The size of the Internet – and the human brain

How many human brains would it take to store the Internet?

Last September I asked if the human brain were a hard drive how much data could it hold?

The human hard drive: the brainI concluded that approximately 300 exabytes (or 300 million terabytes) of data can be stored in the memory of the average person. Interesting stuff right?

Now I know how much computer data the human brain can potentially hold, I want to know how many people’s brains would be needed to store the Internet.

To do this I need to know how big the Internet is. That can’t be too hard to find out, right?

It sounds like a simple question, but it’s almost like asking how big is the Universe!

Eric Schmidt

In 2005, Executive chairman of Google, Eric Schmidt, famously wrote regarding the size of the Internet:

“A study that was done last year indicated roughly five million terabytes. How much is indexable, searchable today? Current estimate: about 170 terabytes.”

So in 2004, the Internet was estimated to be 5 exobytes (or 5,120,000,000,000,000,000 bytes).

The Journal Science

In early 2011, the journal Science calculated that the amount of data in the world in 2007 was equivalent to around 300 exabytes. That’s a lot of data, and most would have been stored in such a way that it was accessible via the Internet – whether publicly accessible or not.

So in 2007, the average memory capacity of just one person, could have stored all the virtual data in the world. Technology has some catching up to do. Mother Nature is walking all over it!

The Impossible Question

In 2013, the size of the Internet is unknown. Without mass global collaboration, I don’t think we will ever know how big it is. The problem is defining what is the Internet and what isn’t. Is a businesses intranet which is accessible from external locations (so an extranet) part of the Internet? Arguably yes, it is.

A graph of the internet

A map of the known and indexed Internet, developed by Ruslan Enikeev using Alexa rank

I could try and work out how many sites there are, and then times this by the average site size. However what’s the average size of a website? YouTube is petabytes in size, whilst my personal website is just kilobytes. How do you average that out?

Part of the graph of the internet

See the red circle? That is pointing at Technology Bloggers! Yes we are on the Internet map.

The Internet is now too big to try and quantify, so I can’t determine it’s size. My best chance is a rough estimate.

How Big Is The Internet?

What is the size of the Internet in 2013? Or to put it another way, how many bytes is the Internet? Well, if in 2004 Google had indexed around 170 terabytes of an estimated 500 million terabyte net, then it had indexed around 0.00000034% of the web at that time.

On Google’s how search works feature, the company boasts how their index is well over 100,000,000 gigabytes. That’s 100,000 terabytes or 100 petabytes. Assuming that Google is getting slightly better at finding and indexing things, and therefore has now indexed around 0.000001% of the web (meaning it’s indexed three times more of the web as a percentage than it had in 2004) then 0.000001% of the web would be 100 petabytes.

100 petabytes times 1,000,000 is equal to 100 zettabytes, meaning 1% of the net is equal to around 100 zettabytes. Times 100 zettabytes by 100 and you get 10 yottabytes, which is (by my calculations) equivalent to the size of the web.

So the Internet is 10 yottabytes! Or 10,000,000,000,000 (ten thousand billion) terabytes.

How Many People Would It Take Memorise The Internet?

If the web is equivalent to 10 yottabytes (or 10,000,000,000,000,000,000,000,000 bytes) and the memory capacity of a person is 0.0003 yottabytes, (0.3 zettabytes) then currently, in 2013, it would take around 33,333 people to store the Internet – in their heads.

A Human Internet

The population of earth is currently 7.09 billion. So if there was a human Internet, whereby all people on earth were connected, how much data could we all hold?

The calculation: 0.0003 yottabytes x 7,090,000,000 = 2,127,000 yottabytes.

A yottabyte is currently the biggest officially recognised unit of data, however the next step (which isn’t currently recognised) is a brontobyte. So if mankind was to max-out its memory, we could store 2,127 brontobytes of data.

I estimated the Internet would take up a tiny 0.00047% of humanities memory capacity.

The conclusion of my post on how much data the human brain can hold was that we won’t ever be able to technically match the amazing feats that nature has achieved. Have I changed my mind? Not really, no.

How much data can the human brain hold?

Last week I was listening to a really interesting radio programme, in which I heard a few facts that amazed me. Firstly, did you know that your brain has around one hundred billion (yes, 100,000,000,000) neurons. Each of those neurons are thought have tens of thousands of connections to other neurons. That means in your brain there are… a lot of connections!

Anyhow, in the radio show they also stated that a cubic millimetre of brain tissue contained a petabyte of data. Unless you know your bits and bytes, you might not realise what that means. To put it simply, one cubic millimetre of brain matter has the capacity to store all the digital images currently on Facebook, i.e. every image the social network has ever had uploaded. This is only possible thanks to the number of connections between brain cells.

