Dec 15 2017

Saturn’s Rings Are Younger Than Previously Thought

Published by under Astronomy
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The gorgeous rings of Saturn are one of the most dramatic features of our solar system, and certainly a favorite of any backyard astronomer. Are they, however, a fixture that have been present for the majority of the life of our solar system, or are they a recent addition?

Of course we have no observations from millions or billions of years ago, so we can only infer their probable age. Up until recently astronomers believed they were probably ancient because the large collisions that likely produced them would have been far more likely in the early crowded solar system. However – recent evidence from Cassini has changed that conclusion.

The Cassini probe made detailed observations of Saturn and its rings for years, until it plummeted into the planet this September. Scientists are still analyzing all the data it sent back home. Two lines of evidence suggest that the rings of Saturn are far younger than previously suspected.

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Dec 14 2017

Antarctic Ice

Perhaps one of the most underrated science stories of 2017 was the separation of a massive iceberg the size of Delaware from the Larsen C Ice Shelf in Antarctica. That is because this is not an isolated event, but just a dramatic part of a larger story – the melting of Antarctica.

Antarctica contains most of the ice on Earth (90%). Much of that ice sits on top of land, unlike Arctic ice which is floating. When floating ice melts it just fills the space that it had displaced. There is a little bit a sea rise due to rising temperatures – water expands as it warms. But this amount of sea rise is small overall. When ice that was sitting on land flows into the ocean, it raises the sea level more significantly.

Antarctica is comprised of glaciers sitting on top of the continent, which itself is mostly below sea level. These glaciers are as thick as three miles. They are divided into a western glacier system and an eastern glacier system. West Antarctica, which is melting faster, contains enough ice to raise the sea level by 14 feet. East Antarctica is more stable but still showing some early signs of melting. All the ice here could raise the sea level by 175 feet.

As the glaciers melt during the warmer months they follow channels out to the ocean. These channels, however, are blocked by ice shelves, which act like a cork, keeping back the ice and helping to maintain the stability of the glaciers.

The ice shelves themselves have a certain structure – they rest on the sea floor but as they extend out from the continent eventually the ice lifts off the sea floor (called the grounding point) and as the ice extends out further it is floating on top of the water. The breakup of these ice shelves is a concern, because that would essentially remove the stopper and greatly accelerate the rate at which glacier melt finds its way to the ocean.

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Dec 12 2017

Space Policy Directive 1 – Return to the Moon

Yesterday President Trump signed Space Policy Directive 1 (SPD1), an executive order that will shape NASAs priorities going forward. Essentially the directive states that NASA’s primary mission is human space exploration, with a specific goal of returning to the moon.

The Directive is the result of recommendations made by the National Space Council (NSC) – a council of experts that advises the executive branch on all matters dealing with space. According to NASA, in June of this year:

President Trump has signed an executive order reestablishing the National Space Council. The council existed previously from 1989-1993, and a version of it also existed as the National Aeronautics and Space Council from 1958-1973. As such, the council has guided NASA from our earliest days and can help us achieve the many ambitious milestones we are striving for today.

The NSC recommended to the White House that NASA’s priority should be the Moon, and SPD1 is the result of that recommendation.

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Dec 11 2017

Goop Nonsense – Yes It Matters

Paltrow has defended her “lifestyle brand” by saying that they are just giving women choices, and being open. Nonsense – don’t be swayed by such distractions.

I unapologetically support reason and scholarship as critical values for human civilization. This is increasingly true as our world gets more complex, as the stakes get higher, the margins for error lower, and as our culture and economy are increasingly global.

We cannot get by just shooting from the hip. We need people with specific expertise who transparently follow a process that is logically valid and based on evidence. We need standards of scholarship and intellectual rigor that are up to the challenges we face. We also need to make this work within an open and democratic society, where public opinion matters.

What all this means is that it is more important than ever to have a well-educated public, and for our public discourse to respect standards of honesty and excellence. It matters if people understand and accept what experts have to say about vaccine safety and effectiveness, the evidence base for manmade climate change, the safety of GMOs, and the nature of health and disease.

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Dec 08 2017

In Half a Second

If you have not yet read Daniel Kahneman’s book, Thinking, Fast and Slow, I recommend it. I have discussed its basic principles here many times, and I am reminded of it by a new study that evaluates how we quickly size-up groups of people.

Before we get to the study, here is a quick overview. Kahneman and Tversky did the foundational research into cognitive biases and heuristics – ways in which our thinking is biased or constrained. Kahneman calls this system 1 thinking, or intuitive thinking, which is the fast sort. There is also system 2 thinking, which is slow and analytical.

He admits that these are metaphors, there probably aren’t two distinct biological systems in our brains, but they help us think about the different ways in which we think. Actually, given that our brains are hierarchical, the two-system model may be based in biology to some extent. There are the primitive older parts of our brain that are more system 1 – instinctive, emotional, and fast. Then there is the neocortex – which gives us executive function, and slow deliberative decision-making. I don’t think you can make a clean separation, but it is a useful schematic that is probably more true than not.

In any case, the two systems work together to shape our perceptions and decision-making. The idea is that we evolved rapid-response cognitive systems that makes quick and dirty judgments that are accurate enough and biased in whatever direction favors survival. We can then follow up these quick perceptions with more careful analysis when we have time.

