## What’s the worst thing about Elon Musk?

What's the worst thing about Elon Musk?

Answer by Nishanth Salinamakki:

It’s true that Elon Musk is seen as nearly perfect (especially in the Quora community). It’s because a very few percentage of people can start one successful company, and he’s founded three (Zip2, SpaceX, PayPal) and been involved in others (Tesla, SolarCity, OpenAI). He’s now leading two companies in two completely different industries that have long-term goals that resemble science fiction. His companies are striving to change the way we

live, not consume goods. That kind of success and drive is unprecedented; that’s why Musk is hailed as one of the greatest entrepreneurs and the reason why everyone is obsessed with him. Everyone wants to be like him.However, no one is perfect, and everyone has a dark side, especially insanely successful men like Elon Musk (often because of the traits that make them successful). Musk’s flaws are highlighted in Ashlee Vance’s comprehensive biography on Musk: Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future: Ashlee Vance: 9780062301239: Amazon.com: Books.

Elon Musk is not the best with relationships. He even whispered to his first wife during the wedding, “I am the alpha in this relationship”.

He never took no for an answer, and he rode his employees hard, right out of their minds, and sometimes right out of the company. Mary Beth Brown was a devoted assistant to Musk, who was there from the beginning of SpaceX (when it was viewed as a joke) and worked the same hours he did. However, when she asked for a raise, Musk still questioned her value to the company and after telling her to take two weeks off, decided that SpaceX could operate fine without her.

He is uncompromising and demanding, forcing employees to work long hours (if any other CEO did this, no one would work for him/her but since Musk’s companies’ goals are so exciting and meaningful, everyone agrees to pour their heart and soul into the company’s mission).

He had laser-like focus; if there was something he wanted, he would stop at nothing to get it, often sacrificing other personal aspects of his life and leaving behind casualties.

Although he’s extremely humble in interviews, he doesn’t truly see anyone else on the same level as him, and will assert his superiority to remind others of that. His second wife explained to Ashlee Vance that “Elon doesn't have to listen to anyone in life. No one. He doesn't have to listen to anything that doesn't fit into his worldview. But he proved he would take s**t from me.” That makes it difficult for him to relate to others and develop meaningful relationships. But his immense confidence and inability to conceive of himself failing allowed him to establish three successful companies in the first place.

As you start to realize, many successful people have flaws that are

not independent. That is, they aren’t separate from all their good traits (work ethic, focus, confidence). In fact,the flaws originate from the very traits that make them successful. Michael Jordan was a ruthless competitor, which made him so great in high-pressure situations and in the game of basketball. However, his gambling problem and intense leadership style stemmed from this incessant competitiveness. Steve Jobs could be vicious to his employees not because he was simply a mean guy, but because of his immense passion for the company, and he demanded utmost perfection from his employees. Nikola Tesla made outlandish claims that he could never live up to. It wasn’t that he was simply a liar and wanted the publicity; he was an engineering visionary and because of this, his mind constantly wandered to these incredible possibilities and visions he dreamt up and as a result, he never focused on one invention.The point is, even people who are worshipped and idolized are not perfect and can sometime have

even more glaring flawsthan ordinary people. Many incredibly successful people have an extremity (whether it be immense confidence or insane work ethic or incessant drive), and often, these extremities cause them other problems in life. But these extremities are what ultimately help them attain that level of success.Moreover, it’s these flaws that humanize them and give us a unique and renewed perspective of who they are. Although most of their imperfections are the result of extremities many people don’t have, it still inspires confidence and helps young generations realize, “Hey, they’re not perfect. They’re humans, just like me. If they’ve come this far and achieved this much, then why can’t I?”

Sources:

Jim Cantrell's answer to How did Elon Musk learn enough about rockets to run SpaceX?

