Edited to remove link to video that was in the original article anyway.
It would be heartbreaking to be told that what you are working on could never succeed--but not anywhere's near the pain you feel when, at long last, a death march comes to an end.
A good start is asking what the fundamental uncertainties are and which ways there are to resolve them. Try to formulate these uncertainties in terms of physical, mathematical, or otherwise experimentally established laws.
From what I understand, this is one thing Elon Musk is decent at, answering "is there any world in which this would even be physically possible, given no constraints on the innovation we can do"?
In a more fluffy example, I started out on a project recently and realised that if I improve on the state of the art along only one dimension, I don't think the product will be good enough to gain traction. So I need to outperform the state of the art along at least two dimensions -- this is significantly harder and I now doubt my ability to do this with the resourcew I'm willing to spend on it. That reasoning requires no technical knowledge, just thinking about the fundamentals of market adoption and what the end product could look like under no constraints on innovation.
Because it was important for the students to have their names on a published paper, we did not abandon our calculations immediately. We finished them and wrote a long paper that was duly published in the Physical Review with all our names on it.
Isn't that shameful for the advance of science? Publishing something that you know is most certainly wrong.But also, even in the other way, this is not a scientific experiment that failed. It is more like a non sense mathematical demonstration with some magic variable that were made up to get the expected result. So it does not really have any value except the content of the current article.
For example if I do a paper like: "Getting a glass of water from starting a TV"
We were able to demonstrate that we can get a glass of water by starting a tv with the following steps: - take the tv remote - power on the tv - assume we have XX - result: we have a glass of water - note: we considered XX to be "Michel brings us a glass of water" for this experiment. - note2: famous mathematician told us that our study is gargabe
Also, probably anything written by Freemon Dyson would be worth reading, just to see how a top-flight might engages with the subject matter, if nothing else.