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Dec 07 2017

Alternative Medicine Kills

If the best available evidence is used to determine which treatment strategy for a serious illness has the best survival, than any “alternative” to this evidence-based treatment should, by definition, have a lower survival.

That is a simple and straightforward fact. You have to believe in some twisted conspiracy theory to avoid the obvious conclusion.

But good scientists like to dot all their “i”s and cross all their “t”s. In August Yale researchers published a study in which they looked carefully at the outcomes of cancer patients treated with conventional treatments vs those who opted for so-called alternative treatments. They only considered patient who used alternative treatments instead of proven treatments.

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Dec 05 2017

Plastic Waste

I know, there are already so many things to worry about. It’s almost painful to hear about one more way in which we may be harming the world. Such reports are also often couched in emotional and dramatic terms.

However, it’s important to sift through the rhetoric and evaluate what the science says about what is actually going on. There is increasing reporting about the coming plastic apocalypse. We are dumping massive amounts of plastic into the environment, and some of that plastic is winding up in the world’s oceans. The world produced 343 million tons of plastic in 2014. Only 10% of that plastic was recycled. In total we have produced 8.3 billion metric tons of plastic, which does not biodegrade for hundreds of years.

The fact is, human civilization is big enough that we have to think about the effects of our massive industry. Producing that much plastic will likely have an impact on the environment. The biggest impact may be the percentage that winds up in the oceans – about 10%. Once there is just breaks down into smaller and smaller bits. Many animals accidentally eat the plastic, which can be fatal.

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Dec 04 2017

The Causes of Science Denial

Over the last few decades the challenges we face promoting science and critical thinking have become greater, but so have the tools at our disposal. The “science of anti-science” has been progressing nicely, and we now have a much more nuanced view of what we are up against.

Carl Sagan was fond of saying that, “Pseudoscience is embraced, it might be argued, in exact proportion as real science is misunderstood.” That was the conventional wisdom among skeptics at the time (quote from Demon Haunted World, published in 1997) – that the problem of pseudoscience or science-denial was essentially one of information deficit. Correct the deficit, and the science-denial goes away. We now know that the real situation is far more complex.

To reduce the acceptance of pseudoscience or the rejection of real science, we need to do more than just promote scientific literacy. We also need to understand what is driving the pseudoscience, and we need to give critical thinking skills.

A recent publication of a series of studies looking at the roots of science rejection is a nice cap on this research: Not All Skepticism Is Equal: Exploring the Ideological Antecedents of Science Acceptance and Rejection.

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Dec 01 2017

Liberation Procedure for Multiple Sclerosis – The Final Chapter?

In 2009 an Italian neurosurgeon, Paolo Zamboni, published a controversial article in which he claimed that patients with multiple sclerosis (MS) suffered from blockage in the veins that drain blood from the brain, that this correlation was strong and the pattern suggested a causal relationship. He called his newly identified condition Chronic Cerebrospinal Venous Insufficiency (CCSVI). His article concluded:

CDMS is strongly associated with CCSVI, a scenario that has not previously been described, characterised by abnormal venous haemodynamics determined by extracranial multiple venous strictures of unknown origin. The location of venous obstructions plays a key role in determining the clinical course of the disease.

I first wrote about the resulting controversy in 2010. At the time I concluded that there was good reason to be skeptical, that there were many “red flags for crankery”, but that further research should be done to put the question to bed. There were many reasons to be skeptical, not the least of which is that an entirely vascular cause of MS went against decades of research showing that MS is an autoimmune disease. In that first article I also wrote:

Then one of two things will happen: either the new idea or treatment will fade, becoming little more than a footnote in the history of science, or a subculture will persist in believing in the treatment and will dismiss contrary evidence and mainstream rejection as a conspiracy. Which course the new idea will take seems to depend largely on the original scientist – if they accept the new evidence and abandon their claims, it will likely fade. If they refuse to give up in the face of new evidence, then a new pseudoscience will likely be born.

Well, here we are 8 years after Zamboni’s original publication. How has this drama played out?

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Nov 30 2017

Semi-Synthetic Life With Expanded Genetic Code

It’s interesting to follow truly cutting edge research that has the potential to significantly change our world. I include in this category research into brain-machine interfaces, regeneration through stem cells, genetic engineering, and fusion energy. I would also add research into creating synthetic life.

Synthetic life research views living organisms like a technology. It is, in a way, the original nanotechnology, using complex tiny machines to manufacture chemicals, collect and store energy, degrade toxins, and other functions. Scientists have been very successful in tweaking existing organisms to harness them as tiny factories. Many modern drugs are now made in this way, making drugs like insulin widely available.

Some researchers, however, want to go beyond tweaking existing organisms. What if we could create synthetic organisms, even just single cells, entirely from scratch? That is Craig Venter’s dream – to strip down cells to their bare essentials, and then use that as a template to create a completely artificial minimal generic cell. That basic artificial cell, which we understand well because we built it from the ground up, can then be modified to perform endless functions – designer cells.

There is more to this vision, however. Once we free ourselves from the constraints of existing organisms we can explore novel properties that did not happen to evolve. Evolution is powerful, and it has had several billion years to experiment with life, but evolution is also constrained by its own history. For example, all life on earth uses the same genetic code, based upon two pairs of bases in the DNA – cytosine bonds with guanine and thymine bonds with adenine. This produces a 4-letter alphabet for the genetic code (CTAG), and also gives DNA the double-stranded structure and its ability to make copies of itself. The code consists of 64 3-letter words.

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