# blueollie

## In defense of “Safe Spaces” (of a type)

Ok, let me make it clear what I am not defending: while I understand male/female bathrooms and locker rooms, I do not approve of having a university sanctioned area where only men, or women, or someone of a specific race are allowed.

What I am talking about: voluntarily limiting one’s social circle when it comes to certain things.

Here is one instance: usually, I make it a point to never discuss mathematics except with other mathematically inclined people (mathematicians or experienced STEM field people).

Reason: I teach for a living, and correcting someone’s elementary error is not a pleasant exercise for me, especially when they try to insist that they are right.

This is not how I want to spend my “off work” time.

I broke my rule of thumb, and paid a small price. Here it is:

Prove: 1 = 2.

$x^2 - x^2 = x^2 - x^2$ Ok, true enough.

$x(x-x) = (x+x)(x-x)$ Yes, this is true: $(x+x)(x-x) = (x(x-x) + x(x-x)) = x^2 -x^2 +x^2 - x^2 = x^2 - x^2$. Yes, this also equals $2x^2 - 2 x^2$.

Now that we have $x(x-x) = (x+x)(x-x)$ Cancel an $x-x$ factor on each side.

This gives $x = 2x$ which leads to 1=2 after cancelling the x.

Of course, this is wrong; we were not allowed to divide both sides by $x-x$ as that is zero.

But someone tried to tell me that iwas ok to divide by zero even if the numerator did NOT go to zero…Oh boy.

February 27, 2017 -