Is anyone on this list using or involved with FORM?  Although the 
account below is for the popular press, the content is relevant, as is 
the retention, tenure, and promotion process for university-based 
faculty who often are the (sub)PI for a HEP experiment (sub-PI may mean 
PI on a grant that depends upon the overall collaboration to be fundable).

https://urldefense.proofpoint.com/v2/url?u=https-3A__www.quantamagazine.org_crucial-2Dcomputer-2Dprogram-2Dfor-2Dparticle-2Dphysics-2Dat-2Drisk-2Dof-2Dobsolescence-2D20221201_&d=DwIDaQ&c=gRgGjJ3BkIsb5y6s49QqsA&r=gd8BzeSQcySVxr0gDWSEbN-P-pgDXkdyCtaMqdCgPPdW1cyL5RIpaIYrCn8C5x2A&m=BVKcgRQ4MjUdslTNpZMW9YNlzNB_l1ZaqYbRjXw-F7AWZ0VY4Ie43vgk-HR5KTSl&s=O1GdXMWyirwUFfFFT0h4UfGn3RAU0ntgYkJTb_bJ_mY&e= 

particle physics
Crucial Computer Program for Particle Physics at Risk of Obsolescence
Maintenance of the software that’s used for the hardest physics 
calculations rests almost entirely with a retiree. The situation reveals 
the problematic incentive structure of academia.
Read Later

Particle physicists use FORM to calculate the precise probabilities of 
different particle collision outcomes by computing thousands of ways the 
collision could play out.

Kristina Armitage/Quanta Magazine
By Matt von Hippel

Contributing Writer

December 1, 2022

Introduction

Recently, I watched a fellow particle physicist talk about a calculation 
he had pushed to a new height of precision. His tool? A 1980s-era 
computer program called FORM.

Particle physicists use some of the longest equations in all of science. 
To look for signs of new elementary particles in collisions at the Large 
Hadron Collider, for example, they draw thousands of pictures called 
Feynman diagrams that depict possible collision outcomes, each one 
encoding a complicated formula that can be millions of terms long. 
Summing formulas like these with pen and paper is impossible; even 
adding them with computers is a challenge. The algebra rules we learn in 
school are fast enough for homework, but for particle physics they are 
woefully inefficient.

Programs called computer algebra systems strive to handle these tasks. 
And if you want to solve the biggest equations in the world, for 33 
years one program has stood out: FORM.

Developed by the Dutch particle physicist Jos Vermaseren, FORM is a key 
part of the infrastructure of particle physics, necessary for the 
hardest calculations. However, as with surprisingly many essential 
pieces of digital infrastructure, FORM’s maintenance rests largely on 
one person: Vermaseren himself. And at 73, Vermaseren has begun to step 
back from FORM development. Due to the incentive structure of academia, 
which prizes published papers, not software tools, no successor has 
emerged. If the situation does not change, particle physics may be 
forced to slow down dramatically.

FORM got its start in the mid-1980s, when the role of computers was 
changing rapidly. Its predecessor, a program called Schoonschip created 
by Martinus Veltman, was released as a specialized chip that you plugged 
into the side of an Atari computer. Vermaseren wanted to make a more 
accessible program that could be downloaded by universities around the 
world. He began to program it in the computer language FORTRAN, which 
stands for Formula Translation. The name FORM was a riff on that. (He 
later switched to a programming language called C.) Vermaseren released 
his software in 1989. By the early ’90s, over 200 institutions around 
the world had downloaded it, and the number kept climbing.

Since 2000, a particle physics paper that cites FORM has been published 
every few days, on average. “Most of the [high-precision] results that 
our group obtained in the past 20 years were heavily based on FORM 
code,” said Thomas Gehrmann, a professor at the University of Zurich.

Some of FORM’s popularity came from specialized algorithms that were 
built up over the years, such as a trick for quickly multiplying certain 
pieces of a Feynman diagram, and a procedure for rearranging equations 
to have as few multiplications and additions as possible. But FORM’s 
oldest and most powerful advantage is how it handles memory.

