Hi reddit! Very excited to be here today. We are:

  • Tiziano Camporesi, experimental physicist and Spokesperson of the CMS Collaboration (tc)
  • Nazila Mahmoudi, theoretical physicist (nm)
  • Giulia Papotti, accelerator engineer (gp)
  • Stefan Lüders, Head of Computer Security (sl)

We'll sign our posts with our initials so you know who said what. Just to be clear, we are speaking with you in our personal capacities and CERN does not necessarily support the views expressed during the AMA. Joining us are a few of our friends from CERN:

We'll answer your questions from 16:00 until 17:30 CEST (GMT+02).


About CERN

CERN is the European Laboratory for Particle Physics, located in Geneva, Switzerland. Its flagship accelerator is the Large Hadron Collider (LHC), which has four main particle detectors: ALICE, ATLAS, CMS and LHCb. Nearly two years ago, CMS and ATLAS announced the discovery of a new particle that we now believe is a Higgs boson.

In addition to the LHC experiments, we have dedicated facilities for studying antimatter, nuclear physics and climate science. Oh, and we also have a particle detector operating on the International Space Station!

For updates, news and more, head over to our unofficial home on reddit: /r/CERN!

Hangout With CERN

CERN has been running weekly Q&A sessions called Hangout With CERN where we bring you the latest news from CERN and answer your questions from social media live on air. HWC will return this Thursday at 17:00 CEST, discussing the latest physics results from the LHC experiments. Here's the schedule of upcoming Hangouts.

Get social!


Thank you, everyone! We really enjoyed this. That's all we have time for now. Don't forget to tune in to Hangout With CERN this Thursday and we'll answer more of your questions on the latest physics results from the LHC: Facebook invite / Google+ invite.

Comments: 2641 • Responses: 38  • Date: 

juanjoli1827 karma

Does the name Okabe Rintarou ring a bell?

askCERN2339 karma

SteinsGate, if I am not wrong. But we don't do time machines yet. Ask me again yesterday, if this has changed in five years.


shiiitpartner864 karma

How much political input/interference is there in your work? Given that so many nations contribute funding, does conflict ever arise in regards to what you can do?

askCERN1523 karma

There is fortunately no political input/interference in our work, and this is regardless of our origine or anything. What we do is just pure science! (nm)

SongOfUpAndDownVotes748 karma

How much hooking up goes on between the scientists at CERN? Please rate on a scale of "Frostier than Elsa's Ice Palace" to "Sexy Cheerleader Camp group cabin"

askCERN982 karma

What I can tell is that there is an intense social life at CERN which I would call inbred: the community at CERN is somewhat special ... Long hours spent at the lab, sometime a geeky attitude, does not favor contacts outside CERN ... end result: I know a lot of people who have found their companion within the community. (TC)

knoxtroll715 karma

What does it sound like when you turn it on? (Seriously)

askCERN833 karma

when we close the LHC after access, the access console beeps. when we send out timing events to synchronise the equipment, we have an announcer that speaks out a line, that recalls what happened.

for the rest, the control room is far from the equipment, so we don't really hear it... but colleagues told me that at the ISR (another accelerator at CERN), they could hear the beam being dumped with a low pitch boom :) (gp)

CountVonTroll317 karma

Would it be technically or bureaucratically difficult to install microphones to record it next year?

askCERN492 karma

we have had microphones installed, to listen to the sound of an asynchronous dump on the collimators :) (gp)

egozani145 karma

If you're referring to the 'sound' a collision makes, then it's non-existent, as it all takes place inside the beam-pipe, which is held in a vacuum.

However, as a Ph.D student there (in ATLAS), I can say that the experiment's control room (above ground, away from all that radiation) has some great 'sound effects' for the various stages of the experiment (ramping up the energy,start of collisions, dumping the beam when it's depleted).

hornwalker120 karma

Please explain what you mean by "dumping the beam when it's depleted". This sounds like something that is required after a jump through hyperspace, and sounds very interesting.

askCERN186 karma

the beam gets dumped whenever it is not interesting for physics anymore (and the operators decide to extract it), or whenever anything on the accelerator side goes wrong (and Machine Protection takes care of extracting it automatically).

by means of a special set of magnets, with very fast rise times, the beam gets extracted from the main ring to a special place, the beam dump itself, where it hits a huge block of graphite and scatters its energy.


Stoooooooo544 karma

What discovery/research should be getting more publicity than it is?

askCERN703 karma

We are doing a lot of research which does not get onto the blogs/newspapers: we have published more than 100 scientific papers on major peer reviewed journals.

Such papers are all about measuring the way Nature works at fundamental level. Today this kind of fundamental research can only be carried out in laboratories like CERN and it is our role to exploit such tools to provide mankind with these measurement which could be the basis of the future 'revolution' in understanding the inner workings of Nature. (TC)

Qzy239 karma

I'm just thinking out loud now: Might this complicate falsifying a scientific statement? If equipment for measurement costs so much (as CERN), how can other scientists replicate your results and perhaps falsify your conclusions?

