Mars One and done?

Mars One, a non-governmental plan to send colonists on way trips to Mars starting in 2025, has been in the news a lot over the last year.  While I’d love to see us establish a human presence on Mars, the Mars One project has always struck me as a flawed plan, with far too many optimistic assumptions.

It turns out that I’m not the only one with that concern: Mars One and done? | MIT News.

In 2012, the “Mars One” project, led by a Dutch nonprofit, announced plans to establish the first human colony on the Red Planet by 2025. The mission would initially send four astronauts on a one-way trip to Mars, where they would spend the rest of their lives building the first permanent human settlement.

It’s a bold vision — particularly since Mars One claims that the entire mission can be built upon technologies that already exist. As its website states, establishing humans on Mars would be “the next giant leap for mankind.”

But engineers at MIT say the project may have to take a step back, at least to reconsider the mission’s technical feasibility.

The MIT researchers developed a detailed settlement-analysis tool to assess the feasibility of the Mars One mission, and found that new technologies will be needed to keep humans alive on Mars.

Among the findings of the researchers are that it would be cheaper to ship food from Earth to the colony than to resolve all the problems with growing it locally, that it would take a lot more Falcon 9 launch vehicles than the Mars One team’s optimistic estimates (at a much higher cost totaling $4.5 billion), and the logistical problems of the vast inventory of spare parts that the colony would need that, in the absence of advanced 3D printing technologies, would have to shipped from Earth.

The MIT teams doesn’t completely rule out the feasibility of Mars One, but they do highlight how many unknowns remain for such an endeavor, how much technology still has to be developed, and how expensive it would really be.

I didn’t see it discussed in the article, but I personally find the idea of sending people on a one way trip to Mars to be a deeply questionable strategy.  Yes, it does eliminate having to relaunch from Mars, which is the most technically difficult aspect of a two-way trip.  But we’re talking about asking people to spend the rest of their lives in a harsh, unforgiving, and utterly isolated environment.

It’s hard to imagine that many of the young people volunteering for this have any real conception of what they’d be getting themselves into.  And, as the years piled up and the initial excitement waned, we should expect a substantial portion of them to come to bitterly regret their decision, with consequences for the morale of the colony, as well as subsequent recruitment efforts.  The colony could become, effectively, the starkest penal colony ever created.

Chaos theory and doubts about determinism

I’ve mentioned a few times before that I’m not a convinced determinist, at least not of the strict or hard variety.  I have three broad reasons for this.  The first is that I’m not sure how meaningful it is to say something is deterministic in principle if it has no hope of ever being deterministic in practice.

The second is quantum physics with its inherent uncertainties, uncertainties that we know bleed into the macroscopic world by the very fact that we know about their existence.  If they didn’t bleed into the world, how would us macroscopic entities know about them?  (If you hold to an interpretation of quantum mechanics that posits unobservable determinism, see my first reason.)

The third reason is chaos theory, the fact that inherent uncertainties in any measure we might make means that many dynamic systems are indeterministic, even in principle.  Along those lines, I discovered this documentary on chaos theory on Amazon today.  If you have an Amazon account, and an hour to spare, it’s a fascinating show.

If you don’t have an Amazon account, or don’t want to spend an hour on it, this Youtube is a pretty good shorter introduction to it.

Are you a strict determinist?  If so, what do you think about chaos theory?  Or quantum uncertainty for that matter?

Fluid tests and quantum reality

The other day, I mentioned that I had some sympathy for the deBroglie-Bohm interpretation of quantum mechanics, namely an interpretation that there isn’t a wave-function collapse as envisioned by the standard Copenhagen interpretation, but a particle that always exists but is guided by a pilot-wave.

It turns out that there are some people doing experiments with fluid dynamics that seem to show results very similar to the dynamics envisioned by the pilot wave interpretation.

The experiments involve an oil droplet that bounces along the surface of a liquid. The droplet gently sloshes the liquid with every bounce. At the same time, ripples from past bounces affect its course. The droplet’s interaction with its own ripples, which form what’s known as a pilot wave, causes it to exhibit behaviors previously thought to be peculiar to elementary particles — including behaviors seen as evidence that these particles are spread through space like waves, without any specific location, until they are measured.

