Here is a concise summary of the provided transcript:
**Title:** Exploring Optical Illusions and Interactive Websites
**Summary:**
* Host Michael shares his collection of online optical illusions, highlighting:
1. **Ghostly Gaze Illusion** (hybrid image): a face appearing to change direction of gaze when blur is adjusted.
2. **Einstein-Monroe Illusion**: an image transforming from Einstein to Monroe when viewed from different distances.
3. **Ambiguous Ballerina**: an interactive illusion where a dancer's rotation direction can be flipped.
4. **Fading Dot Illusion**: a disappearing blue dot that reappears when the viewer moves their eyes.
5. **Motion Illusion**: dots moving in various perceived patterns (up/down, side/side, clockwise/counterclockwise).
6. **Hinged Tessellations**: interactive geometric shapes that can be rotated and locked into new positions.
* The video also promotes **Brilliant.org**, a learning platform offering interactive courses and quizzes, with a special discount for viewers.
Here are the key facts extracted from the text, each with a number and in short sentence form, excluding opinions:
**Optical Illusions and Websites**
1. The speaker collects websites and has thousands of tabs saved across their devices.
2. Michael Bach's website features interactive optical illusions.
3. The Exploratorium has a website with interactive exhibits, including optical illusions.
**Ghostly Gaze Illusion**
4. The Ghostly Gaze illusion is a hybrid image with high and low spatial frequencies.
5. High spatial frequency images have fine details and edges, while low spatial frequency images have more blobs.
6. The image's appearance changes based on the viewer's distance from the image.
**Einstein-Monroe Illusion**
7. The Einstein-Monroe illusion is another example of a hybrid image with high and low spatial frequencies.
8. The image appears to change from Einstein to Monroe when the viewer moves away from it.
**Ambiguous Ballerina Illusion**
9. The Ambiguous Ballerina illusion can be perceived as rotating in either clockwise or counterclockwise direction.
10. Michael Bach's website allows for easy switching between both rotation directions by adding eyeballs to the figure.
**Thatcher Illusion**
11. The Thatcher illusion involves a distorted face that appears more normal when viewed upright.
12. Cognitive tools for analyzing faces are less effective when the face is upside down.
**Color and Motion Illusions**
13. The Fading Dot illusion requires staring at a blue dot within a green blob, causing the blue dot to disappear.
14. Moving one's eyes restores the visibility of the blue dot.
15. A motion illusion with dots can be perceived in different ways (up/down, side to side, clockwise, counterclockwise).
16. Slowing down the frame rate of the animation makes it easier to flip between different motion perspectives.
**Hinged Tessellations**
17. A tessellation is a tiling of figures that can cover a plane indefinitely.
18. A hinged tessellation allows tiles to rotate and lock into a new position.
19. Al Grant's website features a hinged tessellation generator for creating custom patterns.
**Miscellaneous**
20. Brilliant.org is a learning platform that offers courses and quizzes on various subjects, including tessellations.
21. The first 36 viewers to sign up for Brilliant.org using a specific link will receive 20% off their annual subscription.