## 1204: "Detail"

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Quicksilver
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### 1204: "Detail"

http://xkcd.com/1204/
Alt Text:"2031: Google defends the swiveling roof-mounted scanning electron microscopes on its Street View cars, saying they 'don't reveal anything that couldn't be seen by any pedestrian scanning your house with an electron microscope.'"
Why Planck lengths? I'm assuming the resolution refers to screen resolution, am I wrong?

rhomboidal
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### Re: 1204: "Detail"

It's so cool seeing my own bedroom. And epidermal ridges.

And I think Street View has plans to get even more intimately invasive.

Pfhorrest
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### Re: 1204: "Detail"

Quicksilver wrote:Why Planck lengths? I'm assuming the resolution refers to screen resolution, am I wrong?

It's referring to the smallest physical size which can be distinguished in the images on screen. Maximal resolution would be one Planck length squared per pixel.

It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel.
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edenist
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### Re: 1204: "Detail"

Quicksilver wrote:Why Planck lengths? I'm assuming the resolution refers to screen resolution, am I wrong?

It's not screen resolution. It's the resolution of the data which google has [ie: what is the smallest detail you can make out in their images? How big are their "pixels" in real space?]. You start from space, and can zoom in as far as you like up to their "current" resolution limit. Currently, its high quality overhead images from aircraft, or streetview.

The resolution of their images are far beyond the resolution of any monitor, but that's besides the point. It's referring to how far you can zoom in. Eventually, microscopic details? Individuals atoms that make up your house? The Planck length is the limit at which quantum effects take over, therefore making measurement impossible. Thus, it is simply the smallest unit which could ever be "measured" in the traditional sense.
Last edited by edenist on Fri Apr 26, 2013 4:21 am UTC, edited 1 time in total.

Quicksilver
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### Re: 1204: "Detail"

Pfhorrest wrote:
Quicksilver wrote:Why Planck lengths? I'm assuming the resolution refers to screen resolution, am I wrong?

It's referring to the smallest physical size which can be distinguished in the images on screen. Maximal resolution would be one Planck length squared per pixel.

It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel.
Ah, that makes a bit more sense. I knew it was a small unit, just wasn't sure how it applied to the context.

DeGuerre
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### Re: 1204: "Detail"

In my current job, I work with geographers. Geographers have a saying about Google Earth which goes something like this:

Google has undone 400 years of geography by deciding that the Earth is a sphere, because everyone else needs their data to work with Google Earth first, and anything sensible second. But, hey, they're Google, so they probably figure they can always fix the Earth later.

Man, I love geographers.

DeGuerre
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### Re: 1204: "Detail"

Pfhorrest wrote:It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel.

Repeat after me:

A pixel is not a little square.
A pixel is not a little square.
A pixel is not a little square.

(For those who don't get the reference.)

chairman
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### Re: 1204: "Detail"

Having worked with a fair bit of transmission electron microscopes, the alt text made me literally roll on the floor laughing. Well done Randall.

Eternal Density
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### Re: 1204: "Detail"

Relevant xkcd:
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Afrael
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### Re: 1204: "Detail"

Pardon my question.

Does the fact that Randall is using a log scale mean he is projecting an exponential growth of precision? Is that anywhere close to realistic?

Fire Brns
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### Re: 1204: "Detail"

"2031: Google defends the swiveling roof-mounted scanning electron microscopes on its Street View cars, saying they 'don't reveal anything that couldn't be seen by any pedestrian scanning your house with an electron microscope.'"
I read that as "Google defends themselves with swiveling roof-mounted electron microscopes" the first time through.
Would an electron microscope do enough damage to be used against hoards of people angry at the invasion of their privacy?
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ijuin
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### Re: 1204: "Detail"

Even with Street View and such, Google is never going to get coverage of the most sparsely-inhabited areas, so don't expect to get "full" resolution everywhere. Also, the increase in resolution will be limited by the increase in data storage/transfer technology--if your data storage medium could hold one bit per particle, then you would need a storage space the size of the Earth just to map the Earth to the particle level.

DeGuerre
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### Re: 1204: "Detail"

ijuin wrote:Also, the increase in resolution will be limited by the increase in data storage/transfer technology--if your data storage medium could hold one bit per particle, then you would need a storage space the size of the Earth just to map the Earth to the particle level.

Ah, but you only need to map the surface of the Earth.

(Of course, according to the holographic principle, that has the same information density as the whole Earth.)

poop
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### Re: 1204: "Detail"

"neghborhood" should have a red squiggly line underneath it.

ishep
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### Re: 1204: "Detail"

What's a "neghborhood"?

