Kurraga

May 13

vgkait:

It is the start of the year 2000, and something is wrong.
Husbands and wives wake up next to each other, scared. They don’t know who the person in the bed with them is. Who is this person? Why are they in my house? Is this my house? Is this their house?
They go out to investigate. A five-year-old child uses a Windows 98 computer in the living room. The child turns around, and asks, “Is it time for me to go to school, mommy?”
The world is in panic. The President of the United States, who awoke in the Oval Office with no knowledge of being elected, calls for a large-scale investigation.
After weeks of asking adults and children alike what is going on, and looking at the various public records, they realize that the children are not confused at all. The adults can only remember what last happened in 1989. However, the children that can speak say that they were born anywhere from 1991 to 1996. Public officials can only draw one conclusion.
To every adult, the 1990s never happened. The children, however, cannot have come from nowhere.
It doesn’t take long after this conclusion for them to realize that only 90s kids remember the 90s.

It is the start of the year 2000, and something is wrong.

Husbands and wives wake up next to each other, scared. They don’t know who the person in the bed with them is. Who is this person? Why are they in my house? Is this my house? Is this their house?

They go out to investigate. A five-year-old child uses a Windows 98 computer in the living room. The child turns around, and asks, “Is it time for me to go to school, mommy?”

The world is in panic. The President of the United States, who awoke in the Oval Office with no knowledge of being elected, calls for a large-scale investigation.

After weeks of asking adults and children alike what is going on, and looking at the various public records, they realize that the children are not confused at all. The adults can only remember what last happened in 1989. However, the children that can speak say that they were born anywhere from 1991 to 1996. Public officials can only draw one conclusion.

To every adult, the 1990s never happened. The children, however, cannot have come from nowhere.

It doesn’t take long after this conclusion for them to realize that only 90s kids remember the 90s.

(via throughthexhole)

May 9

What is the golden ratio? Well it can be defined like this: a/b = (a+b)/a
Where a>b
So if you set b = 1 you get
a = a/a + 1/a
Also a = a/b,
let’s call this number Φ
Φ = 1 + 1/Φ (Where Φ>1)
This is a nice recursive definition for Φ

Here is a solution to this equation that defines Φ
Φ=(1+√5)/2
Check this using the definition of Φ I just gave you:
Φ=1 + 2/(1+√5)
= (1+√5)/(1+√5)+2/(1+√5)
=(1+√5+2)/(1+√5)
=(3+√5)(1-√5)/((1+√5)(1-√5))
here we do this neat trick mathematicians implement sometimes, it’s called multiplying by one. Except we don’t call it 1 we call it something else like x/x (x= 1-√5, so x can’t be zero, what I just did wouldn’t work if 1 was equal to √5 but 1²≠5 so we’re safe). Also I used the result 1+2=3.
=(3 -5 + √5 - 3√5)/(1-5)
do some boring algebra stuff.
=-2(1 + √5)/(-4) = (1 + √5)/2

Φ ≈ 1.6180339887

This definition can also be thought of as a quadratic, like this: Φ²-Φ-1=0
we now have a polynomial, and it’s degree two so we know we it will have at most two solutions because of this thing called the fundamental theorem of Algebra (although proving it for degree two polynomials is pretty easy).
The other solution is (1-√5)/2 you can go check this yourself. But this number isn’t Φ because we defined Φ > 1.

This is actually my third favourite number, and my favourite algebraic number.

This number is also related to the Fibonacci sequence.
Let’s say take two consecutive Fibonacci numbers a, b.
You can get the next Fibonacci number by summing up the last two: a+b So let’s divide Fibonacci numbers by the previous ones:
a/b
(a+b)/a

Let’s use an example:
610 and 987 are both Fibonacci numbers.
610+987= 1597
987/610 = 1.61803278688…
1597/987 =1.61803444782…

These two are pretty close, and in fact not bad rational approximations of Φ.

So for pretty big consecutive Fibonacci numbers a and b then you get:
a/b ≈ (a+b)/a
And as they approach infinity, they get more exact and you get ever closer to exactly Φ.

And so that’s the golden ratio and where it comes from. Apparently it comes up in nature and shit but I’m not talking about that because it isn’t maths so I don’t really care. Anyway that’s most of what I know about this thing I hope you enjoyed this post, if you have any questions or didn’t understand something you can feel free to ask me I guess.

May 8

“f(x)” (pronounced as “eff-of-eks”).

f(unction) of x

My sister just unfollowed me wow rude.

May 4

the-missing-pink-suitcase:

What if Jessie’s girl is Stacy’s mom?

Apr 7

An Ineffable Experience: The first 1000 digits of 'e,' the Natural Logarithm, because it's not appreciated as much as pi

cavejohnson:

…

Apr 4

It actually doesn’t mean that. It seems a reasonable possibility given that the digits of pi in its base 10 representation seem to be random, but they obviously aren’t random and it hasn’t been proved they will act like they are.

Being a non-algebraic number doesn’t necessarily mean a number will contain every possible finite string of digits

Tags do not go here #this doesnt work #stop it

arishako:

whenever a site tells me i need to be 18 or older to enter i always go all like “lol yeah sure i’m 18 right yeah” and it takes me a second before i actually realize oh wait i actually am over 18

(via the-missing-pink-suitcase)

Apr 2

ironwolf:

TEDEd: How to defeat a dragon with math

PEMDAS: 1) Parentheses 2) Exponents 3) Multiplication 4) Division 5) Addition 6) Subtraction

But what if you get something like 12÷3×2. Your “PEMDAS” method will tell you 2 when really you want 8. I would have multiplication and division (and addition and subtraction) work at the same time.

Equivalently division could come before multiplication (eg, PEDMAS), because if you have a×b÷c then the order you chose multiply the a doesn’t matter. Thanks to commutativity of multiplication it’s equivalent to b÷c×a, but I don’t like defining it that way.