On October the 8th, the winners of the Nobel Prize in Chemistry, Eric Betzig, Stefan W. Hell and William E. Moerner were announced.
The distinction was granted to these researchers for two reasons: the first was the development of STED (Stimulated Emission Depletion) Microscopy, by Stefan Hell. In this technique, a laser beam is used to stimulate molecules that were previously coupled to proteins that are fluorescent. Under certain light stimulation, the molecules emit light, which in turn is controlled by a second laser that eliminates the effect of fluorescence around the focused point, allowing a great sharpness in the image (nanometer resolution).
Thus, traversing the sample to be observed with light, nanometer by nanometer, one can get an image that has a considerably higher resolution than Abbe had predicted as the maximum possible resolution for an image obtained using an optical microscope (which was about resolution half of the average wavelength of visible light) (see image (B)).
In addition to the contributions in STED microscopy, Eric Betzig and William Moerner were recognized for their contribution in developing the method of Single-Molecule Microscopy. This is a method to stimulate (with light) the individual molecules in a sample, obtaining an image of the fluorescence from stimulated molecules. Overlapping different images of the sample obtained by this method, a new image is created with resolution in the nanometer range (see figure (C)).
The contribution of the three researchers and their implications in scientific fields such as medicine were highlighted in several newspapers, television and websites around the world. Several of these sites used as visual aids to the published article, diagrams provided by the Royal Academy of Sciences (figures (A), (B) and (C)).
Some of them are presented here (figures (A), (B) and (C)). Figure A illustrates the resolution limitations of optical microscopy images, stated by Abbe, and the achievement of Hell, Betzig and Moerner regarding this resolution. B illustrates the principle of STED microscopy and image (C) illustrates the principle of single-molecule microscopy.
Regarding the visual communication of science content, it is interesting to highlight the complexity differences that exist among diagrams and their components, both in the case in which the communication is addressed to a wider audience (Figures (A), (B) and (C)) as in the case where it is directed to a more specialized audience (Figures (D), (E) and (F)).
In order to establish such comparison, let’s look at some examples of diagrams of the diffraction limits of optical microscopy and STED microscopy principle, but which illustrate scientific publications:
Comparing the diagrams in Figures (A) and (D) we see that diagram (A) focuses contextualizing the magnitude of the numbers (1 nm, 100 micron …) by comparing them to the size of known organisms (ant, hair, mitochondria ..)
On other hand, in figure (D) the information accuracy is privileged and there is a comparison between different scientific contributions regarding resolution limits in microscopy.
Now let’s take a look at the visual communication of STED microscopy principle for a specialized public (Figures (E) and (F)). The diagrams show there is a comparison between the image quality resulting from STED microscopy technique and a less effective method (confocal microscopy). Moreover, comparing these diagrams with the on in figure B, aimed at a general audience, we can verify that the images (E) and (F) provide more detailed information on the STED microscopy method, as well as a more hermetic technical terminology than in Figure (B).
Another feature that stands out from the comparison of the two types of images (1 – intended for a general audience; 2 – aimed at a specialized audience) is that the information of the first type has a smaller component of quantitative information in the explanation of phenomena. Therefore, while the goal of clarifying is common to both types of images, when they are intended for a general audience, clarifying also stands for simplicity.
In addition, images (A), (B) and (C) allow an understanding of the issue only on a global scale, while the images (D), (E) and (F) also present information to a smaller, more detailed scale.
Finally, we can see that, while figures (D), (E) and (F) represent several different information groups within the same image — both evident because of the differences in the appearance of visual information and the indication of the image segments (represented by the letters a, b, c, …) — the same does not happen with the images intended for the general public, where information is presented as a single block, due the uniformity of shapes, colors, and the proximity of the drawings (although numbers 1,2,3 are used to guide the reader in image (B)).