Yes... I mean, No.

You might have seen this optical illusion. Step back from the screen and determine which side is angry, and which is happy. Then approach your computer, and ask the same question.

How do they do that?

Your visual system is tuned to certain spatial frequencies, so you tend not to notice image content of frequency higher or lower. I did an experiment and created my own version of this optical illusion. I started with these images.

Then I applied a lowpass filter to YES, and a highpass filter to NO. That gave me these images.

Adding them together gives this image...

Yes, your visual system acts as a filter (as does every optical system).

Jeff's brain

Here is a rendering of my brain.

Expanding illusion

I got this illusion from BrainBlogging.

Bombshelter wisdom

Late one night in first year, I was working on a calculus assignment with my friends on campus. A drunk student walked by, returning from an evening of partying in the Bombshelter (the campus bar). He looked over my shoulder at the proof I was working on, saw the word "assume", and imparted this wisdom to me.

Don't assume things, because it makes an ass of u and me.

Midterm bribe

Let's face it, everyone has a price tage. After seeing the results of the midterm, I'll offer you a deal. Follow these directions, and I'll give you all perfect on the midterm.

1. Starting tomorrow, take a collection and give me 1 cent.
2. The day after tomorrow, take a collection and give me 2 cents.
3. On the day after that, take a collection and give me 4 cents.
4. On each subsequent day, take a collection and give me twice as many pennies as the previous day.
5. Continue this process for one month.

If you successfully complete the month, then you all get prefect on the midterm. Congratulations.

Do you know how to ride a tricycle?

Suppose you have a tricycle, and one pedal is in its lowest position. Tie a string to the downward pedal, and gently pull forward, like in the picture below.

Which way will the tricycle move, toward you, or away from you?

Discuss...

A pool of human biomass

Ever wondered how much mass is tied up in the form of human bodies? Yah, me too.

If you were to puree every human body, and pour them all into a giant square pool 1 metre deep, how big would that pool be? How would you go about estimating it?

Discuss...

There are 10 types of people...

There are 10 types of people,
those that understand binary numbers,
and those that don't.