Tag Archives: Space

We Might Live in a Virtual Universe — But It Doesn’t Really Matter


By Maxim Roubintchik – The first thing to realize is this: Our perception of reality is already separate from reality itself.

To paraphrase Morpheus from the movie The Matrix, reality is simply an electrical impulse being interpreted by your brain. We experience the world indirectly and imperfectly. If we could see the world as it is, there would be no optical illusions, no color blindness and no mind tricks.

Further, we only experience a simplified version of all this mediated sensory information. The reason? Seeing the world as it is requires too much processing power — so our brain breaks it into heuristics (or simplified but still useful representations). Our mind is constantly looking for patterns in our world and will match them with our perception.

From this we can conclude the following:

Our perception of reality is already different from reality itself. What we call reality is our brains’ attempt to process the incoming flood of sensory data.

If our perception of reality is dependent on a simplified flow of information, it doesn’t matter what the source of this information is — whether it’s the physical world or a computer simulation feeding us the same information. more> http://goo.gl/fIwQEb

If the universe cares about us, it has a funny way of showing it

BOOK REVIEW

Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False, Author: Thomas Nagel.
Origin of Species, Author: Charles Darwin.
Cybernetics: Or Control and Communication in the Animal and the Machine, Author: Norbert Wiener.
After Virtue, Author: Alasdair MacIntyre.
The End of History and the Last Man, Author: Francis Fukuyama.
The Quantum Universe: Everything That Can Happen Does Happen, Authors: Brian Cox and Jeff Forshaw.
Darwin, Author: Tim Lewens.
The Goldilocks Enigma, Author: Paul Davies.

By Steven Poole – Nagel says that the appearance of conscious beings such as us can be described as the universe waking up. In Mind and Cosmos, Nagel’s suggested teleology does not involve a creator; it is merely a law-like tendency in the universe that somehow loads the dice in favor of the appearance of consciousness.

As Nagel puts it, it might be that the universe exhibits ‘a bias toward the marvelous’. If so, it would not be surprising that consciousness had appeared, because we live in a universe whose very purpose, aim, or telos, is the production of consciousness.

Nagel has a cosmic horror of the fluke, because it is so unconsoling.

But what if the appearance of life and consciousness just were sheer flukes?

What if they probably wouldn’t happen again if you ran the universe from the same initial conditions?

What if there are a great many different universes, and life just happened to arise in ours but not in most of the others? more> https://goo.gl/Dp6dAG

Black-hole computing

By Sabine Hossenfelder – After you die, your body’s atoms will disperse and find new venues, making their way into oceans, trees and other bodies.

But according to the laws of quantum mechanics, all of the information about your body’s build and function will prevail. The relations between the atoms, the uncountable particulars that made you you, will remain forever preserved, albeit in unrecognizably scrambled form – lost in practice, but immortal in principle.

There is only one apparent exception to this reassuring concept: according to our current physical understanding, information cannot survive an encounter with a black hole.

Stephen Hawking‘s [2, 3] discovery of black-hole evaporation has presented theoretical physicists with a huge conundrum: general relativity says that black holes must destroy information; quantum mechanics says it cannot happen because information must live on eternally.

Both general relativity and quantum mechanics are extremely well-tested theories, and yet they refuse to combine. more> https://goo.gl/UVPfVy

Let’s Rethink Space

By George Musser – If a rhinoceros is also able to hurt me, it must be close, too. And if both a lion and a rhino are able to hurt me, then the lion and rhino should also be able to hurt each other. (Indeed, my survival depends on it.)

From this patterning of influences, we extract space. If the threat posed by predators couldn’t be expressed in terms of spatial distance, space would cease to be meaningful.

A less morbid example is triangulation. The signal bars on your mobile phone indicate the strength of the phone’s connection to a cell tower and therefore your distance from that tower. In an emergency, the phone company can locate your phone by measuring your signal at several towers and using triangulation or the related technique of trilateration.

The fact that the measurements converge on a single location is what it means for you to have a location.

The nice thing about defining space in terms of structure is that it sidesteps some of the long-running disputes over the nature of space. more> http://goo.gl/3IYOPD

Related>

Scientists struggle to stay grounded after possible gravitational wave signal

By Ian Sample – Lawrence Krauss [2], a cosmologist at Arizona State university, tweeted that he had received independent confirmation of a rumour that has been in circulation for months, adding: “Gravitational waves may have been discovered!!”

