the time with problems that don't have solutions.