## What is the most ridiculous thing that you have ever convinced someone to believe?

What is the most ridiculous thing that you have ever convinced someone to believe? by @tellmeyourgoal

Answer by Steven Matt:

This is a true story that involves Donald Trump, the Dalai Lama, and a doorman.It was September 2003. I had just arrived in NYC from Arizona to start college. I packed a backpack, shipped some boxes out and didn't look back. I was on a mission.

It was one of those late summer, early autumn nights in NYC where anything was possible. The streets were alive and people had plans. The air was complex and misty. It smelled like the aftermath of a concert. There was an orange glow to everything. Perhaps it was from the streetlights. Or maybe it was the omnipresent charge of NYC energizing everyone and everything through its sheer presence. At least that's how it seemed to me after having just arrived here the night before.

It was about 2am and I was wandering the streets of Brooklyn with two girls I had just met at college. We still had energy and wanted to keep exploring. We decided we would walk across the Brooklyn Bridge to Manhattan. By 4am we were in Times Square. NYC was still alive as ever at that time. No one seemed to sleep. So we didn't either.

We were handed a flyer that announced the Dalai Lama's event in Central Park that morning. That was it. Our destination was set. We had somewhere to be. We started uptown. By then, we had probably walked 15 miles.

When we finally arrived at the south west entrance of Central Park, we quickly realized that the park was closed until the Dalai Lama arrived and we couldn't get in. Police were everywhere and the barricades were up.

The sun was about to rise.

We had been on the streets all night.

We were sweaty and needed some place to sit down.

The girls decided they wanted to watch the sunrise.

Above us rose what seemed to be the tallest building we had seen all night: Trump International Hotel & Tower at 1 Central Park West.

I had to get us to the top. How could we waste a morning like this on the streets without watching the sunrise?

What followed could have been an outtake form Ferris Bueller's Day Off.

You can't just walk into the Trump International Hotel & Tower, but that's exactly what we attempted to do.

There was a doorman on duty. But how could we get by him?

I couldn't believe it but he was asleep. We took the opportunity and quietly walked right by him and into the elevator across the lobby.

We couldn't press a button without a key.

Plan foiled.

Or so we thought.

As we nervously huddled in the elevator, I explained to the girls the plan: we would start making a bunch of noise so we would wake him up as we came out of the elevator seemingly from upstairs. We would then walk out the elevator and approach the doorman as we angrily accuse him of sleeping on the job. He will assume we live in the building and we will take that opportunity to make our demands, which he will be expected to fulfill so as not to lose his job.

It worked just as planned.

We busted out of the elevator screaming about some made up conversation. We were talking about ballet or some pretentious nonsense to add to our wealthy, Trump resident persona.

We stopped and just starred at him as he was waking up rubbing his eyes. He was clearly embarrassed and ashamed. Perfect. Just where I wanted him.

I walked up to him and quietly explained that I didn't want to get him in trouble. I explained that he could avoid any trouble if he sent for a couple of bottles of champagne and breakfast for me and girls on the roof.

He didn't hesitate. He got on his phone and called the kitchen immediately. We asked him to escort us to the roof and set a place for us to dine and enjoy the sunrise.

This whole time he believed we were residents of the Trump International Hotel & Tower on Central Park West. One of the most expensive residences in NYC. Three sweaty, underage college students dressed like scallywags.

When we arrived on the roof, we were surprised to see a beautiful setup. Lounge chairs, tables with umbrellas, and a view of Central Park that was out of Lifestyles of the Rich and Famous.

The champagne and breakfast quickly arrived. Along with a bouquet of flowers.

The three of us were alone on the rooftop of the Trump Tower with two bottles of champagne, a full breakfast, comfortable chairs, and a view that very few people get to see.

The sun was rising.

The Dalai Lama's monks were drumming in the park announcing his arrival and practicing for the main event.

We felt it.

It was NYC's way of welcoming us and showing us what was possible.

It was a taste of the good life.

But it was based on deception and it wasn't our reality.

We knew that if we wanted that reality we would have to earn it.

I don't know what happened to the two girls after that night. I never saw them again.

But I'm positive that they still remember it.