Clumpton
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### Re: 1204: "Detail"

"NEGHBORHOOD"?
Oh dear, a little detail that appears to have escaped everybody so far

Sebastiaan
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### Re: 1204: "Detail"

ijuin wrote:EAlso, the increase in resolution will be limited by the increase in data storage/transfer technology--if your data storage medium could hold one bit per particle, then you would need a storage space the size of the Earth just to map the Earth to the particle level.

Your first condition "if your data storage medium could hold one bit per particle" does not necessitate the second condition "then you would need a storage space the size of the Earth just to map the Earth to the particle level". The key here is lossless compression. We are often able to represent more bits in an exact manner with less bits, thus probably we could store a particle map* of the earth using less bits than the original piece of information.

Lets, for example, consider the bits of a raw wave audio sample as "sound particles". It is often fairly easy to store the configuration and identity of those bits using about 50-60% of the original amount of bits using a lossless compression algorithm such as FLAC (Free Lossless Audio Codec). Even if the earth was a completely random mess of particles, the sheer amount of particles makes it very likely that there are (pseudo-)patterns of particles that can be mapped exactly with less bits than the amount of particles represented.

*) Like the current day Google Maps, this map would not model the state of the earth at any given time point as most data points are sampled at a very different time point.

obarey
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### Re: 1204: "Detail"

I would rather see my neighborhood in live view, so I can see the traffic situation, and check if some shops are still open.

andyfrommk
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### Re: 1204: "Detail"

Anybody else spotted that he misspelled neighborhood?

taemyr
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### Re: 1204: "Detail"

Sebastiaan wrote:
ijuin wrote:Even if the earth was a completely random mess of particles, the sheer amount of particles makes it very likely that there are (pseudo-)patterns of particles that can be mapped exactly with less bits than the amount of particles represented.

No lossless compresion algorithm can achieve a average compression ratio better than 1.0 on random data.

time burglar
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### Re: 1204: "Detail"

andyfrommk wrote:Anybody else spotted that he misspelled neighborhood?

Yes, he forgot the u

It is some sort of profound joke - he's saying "there's no u or i in neighbourhood"?

Antior
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### Re: 1204: "Detail"

edenist wrote:
Quicksilver wrote:Why Planck lengths? I'm assuming the resolution refers to screen resolution, am I wrong?

It's not screen resolution. It's the resolution of the data which google has [ie: what is the smallest detail you can make out in their images? How big are their "pixels" in real space?]. You start from space, and can zoom in as far as you like up to their "current" resolution limit. Currently, its high quality overhead images from aircraft, or streetview.

The resolution of their images are far beyond the resolution of any monitor, but that's besides the point. It's referring to how far you can zoom in. Eventually, microscopic details? Individuals atoms that make up your house? The Planck length is the limit at which quantum effects take over, therefore making measurement impossible. Thus, it is simply the smallest unit which could ever be "measured" in the traditional sense.

This is not 100% correct. Quantum effects take over at a level way, way bigger than the Planck level. Quantum effects are important for subatomic particles such as electrons and even protons. A classical electron has a radius in the range of 10^-15 m, but that's including quantum uncertainty. Wikipedia says that the upper limit of its true radius is around 10^-22 m. To compare, the Planck length sits down at 10^-35 m.

The Planck length is the limit at which physics as we know them stop making sense. This is commonly interpreted as Planck length being the 'base resolution' of the universe. If the string theory is correct, strings exist at this level. Wikipedia does say that at this length, spacetime ITSELF becomes dominated with quantum effects, which I believe means that no possible predictions of anything could be made below this level.

Then, to get back to measuring for a bit. Measuring, in the practical sense means hitting stuff with other stuff and seeing how it reflects. Usually, this is light, but the problem is that the lowest possible resolution equals about half the wavelength. The wavelength of an electron is proportional to its kinetic energy, and with traditional electron microscopy techniques you can get down to at least the nano-level (organelles, nanotech) or the molecular level. Using quantum tunnelling microscopy or similarly advanced techniques it is possible to picture individual atoms. You can do the same thing with small-wavelength x-rays, although you need to use diffraction techniques in this case and you can only calculate the position of atoms, not actually picture them.

Anyway, to get smaller than the atom/electron level is very difficult. We'd need something with an even smaller wavelength, and then we'd need a way to measure the reflection of those waves/particles. Getting down to the Planck length would take a Planck length sized wave. If these exist at all, I would guess that they go everywhere except where you want because of incredibly strong quantum effects. So yes, the ??? in the comic are quite correct.

===

Anyway, electron microscopes only work in a vacuum environment, because electrons are reflected by air molecules. I am wondering how the Streetview car is going to make its environment a vacuum, and how this is not going to kill people.

