# The Rotational Paradox: Unraveling SAT Math Question 17

TLDR; An SAT math question from 1982, initially marked incorrectly, sparked a detailed explanation on rotational paradoxes and their implications in math and astronomy.

### 🧠 SAT Question 17

In 1982, an SAT math question (question 17) stumped every student, including the test writers themselves. The question involved the revolutions of circle A around circle B, and the correct answer was not listed as an option.

The students who identified the mistake, Shivan Kartha, Bruce Taub, and Doug Jungreis, wrote letters to the College Board proving the incorrectness of the listed answers.

The solution to the problem was found by considering the rotations of circle A from the perspective of circle B, leading to the realization that the correct answer was not initially provided in the options.

### 🤔 Coin Rotation Paradox

The coin rotation paradox, demonstrated with two identical coins, illustrates that the outer coin rotates twice as it rolls around the other, contrary to initial expectations.

This paradox also applies to question 17, revealing that the correct answer is four revolutions, one more than logically expected.

The explanation involved creating a to-scale model of the problem and taking into account the perspective from both circle A and circle B.

### 🌌 Astronomical Perspective

The definition of a revolution in astronomy is a complete orbit around another body. Using this definition, circle A only revolves around circle B once.

This interpretation highlights the ambiguity of the question and the potential for multiple justifiable solutions based on different perspectives.

The explanation demonstrates the intersection of mathematical concepts with astronomical definitions, providing insight into the complexities of rotational phenomena.

### 💡 Mathematical Explanation

The segment provides a formal proof of the solution to the problem, demonstrating the relationship between the rotation of a circle and the distance traveled by its center.

The explanation delves into the concept of relative velocities and the general principle that the distance traveled by the center of a rolling circle is equal to the amount the circle has rotated.

This general principle extends beyond a mathematical fun fact and is essential in astronomy for accurate timekeeping, showcasing its real-world applications.

### 📚 Implications and Impact

The rescoring of the 1982 SAT, following the nullification of question 17, resulted in students' scores being scaled without it, impacting their final results by up to 10 points.

This seemingly minor adjustment could affect students' educational opportunities, particularly for universities and scholarships with strict minimum test score cutoffs.

The segment also discusses the diminishing relevance of the SAT, with nearly 80% of undergraduate colleges in the US no longer requiring standardized testing after COVID-19.

### 🚀 Future of Standardized Testing

The discussion highlights the declining significance of the SAT and its diminishing role in college admissions, especially in the context of the evolving educational landscape.

The impact of errors on the SAT, the financial costs associated with rescoring, and the shift away from standardized testing reflect the changing dynamics of higher education.

The segment provides insights into the broader implications of the SAT's evolution and the potential alternatives for assessing academic aptitude.

### 🔍 Hands-On Exploration

The conclusion emphasizes the value of hands-on exploration to understand and appreciate everyday phenomena, bridging the gap between theoretical concepts and practical experience.

It encourages active engagement with math, science, and cutting-edge technology, highlighting the potential for interactive learning experiences to foster deep understanding and appreciation.

The promotion of Brilliant as a platform for interactive learning underscores the importance of practical engagement in gaining a comprehensive understanding of scientific principles and theories.