I'm still trying to find a way back to that metaphorical rooftop.

What is the most ridiculous thing that you have ever convinced someone to believe?

## DIGIT Magazines

**Stable Web archive version: Here.**

Beyond this, any backed up version of this page on web archive will appear broken. Actually, the links still work but it’ll take you an extra click. So if you’re currently viewing this page on web archive, go to the above linked url for best experience.

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Archive.org Hosted file page: https://archive.org/details/digitPDFover32mb

## Encyclopedia Technica

## What are some interesting experiences you’ve had as a teen?

What are some interesting experiences you've had as a teen? by Dana Fletcher

Answer by Dana Fletcher:

A few years ago, I was at my friend Kristina's house, and after a few hours of fun, I was ready to go home. This was before I could drive, so I relied on my dad to pick me up. The only problem was my dad had a few more beers and couldn't come get me.

This also happened to be the night of prom at the local high school. Because of this, every taxi service was booked. So my dad had to arrange a ride for me with the only thing available:

A 33 foot stretch limousine.My family is not rich by any means. But my dad is always doing something weirdly creative, and when the chauffer came to my friends front door and said “I'm here to pick up Dana”, I knew my dad had struck again.

## What’s with 32 bit systems supporting max 4GB of RAM?

So you know that RAMs contain storage space. Common sense. Every **byte** of memory on RAM requires to have an address allocated to it. A 32-bit machine uses 32 bits long address to designate each byte of memory. *And a memory that does not have an address allocated can not be seen by the machine*.

Now let’s understand how these addresses work.

Each bit has a value of 0 or 1. If you have 1 bit long address, you have two possible addresses: 0 or 1. A two-bit system has four possible address: 00 =0, 01=1, 10=2, 11=3. 2^2=4. Three bits have 8 possible addresses: 000=0, 001=1, 010=2, 011=3, 100=4, 101=5, 110=6, and 111=7.

Each bit doubles the potential address space, which is why 2^n tells you how many addresses you use for a given number of bits. 2^1 = 2, 2^2 = 2*2 = 4, 2^3 = 2*2*2 = 8, etc. By the time you get to 32 bits, you have allocated address to 2^32 = 4294967296 bytes of RAM space which is equal to `4GB`

.

(((2^32bytes/2^10)KB)/2^10)MB)/2^10)GB = 2^2GB

Okay, so if the processor, and the operating system designed for that processor, can only handle 4GB, why can’t your PC (if it’s 32-bit) see that much practically?

Because not all of those addresses are available for RAM. There are other pieces of hardware inside your computer that need addresses, such as the PCI bus and the USB host adapter, Graphics card, etc.

Whenever you store something in the memory, you need to save the address to be able to read or manipulate it. Usually, the CPU uses only one register (32 bit in size) to store this address. Since there are only `2^32`

different addresses, anything exceeding the `4GB`

mark remains unused.

However, there are techniques like Physical Address Extension (PAE) that allow a 32-bit OS to address more than `4GB`

of RAM.

## What is the best strategy to improve my skills in competitive programming in 2-3 months?

Answer by Sachin Gupta:

This post has been taken from the blog postLearn to Code by Competitive Programmingwritten byMV Kaushikwhen he was interning atHackerEarth

Here are some steps to get started and be good at it.

