ayjay + time   3

In Defense of the Reality of Time
Why might one think that time has a direction to it? That seems to go counter to what physicists often say.

I think that’s a little bit backwards. Go to the man on the street and ask whether time has a direction, whether the future is different from the past, and whether time doesn’t march on toward the future. That’s the natural view. The more interesting view is how the physicists manage to convince themselves that time doesn’t have a direction.

They would reply that it’s a consequence of Einstein’s special theory of relativity, which holds that time is a fourth dimension.

This notion that time is just a fourth dimension is highly misleading. In special relativity, the time directions are structurally different from the space directions. In the timelike directions, you have a further distinction into the future and the past, whereas any spacelike direction I can continuously rotate into any other spacelike direction. The two classes of timelike directions can’t be continuously transformed into one another.

Standard geometry just wasn’t developed for the purpose of doing space-time. It was developed for the purpose of just doing spaces, and spaces have no directedness in them. And then you took this formal tool that you developed for this one purpose and then pushed it to this other purpose.
philosophy  physics  science  time  from instapaper
may 2017 by ayjay
How the Concept of Deep Time Is Changing
Deep time represents a certain displacement of the human and the divine from the story of creation. Yet in the Anthropocene, ironically we humans have become that sublime force, the agents of a fearful something that is greater than ourselves. A single mine in Canada’s tar sands region moves 30 billion tons of sediment annually, double the quantity moved by all the worlds’ rivers combined. The weight of the fresh water we have redistributed has slowed the Earth’s rotation. The mass extinction of plant and animal species is unlikely to recover for 10 million years.

Surely the ‘sublime’ is not the right way to characterize our visceral response to these phenomena. The ‘uncanny’ might serve us better. One of the most chilling traces of the Anthropocene is the global dispersal of radioactive isotopes since mass thermonuclear weapons testing began in the middle of the 20th century, which means that everyone born after 1963 has radioactive matter in their teeth. The half-life of depleted uranium (U-238) is around 4.5 billion years, roughly the same as the age of the Earth, while that of the plutonium in Chernobyl’s nuclear reactor is 240,000 years. Such timescales resist the imagination, but exist as a haunting presence in our daily lives.
science  anthropocene  time  from instapaper
november 2016 by ayjay
Albert Einstein and Henri Bergson’s Great Showdown About the Nature of Time
In the years that followed, Bergson was largely perceived to have lost the debate against the younger physicist. The scientist’s views on time came to dominate most learned discussions on the topic, keeping in abeyance not only Bergson’s but many other artistic and literary approaches, by relegating them to a position of secondary, auxiliary importance. For many, Bergson’s defeat represented a victory of “rationality” against “intuition.” It marked a moment when intellectuals were no longer able to keep up with revolutions in science due to its increasing complexity. Thus began “the story of the setback, after a period of unprecedented success, of Bergson’s philosophy of absolute time—unquestionably under the impact of relativity.” Most important, then began the period when the relevance of philosophy declined in the face of the rising influence of science.
science  philosophy  time  from instapaper
may 2016 by ayjay

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