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I dunno, but it seems to me universities increasingly focus on press releases and marketing departments... 5D and 13.8 billion years? Phony. I know no sane sci

I dunno, but it seems to me universities increasingly focus on press releases and marketing departments... 5D and 13.8 billion years? Phony. I know no sane scientist or enigneer that would say they use more than 3D physics. Sounds like catch phrases to sell. With such logic plain old HDD is at least 4D, because it uses CHS coordinates and magnetic orientation, to store data. To me such communication style undermines the real scine behind it. Do they have nothing better to brag about than excuses to call invention 5D? Why introduce such noise?

nathanyukai 7y ago
Yeah isn't this '5D' yet another eye grabbing title? I think size and orientation are still 3D data.
- lvh 7y ago
  And yet, in machine learning we regularly talk about dimensions 100 and above! Just because they eventually map to three special dimensions doesn’t mean it’s not useful to talk about the different degrees of freedom you’ve managed to use for storing information. What were y’all expecting? Spider-Man: Into The Spiderverse?
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jarfil 7y ago
Heads is a low resolution dimension, so CHS should probably be more like 2.5D. Magnetic orientation is just binary, so not a dimension. The 5D in the article is kind of fishy, but in this case size and orientation are more of a low resolution dimension like multi-level cells in a flash drive.
- parksy 7y ago
  If it's a property of an object that defines the object, it's a dimension. Spatial location gives us 3 dimensions, rotation and size give us 2 more. The dimensions don't all have to use the same units.
dosshell 7y ago
Just speculating, but if you can index in 5 dimensions to get your data, should it not be called 5D? data = read_bit(x, y, z, yaw, size) But i agree, i would appreciate more information if they are going to use buzz-words.
- theclaw 7y ago
  That seems more like five degrees of freedom than five dimensions.
  - deskamess 7y ago
    Hmm... so the D could be for 'D'egrees of freedom? Who knows... like someone said, it is marketing, and hence a lot could be lost in translation just for easy/popular optics.
    - lvh 7y ago
      What is the difference between dimensionality and degrees of freedom? The standard definition of degrees of freedom is "number of variables that make up the state of the system" and the definition of the dimensionality of the state vector is...
      - jholloway7 7y ago
        There is no difference. I think people just get hung up on the word 'dimension' in the sense of degrees of freedom in a spatial state vector (to reuse your terms). Perhaps these are people who learned linear algebra only in the context of spatial dimensions / geometry and have never had to apply the concepts to any other problem domain.
  - Scarblac 7y ago
    Aren't they synonyms?
    - deleted 7y ago
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hyperbovine 7y ago
> I dunno, but it seems to me universities increasingly focus on press releases and marketing departments... A byproduct of public disinvestment in higher ed. Nowadays, you've got to show the taxpayers, and donors, where their money goes. Which is not all bad in my opinion.
- bluGill 7y ago
  There is a lot of investment in higher ed. Everybody wants more of the limited resources available. Since resources are limited the natural result is marketing trying to show you are worth more.
deleted 7y ago
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ru999gol 7y ago
And the picture they release show the christian bible. Tells you everything you need to know about them really.
- lvh 7y ago
  The university in question is Southampton. Hardly a Christian fundamentalist stronghold. Meanwhile, there is a tradition of using the Bible for new printing media, including one of the first printed works, the Gutenberg bible.
  - hilbert42 7y ago
    Absolutely!
- djdidf 7y ago
  What’s wrong with the Christian bible? What is it telling me about the researchers!
  - skrebbel 7y ago
    Absolutely nothing. The only theory I can come up with is that GP is a snobby atheist who associates Bibles with morons.
    - jalk 7y ago
      Using the Bible could be interpreted as ‘this is one of humanitys most important works so let’s preserve that first’ Yet the majority of people on planet earth are not Christian. I’ll go with the Gutenberg homage though
      - newen 7y ago
        Way more than that many people couldn't care less about Gutenberg though. Point being the bible is the most read book in the world.
Certhas 7y ago
If you make a market out of everything, the marketing departments will rule the day...
petre 7y ago
Heh, that number is suspiciously close to the age of the Universe. Phony indeed. "WMAP estimated the age of the universe to be 13.772 billion years, with an uncertainty of 59 million years. In 2013, Planck measured the age of the universe at 13.82 billion years."
- lvh 7y ago
  Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up and conveniently landed there: they computed a range of options and worked back from that specific number to prove it'd work for as long as we could possibly care. Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that at a specific temperature (462K) the medium will last 13.8Gy -- but their point is that it would last as long as the age of the universe at that temperature, not that the pulled a number out of their backsides. The actual paper is here: https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...
  - layoutIfNeeded 7y ago
