My PhD in 11 limericks

For the next part of my attempt to write 30 Physics themed limericks in a month, I turned to some more recent inspiration – my own PhD! So here it is, years of work summed up in 11 limericks!

19 My PhD part 1

This is pretty much just a summary of what I was studying – usiing an LED-like structure in a semiconductor, but modified to try to ensure I only got the smallest possible amount of light out of it at a time – 1 photon.

Let me tell you of my PhD
And making a strange LED
Just one photon of light
At a time would be right
I studied this for a degree!

20 & 21 My Phd Part 2 – in the clean room

I quite enjoyed the days in the clean room, working methodically through the steps to prepare my samples. At least when things worked and I didn’t accidentally ping my sample off into the deepest recesses of the room when trying to pick it up in tweezers. And working with hydroflouric acid was quite worrying too…

The clean room’s a very strange place
My suit covers all but my face
But it has the tech ample
To prepare my sample
And make sure its workings are ace

Now working in there takes some care
As dangers may lurk everywhere
There’s acids and more
But we’re trained before
So accidents should be dead rare

22 & 23 My Phd Part 3 – Setting up the experiments

The wonders of liquid helium, cooling down my sample to near absolute zero to try to avoid getting any thermal noise (basically just random effects due to hotter things having more energy) affecting my experiments. And then the tedium of trying to align all of the lenses and mirrors so that I could be sure my readings were from the right place of my sample. Two abiding memories of being in the lab!

Getting my sample to cool ain’t a breeze
Any water around will just freeze
First I pump out the air
And when there’s none there
I’ll cool it to a few degrees

With a laser I must then align
All these lenses and mirrors of mine

So the light from my dot
Goes to the right spot
A high reading will be a good sign!

24 & 25 – My Phd Part 4 Measuring in the dark room

And then came the long measurements, because if you’re trying to get just one particle of light at a time, it can take quite a while to measure enough of them! The “dots” referred to here are “quantum dots” – tiny blobs of one semiconducting material inside another, capable of trapping just one or two electrons – precisely what I needed.

I sit on my own in the dark
For some results that will make a mark
But I have a plan
Different dots I will scan
Until one my interest does spark

But even once one dot is picked
The problem is still not quite licked
Correlations take time
So I know that I’m
Stuck here until that box is ticked

26 – My Phd Part 5 – Data Analysis

Raw results are one thing, but until you put them in a form that you can interpret, they aren’t much good. That’s where using a computer to fit all the individual points into a nice peak can help you find out how clear your results are. Or not, sometimes.

Of the results I’ve got an impression
But to check it will take a new session
All my data I’ll mine
Checking widths of the line
By running a linear regression

25 & 26 – My Phd Part 6 – Writing a paper

At long last it’s time to write up the results and send them off to be published. Or more accurately, send them off for someone else to look at and tell you that you need more data, or they don’t like the way you’ve explained them, or something else. Then, eventually, after you’ve made enough changes to make them happy, the results actually can be published.

Months of toiling must then be compressed
And sent off for peer review test
We get a decision
This needs a revision
If it is to be at its best

Took so long just to get this review
And now we must write up anew
Take it all bit by bit
So the new stuff will fit
When they say it is fine we’ll say “phew!”

27 – Writing a thesis

And then having written your results up for a paper, you have to do it all again (along with all of the work you did to get there that wasn’t novel or interesting enough for a scientific journal) for your PhD thesis. I think everyone hates this part, and I was not unusual in that regard!

You might think you’re nearly done when
One document there’s left to pen
But this order is tall
When you must show all
Of your work explained yet again

28 – The viva

This is the exam – two experts in your field, from your university and another, come and talk to you about it. Then they can decide if you’ve done enough to be called “Doctor”.

One examiner there is internal
The second instead is external
For some hours or more
You may be quite sure
Of a grilling that is quite infernal

29 – Corrections

At least once you’ve done the tidying up they ask for. Nearly everyone gets asked to make corrections to their thesis, although I do know one person who avoided this. I was jealous.

If you pass you might think you are set
But your writing may not be done yet
Some errors remove
Some sections improve
Your doctorate then you can get!