Jan 14 2022

Mapping the Universe

Published by under Astronomy
Comments: 0

The first day of my high school astronomy class the teacher began with a task – draw the universe. It was a clever way to engage the class, and immediately brought home that none of us had any idea what the universe, as a whole, looked like. Part of our ignorance was due to the fact that scientists didn’t know much about the structure of the universe at the time (1981). This was before we knew about dark matter or dark energy, knew that the universe’s expansion was accelerating, or had many of the modern instruments we now have to survey the universe and build a model. Most of us just drew a bunch of galaxies, but had no idea about the highest level order of structure.

In the forty years since astronomers have been refining our map of the universe. Recently an international team of scientists have built the largest 3D model of the universe to date, using the Dark Energy Spectroscopic Instrument (DESI). We have peered at the universe not only in visible light, but in infrared, ultraviolet, X-rays, and radio waves. We have also discovered new techniques such as gravitational wave astronomy and neutrino detectors, and a host of new phenomena such as fast radio bursts. Just the idea of mapping the dark energy of the universe was not conceived of back then.

So, if I (or more to the point, a team of expert astronomers) were asked to draw the universe, what would that look like? First we need to consider the fact that the question itself needs some clarification. The picture of the universe would look different in the various electromagnetic spectra. A radio map of the universe looks very different from an infrared map of the universe. We often assume we mean a visible light map, but that is not necessarily the case. Also – what are we mapping, baryonic matter, dark matter, dark energy, or all three? Further, the universe is four dimensional, and how are we going to represent this? Yes, I meant four dimensional, it has three spacial and one temporal dimension (that we know of). When we look out into the universe, we are also looking back in time. We can’t ever see the entire universe at once, as it is “now”. In fact “now” is a tricky concept when dealing with such scales. And finally we can only see (by definition) the visible universe, but we know there is much more we can’t see (because it is beyond the envelope of the speed of light – we can’t see past the beginning of the universe).

What I am really interested in is a mental map of the universe, so we don’t have to worry about how we are going to represent it. Let’s just build our mental map.

Continue Reading »

Comments: 0

Jan 11 2022

The Man with the Pig Heart

David Bennett, 57, had terminal heart disease. He was bed-ridden and kept alive on a heart machine for the last six weeks, a temporary measure at best. He was deemed too sick for a donor heart transplant, which are in limited supply and given to the patients most likely to benefit from them. Essentially, his options were over and death was imminent and unavoidable. For this reason he was considered a viable candidate for an experimental procedure, and the FDA granted emergency use authorization under its compassionate use guidelines.

On January 7th he received a heart transplant from a pig that had been genetically modified to minimize rejection. This is a true milestone – the first successful transplant of a living organ from a non-human donor into a living human (organ xenotransplantation). The reason for the caveats are the fact that pig valves are routinely transplanted into people, but these valves are fixed and therefore not living tissue. Also, you may remember the girl with the baboon heart, Baby Fae, an infant who received a baboon heart in 1984. She lived for 21 days, but this was not considered a viable procedure, which is why it was not repeated. Also, last year a genetically modified pig kidney was transplanted into a human, but they were brain dead at the time.

It remains to be seen how long David Bennett with survive with his new pig heart. Rejection is still a major issue, and he will need to be on powerful immunosuppressant drugs. There is also a reason he was not considered a good candidate for a human heart transplant. But even if the procedure is moderately successful this would represent a true milestone, our entry into the age of routine organ xenotransplantation with genetically modified organs.

Continue Reading »

Comments: 0

Jan 10 2022

A Quantum Gravity Experiment

Perhaps the greatest challenge of current theoretical physics is to come up with a testable theory that unites the principles of general relativity with quantum mechanics. This has proven to be a very challenging problem, one that may take generations of physicists to crack. Right now physicists are mostly stuck in the theoretical realm, trying to come up with theories (like string theory) that may be internally mathematically consistent, but are challenging to falsify experimentally. However, Rana Adhikari, professor of physics at Caltech, and her colleagues are trying to come up with a way to do just that. Their approach derives from another weird concept within theoretical physics – that the universe may be pixelated, and may even be a hologram (three dimensions projected from a two dimensional surface).

