Marx, Lenin and Mao were all, argues CJ Strachan, products of the Enlightenment's belief that reason could reshape humanity. By abandoning faith and tradition, we starved the spirit – and are now living with the consequences.
The post Why the Age of Reason Became a Cul-de-Sac and What Older Wisdom Still Knows appeared first on The Daily Sceptic.
In the event of a nuclear holocaust, the only life remaining on Earth may be cockroaches, Keith Richards and physicists arguing about philosophical interpretations of quantum mechanics. One especially rich source of arguments is a deterministic alternative to the standard Copenhagen interpretation that dates back to the American (and later British, after Princeton University fired him for alleged communist sympathies) theoretical physicist David Bohm. According to Bohm, the position of a quantum particle is well defined everywhere and guided by a “pilot wave” which, alas, cannot be measured directly.
Despite these philosophical differences, Bohmian mechanics makes the same predictions as the Copenhagen interpretation. Except maybe it doesn’t. Occasionally, a bright theorist hypothesizes that, under very specific circumstances, one could distinguish them. Very occasionally, a bright experimentalist conducts an experiment that claims to actually do so.
This is what happened last year when Jan Klärs and colleagues at the University of Twente in the Netherlands sent photons from a laser down one of two coupled waveguides towards a potential step. When the photons reached the step, they could pass through it by quantum tunnelling. They could also pass into the other waveguide. The researchers interpreted the distance the photons travelled through the barrier before tunnelling into the other waveguide as a measurement of their speed.
The key result was that, when the wave functions on both sides of the barrier were the same, the photons still tunnelled at, ahem, light speed – matching the Copenhagen notion that tunnelling occurred equally in both directions. However, the Twente team calculated that Bohmian mechanics predicted that photons inside the step – where the guiding equation didn’t have a real-valued frequency – would be at rest and get stuck. Interferometric measurements showed that wasn’t happening.
Game, set and match to Copenhagen? Er, no. Proponents of Bohmian mechanics immediately disputed the team’s definition of velocity. “It’s just an operational definition,” says Aurélien Drezet of the CNRS University of Grenoble-Alps in France. “It has the units of velocity…but that doesn’t mean that Bohmian mechanics can interpret the result.”
In a “Matters Arising” article in Nature, Drezet and two colleagues at the Technion–Israel Institute of Technology in Haifa now add an experimental qualm. The fact that the Twente team was able to produce an image shows that radiation must be leaking out of the cavity, Drezet claims: “If you go to higher approximations and include cavity losses, you explain the experiment completely using Bohmian mechanics,” he says.
Klärs, who is preparing a formal response, is unconvinced. On the first point, he sees no reason “why the same speed measurement, which correctly captures the Bohmian velocity in the propagating regime, should cease to be a speed measurement in the evanescent regime”. On the second, he says his group did not ignore radiative leakage from the cavity: they measured it and found it “does not have a significant impact on the scattering physics we investigate or on the interpretation of our results”.
This could go on for some time – regardless of how many seconds it is to midnight.
The post Experiment that may or may not disprove Bohmian mechanics continues to spark debate appeared first on Physics World.
People who can’t see images in their minds challenge an old philosophical standby
The post What a Picture of a Dog Has to Do with Reason and Logic appeared first on Nautilus.
Brexit is now 10 years old, but what many Remainers still fail to see, says Professor James Alexander, is that their cause was doomed from the start, for the word 'Leave' is eminently more appealing than 'Remain'.
The post Why Remain Lost, Why Leave Won appeared first on The Daily Sceptic.
In this age of AI anxiety, listen to your heart
The post The Inventor of the Thinking Machine Didn’t Worry. Neither Should You appeared first on Nautilus.
Author and physicist Chanda Prescod-Weinstein on the crisis in American science
The post Science Is Political—and Spiritual appeared first on Nautilus.
University of California, Riverside’s Professor Eric Schwitzgebel and University of Lisbon postdoctoral researcher Jeremy Pober argue that consciousness is substrate flexible, meaning it can arise not just in the biological tissue we find on Earth, but potentially in radically different physical materials found elsewhere in the cosmos.
The post Consciousness is Not Exclusive to Earth’s Biology, Philosophers Argue appeared first on Sci.News: Breaking Science News.
A conversation with a philosopher about extraterrestrial and machine minds
The post Aliens Probably Have Consciousness appeared first on Nautilus.
Einstein’s equations have withstood every experimental test for more than a century. However, according to one philosopher, they have not withstood careful scrutiny of the language used to describe them.
Daryl Janzen, an astronomer and instructor at the University of Saskatchewan, recently published a philosophical challenge in The Conversation. Janzen’s critique does not question the mathematics but instead focuses on how physicists and philosophers describe the nature of space-time itself. He argues that over the past century, the language used to describe space-time has gradually merged two separate concepts into one.
The main focus of this argument is the idea of the “block universe.” In this view, also known as eternalism, space-time is a fixed, four-dimensional structure. All past, present, and future events are equally real within this block, according to this interpretation. Time does not flow, and there is no single present moment. The block contains everything that has ever occurred.
Janzen does not object to the geometry itself. His concern lies with the way the word “exists” is used in this context.
Janzen distinguishes between existence and occurrence. Objects exist because they endure through time. Events occur at a specific place and moment, and then they are over. For example, an elephant standing in a room exists. A cross-sectional snapshot of that elephant, representing a single instant removed from its timeline and frozen in place, does not exist in the same way; it only occurs.
In the block universe model, space-time holds every moment of the elephant’s existence as a four-dimensional world line. This world line shows the animal’s full path through space and time. A single cross-section, or one slice of that path, is not the elephant itself; it is only a record of what the elephant was doing at a certain moment. Janzen says the block is better understood as a representational framework rather than a physical object in the usual sense.
This confusion leads to a fundamental problem. The entire block universe is said to exist, but it is unclear when it exists. A timeless structure that never unfolds cannot endure as the elephant endures from moment to moment. Meanwhile, if the whole block occurs at once, like a single flash, there is no internal experience of time that could be considered an illusion.
To keep the sense of time passing in a block universe, the four-dimensional structure would need to endure in some sense. This would mean adding a fifth dimension, a second time axis outside the block, for the block itself to exist within; however, this extra axis is not part of Einstein’s original theory.
Janzen uses a simpler analogy. He compares the situation to describing a song that exists all at once, complete but unperformed. A song only becomes a song when it unfolds over time.
Austrian-British philosopher Ludwig Wittgenstein warned that philosophical problems arise when “language goes on holiday.” Janzen argues that physics has been in this situation for decades, reusing words such as “timeless,” “exist,” and “become” in technical senses without considering their everyday connotations.
One of the biggest unsolved problems in physics is how to bring together general relativity, which explains gravity and the large-scale universe, with quantum mechanics, which describes matter at the smallest scales. These two frameworks do not fit together, and every real attempt to unify them demands a clear definition of what space-time actually is.
If the language physicists use to describe space-time has been internally inconsistent for more than a century, Janzen suggests the resulting confusion may extend beyond philosophy. Clarifying what physicists mean when they talk about space-time could influence how researchers think about attempts to reconcile general relativity and quantum mechanics.
Janzen does not propose a replacement for the current framework but instead suggests that the fundamental question is not how space-time curves, but how to properly define them in the first place.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.
A conversation with Harvard philosopher Ian Marcus Corbin on material, biological, and spiritual belonging
The post How to Feel at Home in the Modern World appeared first on Nautilus.
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