Tuesday, 10 January 2017

Challenges Of Life

(i) To cope with practical tasks, most basically to survive/earn a living.
(ii) To do more, e.g., to run a business or to advance in a career.
(iii) To engage in meaningful activities that might not become a means of livelihood.
(iv) To understand and respond to society and life.

I have always been impractical and unambitious but interested in (iii) and (iv).
Some people let their received religion address (iv).
Judgementalism is unnecessary. People differ.

Monday, 9 January 2017

What Is The World Made Of?

According to Carlo Rovelli in Reality Is Not What It Seems (Allen Lane, 2016), p. 168:

Newton thought that reality was space, time and particles;
Faraday and Maxwell added fields;
Einstein 1905 united space and time;
Einstein 1915 united space-time and fields as covariant fields;
quantum mechanics referred to space-time and quantum fields;
quantum gravity has just covariant quantum fields.

It is not surprising that covariant fields generate space-time because surely space and time are relationships in any case. Newtonian space was relationships between particles and Newtonian time was relationships between relationships between particles. Now particles are regarded as quanta of fields.

What is counter-intuitive is that there are quanta of space. Mathematically, the number one can be divided into endless smaller fractions but apparently a volume of space cannot be divided into endless smaller volumes.

Addendum: Quantum gravity is a theory of fields but not yet a unified field theory.

Quanta Of Space II

Faraday's lines of force were infinitely thin and continuous and filled space whereas the closed lines or loops of quantum gravity are discrete and finite and are space.
The loops are links between points called nodes.
Each node is a quantum of space.
Two nodes are separated by a small area.
Photons are in space whereas nodes are space.
-Carlo Rovelli, Reality Is Not What It Seems (Allen Lane, 2016), Chapter 6.

Quanta Of Space

To measure a volume of space, it is necessary to place a particle in it.
According to Heisenberg's uncertainty principle, a particle placed at a point in space soon escapes from it.
The smaller the volume, the greater the velocity of the escape.
A particle escaping at a high velocity has a lot of energy.
A lot of energy in a small volume of space curves space so much that the particle becomes a black hole.
Thus, the attempt to measure a small volume of space prevents measurement of it.
The minimum volume of space is the minimum size of a particle before it becomes a black hole.
-Carlo Rovelli, Reality Is Not What It Seems (Allen Lane, 2016), pp. 129-130.

Friday, 6 January 2017

Electromagnetism

Carlo Rovelli, Reality Is Not What It Seems (Allen Lane, 2016), pp. 41-47.

Faraday intuited that "...an entity diffused throughout space...is modified by electric and magnetic bodies and...acts upon..." them. (p. 41) This entity is a field consisting of many infinitely thin lines of force. Maxwell wrote equations that describe these lines of force.

The electromagnetic force:

holds electrons in atoms;
holds atoms in molecules;
makes chemistry, organisms and neurons work.

(I thought that the four forces of nature were gravity, electromagnetism and the strong and weak nuclear forces but here Rovelli describes just two.)

Maxwell's equations predict that lines of force undulate. The speed of their undulations, when calculated, was the same as for light because light is undulating electromagnetic radiation and color is different wavelengths. Maxwell also predicted invisible wavelengths which include radio. Thus, a technological revolution:

radio
television
telephones
computers
satellites
wi-fi
the internet

Thursday, 5 January 2017

Quantum Gravity

This is written from memory late at night so it is going to be wrong in details:

Newton thought of gravity as action at a distance;

Faraday thought of lines of force;

lines became fields;

however, quantum mechanics divides fields back into quanta;

quanta of space/gravity are lines joined by nodes;

moving nodes form lines and moving lines form surfaces.

I will reread the relevant passages of Reality Is Not What It Seems shortly. 

Who Is The Lord?

The Christian Version
The Biblical deity regarded as literally existent.
Jesus regarded as human, divine and resurrected in power.

Other Versions
Other specific deities, variously interpreted.

My Versions
An indeterminate or composite deity regarded as mythological and metaphorical.
The Buddha, who was human and died a long time ago.