For background, prior to the 19th century we comfortably lived in what we now call a classical universe. Our models of how the universe works were based upon our observations and experiments within the frame of macroscopic creatures living on the surface of a planet. Galileo and Newton developed, for example, laws of motion that defined how objects move and behave, including Newton’s theory of gravity. However, classical physics started to break down in the 19th century. For example, astronomers making more and more precise measurements of the orbits of the planets were finding that the orbit of Mercury was different than what our classical equations predicted. Those equations work extremely well, but there was something off about Mercury. Attempts at finding an explanation, such as a hidden planet on the other side of the sun, failed. Eventually we had to conclude that our classical equations were not quite right, or at least could not account for the special case of Mercury.

This is where Einstein comes in. First he proposed in theory of special relativity, which fixed some vexing problems in physics by proposing that the speed of light is an absolute constant regardless of frame of reference, and that it was space and time that are variables which can change based upon frame, specifically with respect to relative velocity. This was considered “special” relativity because it only referred to the speed of light. Einstein would have to work for years more before he was able to account for gravity in a theory of general relativity. His new equations not only solved the problem of Mercury’s orbit (it is close enough to the sun that relativistic effects from the sun’s gravity are measurable) but also made a large number of predictions. Over the last century Einstein’s theories have been confirmed to an extremely high degree.

Continue Reading »

Comments: 0

Jan 07 2022

Interstellar Travel is Hard

The Fermi Paradox points to an apparent contradiction – the universe is a big place, and the laws of physics that have allowed life to evolve on Earth are the same everywhere. Therefore, the universe must be humming with life. Yet, we have not detected any evidence of extrasolar life so far. Given our current technology the only way we could have made such a detection is if such life came visiting to our own solar system. To date there is no convincing evidence of aliens visiting the Earth. (This is obviously a much deeper issue, but I strongly stand by this conclusion and firmly reject the arguments of the so-called UFO crowd.) So where is everyone?

There are many possible solutions to the Fermi Paradox, ways of resolving the apparent contradiction, and many of them have merit. But I think a sufficient explanation is simply that interstellar travel is really hard. It is overwhelmingly likely that the vast majority of science fiction, which depicts some form of faster-than-light (FTL) travel, is wrong. FTL ships are a necessary plot device to have a story span multiple worlds, but the reality is quite different.

At present there is no plausible or even theoretical method for FTL travel. Worm holes almost certainly won’t work. There is no hyperspace or subspace, no warp drive, or jump ships. At this point it seems overwhelmingly likely that the laws of physics simply do not allow for FTL travel. Einstein will not be denied. Of course, we don’t know what we don’t know, and there may be some subtle aspects to the universe we are missing that will allow for FTL travel. But it doesn’t seem likely. And if it is theoretically possible, it is also highly likely that incredibly advanced technologies harnessing massive amounts (prohibitive amounts) of energy would be required.

Continue Reading »

Comments: 0

Jan 06 2022

Gambler’s Fallacy and the Regression to the Mean

Humans overall suck at logic. We have the capacity for logic, but it is only one of many algorithms running in our brains, and often gets lost in the noise. Further, we have many intuitions, biases, and cognitive flaws that degrade our ability to think logically. Fortunately, however, we also have the ability for metacognition, the ability to think about our own thinking. We can therefore learn logic and how to think more clearly, filtering out the biases and flaws. It is impossible to do this perfectly, so it is best to think of metacognition as a life-long project of incremental self-improvement. Further, our biases can be so powerful, that when we learn how to think about thinking we often just make our logical fallacies more and more subtle, rather than eliminating them entirely.

Some cognitive flaws are evolutionarily baked into our thinking, likely resulting from heuristics that are practical mental shortcuts but not strictly logically valid. There also appears to be some cognitive abilities that were not prioritized in our evolutionary history, and so our finite brain resources were simply not allocated to them. This is where most math and statistically related fallacies derive. We do not deal well with large numbers, and we have terrible intuitions regarding statistics and probability. We have developed elaborate formal systems for dealing with math and probability, essentially to replace or at least augment our intuitive thinking, and often these systems produce results that are counterintuitive.

