Large Hadron Collider Week – Day 2

CERN has a reputation for being at the forefront of networking technology – “where the Web was born” is the lab’s motto. When it comes to Grid technology, this is particularly true: CERN is leading some of the most ambitious Grid projects in the world.

CERN has chosen Grid technology to solve a huge data storage and analysis challenge it will face in 2008, when the Large Hadron Collider, the biggest scientific instrument in the world, starts running. At that time, thousands of physicists around the world will start clamouring for access to the streams of data that will come out of the instrument. The data will be a goldmine for finding traces of new exotic fundamental particles of matter, which in turn will tell physicists a lot more about how the Universe was formed and what its future might be.

The data will be produced at about 10 Petabytes a year. That is more than 1000x the amount of information in book form printed every year around the world , and nearly 1% of all information that humans produce on the planet each year – including digital images, photos and what have you. In short, that is a LOT of information.

The only reasonable way to access this amount of information (actually, much more than this, since the cumulative data over more than a decade of operation will have to be stored) seems to be Grid technology.

So CERN has taken a big gamble on Grid technology, and is pushing the technology forward in several ways, in order to make the 2008 LHC deadline.

From the Gridcafe website (http://gridcafe.web.cern.ch/gridcafe/GridatCERN/gridatcern.html)

10 Petabytes. Like our last post, it is hard to imagine something this size. Lets try to put this is perspective.

If we put all of that data on 700MB CD-Rs, how high would the stack of CD-R’s be?

Lets assemble our data first:

CD-R capacity: 700 MB

CD-R Height: 1.2mm

1 Petabyte (PB) = 1,024 Terabytes

1 Terabyte (TB) = 1,024 Gigabytes

1 Gigabyte (GB) = 1,024 Megabytes (MB)

1 km = 1,000 m

1m = 1,000 mm

First, we should convert 10 Petabytes into Megabytes.

There are 1024 Megabytes in a Gigabyte. Since there are 1024 Gigabytes in a Terabyte:

There are 1024 * 1024 Megabytes in a Terabyte. Since there are 1024 Terabytes in a Petabyte:

There are 1024 * 1024 * 1024 Megabytes in a Petabyte.

That equals 1,073,741,824 Megabytes in a Petabyte. Since we want 10 Petabytes in total:

That means we are looking at a total of 10,737,418,240 Megabytes.

Next we need to know how many CD-Rs we would need to hold that much data.

Since 700 Megabytes fit on 1 CD-R, we simply need to divide that large number by 700.

10,737,418,240 / 700 = 15,339,168.91 CD-Rs.

Since we cannot have .91 of a CD-R, we round up.

15,339,169 CD-R’s

Next we need to convert 1.2 mm to km so we will not be working with astronomically large numbers.

There are 1000 millimeters in a meter. Since there are 1000 meters in a kilometer:

There are 1000 * 1000 millimeters in a kilometer.

There are 1,000,000 millimeters in a kilometer.

1.2 mm equals how many kilometers?

1.2 / 1,000,000 = .0000012 km.

So we know that we have 15,339,169 CD-R’s at a height of .0000012 km each. If we stacked them all up, how tall would it be?

We simply need to multiply these two numbers and that will equal our height in kilometers.

15,339,169 * .0000012 = 18.407 km.

Our stack would be approximately 18.4 kilometers tall.

That’s very tall considering Mount Everest is only 8.848 km tall. Our stack of CD-R’s will be over twice the height of the tallest mountain on the planet!

I hope that puts how much data the LHC will generate in perspective.

Please note that if you click the link below the article above, they state that the height will be approximately 20 km tall. There are a few reasons why our answers might be different. They might have rounded 18.4 to 20. They might have had a more precise number about the amount of data (example, 10.45 petabytes.) They might have had smaller CD-R’s in terms of data capacity. Or they might have had a more accurate measurement for the height of a CD-R (example, 1.24 mm). All of these would affect the potential height of our stack of CD-Rs. Regardless, the mathematical technique to find the height would be the same. Check back later this week for the conclusion to Large Hadron Collider Week!

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Large Hadron Collider Week – Day 1

The Large Hadron Collider

Our understanding of the Universe is about to change…

The Large Hadron Collider (LHC) is a gigantic scientific instrument near Geneva, where it spans the border between Switzerland and France about 100 m underground. It is a particle accelerator used by physicists to study the smallest known particles – the fundamental building blocks of all things. It will revolutionise our understanding, from the miniscule world deep within atoms to the vastness of the Universe.