    Ok, we get it. No need to copy-paste the same comment multiple times.
  - kragen 7y ago
    I don't think that's as long as we could possibly care, but it's a good concrete number. The Stelliferous Era is predicted to last some 10¹³ years; looking at their Arrhenius plot, we probably need to keep the temperature below about 400 K to last that long. (However, I suspect that over such long time scales, other decay mechanisms such as cosmic-ray damage will be more important.) Most likely, for long-term archival, we need to make copies of the data from time to time. But this technique will likely allow those intervals to be longer than the current age of the universe, and it offers higher density than you can get with techniques like Norsam's planar discs, which is a useful improvement over existing media.
lvh 7y ago
It’s perfectly reasonable to say you’ve increased dimensionality when you find a new physical property to store things with. If a CHS-addressed HD tomorrow starts using opacity or depth as a way to store 2 bits in each, obviously the dimensionality has increased. In ML, we regularly accept 100+d data (much higher for imaging applications). Even simple mechanical systems have large state vectors. I’m a regular critic of university systems but this isn’t the university making stuff up because it sounds impressive. (Additional evidence: one of the authors is a Microsoft employee, not an academic employed by the University of Southampton.)
- sshine 7y ago
  The criticism that I am also willing to go with is that dimensionality in statistics / linear algebra / machine learning assumes abstract dimensions, where readers of popular science assume physical dimensions. When the number of dimensions is so close to 3, and the subject of discussion is ways to physically store data, this appears misleading.
  - lvh 7y ago
    I agree that’s probably what’s going on, but “the university is making stuff up to look busy” and “no sane engineer would say this” and "clearly they made this up, 13.8Gy is mighty convenient" isn’t exactly a charitable read.
- cgravill 7y ago
  There's a related Microsoft Research project https://www.microsoft.com/en-us/research/project/project-silica/ https://www.microsoft.com/en-us/research/project/project-sil... (I work in the same lab but on different things)
  - matheweis 7y ago
    The one recent (late 2018) publication (1) from that lab hints at the current practical state of the technology: “We have not (yet) built a full storage system and are currently building out (multiple) prototype read and write heads.” “the prototype decoder achieves an accuracy of 99.47% across ... voxels written at two micron lateral separation, over 10 layers.” “we anticipate that in a volume equivalent to a DVD-disk we can write about 1 TB. The technology can potentially get to 360 TB” 1. https://www.microsoft.com/en-us/research/uploads/prod/2018/07/hotstorage18-paper-anderson.pdf https://www.microsoft.com/en-us/research/uploads/prod/2018/0...
GuB-42 7y ago
A light field is typically 5D: 3D position + 2D angle. The concept dates back from 1936 according to https://en.wikipedia.org/wiki/Light_field https://en.wikipedia.org/wiki/Light_field And it looks like it is the idea behind that storage medium. I haven't read the paper though so I can't really comment on whether or not it is justified to call it 5D. Also note that 4+ dimensions are relevant even in a 3D world. For example the Lytro camera really outputs 4D light fields (2D position + 2D angle). Of course, there is nothing extradimensional about that camera, it is just a microlens network in front of a regular CCD, with processing that converts a high resolution 2D image into a low resolution 4D light field.
- saltcured 7y ago
  The problem, I think, is when people conflate coordinates and properties. Each dimension is a component of the coordinate and is expected to increase the extent of simultaneously indexable positions, each of which is assigned its own properties configuration. There is a common conceit to treat a vector of possible properties as one (small) dimension. For example, we can make your light field hold an RGB value at each coordinate. We can alternatively interpret this as a 5D field of 3D luminance vectors or a 6D field of luminance scalars. However, if someone writes out a set of these light-field measurements as individual measurements, they might append the coordinate vector and the properties vector into one longer point (x, y, z, a1, a2, r, g, b) and claim it is 8D. However, that perspective ignores that a real light field cannot store more than one color combination at a given (x, y, z, a1, a2) coordinate. An arbitrary 8D point cloud can represent nonsensical, sparse superpositions of multiple light fields.
PietdeVries 7y ago
What bothers me even more is the precision of time they can keep the data: 13.8 billion years. Not 13.7, not 13.9 - no: they figured out 13.8 exactly. That's fake precision and remarkably close to the current age of the universe...
- lvh 7y ago
  Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up and conveniently landed there! Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that at a specific temperature (462K) the medium will last 13.8Gy: their point is that it would last as long as the age of the universe at that temperature. They could've picked any other point on the time/temp scale, like "here's how long it would last at room temperature". They did not, however, simply make up a number with no justification, let alone commit straight-up academic fraud. The actual paper is here: https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...
  - kragen 7y ago