Particles at the quantum scale seem to do things that human-scale objects do not do. They can tunnel through barriers, spontaneously arise or annihilate, and occupy discrete energy levels. This new body of research reveals that oil droplets, when guided by pilot waves, also exhibit these quantum-like features.

The article notes that most particle physicists aren’t impressed.  Despite my sympathy for the pilot-wave interpretation, I can definitely understand why.  These are experiments with fluid dynamics, not with actual quantum systems.  There doesn’t seem to be any good reason to suppose that these fluid dynamics match the dynamics of actual quantum systems, other than the coincidence of their dynamics matching a possible interpretation of those systems.

Still, the experiments are interesting.

Growing doubt that gravitational waves were actually detected

Nature has an article up describing the problems with the BICEP2 results that are now being identified by various scientists.  It’s actually the second one I’ve seen them publish on this.

The astronomers who this spring announced that they had evidence of primordial gravitational waves jumped the gun because they did not take into proper account a confounding effect of galactic dust, two new analyses suggest. Although further observations may yet find the signal to emerge from the noise, independent experts now say they no longer believe that the original data constituted significant evidence.

Researchers said in March that they had found a faint twisting pattern in the polarization of the cosmic microwave background (CMB), the Big Bang’s afterglow, using a South Pole-based radio telescope called BICEP2. This pattern, they said, was evidence for primordial gravitational waves, ripples in the fabric of space-time generated in the early Universe (see ‘Telescope captures view of gravitational waves‘). The announcement caused a sensation because it seemed to confirm the theory of cosmic inflation, which holds that the cosmos mushroomed in size during the first fraction of a second after the Big Bang.

However two independent analyses now suggest that those twisting patterns in the CMB polarization could just as easily be accounted for by dust in the Milky Way Galaxy12.

The BICEP2 team has reportedly been sticking to their guns, and many theoretical physicists initially downplayed the issues, so I’ve been reluctant to put too much credence to these stories.  But the doubts seem to be gaining more traction, and this caught my attention:

“I had thought that the result was very secure,” Alan Guth, the cosmologist who first proposed the concept of cosmic inflation in 1980, and who is at the Massachusetts Institute of Technology in Cambridge, told Nature after learning about Flauger’s talk. “Now the situation has changed.”

It’s still possible that when the BICEP2 team actually publishes their results, all of the issues will be addressed and results still found to be compelling.  But when the father of cosmic inflation loses confidence in the results, I’d say they’re on the ropes.  Inflation definitely may still be reality, but we might not have proof for it yet.

Tegmark’s Level I Multiverse: infinite space

English: A simulated view of the entire observ...
English: A simulated view of the entire observable universe, approximately 93 billion light years (or 28 billion parsecs) in diameter. (Photo credit: Wikipedia)

I’ve just finished reading Max Tegmark’s latest book, ‘Our Mathematical Universe‘, about his views on multiverses and the ultimate nature of reality.  This is the first in a series of posts that I plan to do on it.  Tegmark postulates four levels of multiverse.  This post is about the first, and simplest version, the Level I Multiverse.

No one knows for sure how large the universe is, but the size of the observable universe is actually pretty well known.  The universe as we know it started expanding from a hot dense state about 14 billion years ago.  Given the fast but finite speed of light, the further away we look, the further back in time we’re looking.

The furthest and oldest thing we can now see is the cosmic microwave background (CMB), which has been traveling for almost the entire history of the known universe, 14 billion years.  However, due to the expansion of space, the CMB we are now seeing originated 46 billions light years away, making that the radius of the observable universe.

Cosmologists often consider the word “universe” to be synonymous with the observable universe.  The reason for this is it’s all we can observe, and given that the speed of light is the fastest speed that any interaction or effect can travel, the edge of the observable universe is the limit of our causal influence, or of things that could influence us.  In other words, we are currently causally disconnected from the regions beyond this point, beyond or cosmological horizon.