Perhaps the most famous example of counter-intuitive statistics is the Monty Hall problem. You are given a choice of three doors, behind one is a prize. You can choose one door. The host of this game, who knows where the prize is, then opens one door without a prize (again – they know where the prize is and deliberately choose one of the unchosen doors without a prize), and then ask if you want to change your choice to the other unopened door. If you change your choice your odds of winning go up from 1/3 to 2/3. If you have not encountered this problem before, this may seem counterintuitive, but it is absolutely correct.

Continue Reading »

Comments: 0

Jan 04 2022

Elizabeth Holmes Guilty of Fraud

There are a lot of complexities to this case, as you might imagine. Some question whether or not Holmes, CEO of the now disgraced Theranos company that claimed it had revolutionized blood testing, was unfairly targeted because she is a woman. Her defense was also complex, including a claim she was abused by her boyfriend. These details are, of course, important in the pursuit of individualized justice. But I want to focus on some big picture factors – what might the results of this case mean?

I first wrote about Theranos in 2016 – I recognized the story as a skeptical cautionary tale. The claims that Holmes was making were implausible in the extreme. She claims her company innovated the technology to perform hundreds of different blood tests with a very small amount of blood and within a short period of time. The public is used to such advances in technology, and this claim, while bold, may seem plausibly incremental. However, medical experts recognized the claim for the nonsense it was. Far from being incremental, such a feat would have required hundreds of scientific breakthroughs all brought to technological fruition in a marketable product. This kind of advance does not come out of nowhere, without a paper trail of scientific research behind it.

Holmes was counting on a general level of scientific illiteracy, specifically to how the process of science works. It is increasingly difficult to make a major discovery or technological advance without all the groundwork being laid by incremental research spread out among various experts and institutions. Often when we hear of a new technology hitting the market, there is 20-30 years of background research. The idea for an mRNA vaccine started in the 1980s, for example. The new medical technologies that are coming online in the last decade have roots that go back decades.

Continue Reading »

Comments: 0

Jan 03 2022

Are Gas and Nuclear “Green”

Whether or not natural gas power and nuclear power plants should be considered “green” (meaning that they are environmentally friendly) is not just an abstract question. The European Commission has proposed plans to label some (emphasis on some) gas and nuclear plants as officially green. This has real-world consequences, such as the ability to receive funding and whether or not they will be considered green financial investments.

Part of the purpose of the proposal is to keep companies from “greenwashing” their portfolio and business activities, by listing which investments are considered officially green (as opposed to ones that may be presented as environmentally friendly when they are not). This proposal, however, has sparked a controversy of its own, with some EU countries, such as Germany, claiming that the proposed rules are a form of greenwashing themselves. Other countries, like France, who depend on nuclear power for 70% of their energy, have pushed for such labeling. Who has the better argument?

Let’s take each technology unto itself, because they really are independent and don’t necessarily have to be taken as a package. Natural gas is a fossil fuel, and burning natural gas for energy does release CO2 into the atmosphere. The supply of natural gas is also increasingly dependent on fracking technology, which injects air and liquids into fossil fuel deposits in order to liberate and gain access to natural gas. This technology has significantly brought down the price of natural gas, resulting in a surge of its use in some countries. This surge has mostly displaced the burning of coal for power, and that is exactly the reason why some believe the technology should be considered green – in comparison to this one alternative.

Continue Reading »

Comments: 0

Dec 21 2021

Fiber Batteries

Technophiles talk a lot about batteries because they are so essential to our electrified and green future. By historical standards we have cheap and powerful batteries today, but because they are so critical to our technological infrastructure, any way they can be incrementally advanced is welcome, and some advances may be game-changers. While there is a lot of focus on energy density (energy storage per volume) and specific energy (energy storage per mass), many other features are important to overall battery utility. One we do not often speak about is the shape of the battery, or the ability to take on a variety of shapes. I have a feeling we might be talking about this feature more in the future.

Imagine, if you will, a car that does not contain a large battery, it is a large battery. The structural components themselves double as battery storage. The same can be true for any part of your house, the casing of a laptop computer, or the structure of any electronic device, like a cell phone. Further, if batteries could be made into very thin fibers, then they could be woven into any shape. They could be thin, flexible, and woven into fabrics.