Two beams of subatomic particles called ‘hadrons’ – either protons or lead ions – will travel in opposite directions inside the circular accelerator, gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams head-on at very high energy. Teams of physicists from around the world will analyse the particles created in the collisions using special detectors in a number of experiments dedicated to the LHC.

There are many theories as to what will result from these collisions, but what’s for sure is that a brave new world of physics will emerge from the new accelerator, as knowledge in particle physics goes on to describe the workings of the Universe. For decades, the Standard Model of particle physics has served physicists well as a means of understanding the fundamental laws of Nature, but it does not tell the whole story. Only experimental data using the higher energies reached by the LHC can push knowledge forward, challenging those who seek confirmation of established knowledge, and those who dare to dream beyond the paradigm.

From the LHC website. (http://public.web.cern.ch/public/en/LHC/LHC-en.html)

Another brief explanation:

The Large Hadron Collider is currently being installed in a 27-kilometer ring buried deep below the countryside on the outskirts of Geneva, Switzerland. When its operation begins in 2007, the LHC will be the world’s most powerful particle accelerator. High-energy protons in two counter-rotating beams will be smashed together in a search for signatures of supersymmetry, dark matter and the origins of mass.

The beams are made up of bunches containing billions of protons. Traveling at a whisker below the speed of light they will be injected, accelerated, and kept circulating for hours, guided by thousands of powerful superconducting magnets.

For most of the ring, the beams travel in two separate vacuum pipes, but at four points they collide in the hearts of the main experiments, known by their acronyms: ALICE, ATLAS, CMS, and LHCb. The experiments’ detectors will watch carefully as the energy of colliding protons transforms fleetingly into a plethora of exotic particles.

The detectors could see up to 600 million collision events per second, with the experiments scouring the data for signs of extremely rare events such as the creation of the much-sought Higgs boson.

From Symmetry magazine’s website. (http://www.symmetrymagazine.org/cms/?pid=1000095)

Today’s math:

These particles will be traveling at a hair less than the speed of light. It is difficult to put in perspective just how fast that really is. According to wikipedia, that speed is exactly 299,792,458 meters per second. We know from the above articles that the LHC is 27 km in circumference.

My questions are: How many laps will these particles make in one second? How can we put this in perspective?

We know that 27 km is 27,000 meters, so we simply need to divide the speed by the distance now that we have matched the units.

299,792,458 divided by 27,000.

I will spare you the long division and let you know the answer is in the range of 11,103.42 laps PER SECOND! When compared to the Indianapolis Motor Speedway at 2.5 miles per lap and an average race time of 3 hours, you realize just how fast these particles are moving. If you are looking at the collider when the particles are up to speed and blink, you will miss between 3300 and 4400 laps depending on how fast you blink. Imagine blinking during the Indy 500. You would not miss much.

The math and science behind the LHC, CERN, and the Grid that CERN utilizes are exciting and interesting and we will be looking at them this entire week. Thanks to Symmetry and the LHC website for the information used. Please take a look at them so you can be part of the excitement this summer when the projects run. Check back tomorrow where we will explore the tremendous amount of data that these experiments will generate.

Average MPH on my way to work using Public Transportation

Today, I would like to explore the rate at which one gets around New York City. I travel to work each day via subway, and I have always wondered what my average speed over the distance of my home to my office. According to www.hopstop.com, my work is exactly 2.58 miles from my home, taking the route it recommends, which happens to be the exact route that I take.

It says:

Walk 0.19 miles to the subway stop.

Travel 2.24 miles on the subway.

Walk 0.15 miles to my office.

It takes me around 25 minutes to make the full trip. How fast am I going?

Well this problem will resemble the last ones we did with percentages. We are looking for miles per hour which can also be stated like this:

Miles

———

Hour

How many miles will it be in one hour if 2.58 miles takes 25 minutes?

2.58 X

——– = ——–

25 60

Cross-multiply and we get:

25x = 60(2.58)

Simplify.

25x = 154.8

Divide both sides by 25.

X = 6.192

I travel at a rate of about 6.2 miles per hour to work. That might not seem like much but it is around twice the speed at which the average person walks. It is also a VERY short commute for living in Manhattan. Also, I am utilizing public transportation and not driving myself, thereby helping the environment.

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