Working microscope

Carl Merrian built this Working microscope. It uses official LEGO elements like the magnifying glass element, technic gears, and fiber optic system to actually allow you to focus in on small objects.

Jupiter control room

During my focus on illusions for the past couple of weeks, I've passed up some great creations, like Legodrome's Jupiter control room, which he created as a commission for the French space agency CNES.

Necker cubes

One last optical illusion for now, and then I'll go back to something else. A Necker cube is a bistable image of a cube where it is unclear which is the front face and which is the back face. Here's a more complex version built of Modulex by Brixe63. Are the small cubes pointing forward from larger cubical recesses, or are the larger cubes pointing forward with little small-cube-shaped bites taken out? Does rotating the whole thing change that perception?

Figure ground perception

The bistable figure featured yesterday is also called a figure ground perception illusion. The idea here is that the mind has to somehow use visual clues to decide if the white part is the foreground against a black background (which would make the image a vase), or if the black part is the foreground against a white background (two faces). When there are no obvious clues, the mind could jump back and forth between the two alternatives. Here is another version, Alex Eylar's Good and Evil. Which do you see?

Rubin's Vase

Rubin's Vase (here by 2x4) is an example of an ambiguous image, or a bistable image. That is, the visual clues could resemble one of two (or more for multistable images) different pictures. In this case you can see either a vase in white or two faces in black. Your mind will hold onto one, but could then switch to the other.

Contrast illusions

Contrast illusions are when you are tricked into thinking that some color is lighter or darker than it actually is. A simple example is demonstrated here by Arthur Gugick. Those gray squares are exactly the same color. A more complicated illusion is the checkershadow illusion invented by Edward Adelson, virtually recreated in LEGO by Nachapon. Here tiles A and B are exactly the same shade. I've seen both physical and mental explanations for these. The physical explanation lies in the way adjacent receptors in the eye enhance or inhibit each other. If a receptor is stimulated by the gray color, and the adjacent receptor is being stimulated by the white, the physical response is different from a receptor stimulated by the gray adjacent to a receptor stimulated by the black. The mental explanation is easier to explain for the second example. Since we know that objects in the shadow will appear darker, when we see that tile shadowed by the barrel, our mind simply assumes that it's actually a lighter color, and the reverse can be said about objects in direct light. So A and B seem to be different based on our assumptions of objects being in light or being in the shade.

Illusory motion

Here's an even better version of illusory motion by Sittiponder. I promise, this is a static mosaic, not some animated gif.

Hermann's Grid

Arthur Gugick built this version of Hermann's Grid. Notice the pale gray dots that appear at the intersections, but disappear when you look directly at the intersection. This is a physical illusion, based on the excitation and inhibition of receptors in the eye. When a receptor is stimulated by a bright region, it is excited. But, if the receptors surround it are also stimulated by bright regions, this serves to inhibit the central receptor. I believe that this is done to enhance contrast, to help you see patterns in areas of similar colors - this will help you see the tiger camouflaged by the tall grass, which will give you some survival advantage. The points at the intersection are surrounded by more bright regions than other portions of the white lines, and so therefore these are somewhat dimmed by inhibition of the receptors. This effect is exaggerated in the peripheral vision, and so the gray dots disappear when you look directly at them.

Pinched checkerboard

Andy_0306uk also built this pinched checkerboard. The explanation is the same here as the bulging checkerboard I posted a couple of days ago, but since the dots angle the other way it seems to pinch in rather than bulge out. I think the previously featured one works better because it has both black dots on the white squares and white dots on the black squares. Here the plain white squares seem to break the illusion somewhat.

