5 ms·

I had the good fortune of taking a field trip there in 2018. The video is a very good overview of the project. One interesting artifact of "the real world sim

I had the good fortune of taking a field trip there in 2018. The video is a very good overview of the project. One interesting artifact of "the real world simulates itself" is version control. At Dynamicland, each version of a program is a sheet of paper (with a unique set of fiducials along the edges). If you want to edit a program, you grab a keyboard and point it at the program. A text editor comes up; you make your changes, and hit commit. When you do, it spits out a new piece of paper with your changes. Put it in the view of the camera to use the new version. Take it away and use the old paper to roll the change back.

breck 2y ago
> with a unique set of fiducials along the edges I suspect each piece of paper, if examined with a good enough camera, has a unique fingerprint, like a snowflake, and perhaps this could be used in the future for an "Isomer Addressed Filesystem". In other words, all pieces of paper ship with a UUID already, woven into their atoms.
- shoxidizer 2y ago
  I would suggest instead convincing every printer manufacturer to embed in every printer a routine that encodes a unique identifier on every print and then reading that using more typical cameras. The hard part has already been done. https://en.m.wikipedia.org/wiki/Printer_tracking_dots https://en.m.wikipedia.org/wiki/Printer_tracking_dots
  - jf 2y ago
    I'm pretty sure that I mentioned the printer tracking dots to the researchers at the lab and certainly mentioned DataGlyphs. So they were aware of alternatives. The trick is to get a workable system with cameras that have the resolution to pick out those details from a dozen feet away, as well as a software stack that can recognize them at ~60fps. The goal has always been to move away from the dots, you can see this in the progress report: https://dynamicland.org/2019/Progress_report/ https://dynamicland.org/2019/Progress_report/ That said, and this is purely my opinion, the system works well enough as it is, and there is so much fun stuff to build on top of what works, that it's hard to prioritize a better object recognition system over the myriad of other interesting things to be done.
    - shoxidizer 2y ago
      I imagine it would very difficult to read these dots from a distance and dynamically. I just mention it because most printed documents already have indentifiers printed on them that don't require seeing individual fibers.
      - jf 2y ago
        Ah, noted! With that in mind, did you know that those printer dots are what the team that won the 2011 DARPA Shredder Challenge used to win? https://en.wikipedia.org/wiki/DARPA_Shredder_Challenge_2011 https://en.wikipedia.org/wiki/DARPA_Shredder_Challenge_2011 Fun fact: Otavio Good, who led the winning team, learned about the printer dots on this very site. As I recall, he said that the dots were like a map that let them reconstruct the shredded documents.
        Jerrrrrrry 2y ago
        I would had thought, even then, that this was not only commonly known, but not the sole only annulment/rule among a generally "rules-free" competition, having been rather obvious, especially to the audience these competitions attract. Thank you for reminding me, and others, how immediate and obvious success can be.
        cma 2y ago
        Is there a better source that talks about it? Didn't see it mentioned on that page.
        jf 2y ago