    Are the error bars on the decay data they're computing from tight enough to justify three significant figures? Three significant figures doesn't seem like very much to me given the precision of modern metrology. Edit: I checked the paper and it looks like in this case the precision is actually ± one order of magnitude, so even one significant figure on the decay lifetime is overstating their precision. They can probably justify 1½ significant figures on the temperature, though.
lvh 7y ago
Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up ("phony", as you put it)! Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that it would last 13.8Gy at a some reasonably high temperature (462K). They could've picked any other point on the time/temp scale, like "here's how long it would last at room temperature" or "here's how hot you could store it if you only cared about it for a billion years". They did not, however, simply make up a number with no justification, let alone commit straight-up academic fraud, as you're implying. The paper is here: https://www.researchgate.net/publication/297892219_Eternal_5.. https://www.researchgate.net/publication/297892219_Eternal_5....
- gnode 7y ago
  I don't think they meant it was fraud, just that it's sensationalist drivel. It's choosing a way to interpret results for the sake of sounding impressive, rather than improving understanding. Choosing a temperature in order to say "this will last as long as the universe's current age", or finding ways to count extra dimensions is the behaviour of marketeers, not academics.
  - lvh 7y ago
    And yet, I pulled those claims out of the paper, which I linked. Are you suggesting Peter G. Kazansky, a research professor with over two decades of experience in optics, does not count as an academic? Or are you saying the paper doesn't make those claims? Or are you saying the paper also isn't a real academic paper and just marketeer noise? (I'm not quoting the other authors, who are of course also distinguished scholars :-))
    - sombremesa 7y ago
      The complaint here appears specifically to be a lamentation that academics are behaving this way, so in attempting to prove their priors you're only strengthening the argument. Your tone seems to be adversarial, so I'm guessing that's not your goal...
ChrisLomont 7y ago
> I know no sane scientist or enigneer that would say they use more than 3D physics. It's completely common for scientists to use more than 3D, since D does not have to mean spatial dimensions. Relativity is 4D (space+time), M-Theory is 11 or 26 or 10 depending on context. Even classical mechanics is formulated as 6D (3 position, 3 momentum). This leads to Hamiltonians and Lagrangians, cornerstones of modern physics, upon which all modern physics is based. As to light, it's east to find multiple dimensions to store light patterns: 3D space, 1 D polarization, 1D frequency, and now we have 5 independent dimensions in which to store data. 5D, if they use 5 independent degrees of freedom to store data, does not undermine the science - it makes it precise. The title of the paper is "5D Data Storage by Ultrafast Laser Writing in Glass" and is an invited paper at a top conference in their field. I suspect the '5D' being in the title means it is not marketing hype but actual physics. EDIT: Here [1] is the paper. They do use 5 degrees of freedom as I expected: 3 position, slow-axis orientation, and retardance. So it most certainly is 5D storage. [1] https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...
parksy 7y ago
Then you know of no sane scientist or engineer, at least any that might have a passing familiarity to n-dimensional data or basic mathematical concepts. Dimensions are the conventional term when talking about aspects of data. It doesn't just have to be spatial data, although that's the common usage of dimensions. If you're using the 3d position with two additional dimensions of size and rotation of the object at that position, you're literally processing 5 measurable dimensions of input in order to extract data. It's not like they're claiming to record data in time and a wibbly wobbly 5th dimension. It's a literal mathematical dimension describing the properties of the recording medium and method.
inflatableDodo 7y ago
>I know no sane scientist or enigneer that would say they use more than 3D physics. Are they from flatland? If not, how do they calculate motion?
spaceheeder 7y ago
I think (and it's possible I'm being too charitable in the face of bad science reporting) it's a reference to the number of independent variables that affect a read operation, and not a statement about new spacial physics. To clarify what I mean when I talk about what I think they mean (yes that sentence is confusing), consider the following example: The pits on a DVD are subject to one-dimensional analysis because every position targeted by the laser for a read operation can be in one of 2 states (i.e. 2^1) The pits on a dual-layer DVD are subject to two-dimensional analysis because every position targeted by the laser for a read operation can be in one of four states (i.e. 2^2, because there are two layers and each layer can be in one of 2 states independently of the other) If I understand the article right, this technology uses 3 physical layers, and adjusts the size and orientation of each air pocket in the glass. So on each individual layer, a dot can be categorized in any one of 8 states (2^3) and there are 3 layers (2^3) of dots. That should give 2^6 possible states per read operation. So why do they say 5 instead of 6? There could be any number of reasons, such as certain adjustments to size and orientation at a higher layer affecting the ability to read from a lower layer, or error correction built into the decoding algorithm. But yeah, that's my lukewarm take on their silly buzzwords.