- Get comfortable writing code in either of one of these languages
C, C++ or Java. Why only C, C++ or Java? Because these are the standard languages allowed in any programming competition.- If you are already good at C, it is suggested to
learn C++. It is the most popular language among competitive programmers because of its speed and an excellent library in the form of STL (Standard Template Library).- Pick an online judge. Recommended ones are
TopcoderandCodeforces. These sites have high quality of problems and also allow you to see other’s code post contest completion. These also categorize problems based on the topic. Some other popular judges include SPOJ, CodeChef (powered by SPOJ) andHackerEarth.- To begin with,
start with simple problemsthat typically require transformingEnglish to code and does not require any knowledge on algorithms. Solving Div 2 250 (Division 2, 250 points) in Topcoder or Div 2 Problem A in Codeforces is a good start.- At the early stages of programming one tends to write long pieces of code, which is actually not required. Try to keep codes
short and simple.Practicethese problems until you become comfortable that you can submit it for 240 odd points on any day.- Start implementing basic(or standard) algorithms. It is suggested to read them from
Topcoder tutorialsorIntroduction to algorithms.1) Graph algorithms: Breadth first search(BFS), Depth first search(DFS), Strongly connected components(SCC), Dijkstra, Floyd-Warshall, Minimum spanning tree(MST), Topological sort.

2) Dynamic programming: Standard dynamic programming problems such as Rod Cutting, Knapsack, Matrix chain multiplication etc.

3) Number theory: Modular arithmetic, Fermat’s theorem, Chinese remainder theorem(CRT), Euclidian method for GCD, Logarithmic

Exponentiation, Sieve of Eratosthenes, Euler’s totient function.3) Greedy: Standard problems such as Activity selection.

4) Search techniques: Binary search, Ternary search and Meet in the middle.

5) Data structures (Basic): Stacks, Queues, Trees and Heaps.

6) Data structures (Advanced): Trie, Segment trees, Fenwick tree or Binary indexed tree(BIT), Disjoint data structures.

7) Strings: Knuth Morris Pratt(KMP), Z algorithm, Suffix arrays/Suffix trees. These are bit advanced algorithms.

8) Computational geometry: Graham-Scan for convex hull, Line sweep.

9) Game theory: Basic principles of Nim game, Grundy numbers, Sprague-Grundy theorem.

The list is not complete but these are the ones that you encounter very frequently in the contests. There are other algorithms but are required very rarely in the contests.

- You can find description and implementation of standard algorithms here
- Once you have sufficient knowledge of popular algorithms, you can start solving the medium level problems. That is Div 2 all problems in Topcoder and Codeforces. It is advisable not to go for Div 1 500 at this point.
- Learning to code is all about practicing.
Participate regularlyin the programming contests. Solve the ones that you cannot solve in the contest, after the contest. Apart from Topcoder and Codeforces you can also look at HackerEarth Challengesor Codechef contests.Read the codesof high rated programmers. Compare your solution with them. You can observe that it is simple and shorter than your solution. Analyse how they have approached and improve your implementation skills.Read the editorialsafter the contest. You can learn how to solve the problems that you were not able to solve in the contest and learn alternative ways to solve the problems which you could solve.- Always
practice the problems that you could solve in the contest. Suppose if you are able to solve Div 2 250 and 500 in the contest but not Div 2 1000 then practice as many Div 2 1000 problems as as you can.Do not spend too much timeif you are not getting the solution or are stuck somewhere.- After you feel that you have spent enough time, look at the editorials. Understand the algorithm and code it. Do not look at the actual solution before you have attempted to write the code on your own.
- Programming is a very practical and hands on skill. You have to continuously do it to be good at it. It’s not enough to solve the problem theoretically,
you have tocode it and get the solution accepted. Knowing which algorithm/logic to use and implementing it are two different things. It takes both to be good at programming.- Programming learning phase is going to take a lot of time and the key is
practicing regularly. It takes some time before you can attempt Div 1 500 and other tough problems. Do not give up on reading the editorials and implementing them, even if it takes many hours/days. Remember everything requires practice to master it.It takes considerable amount of time before you get good at it. You have to keep yourself motivated throughout. Forming a team and practicing is a good choice.

Not giving up is the key here.

What is the best strategy to improve my skills in competitive programming in 2-3 months?

## What was Anudeep Nekkanti’s Competitive Programming strategy to become 35th in Global ranking, in just 6-7 months?

Answer by Anudeep Nekkanti:

What I did ?

- Solved about 300 problems on SPOJ in this order – Sphere Online Judge (SPOJ)

Result ?

