30 JAN 2015 by ideonexus

 Your Birth Star

Name any event in history and you will find a star out there whose light gives you a glimpse of something happening during the year of that event. Provided you are not a very young child, somewhere up in the night sky you can find your personal birth star. Its light is a thermonuclear glow that heralds the year of your birth. Indeed, you can find quite a few such stars (about 40 if you are 40; about 70 if you are 50; about 175 if you are 80 years old). When you look at one of your birth year ...
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07 JUN 2012 by ideonexus

 Type 0 and Type III Civilizations

It's humbling to realise that the developmental gulf between a miniscule ant colony and our modern human civilisation is only a tiny fraction of the distance between a Type 0 and a Type III civilisation – a factor of 100 billion billion, in fact. Yet we have such a highly regarded view of ourselves, we believe a Type III civilisation would find us irresistible and would rush to make contact with us. The truth is, however, they may be as interested in communicating with humans as we are keen...
Folksonomies: perspective
Folksonomies: perspective
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We are closer to ants than the more advanced civilizations, so why would they show anymore interest in us than we the ants?

23 APR 2012 by ideonexus

 The Lifetime of DNA

The messages that DNA molecules contain are all but eternal when seen against the time scale of individual lifetimes. The lifetimes of DNA messages (give or take a few mutations) are measured in units ranging from millions of years to hundreds of millions of years; or, in other words, ranging from 10,000 individual lifetimes to a trillion individual lifetimes. Each individual organism should be seen as a temporary vehicle, in which DNA messages spend a tiny fraction of their geological lifeti...
Folksonomies: evolution wonder dna
Folksonomies: evolution wonder dna
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It exists in living messengers for brief periods of their lifetimes, but communicates across millions of years throughout all life.

01 JAN 2012 by ideonexus

 How Radiometric Dating Works

Briefly, a radioactive isotope is a kind of atom which decays into a different kind of atom: for example. one called uranium-238 turns into one called lead-206. Because we know how long this takes to happen, we can think of the isotope as a radioactive clock. Radioactive clocks are rather like the water clocks and candle clocks that people used in the days before pendulum clocks were invented. A tank of water with a hole in the bottom will drain at a measurable rate. If the tank was filled at...
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A great summary of how we date fossils using Uranium and Carbon atoms and their decay rates.

08 JUN 2011 by ideonexus

 Everything Comes from Stars

What gravity is and why it is, no one knows. Albert Einstein spent most of his life trying to figure it out, but the secret eluded him. it is simply a fact that everything in the universe with mass pulls on everything else. If it weren't for the initial outward impetus of the Big Bang, gravity would have caused the entire universe to collapse into a heap. (Indeed, someday the cosmic collapse may happen, if and when the initial impetus is expended, although the best evidence suggests that the ...
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The Big Bang to the formation of stars, which formed the elements crucial to life. It takes 1,000 calories of sunlight to evaporate one thimbleful of water.

11 APR 2011 by ideonexus

 Atoms Within Our Bodies Still Release the Energy of an An...

Explosions are seldom one hundred per cent efficient. When a star ends as a supernova, the nuclear explosive material, which includes uranium and plutonium together with large amounts of iron and other burnt-out elements, is distributed around and scattered in space just as is the dust cloud from a hydrogen bomb test. Perhaps the strangest fact of all about our planet is that it consists largely of lumps of fall-out from a star-sized hydrogen bomb. Even today, aeons later, there is still enou...
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High amounts of uranium in the Earth's core suggest our sun was in the vicinity of a supernova event, and the atoms within our bodies, if measured with a Geiger counter, can be found to still be releasing the energy from that event.

03 JAN 2011 by ideonexus

 Number of Bits for a Set of Encyclopedias are Minuscule C...

I have estimaged how many letters there are in a the Enclyclopaedia, and I have assumed that each of my 24 million books is as big as an Encyclopaedia volume, and have calculated, then, how many bits of information there are (10^15). For each bit I allow 100 atoms. And it turns out that all of the information that man has carefully accumulated in all the books in the world can be written in this form in a cube of material one two-hundredths of an inch wide--which is the barest piece of dust t...
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Feynman estimates the number of atoms neccessary for storing a set of encyclopedias, and then compares that to the amount of data included in a DNA string.