Just curious - have you given that thought?

cc_cyanotephra544 karma

There are two huge collaborations at CERN (CMS and ATLAS) as well as a number of much smaller collaborations. Each collaboration works independently of each other and so their results can validate each others'.

(Not OP, btw, but...)

askCERN404 karma

Good answer ! (TC)

Philanthropiss499 karma

Do you guys do anything classified?

askCERN985 karma

CERN is an academic environment and we take lots of efforts to publish results, technical designs, etc. We do not do any military research. Therefore, there is few stuff being "classified". Sometimes, there is a period when we keep information internal until we are sure the results are correct. Thus, basically, you find only the "usual" classified stuff at CERN: payslips, medical records of our employees, passwords, financial information.


kuja_11186 karma

That and your time machine research.

askCERN1678 karma

Oh. Yes. But that has been handed over to SERN.


GOASTT372 karma

What is the most mind-boggling thing you have learned or experienced in your time working there?

askCERN558 karma

Diversity of cultures and being able to work with some of the most brilliant minds has been ( and still is after having been at CERN for 28 years) one of the things I consider a unique feature of CERN. (tc)

werktime364 karma

What is each of your's favorite work of fiction involving CERN?

askCERN639 karma

I personally love the big bang theory. I can offer a free tour of the LHC control room for authors and actors if they come over to Geneva. (gp)

askCERN228 karma

Bruno Arpaia's "Energia del Vuoto' : I have read the original italian book..do not know if it has ever been translated. (TC)

billyford290 karma

Do you have any advice for an undergraduate Physics student aspiring to one day work with you at CERN?

askCERN491 karma

Sure! Join CERN as a summer student (too late for this year, I fear) but what about 2015? You'll get hands-on at CERN: weeks of lectures in the morning by professionals, hands-on projects within different CERN groups on your favorite subject, and lots of networking and socializing in the evenings. Meet your peers from all over the world. Sign up here.


SolarGoat234 karma

I'm a physics undergraduate and I'll be making the move to Geneva to work at CERN for a year as a technical student in 2 weeks! I'm extremely excited.

How's the weather over there?

askCERN229 karma

Great! That'll be definitely fun! Wheather is sunny 30degC. Hope that stays!


IBProBro64 karma

Im educated in this field nor smart enough to really understand but i'd love to spend a summer there as a 40 year old summer student.

askCERN108 karma

Age does not really count. I have just seen a 40yrs old applicant to our Technical Student programme. But you would need to be enlisted with an university...


CapnBiscuit264 karma

What common misconceptions do people have about your work i.e. black hole makers?

What range of qualification and experience do you and your colleagues have?

askCERN417 karma

Common misconceptions are the widely advertised black-hole maker thing, but also the fear of us developing new dangerous 'stuff' (the fact that CERN is doing sub- nuclear research adds to the confusion). Another common misconception on the positive side is to think that we might develop the solution to the energy problems of the world. (TC)

u16173257 karma

How close are you to unifying gravity and quantum mechanics?

askCERN349 karma

Not very close yet... This is a big area of research, many people are working on it, there have been some progress already but still a lot of work is needed. (nm)

dwsr214 karma

What is the coolest thing you've ever had the chance to do in your work at CERN (besides smashing particles together, of course)?

askCERN533 karma

I love LEGO. When Google came around and was taking footings of the CERN Computer Centre for their Google Streetview, I had a chance to drop a few LEGO minifigs beforehand. Later we made a treasure hunt of it... Was quite fun. If you want to try yourself, go here. If you want to cheat, solutions are here.


quadtard197 karma

How often are you guys able to predict what discoveries you will make? For example, when you found the Higgs Boson there had already been predictions that it would be found at some point in time, as our technology improved. Are there any other examples of less well known, expected, breakthroughs and does the accuracy of these predictions vary from the different areas of research?

askCERN218 karma

It is a good question: the way we work is by theorist assembling the information that we , experimentalists, make into models. Such models besides explaining what we have already observed make also predictions which we try to verify ( the HIggs boson is a notable example). In terms of 'how often' this is the most common situation we are dealing in our daily research life.

There are many other questions ( like why there is an obvious asymmetry between matter and antimatter) where the model builders and the experimentalist are trying to bootstrap each other with continous progress in understanding.

And there have been times where experimentalists have surprised the theorists by discovering new particles which nobody had foreseen ( example the tau lepton) (TC)

SirLobito138 karma

i am a computer science graduate and will complete my masters next year. besides software engineering my other field of interest is physics. what kind of projects do i embrace so i can one day work at CERN with you?

askCERN188 karma

Computer science is everywhere at CERN! The massive amounts of data collected by the physics experiment must be filtered, transferred and stored. "Big Data Analytics" is a good start here. High bandwidth networking another. Mass storage (>100PB/year) a third.

Within the CERN openlab we work with third parties on such research --- so if you want to fiddel with hardware come here.

If you love software design, there are lots of opportunities, too: developping applications to run the LHC, to serve our physicist community, etc.

In brief: Make your field of interest a hobby and sign up as a student with CERN! A good master is an excellent start, but hands-on experience you just can get on the job.


askCERN113 karma

I've come to CERN for my master thesis in telecom engineering, as a technical student, I worked on optical links for CMS. I did also my PhD at CERN, in digital microelectronics. now I am hired as an applied physicist and work in the LHC control room. There is a very wide range of options here!