airesearcher 7y ago
The 5 dimensions refer to the precise control of 5 degrees of freedom of nanogratings. 3 degrees of position in spatial coordinates and two degrees of polarization aspects. It’s in the paper and not phony, although the word “dimension” might be better replaced with some other word that doesn’t sound like 5 spatial dimensions - which is not what is intended. Before saying something is phony you should probably read the paper(s). That is from one of the top optoelectronics experts in the world.
hilbert42 7y ago
@YayamiOmate I think your emphatic view is somewhat ill-informed. For years it's been theorized that glass-like crystals could store information indefinitely—even well beyond the age of the universe. Here's the reasoning: 1. The oldest crystals known on earth are already some 4.4 billions years old and they are still intact. They are zircon crystals found in various places across the planet but the oldest discovered to date were found in Australia. 2. For all intents and purposes these zircon crystals still contain most of their original encoded information from the time they were formed. The reason we know this is that these crystals have remained essentially intact and structurally undamaged over their lifetime of some 4.4 billion years—by definition, if they'd lost all their information they would no longer be intact crystals. 3. Yes, they will have lost a tiny percentage of their information integrity from the time when they were formed, this data loss would have been the result of small amounts of both internal and external radiation and from external cosmic ray radiation, heat and other environmental effects, nevertheless zircon is a very hardy material and this loss has been minimal. (Essentially, restating the obvious, as zircon has been shown to keep most of its data intact for at least one third of known length of the universe (13.8/4.4 Gy) then by extension the storage time mentioned in the paper [13.8 Gy] for this glassy crystalline structure is highly feasible). 4. If these 4.4 Gy zircon crystals had originally been encoded in ways that allowed lossless data recovery such as Reed-Solomon encoding as used in CDs and DVDs to recover data then today we would be able to recover ALL of the original information from 4.4 Gy ago. 5. We know that under ideal conditions some crystals such as zircon and others have lives of much longer than 4.4 Gy. Why? Well crystal structures are known to be the most stable forms of matter in the universe that goes with the fact that they have the lowest entropy: https://www.livescience.com/50942-third-law-thermodynamics.html https://www.livescience.com/50942-third-law-thermodynamics.h... — to quote: “The entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero (0 K).” 6. Theoretically, a perfect crystal with zero entropy in an ideal environment would keep its information for eternity—which is much longer than the age of the universe. Now, as we know zircon and its data/structural information can exist almost intact for at least 4.4 Gy and that a perfect crystal kept under ideal conditions will do so for ever, logic dictates that we cannot rule out that crystals cannot last the age of the universe which is ≈13.8 Gy. 7. That said however, making crystals that last the age of the universe is one thing but keeping them sufficiently intact to be able to recover all their data after this length of time is another matter altogether. To do so—as mentioned—we would have to encode the crystals with a data recovery algorithm and ensure that they were safe from cosmic radiation etc. (Even with hardy crystals such as zircon we may have to send them to a part of the universe that's very low in ambient cosmic radiation (but we'd have plenty of time to do so given their intrinsically long and hardy life).) 8. The ultimate life of encoded data in near-perfect crystals would be the product of the universe's environment and the degree of how perfect the crystal was (how close to zero its entropy was). A similar problem arises with ancient DNA, no matter how well DNA may me stored against damage it ultimately will succumb to damage from cosmic radiation which on current estimates is about 1 to 2 million years [right, Jurassic Park is not possible by resurrecting DNA at least]. Keep in mind however that zircon-like crystals are millions of times more hardy and resilient than is DNA. 9. As I said, the concept of storing data in stable crystal structures is not new. Seeing the crystal/glass-like photo in this article I cannot help be reminded of the remarkable similarity between it and HAL's crystal-like memory in Kubrick and Arthur C. Clarke's 1968 classic science fiction film '2001: A Space Odyssey'. I'm pretty certain, one way or other, crystal data storage of this type will be the norm before long. 10. Oh, BTW, for those who might worry about the concept of 5D not making much sense, I can assure you it's pretty common these days, it even extends down to what's called 5-axis machine tools: http://www.5-axis.org/ http://www.5-axis.org/
adwf 7y ago
It's fairly standard Physics jargon. Physicists don't like saying the word "impossible", because there's always someone out there that can't stand hyperbole. So they often refer to something as "not likely to happen within the age of the universe" rather than "impossible", hence the 13.8bn year estimate here.
cannabis_sam 7y ago
This account is amazing! Every reply I looked at is a classic middlebrow dismissal (in the sense of pg’s essay) Thanks to lvh, who pushed me to actually look at the paper.
dekhn 7y ago
I work in Science (optical microscopy) and we use this sort of terminology for multidimensional data all the time. It's common in science.

