May 26 2017, 20:31

A very interesting lecture on how the LHC works. Simply out of this world https://habrahabr.ru/company/yandex/blog/329132/

“That’s 40 terabytes of data per second. At the moment, we cannot process such a flow, although technically we are already approaching the capabilities.”

“You can imagine the size of a camera’s sensor. Here, it’s about 200 square meters of sensor. (..) The coolest thing about these experiments is their speed. They shoot at a rate of 40 million frames per second. (..) We can’t record that much; in reality, we record about 200–500 frames per second, but that’s still quite good.”

“The matter and energy that we observe is about 5% of what we measure through various gravitational observations. It’s like having a 20 square meter apartment, and you receive a heating bill for 1000 meters, and it’s correct, somewhere the extra square meters are being heated, only you don’t understand where.”

“We have about a million illuminated cells in the detector, which are recorded at a speed of 40 MHz. That’s 40 terabytes of data per second. (..) In 10 ms, you need to classify the data into interesting and not very. This is a typical classification task. We are now actively applying machine learning methods. We save one event out of a million. The remaining events are lost irretrievably. So it’s very important that this selection has good efficiency. If we lose something—it’s already irrecoverable.”

“For this, we need sufficiently powerful computer resources. High-energy physics uses distributed computer resources. On this slide, to give you an idea of the quantity, for the CMS collaboration, 120 thousand cores and around 200 petabytes of disk capacity are used.”

“CMS article, characterized as the discovery of the Higgs boson. (..) 36 pages. Half of them are the article, 136 references to scientific research and three thousand authors.”

“As an analogy: what we are trying to do is see a snowflake of a certain unseen shape in the light of a camera flash during a snowfall against a backdrop of a large snowy field. And honestly, I think the task with the snowflake I described is significantly simpler.”