Definitely look at the student programs! (gp)

accountdureddit122 karma

Comic Sans. Why Comic Sans?

askCERN173 karma

Because "Arial" sucks, doesn't it?


Jux_101 karma

How much does your electric bill average each month?

askCERN141 karma

a figure I heard is that we use ~180MW on a good day… most of it taken by the accelerator complex. (gp)

Drivegrey101 karma

How strong is the firewall in CERN computer system?Does hacker often try to pringe into CERN sytem?

askCERN144 karma

Q: What is the purpose of a firwall? A: To let traffic through. If we don't need to let traffic through, we would cut the cable...

We use a standard firewall configuration to control traffic. As we serve a world-wide community, there are hundreds of computing services open to the Internet: web servers, SSH gateways, Windows Terminal Servers, conference room booking systems, document stores, web mail servers, etc...

Like any other organization worldwide, these are permanently probed for weaknesses. We monitor this activiely and, so far, successful attacks (detected by us ;-) have been rare.


showmethelove95 karma

What are you most excited to see happen in the near future concerning your respective fields of research?

askCERN151 karma

I can't wait to see the beam at high energy, early next year. on the accelerator side, we have a few things that might cause issues that we'll have to work on: electron clouds in the beam pipe, Unidentified Falling Objects, beam instabilities, … it'll be fun! (gp)

askCERN99 karma

Finding new particles that could confirm the predictions of the theories I am working on! That will allow us to finally know what is the correct direction to go beyond the Standard Model of particle physics! (nm)

karmanaut83 karma

How do you all decide what projects to study and work on? Are you pretty much given free reign? Is it based on budgetary constraints or what could have profitable applications? Is there someone in charge who gets to say "Hey, we should do more research into black holes" or whatever?

askCERN108 karma

As theorists, we are free to work on the projects we wish, depending on what we think more interesting or needed. Experimentalists however have also predecided projects to work on depending on the program and preiorities of the collaborations. We also have sometimes common projects between theorists and experimentalists. (nm)

ThatDeznaGuy81 karma

What do you hope to see happen within physics within your lifetimes? Is there a particular piece of the puzzle that you want solved for closure?

askCERN139 karma

There are many puzzles! One of the most intriguing ones though is the nature of dark matter. (nm)

LongLivetheD79 karma

Is there a secret duplicate LHC, like they did for the machine in the movie Contact, in case some crazy-ass incident occurs?

askCERN78 karma

No! (nm)

nesevis66 karma

What is it like to work at CERN? Schedules, workloads, commutes, social lives, etc?

askCERN103 karma

I love working here, the research and the international environment in particular. my schedule is messy when we have beam, as I take shifts in the control room. the rest of the time, it's normal working hours - which sometimes get extended in case of deadlines that come up.

I live, as many others, close by, so commuting is short (10 minutes). this June many of us are doing bike2work - so I biked in today, the weather is beautiful. my personal interests fit in well also. skiing is close by in between Swiss and French Alps, and the Geneva yoga festival is great too.


backlundt32 karma

So, now you have the higgs. what's next?

askCERN17 karma

We have to measure all the Higgs properties as precisely as we can! We also have new models to go beyond the Standard Model of particle physics and there are active searches ongoing at CERN to look for new particles. (nm)

ositola21 karma

What impact will funding have on future research?

askCERN30 karma

Today's fundamental research is based on tools which require investment (that has always been the case , but in the past this funding was at the level of individual research institutes or of national initiative). Today not even 'continental' investment can cope with the needs of fundamental research. So if we want to progress further there will be need of substantial investment. For example in the last 12 months it has been decided to exploit fully the potential of the LHC accelerator :in order to exploit the potential of the improved accelerator we will need improved detectors. These do not come for free ...

So yes, funding will be essential for fully exploiting what the LHC accelerator can tell us ( and that might be a lot ... as there a lot of unaswered questions like what is dark matter, why is our universe made of matter and so on ) (TC)

DyHydrogenMonoxide19 karma

Whats your favorite part out using scientific linux, or worst part? Btw, pretty cool that cern has adopted linux for research!

askCERN45 karma

I take the chance to point to this picture… I'm in it and the captions are not 100% true. (gp)

sylothix9 karma

How close are we towards a GUT? Is their some technical aspect holding us back or is it something else?

askCERN8 karma

No, I would say we have to verify the GUT model predictions experimentally at the LHC and there are ongoing searches... (nm)

xXGottXx6 karma

Whats the process of decieding which particles you smash together? do you just take random shit and throw it together or are there scientific reasonings for it?

askCERN9 karma

concerning the LHC, it was designed to do proton-proton, and lead-lead. then we also did proton-lead, and lead-proton, which is less obvious that what it sounds like.

I guess what I want to say is that it depends on the physics goals.


dClauzel4 karma

What are Les Horribles Cernettes up to? :)

askCERN4 karma

I missed out on their last show 'cause I was on shift at the LHC! (gp)