Ghost image

Our next illusion is a ghost image by Tom Remy. This one takes a little work, and doesn't always work right the first time, so you may have to try again. Stare steadily at the image for about thirty seconds, focusing on the center of the face. Then quickly turn and look at a blank white paper. You should see a classic yellow smiley for a few moments. This is an example of a negative afterimage, which is a physical illusion based on how the light receptors in the eye work. Your eye has three types of cone receptors, that perceive blue, green and red light. The relative stimulation of these receptors is interpreted by the brain to give the perception of the whole spectrum of colors. When you stare at the figure, the blue receptors are overstimulated, and adapt by losing sensitivity. When you shift your vision to the white paper, the blue receptors are slower to respond than the red and green receptors, and so your brain receives stronger signals from those two types, which is interpreted as the negative of blue, or yellow. If the illusion didn't work for you it's probably because you didn't hold your eyes steady enough, as your body normally compensates for this receptor overload by flitting the eyes back and forth.

Bulging Checkerboard

Andy0306uk built this great bulging checkerboard, an illusion first created by Akiyoshi Kitaoka. The explanation lies in how our mind tries to make straight lines out of the patterns of small dots that alternate back and forth around the lines that are actually straight. BTW, Arthur Gugick and Tom Remy have also built versions of this illusion.

Cafe Wall

Our next illusion is the Cafe Wall, here in LEGO by Katie Walker. In 1973, Steve Simpson, a student working with psychologist Richard Gregory, was eating lunch and noticed that the black and white bricks in the wall appeared to follow curving lines, but when you looked close you could see they were straight. One explanation for this geometrical-optical illusion is based on physical differences in how the receptors in the retina perceive the black and white area. The thought is that the black areas bleed over and stimulate the nearby receptors that should be seeing the white area. And so instead of looking square, the black shapes seem to flare out a little as trapezoids. Since the mind sees that these all come together in a pattern, it tries to fit trapezoids together, which leads to the perception of lines sloping this way and that. But they're straight, really. If you don't believe me, hold a piece of paper up to your screen and you can see that every edge is parallel.

Optical illusions

Optical illusions occur when we think we see something that isn't really there, or in some other way our perception doesn't exactly match up with the actual visual stimuli. I've done a little reading to learn more about these, and it seems that there are two different reasons for these illusions - physical and mental. By physical I mean that there is something about how the nerves are stimulated in the eye, or how they interact in the brain, that gives rise to the illusion. Mental illusions are when our perception (and I'm NOT going to try to dig into the whole mind/brain discussion* here) makes mistakes when it to fit conflicting or incomplete visual inputs into some recognizable pattern. There have been a lot of LEGO renditions of optical illusions, so I'm going to do a small series. I'll start out with the one that inspired this series. A couple of days ago Katie Walker posted this zig zag. I noticed that if you stare at it, the lines appear to be wiggling back and forth. This is a form of illusory motion. There seem to be conflicting views on why these work, but in general they overstimulate our eyes with repetitive patterns of colors and light and dark. They also are related to fixation jitter - our eyes don't sit still, but actually move around. I think that the differences between the way we perceive objects at the center of our visual field vs objects in our peripheral vision are also very important to these illusions, as with most of them the area at the center of focus is sitting still, but it's the areas just to the side that are moving (but when you shift your focus those areas sit still and the other starts moving).



* Okay, just a little bit in case anyone wants clarification. The mind/brain discussion is the question of whether your consciousness/self/mind is, at one extreme, simply a series of chemical interactions in the brain, or, at the other extreme, a nonphysical identity (a soul) that somehow interacts with the brain. Or is it somewhere in between. That's a deep subject that would involve neuroscience and philosophy and religion.

Synchrotron

The Canadian Light Source is a national research center located at the University of Saskatchewan. They pursue research using a synchrotron. This is a type of cyclic particle accelerator that accelerates electrons to speeds approaching the speed of light. This leads to extremely powerful beams of light that can be tuned to any desired wavelength. CLS scientist built this end station. As I understand from their description, the beam of light coming off the synchrotron enters the optics hutch, the white bit that takes up about 2/3 of the right portion of this model, via that gray nozzle on the right side. Inside the optics hutch, the beam is focused and tuned to the desired wavelength. The resulting narrow beam leaves the optics hutch and hits the experimental hutch, the white bit on the left hand side of this photo. There scientists study how the light energy affects or interacts with some sample they are interested in.

