Entries Tagged 'Quandaries' ↓

Q's Quandaries #2: What is 20dB/decade?

I enjoyed the last Q’s Quandaries where we took a relatively little trip around general relativity and talked about gravity. In an effort to mix things up, the quandaries will cover as many different fields as I can manage. This is another simple one (if you know the answer). Up for grabs to the first & best answer, a stylish and hip Tech-Recipes.com T-shirt.

In engineering school, one is quickly assaulted with a number of interesting new ways of expressing otherwise simple concepts. And by interesting I mean unnecessarily complex. This is probably true in many fields.. doctors have Latin names for silly body parts (we all have tiny holes in our head named the innominate foramina, aka, “tiny little holes with no name”). Anyway, when doing frequency-domain analyses of systems, one value keeps cropping up over and over again.

20 decibels/decade

There are elaborate ways to describe this, but it took me years of using this value (and multiples of it) in answers to engineering questions before I finally understood a deeper meaning (I’ve always feared that everyone else got this from day one). In fact, it wasn’t until I was a grad student teaching a bioinstrumentation lab (and trying to explain it to the one student who actually had the capacitors to ask) that I had my epiphany.

So, here’s the quandary: what is a simple explanation of 20 dB/dec?

Q's Quandaries #1

Something recently reminded me of a fun question that I loved to taunt folks with back in grad school. It wasn’t an apple falling on my head, but close enough. It’s fun because the answer is simple (and there aren’t many choices), but the justifications of the answers often border on the epic.

To make this more interesting, the first person with the correct answer AND and an explanation that I like will get a free Tech-Recipes “Computers Fear Me” t-shirt. If we all have fun with it, there may be more quizes in the future. So here goes:

According to Einstein’s equivalence principle, the effects of a gravitational field are indistinguishable from that of linear acceleration. So, in what direction are we accelerating as a result of Earth’s gravity?