Of course, there’s no real reason to think the universe ends at the limits of our observation.  Indeed, attempts to measure the curvature of space seem to indicate that the whole universe is at least hundreds of times the size of the observable universe.

Considering the observable universe to be our universe, Tegmark refers to the regions beyond as other universes.  Semantically, this seems like a questionable move.  These regions seem like more of just the same universe.  Initially I suspected this might be an attempt to redefine the multiverse into something non-controversial so the controversial versions wouldn’t be as much of a leap.

However, if the  universe is infinite, it leads to strange conclusions, and with enough distance, the phrase other universes starts to make sense.  Within each local observable universe, there are a finite number of ways that the atoms can be arranged.  (Note: a very large number of combinations, but a finite number.)  This means that in an infinite universe, every possible configuration of matter will eventually be realized.  Furthermore, if you could look far enough in this infinite space, eventually every configuration will repeat itself, infinitely.

In other words, in an infinite universe, somewhere there would be another observable universe, also with a 46 billion light year radius, that is identical to ours.  If so, it would contain a duplicate version of you reading a duplicate of this blog entry.  Actually, throughout infinite space, there would be infinite copies of you reading infinite copies of this blog entry.  And there would be an infinite number of you in every possible variation of you leading every possible variation of  your life.

These duplicate universes would exist within the same space that we inhabit, have the same laws of physics, and the same or varying histories.  But even the closest would be unimaginably far way.  Tegmark states that current calculations show that it would be 101029 meters from here, which of course is an indescribable distance.

Do these duplicate regions, these parallel universes, exist?  If space is infinite, or at least 101029 meters in extent, it seems hard to argue that they don’t.  If space is that large.  But we don’t know yet whether or not it is.  It might be, or it might not be.

Current measurements show space to be flat, but as I said above, the margin of error on these measurements leaves room for space to still eventually loop back onto itself, to make it that if you could travel in a certain direction long enough, you’d end up back at your starting point, similar to what happens on Earth, but in three dimensions.

But if space is flat and infinite, and these duplicate regions do exist, it’s hard to imagine how their existence could ever have an effect on us (unless maybe if someone invented an intergalactic warp drive).  This also seems to make the idea unfalsifiable.  Still, the concept, while speculative, is a fascinating one.

This is the simplest of the multiverses that Tegmark discusses in his book.  In the next post in this series, I’ll discuss his Level II Multiverse.

Microbes May Have Fueled Permian Extinction, Earth’s Biggest

A microbial feeding frenzy may have fueled the biggest mass extinction in Earth’s history, new research suggests.

The findings suggest that bacteria, with a little help from massive volcanism, produced large quantities of methane, thereby killing 90 percent of life on the planet.

more at Microbes May Have Fueled Permian Extinction, Earth’s Biggest.

I’ve often wondered if some of the mass extinctions were caused by life itself.  Now, it sounds like that might have been true for the Permian Extinction.

If you think about it, the current Holocene Extinction, which we’re currently going through, is the same thing.  We’re life, and we’re causing extinctions all over the biosphere.   The question is whether we’ll eventually take it to the extent that we wreck our own food chain and go extinct ourselves.

Using distant quasars to close the “free will” loophole

Given the conversations some of us have had over determinism and the possibility of quantum hidden variables, I thought this was particularly interesting.

In a paper published this week in the journal Physical Review Letters, MIT researchers propose an experiment that may close the last major loophole of Bell’s inequality—a 50-year-old theorem that, if violated by experiments, would mean that our universe is based not on the textbook laws of classical physics, but on the less-tangible probabilities of quantum mechanics.

Though two major loopholes have since been closed, a third remains; physicists refer to it as “setting independence,” or more provocatively, “free will.” This loophole proposes that a particle detector’s settings may “conspire” with events in the shared causal past of the detectors themselves to determine which properties of the particle to measure—a scenario that, however far-fetched, implies that a physicist running the experiment does not have complete free will in choosing each detector’s setting. Such a scenario would result in biased measurements, suggesting that two particles are correlated more than they actually are, and giving more weight to quantum mechanics than classical physics.

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