nathanyukai 7y ago

Yeah isn't this '5D' yet another eye grabbing title? I think size and orientation are still 3D data.

lvh 7y ago
And yet, in machine learning we regularly talk about dimensions 100 and above! Just because they eventually map to three special dimensions doesn’t mean it’s not useful to talk about the different degrees of freedom you’ve managed to use for storing information. What were y’all expecting? Spider-Man: Into The Spiderverse?
- deleted 7y ago
  [deleted]

jarfil 7y ago

Heads is a low resolution dimension, so CHS should probably be more like 2.5D. Magnetic orientation is just binary, so not a dimension. The 5D in the article is kind of fishy, but in this case size and orientation are more of a low resolution dimension like multi-level cells in a flash drive.

parksy 7y ago
If it's a property of an object that defines the object, it's a dimension. Spatial location gives us 3 dimensions, rotation and size give us 2 more. The dimensions don't all have to use the same units.

dosshell 7y ago

Just speculating, but if you can index in 5 dimensions to get your data, should it not be called 5D? data = read_bit(x, y, z, yaw, size) But i agree, i would appreciate more information if they are going to use buzz-words.

theclaw 7y ago
That seems more like five degrees of freedom than five dimensions.
- deskamess 7y ago
  Hmm... so the D could be for 'D'egrees of freedom? Who knows... like someone said, it is marketing, and hence a lot could be lost in translation just for easy/popular optics.
  - lvh 7y ago
    What is the difference between dimensionality and degrees of freedom? The standard definition of degrees of freedom is "number of variables that make up the state of the system" and the definition of the dimensionality of the state vector is...
    - jholloway7 7y ago
      There is no difference. I think people just get hung up on the word 'dimension' in the sense of degrees of freedom in a spatial state vector (to reuse your terms). Perhaps these are people who learned linear algebra only in the context of spatial dimensions / geometry and have never had to apply the concepts to any other problem domain.
- Scarblac 7y ago
  Aren't they synonyms?
  - deleted 7y ago
    [deleted]

hyperbovine 7y ago

> I dunno, but it seems to me universities increasingly focus on press releases and marketing departments... A byproduct of public disinvestment in higher ed. Nowadays, you've got to show the taxpayers, and donors, where their money goes. Which is not all bad in my opinion.

bluGill 7y ago
There is a lot of investment in higher ed. Everybody wants more of the limited resources available. Since resources are limited the natural result is marketing trying to show you are worth more.

deleted 7y ago

[deleted]

ru999gol 7y ago

And the picture they release show the christian bible. Tells you everything you need to know about them really.

lvh 7y ago
The university in question is Southampton. Hardly a Christian fundamentalist stronghold. Meanwhile, there is a tradition of using the Bible for new printing media, including one of the first printed works, the Gutenberg bible.
- hilbert42 7y ago
  Absolutely!
djdidf 7y ago
What’s wrong with the Christian bible? What is it telling me about the researchers!
- skrebbel 7y ago
  Absolutely nothing. The only theory I can come up with is that GP is a snobby atheist who associates Bibles with morons.
  - jalk 7y ago
    Using the Bible could be interpreted as ‘this is one of humanitys most important works so let’s preserve that first’ Yet the majority of people on planet earth are not Christian. I’ll go with the Gutenberg homage though
    - newen 7y ago
      Way more than that many people couldn't care less about Gutenberg though. Point being the bible is the most read book in the world.

Certhas 7y ago

If you make a market out of everything, the marketing departments will rule the day...

petre 7y ago

Heh, that number is suspiciously close to the age of the Universe. Phony indeed. "WMAP estimated the age of the universe to be 13.772 billion years, with an uncertainty of 59 million years. In 2013, Planck measured the age of the universe at 13.82 billion years."

lvh 7y ago
Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up and conveniently landed there: they computed a range of options and worked back from that specific number to prove it'd work for as long as we could possibly care. Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that at a specific temperature (462K) the medium will last 13.8Gy -- but their point is that it would last as long as the age of the universe at that temperature, not that the pulled a number out of their backsides. The actual paper is here: https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...
- layoutIfNeeded 7y ago
  Ok, we get it. No need to copy-paste the same comment multiple times.
- kragen 7y ago
  I don't think that's as long as we could possibly care, but it's a good concrete number. The Stelliferous Era is predicted to last some 10¹³ years; looking at their Arrhenius plot, we probably need to keep the temperature below about 400 K to last that long. (However, I suspect that over such long time scales, other decay mechanisms such as cosmic-ray damage will be more important.) Most likely, for long-term archival, we need to make copies of the data from time to time. But this technique will likely allow those intervals to be longer than the current age of the universe, and it offers higher density than you can get with techniques like Norsam's planar discs, which is a useful improvement over existing media.