All that in just one cubic millimetre of your brain! Gosh.

This got me thinking, how much data can the human brain hold? To start investigating this I first needed to brush up on my knowledge of storage units.

Bits And Bytes

Okay, lets start from the beginning. The smallest packet of data you can get is a bit, which is equivalent to one binary digit. A byte is equivalent to 8 bits of data, therefore a bit is equal to 0.125 bytes. Make sense so far?

In between bit an byte is the less well known nibble, which is equivalent to 4 bits. I suspect whoever invented bits, nibbles and bytes was either a little obsessed with food, or quite peckish at the time!

The next step up from a byte is a kilobyte, which is equal to 1,000 bytes in terms of storage space. If you wanted to talk about processing ability, one kilobyte is equal to 1,024 bytes – lets stick to storage though!

1kB = 1,000 (one thousand) bytes

This is still really tiny. To put it into perspective the size of a typical 80 word plain text email is around 10kb (or 10,000 bytes) – source About.com.

From kilobytes we climb to megabytes which equal 1,000 kilobytes.

1MB = 1,000,000 (one million) bytes

On my digital camera, I have it set to the highest quality and image size to 3264 by 2448 which produces images usually between 2 and 5MB. Quite big relative to a kilobyte.

The megabyte has nothing on the gigabyte though, which is 1,000 megabytes!

1GB = 1,000,000,000 (one billion) bytes

The maximum any CD ROM can hold is 900 megabytes of data which is 100MB less than a gigabyte. So a gigabyte is just bigger than a CD.

After a gigabyte comes a 1,000 times bigger terabyte.

1TB = 1,000,000,000,000 (one trillion) bytes

In my current computer I have a terabyte sized hard disk. Many computers come with terabyte or half terabyte hard disks nowadays, however go back seven or eight years and 80gb (8% of a terabyte) was around the average hard disk size, showing the advancements that have been made in just a few years.

Eventually we reach the petabyte, and you guessed it, it is 1,000 times bigger again.

1PB = 1,000,000,000,000,000 (one quadrillion) bytes

One petabyte is the amount of data one cubic millimetre of brain tissue can hold. That’s two petanibbles and eight petabits.

How Much Data Could A Brain Be?

There are so many factors which affect brain size that it is going to be hard for me to work this out with any sort of accuracy, but I will try. Ethnicity, gender and body size along with many other factors affect brain size. The amount of data the brain can store isn’t solely dependant on size, but lets ignore that for now. The average female brain is around 1130 cubic centimetres, whilst the average male brain is 1260 cubic centimetres. That said women have more connections between the two hemispheres than men do.

Averaging it out, that means that the average brain size is 1195 cm3. So how many cubic millimetres go into 1195 cm3? 1,195,000 – to be precise.

The brain is 1.2 zettabytes in sizeThat means that the human brain can store 1,195,000 petabytes of data! That is equivalent to 1.195 zettabytes, as an zettabyte is equal to 1,000,000 petabytes.

What Percentage Of The Brain Is Storage?

Not all of your brain is dedicated to storage though, meaning that 1.195 zettabytes isn’t true to the amount of data we can store. So, how much of the human brain is storage?

From my understanding, most memory processes and storage happens in the temporal lobe. This is approximately 25% of the brain – that is a very approximate percentage!

How Much Data Can A Brain Hold?

In order to answer the above question, I am assuming that 25% of the brain is dedicated to memory, whilst the rest is required for other functioning, and that the average brain is 1,195,000 cubic millimetres in size.

25% of 1,195,000 cubic millimetres is 298,750 cubic millimetres. If one cubic millimetre of brain tissue contains a petabyte of data then the average human brain is able to hold 298,750 petabytes of data.

298,750 petabytes of data is equivalent to:

  • 2,390,000,000,000,000,000,000 bits
  • 298,750,000,000,000,000,000 bytes
  • 298.750 exabytes (approx 300 exabytes)
  • 0.29875 zettabytes (approx 0.3 zettabytes)

So there you have it, were you to max out your memory, you could probably store around 300 exabytes of data.

To put 300 exabytes into perspective, one standard single layer Blu-Ray disc can hold 25GB of data – approximately 5 hours of HD video. Therefore your brains memory could theoretically hold 12,000,000,000 Blu-Ray discs – around 60 billion hours of HD video!

Will we ever be able to technically match the amazing feats that nature has achieved? I am not so sure you know…