Building construction is actually a good analogy.<p>For stuff that&#x27;s been built a thousand times, you can state with a fair amount of confidence how long a project should take and how much it should cost. You can obtain financing and insurance because the dataset is large enough.<p>For stuff that&#x27;s unusual or bespoke -- the kind of thing that will appear in an architecture magazine or in a newspaper investigatory report -- then estimates are very likely to be wildly optimistic.<p>So it&#x27;s the same, insofar as the further you stray into research, the less certainty there is. The bigger the bet, the fewer such things have been built, the bigger the risk will be that things go awry.<p>I have a book in my collection -- <i>Industrial Megaprojects</i> -- which makes fascinating reading for enumerating all the ways that chemical process plants, giant mines, gas pipelines, gigantic factories etc can blast through the budgets and schedules.<p>My personal favourite: a chemical plant built relying on an adjacent river for cooling. To save costs, only one water temperature sample was taken during planning ... in winter. Three billion dollars later, the owners found that the plant was inoperable for about half the year because the river water was too warm.