Mars Science Laboratory Curiosity Rover will be an official set

Today LEGO announced that they approved Stephen Pakbaz's Mars Science Laboratory Curiosity Rover as the next Cuusoo set. Cuusoo is a crowd-source site where LEGO builders can propose set ideas, and if they get 10,000 votes, LEGO will consider releasing them as official sets. I love the fact that they're choosing this, and not the latest proposal inspired by TV/movies/video games. This set is very much in the spirit of the Shinkai 6500 and Hayabusa sets, the first two Cuusoo sets, and also ongoing collaborations between LEGO and NASA. Stephen is a JPL engineer, and he's said that he was inspired by previous LEGO NASA sets. Here's to the future generations that will be inspired by this new set to look to the stars (er, planets)! Congratulations, Stephen! Via the Brothers-Brick.

DNA patent ruling

Here's some DNA. I'm not sure who built this, as this was at a public display and turns up in several people's photo streams. Anyway, you might ask why post this today, as I just posted a model of DNA in my last post. Well, this gives me a chance to write about the ruling from the US Supreme Court in the case of Association for Molecular Pathology v. Myriad Genetics, Inc. As I understand it, Myriad held a series of patents, and some were upheld while others were struck down. To understand this case, we have to start with a description of transcription/translation. DNA resides in the nucleus, and protein synthesis takes place at the ribosome outside the nucleus. In order to get the information from the DNA to the ribosome, a copy is made, the complementary strand of RNA. So, for instance, let's say there is a DNA strand that goes GCGCAAGC. The complementary strand of messenger RNA is CGCGTTCG (C's match with G's, G's match with C's, T's match with A's). But, let's go a little further. About 98% of the human genome is not used for making proteins. When this non-coding DNA (sometimes called 'junk DNA', but it does actually have important regulatory function) comes in the middle of a DNA sequence, it is called an intron. So the unwanted parts are removed. So, for instance, our CGCGTTCG strand could be trimmed down to just CGCGCG, and this mature mRNA would code for the protein Arg-Ala (groups of three RNA bases are called 'codons', and code for different amino acids). Okay, back to Myriad Genetics. They found that a mutation in the code for a particular protein is associated with certain kinds of breast cancer. So, in our example the healthy cell has DNA GCGCAAGC, which leads to mRNA CGCGTTCG, which is modified to mature mRNA CGCGCG, which codes for protein Arg-Ala. Let's say the potentially cancerous cell has DNA CCGCAAGC, which leads to mRNA GGCGTTCG, which is modified to mature mRNA GGCGCG, and this would code for protein Gly-Ala, and let's say this protein is associated with cancer. Myriad came up with a test for the presence of this mutation. Their test involved creating a shortened form of DNA with the introns removed, called complementary DNA. In our example this would be CCGCGC (note it is missing the AA from above). They take mRNA from the patient, and see if it binds to this complementary DNA. If it does, it indicates the presence of a mutation that could lead to cancer. They then took out patents on the process of comparing the mRNA to their complementary DNA, the sequence in the complementary DNA (CCGCGC), and also the sequence in the initial DNA (CGCGCAAGC). What the Supreme Court ruled yesterday is that the third type of patent is invalid, as the sequence of DNA in the living cell (either healthy or cancerous), is a 'product of nature'. That is, Myriad did not invent it, so they cannot patent it. OTOH, the complementary DNA is not naturally existing, and so therefor may be patented. It is also valid to patent a novel method involving this complementary DNA. So it was a mixed ruling, but IMO a correct one. The human genome is still there available for anyone to do research without fear of being sued for patent infringement, but there is still incentive for companies to produce new types of tests that they can protect with patents.