YellowYeti
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### Re: 1204: "Detail"

Fire Brns wrote:
"2031: Google defends the swiveling roof-mounted scanning electron microscopes on its Street View cars, saying they 'don't reveal anything that couldn't be seen by any pedestrian scanning your house with an electron microscope.'"
I read that as "Google defends themselves with swiveling roof-mounted electron microscopes" the first time through.
Would an electron microscope do enough damage to be used against hoards of people angry at the invasion of their privacy?

Well a scanning electron microscope uses pretty much the same technology as an old CRT television, so subduing hoards of people and turning them into mindless couch potatoes is kind of what it does

speising
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### Re: 1204: "Detail"

Afrael wrote:Pardon my question.

Does the fact that Randall is using a log scale mean he is projecting an exponential growth of precision? Is that anywhere close to realistic?

he is making a bold projection from his three data points shown.

J L
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### Re: 1204: "Detail"

Jean Baudrillard wrote:When the map covers the whole territory, something like the principle of reality disappears.

Brace yourselves, the age of simulacra is coming ...

webdude
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### Re: 1204: "Detail"

Next time I need to ascertain the mass of a log, I'll be sure to use a log scale.
------------

Years ago I saw a box - a large crate, actually, a bit bigger than a large refrigerator/freezer. It was on a wheeled platform, and was being VERY slowly and carefully guided down the rather steep sidewalk towards one of the biology buildings. The number of men clustered around the crate seemed excessive - so many that some could not fit in to handle the crate, but were walking along, keeping an eye on the move. The men were so intent on their work I didn't want to interrupt them. I asked my brother, a Plant Sciences T.A., what was going on. He said, "oh, it's the new scanning electron microscope."

I asked why so they were using so many guys. My brother replied, "they dropped the first one; that's the replacement."

This was back in the days when you could easily buy three or four nice houses for the price of one SEM. Ouch!

Sebastiaan
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### Re: 1204: "Detail"

taemyr wrote:
Sebastiaan wrote:
ijuin wrote:Even if the earth was a completely random mess of particles, the sheer amount of particles makes it very likely that there are (pseudo-)patterns of particles that can be mapped exactly with less bits than the amount of particles represented.

No lossless compresion algorithm can achieve a average compression ratio better than 1.0 on random data.

Point taken, you're absolutely right, the counting argument. The thing is that we do not have to store any possible, random configuration of earth's particles, we might just start with one. Chances are* that there is an algorithm that can store that piece of information in less bits that piece itself amounts. This algorithm might be useless on another random configuration of Earth's particles, as on average no algorithm can achieve a compression ratio better than 1.0, but for a single configuration or a subset of configurations, you might find a more effective algorithm.

*) Indeed, chances are, not "there is a always a function that...".
Last edited by Sebastiaan on Fri Apr 26, 2013 9:32 am UTC, edited 1 time in total.

Wooloomooloo
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### Re: 1204: "Detail"

DeGuerre wrote:
Pfhorrest wrote:It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel.

Repeat after me:

A pixel is not a little square.
A pixel is not a little square.
A pixel is not a little square.

(For those who don't get the reference.)

That's either nitpicking or trolling, take your pick (yeah so I took the bait).

That paper is right that you need to think of pixels as point samples rather than small rectangles if you do image processing (including various rescaling etc.); which is nitpicking inasmuch that more mundane tasks involving images - like displaying them in a piece of software (copying / laying out the data in a grid) or editing them as super-high-zoom art ("pixel art") - can and does use the rectangle concept quite successfully. Even the paper itself admits that the most basic way to represent information encoded in pixels (the box filter) is, well, as rectangles of solid color - and as long as you're only handling but not resampling them, you won't need anything more elaborate.

The insistence of the paper on little rectangles not corresponding to anything physical in actual imaging gear is also rather questionably slanted and/or misguided - while we can argue all day in how a matrix of color data gets represented in circular triplets of phosphor or color subpixels of a pentile LCD (which were rather more relevant in the ole' days of the quoted "Sony Trinitron CRTs" of yore and such, and may or may not in fact need / employ some level of resampling of the ideal image data into viewable dots color), the truth is that the prevalent display technology of today - a uniform rectangular matrix of RGB subpixels (more often than not also rectangular-ish areas of liquid crystal) are pretty much exactly rectangular areas of uniform color; furthermore, against all contrary argument they absolutely DO correspond 1:1 to pixels these days - woe betide you trying to use your shiny new LCD monitor on something else than its native resolution (not to even mention downloading a piece of software to your smartphone that doesn't recognize you screen's PHYSICAL resolution correctly); since any non-1:1 representation does need a good resampling filter to not look horrible and even then won't ever look as sharp as 1:1 mapping no matter how good the filter is, that's exactly what gets preferred if possible. One pixel to one RGB rectangle...

