02 MAR 2019 by ideonexus
The Anthropic Principle
As an example of the power of the Anthropic Principle, consider the number of directions in space. It is a matter of common experience that we live in three-dimensional space. That is to say, we can represent the position of a point in space by three numbers. For example, latitude. longitude and height above sea level. But why is space three-dimensional? Why isn't it two, or four, or some other number of dimensions, hke in science fiction? In fact, in M-theory space has ten dimensions (as wel...Folksonomies: anthropic principle
Folksonomies: anthropic principle
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notes24 FEB 2013 by ideonexus
Hypothesizing on a World Without Stars
'Well, then, supposing there were other suns in the universe.' He broke
off a little bashfully. 'I mean suns that are so far away that they're too
dim to see. It sounds as if I've been reading some of that fantastic
fiction, I suppose.'
'Not necessarily. Still, isn't that possibility eliminated by the fact
that, according to the Law of Gravitation, they would make themselves
evident by their attractive forces?'
'Not if they were far enough off,' rejoined Be...
2 Asimov's world with so many suns there is no night is a place where people hypothesize other configurations of worlds they cannot see and do not believe exist.
04 JUN 2012 by ideonexus
The Total Energy of the Universe is Zero
There are something like ten million million million million million million million million million million million million million million (1 with eighty zeroes after it) particles in the region of the universe that we can observe. Where did they all come from? The answer is that, in quantum theory, particles can be created out of energy in the form of particle/antiparticle pairs. But that just raises the question of where the energy came from. The answer is that the total energy of the uni...
1 Because gravity represents negative energy.
29 MAR 2012 by ideonexus
Gravity Travels at the Speed of Light
Here's the rub. In Newton's theory of gravity, one body exerts a gravitational pull on another with a strength determined solely by
the mass of the objects involved and the magnitude of their separation. The strength has nothing to do with how long the objects
have been in each other's presence. This means that if their mass or their separation should change, the objects will, according to
Newton, immediately feel a change in their mutual gravitational attraction. For instance, Newton's theor... 1 notes
notesAccording to Einstein, overturning Newton.
29 MAR 2012 by ideonexus
The Delicate Balance of the Forces of the Universe
the universe
would be a vastly different place if the properties of the matter and force particles were even moderately changed. For example, the
existence of the stable nuclei forming the hundred or so elements of the periodic table hinges delicately on the ratio between the
strengths of the strong and electromagnetic forces. The protons crammed together in atomic nuclei all repel one another
electromagnetically; the strong force acting among their constituent quarks, thankfully, overcomes t... 1 notes
notesIf they were slightly different, the Universe wouldn't look the way it does.
13 DEC 2011 by ideonexus
Stable Orbits are Impossible in More Than Three Dimensions
If one assumes that a few hundred million years in stable orbit are necessary for planetary life to evolve, the number of space dimensions is also fixed by our existence. That is because, according to the laws of gravity, it is only in three dimensions that stable elliptical orbits are possible. Circular orbits are possible in other dimensions, but those, as Newton feared, are unstable. In any but three dimensions even a small disturbance, such as that produced by the pull of the other planet...The force of gravity gets weaker the more dimensions you add to the Universe, making stable planetary orbits impossible.
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.