According to the rumours, scientists on the team are in the process of writing up a paper that describes a gravitational wave signal. If such a signal exists and is verified, it would confirm one of the most dramatic predictions of Albert Einstein’s century-old theory of general relativity [2, 3, 4]. more> http://goo.gl/q0L2Q8

New approach needed to detect dark matter

By Birgitte Svennevig – The majority of the mass in the universe remains unknown. Despite knowing very little about this dark matter, its overall abundance is precisely measured.

In other words: Physicists know it is out there, but they have not yet detected it.

“There is no way of predicting what we can do with dark matter, if we detect it. But it might revolutionize our world. When scientists discovered quantum mechanics, it was considered a curiosity. Today quantum mechanics plays an important role in computers,” Ian Shoemaker says. more> http://tinyurl.com/p8cufda

Old astronomic riddle soon to be solved

By Olivia Poisson – Almost 100 years ago, astronomers discovered that the spectrum of star light arrived on earth with dark gaps, so-called interstellar bands.

Ever since, researchers have been trying to find out which type of matter in space absorbs the light and is responsible for these “diffuse interstellar bands” (DIB) of which over 400 are known today.

The research team led by Prof. John P. Maier from the Dept. of Chemistry at the Univ. of Basel has been studying the electronic absorption of the ionized Buckminsterfullerene since 1993. In fact, the spectrum measured in the lab did show absorption features at two wavelengths that were near two DIB that had been discovered by astronomers the following year. more> http://tinyurl.com/qjq2bjq

New model of cosmic stickiness favors ‘Big Rip’ demise of universe

By Vanderbilt University – The universe can be a very sticky place, but just how sticky is a matter of debate.

That is because for decades cosmologists have had trouble reconciling the classic notion of viscosity based on the laws of thermodynamics with Einstein’s general theory of relativity. However, a team from Vanderbilt University has come up with a fundamentally new mathematical formulation of the problem that appears to bridge this long-standing gap.

The new math has some significant implications for the ultimate fate of the universe. It tends to favor one of the more radical scenarios that cosmologists have come up with known as the “Big Rip.” It may also shed new light on the basic nature of dark energy.

The new approach was developed by Assistant Professor of Mathematics Marcelo Disconzi in collaboration with physics professors Thomas Kephart and Robert Scherrer. more> http://tinyurl.com/q9lp9ep

Discovering a new stage in the galactic lifecycle

By Jessica Stoller-Conrad – By observing the clouds of gas and dust within a galaxy, astronomers can determine important information about the history of star formation and the evolution of galaxies.

Dust in galaxies is created by the elements released during the formation and collapse of stars. Although the most abundant elements in the universe—hydrogen and helium—were created by the Big Bang, stars are responsible for making all of the heavier elements in the universe, such as carbon, oxygen, nitrogen, and iron. And because young, distant galaxies have had less time to make stars, these galaxies should contain less dust. Previous observations had suggested this, but until now nobody could directly measure the dust in these faraway galaxies.

Because it is impossible to watch this evolution from young galaxy to old galaxy happen in real time on the scale of a human lifespan, the researchers use telescopes like ALMA (Atacama Large Millimeter Array) to take a survey of galaxies at different evolutionary stages. more> http://tinyurl.com/pz9gvm5

A cold cosmic mystery solved

Univ. of Hawaii at Manoa – The supervoid is only about 3 billion light-years away from us, a relatively short distance in the cosmic scheme of things.

Imagine there is a huge void with very little matter between you (the observer) and the CMB (cosmic microwave background). Now think of the void as a hill.

As the light enters the void, it must climb this hill. If the universe were not undergoing accelerating expansion, then the void would not evolve significantly, and light would descend the hill and regain the energy it lost as it exits the void.

But with the accelerating expansion, the hill is measurably stretched as the light is traveling over it. By the time the light descends the hill, the hill has gotten flatter than when the light entered, so the light cannot pick up all the energy it lost upon entering the void. The light exits the void with less energy, and therefore at a longer wavelength, which corresponds to a colder temperature. more> http://tinyurl.com/mtkgwwn