Roberto Abraham Scaruffi

How do I make money online from home? Faisal Khan, Banking & Payments Consultant 1.6k votes ​ I love this question! Why? Because as someone who makes a full-time income from working at home, I think I'm a tad bit qualified to give some input. ... Read More »

How do I prove ab=0 if and only if a=0 or b=0? David Joyce, always learning 115 votes This theorem is valid in any field. A field has the usual operations of addition, subtraction, multiplication, and division and satisfies the usual properties of these ope... Read More »

Why don't tanks have two or more turrets? Dan Rosenthal, Former Foreign Service Officer, Iraq ... 412 votes More than anything else, the weight will be the limiting factor here. An M1A2 weighs roughly 68 tons. That's freaking heavy. In order to propel that tank, you need one hel... Read More »

Is it possible to teach yourself math to the level of a post-doctorate or PhD? Alan Bustany, Trinity Wrangler, Poker Player 80 votes Srinivasa Ramanujan (1887–1920) managed this but there are, have been, and will be very few "Ramanujan"s in this world. Your logic that "you don't have time" seems flawed.... Read More »

What would society be like if there was another species of animal as intelligent as humans? James Pitt, Harvard HEB graduate. 1.2k votes There was another species close to as intelligent as humans.  They're dead. Though we hooked up with some of them first. Most humans today can trace a tiny bit of our ance... Read More »

Should we ban junk food? Peter Flom, Independent statistical consultant fo... 210 votes TL:DR No Explanation: First, banning things is usually a bad idea. It doesn't often work. See e.g. prohibition or the "war on drugs". Let's create a black market in ding... Read More »

How brutal was medieval combat? Seth Pace 522 votes Archaeology has much to say on the subject. The overriding theme, though, is that it was thoroughly horrific. Spend some time on Google Images with a search of "Battle of ... Read More »

What makes a mathematical proof "elegant"? Ray Li, Phillips Exeter '13, CMU '17 1.7k votes I will illustrate with one of my favorite problems. Problem: There are 100 very small ants at distinct locations on a 1 dimensional meter stick. Each one walks towards one... Read More »

What are some things that mechanical engineers know and others don't? Hemanth Putrevu, Mechanical engineering undergrad.. 7.4k votes We mechanical engineers know about the Geneva Mechanism. Ever wondered how to convert a continuous rotatory motion to an intermittent one? Well, the Geneva drive, or comm... Read More »

What are your top five suggestions for getting out of depression? Jay Bazzinotti, No one is perfect... but I am as clos... 1.3k votes This is a good question. Here is what I suggest: 1) Drink alot of water. The single best thing you can do for yourself is drink more water. 2) Take a lot of Vitamin D. At ... Read More »