Question: is their any mathematical , scientific rules / formulas that you use at work and how do you apply them to your work ?

Nathan Langford answered on 27 Jun 2012:

Hi zmzmzm,

As a physicist, I use mathematical and scientific rules and formulas in my work all the time. One of the most important thing about using rules and formulas is that it’s really important to try and understand the physical meaning behind them. There are so many of them, that it’s almost impossible to sit down and just try and memorise them… and also, when you come to using them every day, just having them memorised doesn’t necessarily help you understand how to use them. But if you think hard about the concepts and ideas that the formulas are based on (and which are usually much easier to remember once you understand them), then you can often work out the formula yourself anyway and you can certainly understand how to use them better. When you’re working as a scientist, you can always go to a textbook or even google or wikipedia to look up exactly what a formula is, but you can’t do that unless you try to think about the concepts.

I’ll give you a couple of quick examples of specific simple formulas I use a lot.

1) When I was working with lasers, I often had to use Snell’s Law of refraction: n1 sin a1 = n2 sin a2. This told me how my laser beams would travel around the experimental set up, so that I could design how I would align them properly.

2) In my new job, we work with electrical circuits all the time and probably the most important rule we use *all the time* is Ohm’s Law: V = IR (voltage = current x resistance). Many of the measurements we make are voltage or current measurements and we need to know this law to be able to calculate the answers to our measurements from the actual numbers we measure.

Remember, the most important thing to doing science, and particularly physics, is not to be able to know formulas, but to be able to understand ideas.

Cheers,
Nathan.