Just as humans have two types of memory, short-term and long-term, 
computers have two types: main and external. Main memory — your 
computer’s RAM — is easy to access on the fly but limited in size. 
External memory devices like hard disks and solid-state drives hold much 
more information but are slower. To solve a long equation, you need to 
store it in main memory so you can easily work with it.

In the ’80s, both types of memory were limited. “FORM was built in a 
time when there was almost no memory, and also no disk space — basically 
there was nothing,” said Ben Ruijl, a former student of Vermaseren’s and 
FORM developer who is now a postdoctoral researcher at the Swiss Federal 
Institute of Technology Zurich. This posed a challenge: Equations were 
too long for main memory to handle. To calculate one, your operating 
system needed to treat your hard disk as if it was main memory too. The 
operating system, not knowing how big to expect your equation to be, 
would store the data in a collection of “pages” on the hard disk, 
frequently switching between them as different pieces were needed — an 
inefficient process called swapping.

This xkcd comic illustrates the situation well.

xkcd.com

FORM bypasses swapping and uses its own technique. When you work with an 
equation in FORM, the program assigns each term a fixed amount of space 
on the hard disk. This technique lets the software more easily keep 
track of where the pieces of an equation are. It also makes it easy to 
bring those pieces back to main memory when they are needed without 
accessing the rest.

Memory has grown since FORM’s early days, from 128 kilobytes of RAM in 
the Atari 130XE in 1985 to 128 gigabytes of RAM in my souped-up desktop 
— a millionfold improvement. But the tricks Vermaseren developed remain 
crucial. As particle physicists pore through petabytes of data from the 
Large Hadron Collider to search for evidence of new particles, their 
need for precision, and thus the length of their equations, grows longer.

“These things will forever stay relevant, however large the memory 
grows, because there’s always a physics problem that can push it beyond 
the size of the memory,” said Ruijl.

Computer capabilities have grown roughly exponentially, doubling about 
every two years. But there are faster forms of growth than exponential 
growth. Consider the task of writing three letters — a, b and c — in all 
possible orders. There are three choices for the first letter (a, b or 
c), two for the second, and one for the third. The problem scales as a 
factorial, a mathematical relationship that grows even faster than 
exponential growth. Factorials show up often when you try to count 
possible combinations of things, such as all the different Feynman 
diagrams you can draw for a set of colliding particles. The factorial 
growth of these particle physics calculations outpaces the exponential 
growth of computing power.

As crucial as software like FORM is for physics, the effort to develop 
it is often undervalued. Vermaseren was lucky in that he had a permanent 
position at the National Institute for Subatomic Physics in the 
Netherlands, and a boss who appreciated the project. But such luck is 
hard to come by. Stefano Laporta, an Italian physicist who developed a 
crucial simplification algorithm for the field, has spent most of his 
career without funding for students or equipment. Universities tend to 
track scientists’ publication records, which means those who work on 
critical infrastructure are often passed over for hiring or tenure.

“I have seen over the years, consistently, that people who spend a lot 
of time on computers don’t get a tenure job in physics,” said Vermaseren.

“It’s more prestigious, maybe, to actually produce physical results than 
to work on tools,” said Ruijl.

While a few younger physicists like Ruijl work on FORM sporadically, for 
their careers’ sake they need to spend most of their time on other 
research. This leaves much of the responsibility for developing FORM in 
the hands of Vermaseren, who is now mostly retired.

Without ongoing development, FORM will get less and less usable — only 
able to interact with older computer code, and not aligned with how 
today’s students learn to program. Experienced users will stick with it, 
but younger researchers will adopt alternative computer algebra programs 
like Mathematica that are more user-friendly but orders of magnitude 
slower. In practice, many of these physicists will decide that certain 
problems are off-limits — too difficult to handle. So particle physics 
will stall, with only a few people able to work on the hardest calculations.

In April, Vermaseren is holding a summit of FORM users to plan for the 
future. They will discuss how to keep FORM alive: how to maintain and 
extend it, and how to show a new generation of students just how much it 
can do. With luck, hard work and funding, they may preserve one of the 
most powerful tools in physics.

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