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Neil deGrasse Tyson and Brian Greene: Is Reality a Computer Simulation?
Are we living in a simulation? Theoretical physicist Brian Greene and Neil deGrasse Tyson walk us through the ideas, which might support this fantastic and unnerving concept.
Are we living in a simulation? This idea was hypothesized by Philosopher Nick Bostrom in a paper in 2003 simply titled, Are you living in a computer simulation?
This hypothesis provides an interesting thought experiment, which asks us to question the very nature of our reality. But how might we deduce whether or not we're living in such a world?
If you ever wanted a guide through this unnerving line of questioning, take a listen to this episode of StarTalk where Neil deGrasse Tyson and theoretical physicist Brian Greene sit down to about how physics might play a role in this hypothesis and how we might observe this possible reality.
“One thing that later generations might do with their super-powerful computers is run detailed simulations of their forebears or of people like their forebears. Because their computers would be so powerful, they could run a great many such simulations. Suppose that these simulated people are conscious (as they would be if the simulations were sufficiently fine-grained and if a certain quite widely accepted position in the philosophy of mind is correct). Then it could be the case that the vast majority of minds like ours do not belong to the original race but rather to people simulated by the advanced descendants of an original race. It is then possible to argue that, if this were the case, we would be rational to think that we are likely among the simulated minds rather than among the original biological ones. Therefore, if we don’t think that we are currently living in a computer simulation, we are not entitled to believe that we will have descendants who will run lots of such simulations of their forebears.”
So, are we living in The Matrix? Tyson and Greene say, it’s possible, so what evidence might we have to prove our world lives in a computer?
1. The first suggestion often proposed is inspired by The Matrix: Look for glitches.
“Real universes don’t have glitches, but computers can have them,” Greene explains. “But I say to that… if it’s a really good simulation it should be able to rewind, erase the memory of the glitch, fix it, and then the simulated beings have no memory of it ever happening.”
2. The next issue is our simulation could simulate evidence for us to block our progress towards this realization. Likewise, a simulated universe might be created to be purposefully complex as a way to hinder us from progress.
3. The last piece of evidence the show puts forth is the observation of mass power shortages could be an indication of a simulation. Why?
If we are simulation then eventually the technology might progress to a point where we decide to build a simulation. This idea gives rise to the idea of the multiverse. Simulations would begin to eat up a lot of computing power, which might cause power shortages in the original universe.
In addition to this issue, Gödel’s incompleteness theorem would argue that these simulations would gradually become less complex. The reason being a simulation cannot exceed the level of complexity that its universe can support.
Greene argues that the idea of living in a simulation is not just the result of a physicist's overactive imagination—the math is there.
“We used to consider the Big Bang a singular event that gave rise to one universe, but the math shows you don’t use up all that fuel in a single big bang. In fact, the bang itself winds up generating more of the fuel which generates other bangs—other universes.”
But questioning the nature of our reality would complicate one huge concept many people consider truth, which is the existence of a God. Indeed, what does a simulated universe say about the concept of a creator?
Greene and Tyson joked in the episode that our creator in a simulated world could be a 15 year old kid in his garage. It could explain why our world comes so close to how a kid plays The Sims. It might not be a comfort to anyone considering the simulation hypothesis to realize everything good or bad that has ever happened in your life is the result of a child’s whim.
A Mercury-bound spacecraft's noisy flyby of our home planet.
- There is no sound in space, but if there was, this is what it might sound like passing by Earth.
- A spacecraft bound for Mercury recorded data while swinging around our planet, and that data was converted into sound.
- Yes, in space no one can hear you scream, but this is still some chill stuff.
First off, let's be clear what we mean by "hear" here. (Here, here!)
Sound, as we know it, requires air. What our ears capture is actually oscillating waves of fluctuating air pressure. Cilia, fibers in our ears, respond to these fluctuations by firing off corresponding clusters of tones at different pitches to our brains. This is what we perceive as sound.
All of which is to say, sound requires air, and space is notoriously void of that. So, in terms of human-perceivable sound, it's silent out there. Nonetheless, there can be cyclical events in space — such as oscillating values in streams of captured data — that can be mapped to pitches, and thus made audible.
Image source: European Space Agency
The European Space Agency's BepiColombo spacecraft took off from Kourou, French Guyana on October 20, 2019, on its way to Mercury. To reduce its speed for the proper trajectory to Mercury, BepiColombo executed a "gravity-assist flyby," slinging itself around the Earth before leaving home. Over the course of its 34-minute flyby, its two data recorders captured five data sets that Italy's National Institute for Astrophysics (INAF) enhanced and converted into sound waves.
Into and out of Earth's shadow
In April, BepiColombo began its closest approach to Earth, ranging from 256,393 kilometers (159,315 miles) to 129,488 kilometers (80,460 miles) away. The audio above starts as BepiColombo begins to sneak into the Earth's shadow facing away from the sun.
The data was captured by BepiColombo's Italian Spring Accelerometer (ISA) instrument. Says Carmelo Magnafico of the ISA team, "When the spacecraft enters the shadow and the force of the Sun disappears, we can hear a slight vibration. The solar panels, previously flexed by the Sun, then find a new balance. Upon exiting the shadow, we can hear the effect again."
In addition to making for some cool sounds, the phenomenon allowed the ISA team to confirm just how sensitive their instrument is. "This is an extraordinary situation," says Carmelo. "Since we started the cruise, we have only been in direct sunshine, so we did not have the possibility to check effectively whether our instrument is measuring the variations of the force of the sunlight."
When the craft arrives at Mercury, the ISA will be tasked with studying the planets gravity.
The second clip is derived from data captured by BepiColombo's MPO-MAG magnetometer, AKA MERMAG, as the craft traveled through Earth's magnetosphere, the area surrounding the planet that's determined by the its magnetic field.
BepiColombo eventually entered the hellish mangentosheath, the region battered by cosmic plasma from the sun before the craft passed into the relatively peaceful magentopause that marks the transition between the magnetosphere and Earth's own magnetic field.
MERMAG will map Mercury's magnetosphere, as well as the magnetic state of the planet's interior. As a secondary objective, it will assess the interaction of the solar wind, Mercury's magnetic field, and the planet, analyzing the dynamics of the magnetosphere and its interaction with Mercury.
Recording session over, BepiColombo is now slipping through space silently with its arrival at Mercury planned for 2025.
Erin Meyer explains the keeper test and how it can make or break a team.
- There are numerous strategies for building and maintaining a high-performing team, but unfortunately they are not plug-and-play. What works for some companies will not necessarily work for others. Erin Meyer, co-author of No Rules Rules: Netflix and the Culture of Reinvention, shares one alternative employed by one of the largest tech and media services companies in the world.
- Instead of the 'Rank and Yank' method once used by GE, Meyer explains how Netflix managers use the 'keeper test' to determine if employees are crucial pieces of the larger team and are worth fighting to keep.
- "An individual performance problem is a systemic problem that impacts the entire team," she says. This is a valuable lesson that could determine whether the team fails or whether an organization advances to the next level.