Why do some people who are not related by blood look alike?

We all are related. Genetically. We all belong to the same gene pool.

Everybody on earth is at least 50th cousin with everybody else on the earth. Biologically, it is not so difficult to be almost identical. 

If you go back just 65 generations (the time when Rome empire what building), you will require at least 1,000,000,000,000,000,000 people (I mean your parents, their parents, their parents, etc.) in all. This number is larger that the total number of human ever to be present on this planet. In fact larger that the total number of all of monkeys and primates together. This makes no sense. The only valid inference for this is that our ancestor were mostly practicing incest.

The further back in time you go, the lesser is the number of people. This suggests that there was a lot of incest. In fact there is a 1 in 5 chance that your neighbor(or your wife/date) and you were are from same family fewer than 10 generations ago. 

There is no surprise as to why so many people look alike. In fact the picture you have posted are of famous people. There are other too. Lot of them. You may also be interested in the study that says everybody has a twin somewhere on this planet. 
They do say EVERYBODY has a twin: Mind-boggling portraits of unrelated look-alikes

Also, if you might observe, most of mentally disabled people look amazingly alike!!!

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The following answer from Reddit makes sense.

When a sperm and egg come together and it grows into a baby, there are a million things that can go wrong. It's really common to have an extra chromosome, or a missing chromosome, or a large piece of one that's missing or upside-down.
Most of the time, these mutations lead to death (miscarriage) of the fetus.
Only a tiny number of mutations to your genetic code actually allow the fetus to survive. So those are the ones who are born, and what we observe is that babies who have something wrong with them typically have one of a set of common genetic abnormalities. It's not that those are the only possible abnormalities - it's that all of the other abnormalities are too severe.

Why do men choose to date/sex/marry slimmer women over larger women?

Preface
Matt Ridley in his book, The Red Queen puts a very good case for why men prefer slim and thin women and not fat and huge one. 

Thinness as a factor of beauty is a recent invention.During the renaissance, it was quite opposite. Huge fat bulky women were consider more elite than thin skinny one. This was due to the obvious reasoning that the weight of the body defines the financial status of the women. The queen and the royal ladies were having good hygienic food to eat, less to work and hence were healthier and, as it turns out, more huge than, say, the wife of a peasants or farmers who had to work harder and have less hygienic food.

Portray of women during the renaissance period

An add during the early 20th century showing how to add weight if you are skinny.

Fashion = Beauty

Wallis Simpson has a quote saying  "A woman can never be too rich or too thin"

Fashion changes with time. And, we can know, beauty is subjected to fashion. So indirectly it also changes. Beauty of the women is a moving target. We need not rely only on our own culture for evidence that plump women can be more attractive than thin ones.

Robert Smuts of the University of Michigan has argued, thinness was once all too common and was a sign of relative poverty: Nowadays, poverty-induced thinness is confined to the Third World.

In the industrialized nations, wealthy women are able to afford a diet low in fat and spend their money on dieting and exercise. Thinness has become what fatness was: a sign of status.

Smuts argues that male preferences, keying in on whatever signs of status prevailed, simply switched. They did this presumably by a switch of association.

A young man growing up today is bombarded with correlations between thinness and wealth, from the fashion industry in particular. His unconscious mind begins to make the connection during his critical period, and when he is forming his idealized mental preference for a woman, he accordingly makes her slim.

Miss Americas falls steadily year after year. So does that of Playboy centerfolds. Both categories of women are 15 percent lighter than the average for their ages. Today thinness defines "healthier food with low fat and calories". That is a costly thing to purchase as compared to other food. 

PS- My answer is what I read in Matt's book. Most of the wordings are borrowed from the book. Emphasis are mine.

The logic of God and Evil

Although I always wanted to make a flowchart like this, I was too busy (lazy) to do so.

But somebody made it, by God's grace. I stumbled upon it over the web.

Credit to Steven Butler.

Empathy and Sympathy

"The truth is, rarely a response can make something better, 

what makes something better is connection"

The Chaos Theory - A layman introduction

I spent my Sunday learning about Chaos, Fractal and Self Organisation.

A beautiful and charming concept. I have been trying to get my grip over it for since I first came across it(~2011), but I was always left in bits and piece. A recent book I read made the magic.

The reason why this is beautiful is because of its elegance and importance in understanding the very basic working of nature.

PS- There is a movie based on Chaos Theory. :)

Before you go-to IMDB, you gotta know what Chaos theory actually is.

Chaos- In layman term.

Let say you are practicing basketball. But instead of ball, you have marbles. Now you throw the marble for the first time. You miss the basket by huge distance. Now you realize you have to throw it a bit left. You do this. Again you fail, but this time the distance is reduced. You shift you trajectory a bit more and again you fail but with a lesser distance.

After number of try, you realize the actual trajectory and the elbow angle needed for throwing the marble right in the center of the basket. Yupi!!!

The twist is here. Now even if you throw the marble a little bit left or right, you have a chance of not missing the basket. What this means is, a little bit of change in the initial condition does not change the result of the system to tremendous amount.

This is what we call as Newtonian Systems or Deterministic system. These are system which have initial conditions (the elbow orientation, the trajectory, the size of marble), set of fixed rules/laws (the law of motions, the law of gravity governing the marble, the air friction, etc) and the output (in this case the marble landing in the basket).

Simply, INPUT + LAWS -----determines-----> OUTPUT.

In a Newtonian system, if we know the initial condition and the laws, we can predict the outcome (as in case of marble-basket game, you can predict that if you keep the initial condition and set of rules same, the marble will land in the basket).