        I'm not sure if there's a source online as I learned about it from Otavio directly. The slightly longer story, as I recall it, is that their team basically built a "game" to help humans unshred documents, and was using that approach until Otavio happened to read about the printer dots on HN. He updated his code to take those into account and was astonished at how helpful they were.
  - sedatk 2y ago
    Oh, that’s why my HP inkjet refuses to print a black & white page when it’s low on yellow.
    - jf 2y ago
      Woah! I never considered that until now. I'll bet you're right.
    - rtkwe 2y ago
      Not entirely it also uses bits of color ink to make the black and white page look better, at least according to the printer companies who conveniently also benefit by selling you more ink.
      - sedatk 2y ago
        How can it make black look better by adding yellow to it?
        calfuris 2y ago
        Black ink isn't perfectly black. Adding other colors of ink makes it darker. If you don't really care about how dark the result is, the term you're probably looking for in settings is "rich black."
    - max-ibel 2y ago
      If you are happy to live with B&W printing for your untraceable printing needs, maybe you can fill the yellow cartridge with clear ink (not sure if water is OK). But then, how do B&W laser printer allow for tracing ?
      - yellowapple 2y ago
        > But then, how do B&W laser printer allow for tracing ? They don't, because they don't need to. The point of the yellow dots is to prevent the printing of counterfeit currency, which itself tends to require the use of more ink colors than only black. It's probably possible to refill a "black" ink/toner cartridge with the exact shade of green (or whatever) to replicate the color of a currency note, but if it was easy to do then there'd probably be a lot more counterfeit bills floating around. The ink/toner is also half the battle. The other half is the paper, since obviously the US Treasury doesn't use ordinary printer paper to print $20 bills. The usual trick is to take a $1 or $5 bill, bleach it (or otherwise remove the existing printing), and print a $20 bill design onto it - but that's easier said than done, due to both the ink/toner color issue mentioned above and due to the difficulty of getting the donor bill exactly aligned (and doing so again, in the exact same way, for the other side of the bill).
d--b 2y ago
Can you “pipe” the results of one paper onto one of the inputs of the next? That’d be pretty funky.
- jf 2y ago
  Yes. Though not in the traditional way that we think of "pipe" working. A good example of this was the "zoom lens" in Omar Rizwan's Geokit: https://omar.website/posts/notes-from-dynamicland-geokit/ https://omar.website/posts/notes-from-dynamicland-geokit/
- rtkwe 2y ago
  Anything on the table is open to reference by anything else on the table afaik. Direct references are usually done as cursors projected off the page so you can "point" and "click" on other objects to control precisely what you reference or select with the other tool. You could also implement input and output piping between programs in a more organized way where their physical orientation isn't as critical as most page references seem to be. eg: Put a tag on a sticky note that represents a pipe, put it close enough to the 'output' of one page then stick it to the input of another compatible page. Not sure how protected the individual pages are from outside modification because real details are quite thin on the ground. I think right now you could probably turn every display page into a rick roll if you wanted.
  - d--b 2y ago
    Right, I guess that's why it's called Realtalk, it's sort of messge based like smalltalk but with real stuff. Infinite recursions and resource conflicts must be tough to handle.

