Forever young

rhamphotheca:

Immortal Flatworms Defy Age

by PhysOrg staff

The discovery, published in the , may shed light on the possibilities of alleviating ageing and age-related characteristics in .

Planarian worms have amazed scientists with their apparently limitless ability to regenerate. Researchers have been studying their ability to replace aged or damaged tissues and cells in a bid to understand the mechanisms underlying their .

Dr Aziz Aboobaker from the University’s School of Biology, said: “We’ve been studying two types of planarian worms; those that reproduce sexually, like us, and those that reproduce asexually, simply dividing in two. Both appear to regenerate indefinitely by growing new muscles, skin, guts and even entire brains over and over again…

(read more: PhysOrg)     (image: Eduard Sola | Wikipedia)

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Provided by University of Nottingham (news : web)

minecanary:

Langston’s ant

Langton’s ant is a two-dimensional Turing machine with a very simple set of rules but complicated emergent behavior. It was invented by Chris Langton in 1986 and runs on a square lattice of black and white cells. The universality of Langton’s ant was proven in 2000. The idea has been generalized in several different ways, such as turmites which add more colors and more states.

Squares on a plane are colored variously either black or white. We arbitrarily identify one square as the “ant”. The ant can travel in any of the four cardinal directions at each step it takes. The ant moves according to the rules below:

1. At a white square, turn 90° right, flip the color of the square, move forward one unit

2. At a black square, turn 90° left, flip the color of the square, move forward one unit

These simple rules lead to surprisingly complex behavior: after an initial period of apparently chaotic behavior, that lasts for about 10,000 steps (in the simplest case), the ant starts building a recurrent “highway” pattern of 104 steps that repeat indefinitely. All finite initial configurations tested eventually converge to the same repetitive pattern suggesting that the “highway” is an attractor of Langton’s ant, but no one has been able to prove that this is true for all such initial configurations. It is only known that the ant’s trajectory is always unbounded regardless of the initial configuration.

Before I met you I was quite content

and happy with my life

But then you came and introduced

an extension of my world

which I thought didn’t exist

And every time I enter this extended world

I find myself intrigued, amazed, awed

This extended world somehow revolves

around you.

You’re the center of it all

Just as the four inner planets revolve

around our Sun, in the Sol star system

and so do the four Jovian planets

As Newton’s law of universal gravitation states

The force which attracts me to you is

inversely proportional to the square

of the distance between us

Which is why I prefer to be near you

so the force of attraction between us

will be so much stronger

and so I can gravitate more towards you

The locus of points equidistant to a single point

me being part of those points,

and you being the single point

Which is why you’re at the center,

and I find myself circling around you.

Oh sweet Feynman,  you made me cry. <3

kayfabe:

Letters of Note has a heartbreaking entry from Richard Feynman to his wife, who had died 16 months prior. It remained sealed until his death.

I adore you, sweetheart. 

I know how much you like to hear that — but I don’t only write it because you like it — I write it because it makes me warm all over inside to write it to you. 

It is such a terribly long time since I last wrote to you — almost two years but I know you’ll excuse me because you understand how I am, stubborn and realistic; and I thought there was no sense to writing. 

But now I know my darling wife that it is right to do what I have delayed in doing, and that I have done so much in the past. I want to tell you I love you. I want to love you. I always will love you.

I find it hard to understand in my mind what it means to love you after you are dead — but I still want to comfort and take care of you — and I want you to love me and care for me. I want to have problems to discuss with you — I want to do little projects with you. I never thought until just now that we can do that. What should we do. We started to learn to make clothes together — or learn Chinese — or getting a movie projector. Can’t I do something now? No. I am alone without you and you were the “idea-woman” and general instigator of all our wild adventures.

When you were sick you worried because you could not give me something that you wanted to and thought I needed. You needn’t have worried. Just as I told you then there was no real need because I loved you in so many ways so much. And now it is clearly even more true — you can give me nothing now yet I love you so that you stand in my way of loving anyone else — but I want you to stand there. You, dead, are so much better than anyone else alive.

I know you will assure me that I am foolish and that you want me to have full happiness and don’t want to be in my way. I’ll bet you are surprised that I don’t even have a girlfriend (except you, sweetheart) after two years. But you can’t help it, darling, nor can I — I don’t understand it, for I have met many girls and very nice ones and I don’t want to remain alone — but in two or three meetings they all seem ashes. You only are left to me. You are real.

My darling wife, I do adore you. 

I love my wife. My wife is dead.

Rich.

PS Please excuse my not mailing this — but I don’t know your new address.