So yeah - do you do math on your image? Are you trying to resize it? Display it on an exotic subpixel geometry? Sure, grasshopper, don't think of pixels as rectangles. Everybody else? Oh just get a life...

And to not be completely off-topic: the atmosphere hindering electron scanning? Bah, you just have to think big:
1) Offer a promotional (and compulsory) visit to Mars to the entire population of Earth (fine, the Moon will do too...)
2) Briefly borrow (or build) the giant vacuum from Spaceballs to temporarily remove and store Earth's atmosphere
3) Let loose the Google e-scanner cars (driverless autonomous ones of course - don't they already have that?) on the deserted planet
4) Profit!!! When everyone returns, present gorgeous electron-scanned map.
Surely that's nothing for a giant with a vision like the Goog...

P.S. Wildlife...? What wildlife?!? I swear, officer, it was like that when I found it...!

Klear
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### Re: 1204: "Detail"

Eternal Density wrote:Relevant xkcd:

Also this:

The previous two seem much funnier to me than this one =(

Tar
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### Re: 1204: "Detail"

time burglar wrote:
andyfrommk wrote:Anybody else spotted that he misspelled neighborhood?

Yes, he forgot the u

It is some sort of profound joke - he's saying "there's no u or i in neighbourhood"?

Haha, maybe that's why the comic is called 'Detail'

Kit.
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### Re: 1204: "Detail"

DeGuerre wrote:
Pfhorrest wrote:It's basically "how far can you zoom". A resolution of one meter would mean everything within a given 1m square on the ground would show up as just a block of a single color, i.e. one pixel.

Repeat after me:

A pixel is not a little square.
A pixel is not a little square.
A pixel is not a little square.

(For those who don't get the reference.)

Microsoft at its... well, not exactly worst, but you got the idea.

A pixel is a little square (rectangle, actually, but anyway). If you want to describe images in something that is not little squares, go find your own word.

peewee_RotA
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### Re: 1204: "Detail"

I'm sure that Randall's house has some kind of crazy joke on street view. Most likely he has a sign that says:
3.14159765358979

Pi to the 14th decimal place.
One digit is wrong.

The next street view image in the sequence is from a completely different season, and shows tire tracks leading off into a ditch filled with the charred rubble of at least 2 google street view cars.
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andyfrommk
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### Re: 1204: "Detail"

time burglar wrote:
andyfrommk wrote:Anybody else spotted that he misspelled neighborhood?

Yes, he forgot the u

It is some sort of profound joke - he's saying "there's no u or i in neighbourhood"?

Being British, I almost spelt it that way.
I think there hidden depth in every XKCD comic that I don't get

ctdonath
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### Re: 1204: "Detail"

Running the numbers, and assuming 24 bits per pixel, I'm coming up with 5.8573561e+90 pixels at the ultimate uncompressed resolution. Someone check my math.

philsov
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### Re: 1204: "Detail"

Would an electron microscope do enough damage to be used against hoards of people angry at the invasion of their privacy?

Not directly, at least against a horde.

But something to remember is air pressure. A good SEM operates in a vacuum. Being below 1 pascal of pressure will cause damage to a horde of angry people
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sep332
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### Re: 1204: "Detail"

andyfrommk wrote:
time burglar wrote:
andyfrommk wrote:Anybody else spotted that he misspelled neighborhood?

Yes, he forgot the u

It is some sort of profound joke - he's saying "there's no u or i in neighbourhood"?

Being British, I almost spelt it that way.
I think there hidden depth in every XKCD comic that I don't get

I think you mean "spelled"

The Plank length is just one of the Plank units https://en.wikipedia.org/wiki/Planck_units which are derived from universal constants instead of "how big is the king's foot" or "how far is it from the equator to the pole" kind of units.

thevicente
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### Re: 1204: "Detail"

Antior wrote:The Planck length is the limit at which physics as we know them stop making sense.

Measuring, in the practical sense means hitting stuff with other stuff

Anyway, to get smaller than the atom/electron level is very difficult.

Oh, hey i didn't see you guys all the way over there. http://xkcd.com/435/

RogueCynic
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### Re: 1204: "Detail"

Just let me know when Google can tell me when I have a booger hanging from my nose.
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chaosmage
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### Re: 1204: "Detail"

My life is complete, I found a typo on xkcd.

There's an I missing in "NEGHBORHOOD".

ctdonath
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### Re: 1204: "Detail"

RogueCynic wrote:Just let me know when Google can tell me when I have a booger hanging from my nose.

Google search roguecynic "I have a booger hanging from my nose" already does.