- Became very good with C++ and STL
- Got introduced to most Competitive programming KEYWORDS (like DP, maxflow, sets, hashing, etc)
- Learned Standard Problems and Algorithms
- Indenting code
- Fast typing 😛

How ?

Before starting programming, I searched about how and where to start, many said “Learn an Algorithm, implement it, solve problems related to it”. I didnotdo it that way, If you know what algorithm to use you generally think in that direction and leave about correctness. I did them problem by problem, easy to hard, I spent 1 – 4 hours on a problem.

I get the idea, I code it, Get it Accepted. (I used to test a lot, I always wanted to get AC on first go)I do not get the idea, I save that problem and try it after a month again. If I still do not get them, then search for hints. If it clearly needed some algorithm which I never used then I first smile (? I could not only because I did not knew the algorithm 😛 ) and then start reading about that algorithm. TopCoder had tutorials of almost all common algorithms. This is where I did a

BIG MISTAKE. I never cared about correctness or run-time analysis proof, I always learned how to solve the problem using that algorithm, I hardly learned about how the algorithm works. I feel bad about it now, but that is how I solved those problems then. I solved max-flow, convex hull, etc., problems using described algorithms but I did not UNDERSTAND those algorithms then.

Mistake:Once I started taking part in contests, I completely stopped practice.

35th in Global Ranking

- CodeChef long contests are comparatively easy ( Which is good, You can learn a lot), you get a lot of time to think about a problem, search for resources. You only need KEYWORDS to search for similar problems.
- I gave a lot of time for each contest. I used to solve 4 easy problems in 2-3 days, then take 5-6 days for other 3 problems.
- CodeChef rating system is not good. It is highly Volatile.

If I am to start programming now, I would do it this way

- Solve 200 most solved problems on SPOJ, Problem by problem. In 2 months.

(This will teach all standard problems, algorithms and implementation skills)- Solve problems from CodeChef and CodeForces for 2 months.

(This will teach variations, we can read others solutions and learn better ways. Skip easy problems)- Solve problems from TopCoder for 2 months.

(This will teach Dynamic Programming. Div 1 500p)- Check past ACM ICPC Regional’s Problems

(Great quality problems)

If I am to learn a new Algorithm now, I would do it this way

- Read it from at least 3-4 different sources.
- Understand correctness proof and run-time analysis.

(This is very very important, you will know it only when you deal with non standard and hard problems)- Question yourself on every step for correctness. Try to tweak the implementation.
- Check other implementations.

Final Note

Thought I became good in solving problems and had good rank. I later(Feb 13) realized that I learned it the wrong way. I then started learning again. I learned all the algorithms again this time gave importance to the algorithm itself, correctness proof and mathematical analysis. It is worth the time.Lucy and the Flowers – Problem from December long contest, Try to solve it with suffix arrays. You can only if you understand suffix arrays and LCP completely.

I was able to solve a not-so-obvious medium level Max-Flow problem at ACM KGP Onsite only because I completely understood how the algorithm works. It was at 4 hour 25 minutes I got 5th problem accepted, then I read this problem and got it accepted 4 minutes before end. Learning the algorithm helped. Dot.

## Why does breaking the sound barrier create a sonic boom?

Boom is really a misleading word for it because it implies something like an explosion – when really it’s more of a constant roar. It just sounds like a boom from land, because unlike normal sound, which would reach you from the plane constantly as it flies by, the boom is like the wake of a boat, only hitting you once for each pass.

I think part of the reason this isn’t well known is because of all the photos of jets breaking the sound barrier.

http://res.cloudinary.com/dk-find-out/image/upload/q_80,w_1440/A-iStock_000017498245Large_pxojdi.jpg

That plane wasn’t going supersonic though. The cone happens at transonic speeds, so when the plane is accelerating, as it nears Mach 1 a shock cone can appear. You can tell in the video that it is very close to Mach 1 because there is no sonic boom and the sound from the plane appears just before it passes.