No, this article is not about whether it’s Bitcoin’s moment to shine. It is a somewhat technical explainer on how Bitcoin implements time, or timestamps. First, we need to understand why Bitcoin needs a notion of time at all. If you don’t care for this, you can directly jump to the “How” section of the […]

# Category: computer science

## Trusting Trust

Ken Thompson is a Turing Award winner and an all-around genius – gave a seminal talk during his 1984 Turing Award acceptance called “Reflections on Trusting Trust.” In this lecture, he shows how to sneak a Trojan horse into your application (in his case, the Unix operating system) while you compile the source code of […]

## Governance, Decentralized

Define Governance: the act or process of governing or overseeing the control and direction of something (such as a country or an organization). In this article, I will focus on whether any organization can have decentralized governance, and what does that even mean? And how is this related to cryptocurrencies. Let’s start with a very basic organization, and […]

## So much to learn, ponder about, and do….

And so much time to do it. Scott Aaronson’s “rant” on naysayers of complexity theory got me pondering. Over the last few months, my general scientific pondering has suffered at the hands of real work, startup life routine, system building, and a general state of being occupied by the trite. It’s fascinating, but not inspiring. […]

## Genius

The Feynman Method Richard Feynman was fond of giving the following advice on how to be a genius. You have to keep a dozen of your favorite problems constantly present in your mind, although by and large they will lay in a dormant state. Every time you hear or read a new trick or a […]

## Counter Example

Finding counter examples to conjectures can be notoriously hard (pun? I think not). This is an area of creativity that mostly goes unappreciated. Here’s a personal anecdote: my father once came up with an algorithm to solve a hugely constrained version of the traveling salesman problem. The greedy proof was slightly hand-wavy, and I felt […]

## Eigen

Jatin forced a comment which is worth expanding a little more. Ever since I found that the PageRank vector of the web-graph is the dominant eigenvector of its matrix representation, I have been meaning to get to the bottom of this eigenvector-eigenvalue concept. I am still snorkeling; long time to scuba dive. Most of us […]

## Quantum Brain?!?!

In my last post on heuristics and approximation, I asked the question – Given realistic scale and scope, how does the human brain solve such problems (like question-answering)? Does the brain map everything to combinatorial optimization? Can its modus operandi be applied to automated systems so that they solve our problems…. – which leads to […]

## Heuristics vs. Provability

Given a problem, we can: Give efficient methods to find exact solutions. When this is possible, all’s well. But alas, this is not possible all the time. Give inefficient methods to find exact solutions (brute force), and bemoan that P != NP (mostly). Propose intuitively appealing heuristics that are quick, and give “mostly good” results […]

## Traveling Salesman

The traveling salesman problem (TSP) is a very simple combinatorial optimization problem. Given a set of cities and distances between each pair, the problem is to find the tour of least distance that travels each city exactly once. Simple – as in simple to state. But from what I have seen this seems to be […]