Profile

Cover photo
Martin Andersson
AboutPostsCollections

Stream

Martin Andersson

Shared publicly  - 
 
Interesting post about Alicia Bool (Daughter of George, the father of Boolean logic) and her work to visualize 4D geometries in lower dimensions.
 
See 4D
with Alicia Boole

Starting at eighteen, with little specially coloured cubes, that had been devised by a regular visitor to her home, Charles Howard Hinton, to visualise the four dimensional Tesseract which he had named, Alicia Boole was able to develop a phenomenal ability to visualise four dimensions. She went on, as Alicia Boole Stott, to publish papers on the subject, share her models and collaborate with other mathematicians.

In the same way that we cut through three dimensional shapes with an infinitely thin knife in order to visualize their two dimensional cross-sections, and perhaps with a lot of practice, and the right use of angles, we can work backwards from cross-sections to reproduce the solid, Alicia was able to mentally cut through four dimensional polytopes to see the three dimensional shapes that are their sections. She was able to see these polyhedra change size and for new three dimensional shapes to appear and disappear as she cut further through the four dimensional object in her mind.  Alicia then drew what she saw and made nets and models to explain the 4 dimensional polytopes she visualised to other people.

Given the fact that her father was the logician Boole, of Boolean logic fame, and her mother was related to the Everests of Mount Everest, it seems likely that Alicia could have accomplished more if her father had not died when she was four years old and she was plunged into penury, and it may have helped if the education system had provided better formal education to the females of the time.

However, she certainly received a good tuition from her mother. Mary Everest Boole had studied with her husband, George Boole. When Boole died, Everest Boole moved to England and was offered a job at Queen’s College in London as a librarian. Her passion however was teaching, and she liked giving advice to the students [Mich]. She had innovating ideas about education, believing for example that children should manipulate things in order to make the unconscious understanding of mathematical ideas grow [Mich]. Her belief that models should be used in order to visualize and understand geometrical objects is reflected in the following words:

There is another set of models, the use of which is to provide people who have left school with a means of learning the relation between three dimensions and four. [Eve1] The geometric education may begin as soon as the child’s hands can grasp objects. Let him have, among his toys, the five regular solids and a cut cone. [Eve2]

The Princess of Polytopia: Alicia Boole Stott and the 120-cell: http://goo.gl/cul3bd

Dissertation (open) on Alicia and her polytopes (from Groningen): http://goo.gl/igTCqK
And as a (closed) paper by Irene Polo-Blanco: http://goo.gl/xYQPaX

Using Cross sections: http://goo.gl/JqNE8l
Which is part of:
A fascinating guide to visualising 4D polytopes: http://goo.gl/Npmld5

Charles Howard Hinton: http://goo.gl/yS0SY2

Image: http://goo.gl/uJJFdH
7 comments on original post
4
Add a comment...

Martin Andersson

Shared publicly  - 
 
Hyperbolic rust.

Playing around with +Malin Christersson 's hyperbolic tiling software ( http://www.malinc.se/m/ImageTiling.php) 
2
Malin Christersson's profile photo
 
That's art!
Add a comment...

Martin Andersson

Shared publicly  - 
1
Add a comment...

Martin Andersson

Shared publicly  - 
 
Put in another way, 20.828 micro Watt seconds, but incredibly focused in time and space.
#todaysthought
1
Martin Andersson's profile photoMarc Paul Rubin's profile photoHenk van der Gaast's profile photo
5 comments
 
People are still concerned about CERN??.. thank god they despise the internet then..
Add a comment...

Martin Andersson

Shared publicly  - 
 
Pretty cool stuff. 
 
Wow. This is one of the most amazing things I have seen in a while. It is SO fast, and leaves smooth (whole) objects instead of many layers of thin filaments. Absolutely stunning.

More here : http://www.washingtonpost.com/news/speaking-of-science/wp/2015/03/16/this-new-technology-blows-3d-printing-out-of-the-water-literally/
2 comments on original post
2
Marc Paul Rubin's profile photo
 
Great find, I can imagine this evolving into a full-color process. Reshared from the OP. 
Add a comment...

Martin Andersson

Shared publicly  - 
 
Wait what?

I tried to get the monkey off my back, but there was no weaseling out of this.

(Could be a Dylan lyric)


You've almost certainly seen this crop up in your Twitter feed more than once.
5
1
Martin Andersson's profile photoMarc Paul Rubin's profile photoGreg Metcalfe's profile photo
5 comments
 
+1
Add a comment...

Martin Andersson

Shared publicly  - 
 
When you put it that way.... 
3
Martin Andersson's profile photoGreg Metcalfe's profile photo
3 comments
 
Martin shoots and scores! I guess we wouldn't really care about length, would we. 
Add a comment...

Martin Andersson

Shared publicly  - 
 
Torolf Sauermann cleaning his Blender lint filter.

I thought this blender fractal image was pretty neat. Then the pareidolia kicked in, and now I can't unsee the skull trapped in moldy growth.
 
mandelbulb3d voxel stack image 1024 x 1024 blender cycles demo
13 comments on original post
2
Greg Metcalfe's profile photoMartin Andersson's profile photo
2 comments
 
Glad I could introduce you to the wondrous world of pareidolia +Greg Metcalfe. I am only vaguely aware of the Däniken guy that you mention, and I don't have time to look him up at the moment. Is he the 'German Accent Guy' pairing up  with  'Wild Hair Dude' on History Channel saying they are 'not saying it is aliens', but it probably is anyways?
Add a comment...

Martin Andersson

Shared publicly  - 
 
 
algebra + droste 2d + fraktal + Hyperbolic Tilings
Malin Christersson: Hyperbolic Tilings http://www.malinc.se/m/ImageTiling.php
 ·  Translate
View original post
1
Add a comment...

Martin Andersson

Shared publicly  - 
 
The most surprising thing about this goldfish isn't that it is using this wooden sake tumbler as its abode, but rather the fact that it doesn't exist.

Or well, it obviously exists, but it is three dimensional art painstakingly painted in multiple layers of resin.
4
Martin Andersson's profile photoMarc Paul Rubin's profile photo
4 comments
 
+1
Add a comment...

Martin Andersson

Shared publicly  - 
 
This speaks to me....
 
#Buongiorno #Arte
"Telphone Sheep" Jean-Luc Cornec
 ·  Translate
View original post
7
1
Cindy Brown's profile photo
Add a comment...

Martin Andersson

Shared publicly  - 
 
DRAM security flaw and exploit.
 
This is crazy stuff. I'd recommend anyone who cares about security of their systems to read this.
Posted by Mark Seaborn, sandbox builder and breaker, with contributions by Thomas Dullien, reverse engineer [This guest post continues Project Zero’s practice of promoting excellence in security research on the Project Zero b...
12 comments on original post
4
1
Marc Paul Rubin's profile photoMartin Andersson's profile photoPer Siden's profile photoGreg Metcalfe's profile photo
4 comments
 
I don't know, ECC is a good thing, but not immune to rowhammer as such, from what I can understand. It takes a hell of a lot more tries, but it's just down to CPU time. Hackers can afford to be patient. You would need some sort of protection above just the bit layer, more than ECC offers anyway.

Address-space randomization sounds like it may very well make it near impossible to use the exploit. What other ways of protection are possible? Striped memory? Ways to detect suspicious writing to memory?
Add a comment...
Martin's Collections
Collections Martin is following
Basic Information
Gender
Male
Story
Tagline
Tagline, broken
Links