breck 2y ago

> with a unique set of fiducials along the edges I suspect each piece of paper, if examined with a good enough camera, has a unique fingerprint, like a snowflake, and perhaps this could be used in the future for an "Isomer Addressed Filesystem". In other words, all pieces of paper ship with a UUID already, woven into their atoms.

shoxidizer 2y ago
I would suggest instead convincing every printer manufacturer to embed in every printer a routine that encodes a unique identifier on every print and then reading that using more typical cameras. The hard part has already been done. https://en.m.wikipedia.org/wiki/Printer_tracking_dots https://en.m.wikipedia.org/wiki/Printer_tracking_dots
- jf 2y ago
  I'm pretty sure that I mentioned the printer tracking dots to the researchers at the lab and certainly mentioned DataGlyphs. So they were aware of alternatives. The trick is to get a workable system with cameras that have the resolution to pick out those details from a dozen feet away, as well as a software stack that can recognize them at ~60fps. The goal has always been to move away from the dots, you can see this in the progress report: https://dynamicland.org/2019/Progress_report/ https://dynamicland.org/2019/Progress_report/ That said, and this is purely my opinion, the system works well enough as it is, and there is so much fun stuff to build on top of what works, that it's hard to prioritize a better object recognition system over the myriad of other interesting things to be done.
  - shoxidizer 2y ago
    I imagine it would very difficult to read these dots from a distance and dynamically. I just mention it because most printed documents already have indentifiers printed on them that don't require seeing individual fibers.
    - jf 2y ago
      Ah, noted! With that in mind, did you know that those printer dots are what the team that won the 2011 DARPA Shredder Challenge used to win? https://en.wikipedia.org/wiki/DARPA_Shredder_Challenge_2011 https://en.wikipedia.org/wiki/DARPA_Shredder_Challenge_2011 Fun fact: Otavio Good, who led the winning team, learned about the printer dots on this very site. As I recall, he said that the dots were like a map that let them reconstruct the shredded documents.
      - Jerrrrrrry 2y ago
        I would had thought, even then, that this was not only commonly known, but not the sole only annulment/rule among a generally "rules-free" competition, having been rather obvious, especially to the audience these competitions attract. Thank you for reminding me, and others, how immediate and obvious success can be.
      - cma 2y ago
        Is there a better source that talks about it? Didn't see it mentioned on that page.
        jf 2y ago
        I'm not sure if there's a source online as I learned about it from Otavio directly. The slightly longer story, as I recall it, is that their team basically built a "game" to help humans unshred documents, and was using that approach until Otavio happened to read about the printer dots on HN. He updated his code to take those into account and was astonished at how helpful they were.
- sedatk 2y ago
  Oh, that’s why my HP inkjet refuses to print a black & white page when it’s low on yellow.
  - jf 2y ago
    Woah! I never considered that until now. I'll bet you're right.
  - rtkwe 2y ago
    Not entirely it also uses bits of color ink to make the black and white page look better, at least according to the printer companies who conveniently also benefit by selling you more ink.
    - sedatk 2y ago
      How can it make black look better by adding yellow to it?
      - calfuris 2y ago
        Black ink isn't perfectly black. Adding other colors of ink makes it darker. If you don't really care about how dark the result is, the term you're probably looking for in settings is "rich black."
  - max-ibel 2y ago
    If you are happy to live with B&W printing for your untraceable printing needs, maybe you can fill the yellow cartridge with clear ink (not sure if water is OK). But then, how do B&W laser printer allow for tracing ?
    - yellowapple 2y ago
      > But then, how do B&W laser printer allow for tracing ? They don't, because they don't need to. The point of the yellow dots is to prevent the printing of counterfeit currency, which itself tends to require the use of more ink colors than only black. It's probably possible to refill a "black" ink/toner cartridge with the exact shade of green (or whatever) to replicate the color of a currency note, but if it was easy to do then there'd probably be a lot more counterfeit bills floating around. The ink/toner is also half the battle. The other half is the paper, since obviously the US Treasury doesn't use ordinary printer paper to print $20 bills. The usual trick is to take a $1 or $5 bill, bleach it (or otherwise remove the existing printing), and print a $20 bill design onto it - but that's easier said than done, due to both the ink/toner color issue mentioned above and due to the difficulty of getting the donor bill exactly aligned (and doing so again, in the exact same way, for the other side of the bill).

d--b 2y ago

Can you “pipe” the results of one paper onto one of the inputs of the next? That’d be pretty funky.

jf 2y ago
Yes. Though not in the traditional way that we think of "pipe" working. A good example of this was the "zoom lens" in Omar Rizwan's Geokit: https://omar.website/posts/notes-from-dynamicland-geokit/ https://omar.website/posts/notes-from-dynamicland-geokit/
rtkwe 2y ago
Anything on the table is open to reference by anything else on the table afaik. Direct references are usually done as cursors projected off the page so you can "point" and "click" on other objects to control precisely what you reference or select with the other tool. You could also implement input and output piping between programs in a more organized way where their physical orientation isn't as critical as most page references seem to be. eg: Put a tag on a sticky note that represents a pipe, put it close enough to the 'output' of one page then stick it to the input of another compatible page. Not sure how protected the individual pages are from outside modification because real details are quite thin on the ground. I think right now you could probably turn every display page into a rick roll if you wanted.
- d--b 2y ago
  Right, I guess that's why it's called Realtalk, it's sort of messge based like smalltalk but with real stuff. Infinite recursions and resource conflicts must be tough to handle.