Tag Archives: Emmy Noether

March 23, 2015

SR #5: Diagrams!

Flatland Last week I introduced you to the idea of relative motion between frames of reference. We’ve explored this form of relativity scientifically since Galileo, and it bears his name: Galilean Relativity (or Invariance). Moving objects within a (relatively) moving frame move differently according to those outside that frame.

I also introduced you to the idea that light doesn’t follow that rule; that light moves the same way to all observers. This is what makes Special Relativity different. It turns out that, if a frame is (relatively) moving fast enough, some bizarre things happen.

Time-space diagrams will help us explore that.

2 Comments | tags: 1D, 2D, 3D, diagrams, dimensions, Edwin Abbott, Emmy Noether, Flatland, maps, motion, Special Relativity, time, time-space, time-space diagram | posted in Physics

March 19, 2015

SR #3: Relative Velocity

By Wyrd Smythe

Throwing like a girl!

I’ve introduced the idea of an inertial frame of reference. This is when we, and objects in our frame, are either standing still or moving with constant (straight-line) motion. In this situation, we can’t tell if we’re really moving or standing still relative to some other frame of reference. In fact, the question is meaningless.

I’ve also introduced the idea that objects moving within our frame — moving (or standing still) along with us, but also moving from our perspective — move differently from the perspective of other frames. Specifically, the speed appears different.

Now I’ll dig deeper into that and introduce a crucial exception.

11 Comments | tags: Albert Einstein, Emmy Noether, Galilean invariance, Galileo Galilei, Mo'ne Davis, motion, scalars, Special Relativity, speed, vectors, velocity | posted in Physics

March 18, 2015

SR #2: Relative Motion

By Wyrd Smythe

sr2-0 In the last two posts I’ve explained how Special Relativity concerns relative motion between two frames of reference, and that the motion involved is constant, straight-line motion that allows us to view either frame as the “moving” one or the “standing still” one.

Today I’m going to dig a little bit deeper into the idea of relative motion and what that involves for actions within a constantly moving frame of reference versus what observers in a different frame perceive. In other words: trains, planes, and automobiles.

(Warning: this gets a little math-y, but you can ignore those bits.)

25 Comments | tags: Albert Einstein, bowling ball, Emmy Noether, frame of reference, Galileo Galilei, James Maxwell, motion, relative motion, relativity, Special Relativity | posted in Physics

March 14, 2015

Special Al Day!

By Wyrd Smythe

Okay. I’ve been teasing doubly special Saturday and (especially this year) since last Monday (and planting hints along the way). If you haven’t figured it out by now, today is Albert Einstein’s birthday. It’s also pi day, and how cool is it that a guy like Al was born on pi day?

So: Happy Birthday Albert! The (especially this year) part is because it’s extra-special pi day (3/14/15) and because this year I’m finally going to do what I’ve been wanting to do here to commemorate Einstein’s birthday since I started this blog back in ought-eleven.

I’m going to write — at length — about Special Relativity!

8 Comments | tags: Albert Einstein, Emmy Noether, faster than light, FTL, Happy Birthday, light speed, pi day, Special Relativity | posted in Math, Physics