Are you ready? Here goes…

Einstein notation is the simplest way to multiply stuff in math. It’s like a secret code for mathematicians and physicists that allows us to write equations faster than ever before! And, it’s not just any old code it’s named after Albert Einstein himself!

So what exactly is this magical notation? Well, let me explain…

In traditional math, when we want to multiply two matrices together, we have to use those ***** parentheses and write out the indices explicitly. For example:

Cij = Aik * Bkj

But with Einstein notation, we can just skip all that nonsense and write it like this:

Cij = AikBkj

See how much simpler that is? No more ***** parentheses or explicit indices! It’s like magic.

Now, you might be wondering what about summation signs? Don’t we need those to indicate a sum over all possible values of the index? Well, in Einstein notation, we assume that any repeated index is being summed over automatically. So if we see an expression like this:

Cij = AikBkj

We know that what we really mean is:

Cij = _k Aik * Bkj

Pretty cool, right? And it gets even better! We can use Einstein notation to write down entire equations in a single line. For example, let’s say we want to write out the equation for the Lorentz force on a charged particle moving through an electromagnetic field:

Fα = qEα + qvβ(Bγ)

But with Einstein notation, we can just write it like this:

Fα = qEα + qvβBγ

See how much simpler that is? No more ***** parentheses or explicit indices! It’s like magic.

The simplest way to multiply stuff in math, named after the greatest physicist of all time. Give it a try and see how much faster your equations become!