When the UK's Sir John Gurdon won the Nobel Prize along with Shinya Yamanaka, it acted as a reminder that the practical use of scientific discoveries can take decades to reveal themselves.
Gurdon's work used frogs to prove that a single cell in your body contains all the DNA you need to make another you. Taking a cell from the intestines of a frog, he inserted the genetic information within into a frog egg, creating a clone frog. The same technique was used by the next generation of scientists to make Dolly the Sheep in 1996.
Forty years later, Shinya Yamanaka built on Gurdon's work to 'reset' cells. The cells in our body start out as stem cells, before specialising to do different things. Prof Yamanake managed to reverse this process, to render specialised cells in a state where they could develop into anything. This is particularly exciting for medicine, for a number of reasons. As Yamanaka himself puts it "My goals over the decade include to develop new drugs to intractable diseases by using iPS cell technology and to conduct clinical trials using it on a few patients with Parkinson's disease, diabetes or blood diseases."
In the same way that Prof Yamanaka's work was informed by the breeding of that cloned frog 40 years previously, Prof Gurdon was himself inspired by other scientists including Robert Brigg, Thomas J. King and Donald D. Brown. What this again shows is the incremental nature of scientific discovery, with different scientists, often across different generations, each providing a piece of the puzzle.
In that sense, there is really no such thing as a failed experiment - an experiment shows something to be the case or not and sometimes leads to surprising discoveries that could not have been foreseen. The sequence of discoveries that led to breast cancer drug Herceptin, for instance, started decades earlier with the discovery of a mouse hormone, which is not in itself particularly useful.
Scientists are often criticised, particularly by people with only a lay understanding of their work, because people cannot see the immediate application of their research, but this does not mean that there will not be an application in the future.
Some benefits, of course, are obvious, such as vaccines. Dolly the sheep was killed by the JSRV virus, which causes cancer in sheep if contracted and for which there is currently no vaccine. In contrast, Western lowland gorillas, which have lost 25% of their natural population to the Ebola virus in recent years, can be treated with the human Ebola vaccine. What seems clear in this respect is that all of nature is in an arms race against communicable diseases and mankind is more or less doomed to be forever working on developing new treatments to emerging natural threats to humans, animals and the environment.
However, other discoveries take longer to become practical. Work done involving animals in the 1970s, for example, is now used to keep premature babies alive. Back then, protesters were calling for that work to be stopped because it involved animals, yet this research will be a gift that keeps on giving as generations of children benefit. Imagine, too, that scientists discovered that when testing a potential cure it caused other health problems - the drug trial might be considered a commercial failure, but its scientific value and its value to you and I is nevertheless considerable.
Every life scientist is standing on the shoulders of the previous generation. As we make ever greater inroads to understanding the functioning of living bodies, we should remember that, just because the utility of a piece of knowledge is not yet clear, doesn't mean the process of obtaining that knowledge can be considered a waste of time. We should always bear in mind that, when thinking about science, There Is No Such Thing As A Failed Experiment.