lvh 7y ago

It’s perfectly reasonable to say you’ve increased dimensionality when you find a new physical property to store things with. If a CHS-addressed HD tomorrow starts using opacity or depth as a way to store 2 bits in each, obviously the dimensionality has increased. In ML, we regularly accept 100+d data (much higher for imaging applications). Even simple mechanical systems have large state vectors. I’m a regular critic of university systems but this isn’t the university making stuff up because it sounds impressive. (Additional evidence: one of the authors is a Microsoft employee, not an academic employed by the University of Southampton.)

sshine 7y ago
The criticism that I am also willing to go with is that dimensionality in statistics / linear algebra / machine learning assumes abstract dimensions, where readers of popular science assume physical dimensions. When the number of dimensions is so close to 3, and the subject of discussion is ways to physically store data, this appears misleading.
- lvh 7y ago
  I agree that’s probably what’s going on, but “the university is making stuff up to look busy” and “no sane engineer would say this” and "clearly they made this up, 13.8Gy is mighty convenient" isn’t exactly a charitable read.
cgravill 7y ago
There's a related Microsoft Research project https://www.microsoft.com/en-us/research/project/project-silica/ https://www.microsoft.com/en-us/research/project/project-sil... (I work in the same lab but on different things)
- matheweis 7y ago
  The one recent (late 2018) publication (1) from that lab hints at the current practical state of the technology: “We have not (yet) built a full storage system and are currently building out (multiple) prototype read and write heads.” “the prototype decoder achieves an accuracy of 99.47% across ... voxels written at two micron lateral separation, over 10 layers.” “we anticipate that in a volume equivalent to a DVD-disk we can write about 1 TB. The technology can potentially get to 360 TB” 1. https://www.microsoft.com/en-us/research/uploads/prod/2018/07/hotstorage18-paper-anderson.pdf https://www.microsoft.com/en-us/research/uploads/prod/2018/0...

GuB-42 7y ago

A light field is typically 5D: 3D position + 2D angle. The concept dates back from 1936 according to https://en.wikipedia.org/wiki/Light_field https://en.wikipedia.org/wiki/Light_field And it looks like it is the idea behind that storage medium. I haven't read the paper though so I can't really comment on whether or not it is justified to call it 5D. Also note that 4+ dimensions are relevant even in a 3D world. For example the Lytro camera really outputs 4D light fields (2D position + 2D angle). Of course, there is nothing extradimensional about that camera, it is just a microlens network in front of a regular CCD, with processing that converts a high resolution 2D image into a low resolution 4D light field.

saltcured 7y ago
The problem, I think, is when people conflate coordinates and properties. Each dimension is a component of the coordinate and is expected to increase the extent of simultaneously indexable positions, each of which is assigned its own properties configuration. There is a common conceit to treat a vector of possible properties as one (small) dimension. For example, we can make your light field hold an RGB value at each coordinate. We can alternatively interpret this as a 5D field of 3D luminance vectors or a 6D field of luminance scalars. However, if someone writes out a set of these light-field measurements as individual measurements, they might append the coordinate vector and the properties vector into one longer point (x, y, z, a1, a2, r, g, b) and claim it is 8D. However, that perspective ignores that a real light field cannot store more than one color combination at a given (x, y, z, a1, a2) coordinate. An arbitrary 8D point cloud can represent nonsensical, sparse superpositions of multiple light fields.

PietdeVries 7y ago

What bothers me even more is the precision of time they can keep the data: 13.8 billion years. Not 13.7, not 13.9 - no: they figured out 13.8 exactly. That's fake precision and remarkably close to the current age of the universe...

lvh 7y ago
Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up and conveniently landed there! Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that at a specific temperature (462K) the medium will last 13.8Gy: their point is that it would last as long as the age of the universe at that temperature. They could've picked any other point on the time/temp scale, like "here's how long it would last at room temperature". They did not, however, simply make up a number with no justification, let alone commit straight-up academic fraud. The actual paper is here: https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...
- kragen 7y ago
  Are the error bars on the decay data they're computing from tight enough to justify three significant figures? Three significant figures doesn't seem like very much to me given the precision of modern metrology. Edit: I checked the paper and it looks like in this case the precision is actually ± one order of magnitude, so even one significant figure on the decay lifetime is overstating their precision. They can probably justify 1½ significant figures on the temperature, though.

