24 JAN 2015 by ideonexus
Warm-Blooded Plants: Zero-g, Zero-T, and Zero-P
There are three principal obstacles to be overcome in adapting a terrestrial species to life in space. It must learn to live and be happy in zero-g, zero-T, and zero-P, that is to say, zero-gravity, zero-temperature, and zero-pressure. Of these, zero-g is probably the easiest to cope with, although we are still ignorant of the nature of the physiological hazards which it imposes. To deal with zero-T is simple in principle although it may be complicated and awkward in practice. Fur and feather...
1 17 SEP 2013 by ideonexus
Neurons are Domesticated Cells
You really don't have to worry about one part of your laptop going rogue and trying out something on its own that the rest of the system doesn't want to do. No, they're all slaves. If they're agents, they're slaves. They are prisoners. They have very clear job descriptions. They get fed every day. They don't have to worry about where the energy's coming from, and they're not ambitious. They just do what they're asked to do and do it brilliantly with only the slightest tint of comprehension. Y...
1 But they are also slightly feral. Neurons compete with one another, the brain works by neural pruning, natural selection. Cells that don't get used are allowed to die. Thus, neurons are motivated to survive, to have some independence.
04 JUN 2012 by ideonexus
The Physics of Black Hole Creation
Let me describe briefly how a black hole might be created. Imagine a star with a mass 10 times that of the sun. During most of its lifetime of about a billion years the star will generate heat at its center by converting hydrogen into helium. The energy released will create sufficient pressure to support the star against its own gravity, giving rise to an object with a radius about five times the radius of the sun. The escape velocity from the surface of such a star would be about 1,000 kilom...Folksonomies: physics black hole
Folksonomies: physics black hole
1 
notes
notesAt a point in the star's collapse, it's escape velocity exceeds the speed of light.
25 APR 2012 by ideonexus
Life Can Go On for Billions of Years
I believe that life can go on forever. It takes a million years to evolve a new species, ten million for a new genus, one hundred million for a class, a billion for a phylum—and that's usually as far as your imagination goes. In a billion years, it seems, intelligent life might be as different from humans as humans are from insects. But what would happen in another ten billion years? It's utterly impossible to conceive of ourselves changing as drastically as that, over and over again. All y...Freeman Dyson quote about the future of humanity.
31 JAN 2012 by ideonexus
Stones Speak Through Geology
For a billion years the patient earth amassed documents and inscribed them with signs and pictures which lay unnoticed and unused. Today, at last, they are waking up, because man has come to rouse them. Stones have begun to speak, because an ear is there to hear them. Layers become history and, released from the enchanted sleep of eternity, life's motley, never-ending dance rises out of the black depths of the past into the light of the present.Folksonomies: geology
Folksonomies: geology
1 notes
notesThe Earth has been writing into the strata, and now humans have arisen to read it.
01 JAN 2012 by ideonexus
Big History as a Fable
Once upon a time, about ten or fifteen billion years ago, the universe was
without form. There were no galaxies. There were no stars. There were no
planets. And there was no life. Darkness was upon the face of the deep. The
universe was hydrogen and helium. The explosion of the Big Bang had passed, and
the fires of that titanic event – either the creation of the universe or the ashes of a
previous incarnation of the universe – were rumbling feebly down the corridors of
space.
But the gas...Folksonomies: wonder big history
Folksonomies: wonder big history
Carl Sagan tells the story of our Universe's history as a fairy tale.
13 DEC 2011 by ideonexus
The Weak Anthropic Principle
Our very existence imposes rules determining from where and at what time it is possible for us to observe the universe. That is, the fact of our being restricts the characteristics of the kind of environment in which we find ourselves. That principle is called the weak anthropic principle. (We'll see shortly why the adjective weak" is attached.) A better term than "anthropic principle" would have been "selection principle," because the principle refers to how our own knowledge of our existenc... 1 notes
notesA quick definition and explanation of this theory of why we live in a universe where we could emerge.
12 DEC 2011 by ideonexus
Human Behavior is Dictated by Laws of Nature, but Too Com...
While conceding that human behavior is indeed determined by the laws of nature, it also seems reasonable to conclude that the outcome is determined in such a complicated way and with so many variables as to make it impossible in practice to predict. For that one would need a knowledge of the initial state of each of the thousand trillion trillion molecules in the human body and to solve something like that number of equations. That would take a few billion years, which would be a bit late to ... 1 notes
notesSo the hypothesis that we have freewill is convenient, and the Economic model that we act in our best interests helpful, but not always correct.
21 SEP 2011 by ideonexus
Seeing How Species Arise is Similar to Understanding Star...
The way we discovered how species arise resembles the way
astronomers discovered how stars “evolve” over time. Both processes
occur too slowly for us to see them happening over our lifetime. But we
can still understand how they work by finding snapshots of the process
at different evolutionary stages and putting these snapshots together
into a conceptual movie. For stars, astronomers saw dispersed clouds
of matter (“star nurseries”) in galaxies. Elsewhere they saw those clouds condens... 1 notes
notesJust as astronomers search the skies for stars in varying stages of life, biologists look for species in varying degrees development.
08 JUN 2011 by ideonexus
Spring Recapitulates Evolution
Spring provides a kind of annual recapitulation of the evolution of life on Earth, an opportunity to celebrate anew the greening of the planet three and a half billion years ago by the first photosynthesizing bacteria. All life—the whole glorious parade along the path—depends upon the photosynthesizers. As spring dresses the deciduous woodlands in its Easter best, the nonphotosynthesizers get moving too. Suddenly the woods are skittering, fluttering, munching. singing. From rock-hard seed... 1 notes
notesFirst the leaves come back, photosynthesizing to produce the energy the animals will consume for life as well.