But there are some system in nature which is not predictable. What we mean by this is, even if you keep the keep the laws/rules the same and just change the input a little bit, the outcome can be drastically different from the predicted.

Simply, INPUT + LAWS ------doesn't determines -----> OUTPUT

This is a what we called chaos. What it means is "even if you know the exact input and the set of rules governing the system, you can never ever predict the outcome of that system."

Example-

The first mention of chaos theory was by MIT meteorologist Edward Lorenz. Lorenz was working on a new software which was built to predict the weather for future based on same input data (temperature, pressure, humidity,wind velocity, etc). This was based on mathematical equations.

When Lorenz gave some input to the system, he got a graph like this.

|

|

|........---__----.....-----....-------.......------

|

|_________________________________________

Lorenz just re-ran the whole program again with the same input and same software. Surprisingly, this time the input was astonishing different.

|

|         /\             / \

|......../ \..., ,......./ \......., ,......./\.../\......

|              \/                   \/

|_________________________________________

Lorenz was amazed. He checked the input and the calculation once again thinking it was his mistake. Astonishingly, every thing was similar to the last run. Why has the system produced such a different output.

Lorenz realized that there is some changes in the initial input values.

In the first run, the values were like 0.98453 or 12.32470 or 3.6614.

In the second run, the values were 0.984 or 12.324 or 3.661. i.e., the values were rounded off to 3 decimal places.

Lorenz realized that the determinism fails even if you change the value by just 0.0001. That means if there is just a minor change in the input field, the software will show rain instead of winter at particular place. He realized that this is a big failure and that not all system in the nature is deterministic. What this means,there are some system to which you can never determine the output to utmost accuracy, no matter how hard you try, this is because the initial data of some system can never be known with complete accuracy (like weather).

The consequence of this theory is something called as Butterfly Effect. 

It says that flapping of a butterfly's wings in South America could affect the weather in Texas

This is CHAOS THEORY in a nutshell. Happy learning!

The Conversion Factor

Going around Mumbai roads, you will quite frequently  come across this hoarding these days.

Pay attention, keep your mobile phone aside. Think about the following.

• This poster or advertisement has no “responsibility tag”. What I mean by this, the poster has no names of the organization of the committee who are responsible for this.
• This poster has no “description” of what it is all about. All it speaks about is change or parivartan (in hindi).
• It has Johnny Lever and Nagma. Both of them a known television stars. Good selling point.
• It offers you free books and free sessions. Just call on the number. Maybe just a miscall will do

Read more

It is always now....

"It is always now 

i actually want to talk 

today about death 

now most of us do our best to not to think about death 

but there's always part of our minds that knows 

this cant go on forever 

part of us always knows 

they were just a doctor's visit away or a phone call away from being starkly 

reminded 

with the fact of our own mortality 

or of those closest to us.

Now i'm sure many of you in this room have experienced this in some form 

you must know how uncanny it is 

to suddenly 

be thrown out of the normal course of your life 

and just be given the full time job of not dying 

or caring for someone who is.

But the one thing people tend to realize 

at moments like this is that they wasted a lot of time 

when life was normal 

and it's not just what they, it's not just what they did with their time, it's not just 

that they 

spent too much time working or or compulsively checking email 

it's that they cared about the wrong things 

they regret what they cared about 

their attention was bound up in petty concerns 

year after year 

when life was normal 

and this is a paradox of course because 

we all know 

this epiphany is coming 

i mean, don't you know this is coming? 

don't you know there's going to come a day 

when you'll be sick or someone close to you will die 

and you'll look back 

at the kinds of things that captured your attention 

and you'll think, "what, what was I doing?" 

you know this, and yet if you're like most people, 

you'll spend most of your time in life 

tacitly presuming you'll live forever 

it's like watching a bad movie for the fourth time 

or bickering with your spouse 

I mean this, these things only makes sense 

in light of eternity 

there better be a heaven if we're gonna waste our time like that 

there are ways to 

really live in the present moment 

what what's the alternative? 

it is always now 

however much you feel you may need to plan for the future 

to anticipate it, to mitigate the risks, 

the reality of your life is now 

this may sound trite 

but it's the truth 

it's not quite true as a matter of physics, in fact there is no now 

that encompasses the entire universe you can't talk about an event 

being simultaneously 

occurring here and one 

at the same moment occurring in Andromeda 

the truth is, now is not even well-defined as a matter of neurology because 

we know that inputs to the brain 

 come at different moments and that consciousness is built upon layers 

of inputs whose timing to have to be different 

are conscious awareness of the present moment is 

in some relevant sense already a memory 

but as a matter of conscious experience 

the reality of your life 

is always now 

and i think this is a liberating truth about the nature of the human mind in 

fact i think there's probably nothing more important to understand 

about your mind than that 

if you want to be happy 

the past is a memory 

it's a thought 

arising in the present 

the future is merely anticipated, it is another thought 

arising now 

what we truly have 

is this moment 

and this 

and we spend most of our lives forgetting this truth 

repudiating it, fleeing it, overlooking it, 

and the horror 

is that we succeed 

we we've managed to 

never really connect with the present moment and find fulfillment there because we 

are we are 

continually hoping to become happy in the future 

and the future never arrives 

even when we think we're in the present moment we're, we're in very 

subtle ways, always looking over its shoulder 

anticipating what's coming next 

we're always solving a problem 

and it's possible to simply drop your problem 

if only for a moment 

and enjoy whatever is true of your life in the present 

this is not a matter of new information 

or more information, it requires a change in attitude 

it requires a change in the attentiveness you pay 

to your experience in the present moment "

Part of script adopted from Sam Harris Lecture 

Sam Harris - Death and the Present Moment

Sam Harris