lvh 7y ago

Yes, 13.8Gy is the approximate age of the universe and yes the researchers used that number. But it's not like they made this up ("phony", as you put it)! Turns out the biggest decay factor is nanograting and the biggest contributing physical quantity is temperature. They plotted what decay would look like on an Arrhenius plot. They both computed estimates and measured to confirm: the measurements are quite accurate. The specific claim is that they computed that it would last 13.8Gy at a some reasonably high temperature (462K). They could've picked any other point on the time/temp scale, like "here's how long it would last at room temperature" or "here's how hot you could store it if you only cared about it for a billion years". They did not, however, simply make up a number with no justification, let alone commit straight-up academic fraud, as you're implying. The paper is here: https://www.researchgate.net/publication/297892219_Eternal_5.. https://www.researchgate.net/publication/297892219_Eternal_5....

gnode 7y ago
I don't think they meant it was fraud, just that it's sensationalist drivel. It's choosing a way to interpret results for the sake of sounding impressive, rather than improving understanding. Choosing a temperature in order to say "this will last as long as the universe's current age", or finding ways to count extra dimensions is the behaviour of marketeers, not academics.
- lvh 7y ago
  And yet, I pulled those claims out of the paper, which I linked. Are you suggesting Peter G. Kazansky, a research professor with over two decades of experience in optics, does not count as an academic? Or are you saying the paper doesn't make those claims? Or are you saying the paper also isn't a real academic paper and just marketeer noise? (I'm not quoting the other authors, who are of course also distinguished scholars :-))
  - sombremesa 7y ago
    The complaint here appears specifically to be a lamentation that academics are behaving this way, so in attempting to prove their priors you're only strengthening the argument. Your tone seems to be adversarial, so I'm guessing that's not your goal...

ChrisLomont 7y ago

> I know no sane scientist or enigneer that would say they use more than 3D physics. It's completely common for scientists to use more than 3D, since D does not have to mean spatial dimensions. Relativity is 4D (space+time), M-Theory is 11 or 26 or 10 depending on context. Even classical mechanics is formulated as 6D (3 position, 3 momentum). This leads to Hamiltonians and Lagrangians, cornerstones of modern physics, upon which all modern physics is based. As to light, it's east to find multiple dimensions to store light patterns: 3D space, 1 D polarization, 1D frequency, and now we have 5 independent dimensions in which to store data. 5D, if they use 5 independent degrees of freedom to store data, does not undermine the science - it makes it precise. The title of the paper is "5D Data Storage by Ultrafast Laser Writing in Glass" and is an invited paper at a top conference in their field. I suspect the '5D' being in the title means it is not marketing hype but actual physics. EDIT: Here [1] is the paper. They do use 5 degrees of freedom as I expected: 3 position, slow-axis orientation, and retardance. So it most certainly is 5D storage. [1] https://www.researchgate.net/publication/297892219_Eternal_5D_data_storage_via_ultrafast-laser_writing_in_glass https://www.researchgate.net/publication/297892219_Eternal_5...

parksy 7y ago

Then you know of no sane scientist or engineer, at least any that might have a passing familiarity to n-dimensional data or basic mathematical concepts. Dimensions are the conventional term when talking about aspects of data. It doesn't just have to be spatial data, although that's the common usage of dimensions. If you're using the 3d position with two additional dimensions of size and rotation of the object at that position, you're literally processing 5 measurable dimensions of input in order to extract data. It's not like they're claiming to record data in time and a wibbly wobbly 5th dimension. It's a literal mathematical dimension describing the properties of the recording medium and method.

inflatableDodo 7y ago

>I know no sane scientist or enigneer that would say they use more than 3D physics. Are they from flatland? If not, how do they calculate motion?

spaceheeder 7y ago

I think (and it's possible I'm being too charitable in the face of bad science reporting) it's a reference to the number of independent variables that affect a read operation, and not a statement about new spacial physics. To clarify what I mean when I talk about what I think they mean (yes that sentence is confusing), consider the following example: The pits on a DVD are subject to one-dimensional analysis because every position targeted by the laser for a read operation can be in one of 2 states (i.e. 2^1) The pits on a dual-layer DVD are subject to two-dimensional analysis because every position targeted by the laser for a read operation can be in one of four states (i.e. 2^2, because there are two layers and each layer can be in one of 2 states independently of the other) If I understand the article right, this technology uses 3 physical layers, and adjusts the size and orientation of each air pocket in the glass. So on each individual layer, a dot can be categorized in any one of 8 states (2^3) and there are 3 layers (2^3) of dots. That should give 2^6 possible states per read operation. So why do they say 5 instead of 6? There could be any number of reasons, such as certain adjustments to size and orientation at a higher layer affecting the ability to read from a lower layer, or error correction built into the decoding algorithm. But yeah, that's my lukewarm take on their silly buzzwords.