DNA

There are a lot of LEGO renditions of DNA out there, indeed I chose one for the banner of this blog, but most don't really have an accurate structure. This one by SICP_DNA, though, is very good about keeping to the actual structure of DNA. In DNA, the strands on either side are pointing in opposite directions, and the white and gray backbones have the studs pointing in different directions here. Since the backbone sugars are asymmetric, the 'grooves' are different sizes. Another aspect of DNA is that two of the bases, the purines A and G, are larger than the other two, the pyrimidines T and C. The connections here are such that it only works out when A lines up with T or G lines up with C. They also got the sizes right here, so that one complete twist takes ten steps, and the width to height ratio is approximately correct.




Here you see a comparison between the 'real' structure of DNA, and a simplified depiction. BTW, the LEGO version below is from Nathan Sawaya's Building Bricks of Life. I certainly mean no disrespect, as it is a great model. But as Nathan has said elsewhere he's an artist, not a scientist, and he writes that he decided to go with this more artistic approach (as a commissioned piece for the Archon Genomics X Prize) rather than try to do a more accurate version. Someday I'd like to see him go back and do an accurate depiction of DNA. He's a great sculptor and I'm sure it would be quite cool.



BTW, since I've posted two Cuusoo projects in a row, I wanted to say a little about that. I was corresponding with another LEGO blogger the other day about these, and I agree with him that a great number of the things posted there are not actually viable LEGO sets, including this one (sorry, SICP_DNA). So if I blog something, it is not necessarily true that I am supporting it as a Cuusoo project. I just see Cuusoo as another place where LEGO builders post their creations, along with other photo sharing sites.

Female figs Cuusoo project

Cuusoo is a LEGO website for crowdsourcing set ideas. You propose a set, and if it gets 10,000 votes, LEGO promises to take a serious look at producing the set. Most of the sets that have made it to 10,000 have been attached to some movie/TV show/video game, and fans of that movie/show/game help push it over the top. That said, there have been two science driven sets already produced, the Shinkai submarine and the Hayabusa space probe, in the original Japan-only version of Cuusoo, and the Mars Curiosity Rover is being considered in the most recent round of creations that have reached 10,000. Now it seems that socio-political forces are pushing another to the top. Alatarial designed Female Minifigs to help correct the gender imbalance in Legoland, putting women in small scenes depicting different occupations. The cool thing, and the reason why I'm posting this here on SciBricks, is that many of those occupations are as scientists, probably because Alatarial is herself a geochemist: paleontologist, astronaut, astronomer, chemist, (falconer), geologist, and engineer (plus six others in non-science roles not shown here). I assume that this was recently posted on some social media site, or featured in some news source, because the project jumped from 2500 votes to 7500 in just three days.

NASA's Missions: Imagine and Build

I noted this a couple of weeks ago, but did not have details at that point. LEGO has teamed with NASA for a contest, NASA's Missions: Imagine and Build. Two categories (subdivided into age ranges) challenge you to either build a MOC based on a currently planned NASA mission, or to build the aircraft of tomorrow. The second category is supposed to be accompanied by a technical paper, so they're looking for someone with some knowledge, not just clicking some bricks together and swooshing the creation around your room. We're all looking at you, Apojove (jk, I know there are a ton of AFOLs out there with real science and engineering expertise).

ATV-4 "Albert Einstein"

Brainbikerider built the ATV-4 "Albert Einstein". I'll just be lazy and copy his whole description:

The ATV (Automated Transfer Vehicle) is ESA’s unmannded resupply spacecraft for the ISS. The mission of this “real world X-Wing” is not only to transport cargo and propellant, but also to reboost the Space Station into a higher orbit. Currently, it’s the most powerful resupply spacecraft with a cargo capacity of more than 6.5 tonnes. The fourth ATV, named after the famous scientist Albert Einstein, will be launched today on an Ariane 5 rocket at ESA’s spaceport in Kourou. You can read more about the ATV here.