1 December 2009

The life of an experiment

From idea to published paper, every experiment follows a similar path of inquiry.

By Amy Mast, This email address is being protected from spambots. You need JavaScript enabled to view it.

A scientist has an idea, does an experiment, gets a result, and writes a paper about it. Simple, right? Yes – and no. If you've ever hung out with a little kid who asks "why" over and over and over for every answer you give, it's more like that. From the time a scientist finds a question he or she wants to ask, to the time the answer to that question is publishable as a paper, several people, states and countries can be involved, and each question only leads to asking more.

Stuart BrownUCLA physicist Stuart Brown works on an experiment in the MagLab's DC Field Facility. As the director of DC user programs and as a researcher himself, Eric Palm knows a thing or two about the process of planning, guiding and publishing an experiment. Rather than a straight line from start to finish, he describes the process of gathering data as circular.

"With any halfway decent experiment, you end up with more questions than you answer, and that's the cool thing about science," said Palm. "Science isn't about determining actual truth – it's about getting to our best understanding of the world we live in. We can get to a better and better understanding, but each new level kind of brilliantly reveals all these things we still don't know."

Users who come to the Magnet Lab are in the experimental, data-gathering phase of this process. Stuart Brown of UCLA is a longtime user who makes his living learning about how matter behaves at very low temperatures. He visited the lab this fall, using a resistive magnet to discover more about the properties of a superconductor he finds exciting.

A TYPICAL EXPERIMENT INVOLVES

  1. Asking a question.
  2. Deciding which tools will be best to get an answer.
  3. Requesting magnet time and scheduling a trip to the lab.
  4. Working with his own team, plus magnet lab support staff, to gather experimental data.
  5. Going home with the data and figuring out what it means.
  6. Assembling data into a paper that includes the original question, a description of the experiment and figures.
  7. Submitting the completed paper for publication.
  8. Making any changes reviewers suggest.
  9. Celebrating!

If they were on a soap opera together, superconductors and magnets would have a stormy relationship. Magnetism has a nasty tendency to kill superconductivity, and Brown's at the lab to study a superconductor that performs better than usual in a high magnetic field.

For his experiment, Brown is using the magnet in cell 7, set to a magnetic field between 15 and 30 tesla. This magnet is ideal for experiments when a user needs to be able to note all the subtleties of his or her data.

About 1,000 users such as Brown gather data at one of the lab's seven user programs each year. All prospective users apply for magnet time, then wait to see if they're one of the 25 to 50 percent whose applications are accepted. Because magnet science is a comparatively small field, most users have been here before (though about 1 in 5 resistive magnet users during the past year were making their first trip).

"With the type of experiments that I do, from start to finish it can take a couple of years before I'm ready to share some data," Brown explained. "You can conjecture at first but you don't know what's going to happen when your sample goes into the magnet, and you have to have the patience to see where it takes you. There are always unanticipated circumstances, because you're not measuring where someone has been before."