airesearcher 7y ago

The 5 dimensions refer to the precise control of 5 degrees of freedom of nanogratings. 3 degrees of position in spatial coordinates and two degrees of polarization aspects. It’s in the paper and not phony, although the word “dimension” might be better replaced with some other word that doesn’t sound like 5 spatial dimensions - which is not what is intended. Before saying something is phony you should probably read the paper(s). That is from one of the top optoelectronics experts in the world.

hilbert42 7y ago

@YayamiOmate I think your emphatic view is somewhat ill-informed. For years it's been theorized that glass-like crystals could store information indefinitely—even well beyond the age of the universe. Here's the reasoning: 1. The oldest crystals known on earth are already some 4.4 billions years old and they are still intact. They are zircon crystals found in various places across the planet but the oldest discovered to date were found in Australia. 2. For all intents and purposes these zircon crystals still contain most of their original encoded information from the time they were formed. The reason we know this is that these crystals have remained essentially intact and structurally undamaged over their lifetime of some 4.4 billion years—by definition, if they'd lost all their information they would no longer be intact crystals. 3. Yes, they will have lost a tiny percentage of their information integrity from the time when they were formed, this data loss would have been the result of small amounts of both internal and external radiation and from external cosmic ray radiation, heat and other environmental effects, nevertheless zircon is a very hardy material and this loss has been minimal. (Essentially, restating the obvious, as zircon has been shown to keep most of its data intact for at least one third of known length of the universe (13.8/4.4 Gy) then by extension the storage time mentioned in the paper [13.8 Gy] for this glassy crystalline structure is highly feasible). 4. If these 4.4 Gy zircon crystals had originally been encoded in ways that allowed lossless data recovery such as Reed-Solomon encoding as used in CDs and DVDs to recover data then today we would be able to recover ALL of the original information from 4.4 Gy ago. 5. We know that under ideal conditions some crystals such as zircon and others have lives of much longer than 4.4 Gy. Why? Well crystal structures are known to be the most stable forms of matter in the universe that goes with the fact that they have the lowest entropy: https://www.livescience.com/50942-third-law-thermodynamics.html https://www.livescience.com/50942-third-law-thermodynamics.h... — to quote: “The entropy of a perfect crystal is zero when the temperature of the crystal is equal to absolute zero (0 K).” 6. Theoretically, a perfect crystal with zero entropy in an ideal environment would keep its information for eternity—which is much longer than the age of the universe. Now, as we know zircon and its data/structural information can exist almost intact for at least 4.4 Gy and that a perfect crystal kept under ideal conditions will do so for ever, logic dictates that we cannot rule out that crystals cannot last the age of the universe which is ≈13.8 Gy. 7. That said however, making crystals that last the age of the universe is one thing but keeping them sufficiently intact to be able to recover all their data after this length of time is another matter altogether. To do so—as mentioned—we would have to encode the crystals with a data recovery algorithm and ensure that they were safe from cosmic radiation etc. (Even with hardy crystals such as zircon we may have to send them to a part of the universe that's very low in ambient cosmic radiation (but we'd have plenty of time to do so given their intrinsically long and hardy life).) 8. The ultimate life of encoded data in near-perfect crystals would be the product of the universe's environment and the degree of how perfect the crystal was (how close to zero its entropy was). A similar problem arises with ancient DNA, no matter how well DNA may me stored against damage it ultimately will succumb to damage from cosmic radiation which on current estimates is about 1 to 2 million years [right, Jurassic Park is not possible by resurrecting DNA at least]. Keep in mind however that zircon-like crystals are millions of times more hardy and resilient than is DNA. 9. As I said, the concept of storing data in stable crystal structures is not new. Seeing the crystal/glass-like photo in this article I cannot help be reminded of the remarkable similarity between it and HAL's crystal-like memory in Kubrick and Arthur C. Clarke's 1968 classic science fiction film '2001: A Space Odyssey'. I'm pretty certain, one way or other, crystal data storage of this type will be the norm before long. 10. Oh, BTW, for those who might worry about the concept of 5D not making much sense, I can assure you it's pretty common these days, it even extends down to what's called 5-axis machine tools: http://www.5-axis.org/ http://www.5-axis.org/

adwf 7y ago

It's fairly standard Physics jargon. Physicists don't like saying the word "impossible", because there's always someone out there that can't stand hyperbole. So they often refer to something as "not likely to happen within the age of the universe" rather than "impossible", hence the 13.8bn year estimate here.

cannabis_sam 7y ago

This account is amazing! Every reply I looked at is a classic middlebrow dismissal (in the sense of pg’s essay) Thanks to lvh, who pushed me to actually look at the paper.

dekhn 7y ago

I work in Science (optical microscopy) and we use this sort of terminology for multidimensional data all the time. It's common in science.