On this day in physics: 25 February 1837- Thomas Davenport patented the electrical motor. [Source]
Word of the Day- Tangent- A tangent is a line which touches a curve at one and only one point. There is a special definition of tangent in calculus, however. The derivative is the slope of the line tangent to the curve at that point. So, I personally have had a very difficult time envisioning this in my mind. If I think of a curve, such as a sine, cosine, parabola, etc. I feel like there are many lines which can touch the curve at one specific point and satisfy this definition. So, we will defer to the man who independently invented calculus alongside Issac Newton, Gottfried Leibniz. He says that the tangent line is the line which passes through two points on a curve which are "infinitely close" together. That to me makes much more sense. Take two points on the curve, and envision the line which goes through this, then bring those points closer and closer together, towards the point you desire, and the line that it approaches is your tangent line. Because of their usefulness in derivatives, tangent lines are very important in almost every aspect of physics.
Quote of the Day: "Prediction is very difficult, especially when it's about the future" -Niels Bohr
Keywords: Tangent, Line, Derivative, Calculus, Curve.
