Mirror, mirror

by | Thursday, August 07, 2008

Imagine you are standing in front of a bathroom mirror; how big do you think the image of your face is on the surface? And what would happen to the size of that image if you were to step steadily backward, away from the glass?

A recent article in the NYTimes (Mirrors used to explore how the brain interprets information) has some interesting nuggets in it. The one that stood out was the rather straightforward one quoted above…

According to the researchers quoted in the article, most people answer the questions with some variation of the following:

To the first question they say, well, the outline of my face on the mirror would be pretty much the size of my face. As for the second question, that’s obvious: if I move away from the mirror, the size of my image will shrink with each step.

Turns out both of these typical answers are wrong!

I knew the answer to the first one – that the outline of my face in the mirror would be exactly half of the size of my real face. There are two main reasons for this. The first is the basic geometry of the fact that the mirror is exactly halfway between me and my image and second, that our brains over-compensate for size differences with distance (known as the size constancy effect). It is the combination of the two that (a) leads to the smaller, exactly half, size and (b) to our inability to realize that.

However, I had not truly understood the consequences of the geometry… So even though at some intellectual level I knew that that the image of my face would always be half its size in the mirror, I didn’t understand the consequence that it would always have to be that, irrespective of how far (or how close to the mirror I was). Wow… Turns out even things I thought I had understood, I didn’t fully understand!!

A good example of a véjà du moment!

You can find out more about size constancy by going here

A few randomly selected blog posts…

India Week @ Erickson Hall

The Indian community in the greater Lansing area celebrates India Week every year (more or less) around March. [More details here and here.] As a part of this event I (and other members of the College of Education) have been organizing an Indian themed breakfast and...

Computerized aesthetics… what’s right with that idea?

I just came across this... Online System Rates Images by Aesthetic Quality Pennsylvania State University (PSU) has launched the Aesthetic Quality Inference Engine (ACQUINE), an online system for determining the aesthetic quality of an image. The online photo-rating...

AACTE Major Forum on TPCK

Matt and I will be at New Orleans in a few weeks presenting at a major forum organized as a part of the AACTE conference. The title of the major forum is When Multiple Technologies Take Learning to a higher level: the technological Pedagogical content Knowledge (TPCK)...

The “O” in Obama

Steven Heller continues his series on political typography and branding with an interview with the design team that developed the now iconic symbol for the Obama campaign. Check out The "O" in Obama. Previous postings on this theme can be found here and here.

New TPACK themed book on English Education

My friend Carl Young of NCState recently released an edited volume (co-editor, Sara Kajder a the University of Pittsburgh) titled Research on Technology in English Education. It is a volume in the series: Research Methods for Educational Technology, edited by Walt...

Welcome…

...to my new website. It has taken a while, but it is finally here. Of course, as in all things web, this is still a work in progress, but it is getting there. I will be phasing out my old site gradually. The most significant change has been a shift from static HTML...

Plugin’ into superpowers

Plugin’ into superpowers

I have been playing with couple of the newly released ChatGPT plugins (you have to have the paid version to use them) and want to share some of my early experiments. The two I am going to talk about are the ChatWithPDF and the Wolfram plugins. Short answer, they are...

Technology & research

Patrick Dickson just forwarded an article in the APA Monitor titled Beyond chalk and talk, in which Art Graesser, the new editor of Journal of Educational Psychology, indicates an openness to including more technology related articles in JEP. Patrick argued that this...

0 Comments

Submit a Comment

Your email address will not be published. Required fields are marked *