That is exactly what a team from MIT has accomplished. They created a process by which a lithium-ion battery can be stretched into a thin fiber, while maintaining the structural arrangement and integrity of all of its components. The battery fiber can then be coated in a protective material, making it waterproof. The authors write:

Here, we present a Li-ion battery fiber, fabricated for the first time using a thermal drawing method which occurs with simultaneous flows of multiple complex electroactive gels, particles, and polymers within protective flexible cladding. This top-down approach allows for the production of fully-functional and arbitrarily long lithium-ion fiber batteries. The continuous 140 m fiber battery demonstrates a discharge capacity of ∼123 mAh and discharge energy of ∼217 mWh.

Continue Reading »

Comments: 0

Dec 20 2021

Debate Over Octopus Farm

Spanish company Nueva Pescanova is close to opening a commercial octopus farm in the Canary Islands. The purpose of this farm is to raise octopuses (and yes, that is an acceptable plural) for food, sparking another round in the debate over the ethics of raising animals for food. This also comes on the heels of the UK adding the octopus to the list of “sentient” animals, garnering for them certain legal protections.  This is a good opportunity to discuss what sentience means and ethics of eating animals.

Consciousness as a phenomenon of living things is a continuum, with things like bacteria, algae, and fungi at one end of the spectrum and humans at the other (humans are objectively the most encephalized or sapient species on Earth). Nowhere along this continuum are there any sharp demarcation lines. Therefore, as humans develop an ethical and moral philosophy for how we should treat each other, the obvious question becomes – to what extent should our ethical philosophy apply to other living things?

First we need to dispense with the extremist position that all life is equally deserving of dignity, respect, autonomy, and all the ethical considerations that flow from these principles. This is an unworkable position, and also does not stand up to close scrutiny. First, all living things exist to some extent in competition with each other. No living thing affords all other living things equal respect. If someone is infected with bacteria, those bacteria may very well kill them (after subjecting them to a horrible illness). Taking antibiotics is mass bacterial murder. Insects are definitely a step up from single-celled creatures, having a primitive neural algorithm that determines their behavior. And sometimes we need to control the population of insects as they try to eat our food, spread infections, destroy our homes, or otherwise be pests.

At the other end of the spectrum there are chimpanzees, our closest cousins, and the other great apes. They clearly have a highly sophisticated central nervous system. They can experience grief, have personalities, can plan ahead, and communicate. Because they are closely related to us, we have an easy time understanding that they are intelligent creatures who deserve to also be treated with dignity and respect. Still, this does not mean the same thing as for humans. Chimpanzees do not deserve the right to vote, or be held criminally accountable for their behavior or enter into a legal contract. While very close to humans, chimps have some obvious limits. There is a solid case to be made, however, that chimps should not be farmed for food or subjected to cruel experiments. They are intelligent sensitive creatures and should not be made to suffer at the hands of humans.

Continue Reading »

Comments: 0

Dec 16 2021

Mask Up

The COVID-19 pandemic is not done with us yet. We are still in the middle of the delta surge, and while delta will eventually pass, the omicron variant is right on its heels. In the US we just passed the milestone of 800,000 people dead from COVID with over 50 million cases. More Americans died of COVID in 2021 than in 2020, although in 2021 most deaths were among the unvaccinated. The vaccines remain our best defense against this pandemic, which is why it is tragic that there are still holdouts for tribal or ideological reasons. Regardless, it is extremely likely that we will be dealing with COVID through 2022. It is also likely that COVID is now endemic, and while it may fade down to flu-like proportions, we will also very likely have to deal with it for years to come. COVID is also likely not the last respiratory pandemic we will have to deal with this century.

All of this is why masks are still important. We just have to accept the fact that face masks are now an important part of life. At least for the foreseeable future we will need face masks as a layer of protection in health care settings, large indoor crowds, among vulnerable populations, and for anyone who is symptomatic. Walking around in the public maskless, sneezing and coughing from a “cold” is no longer socially acceptable. If you want to avoid the mask in small or outdoor crowds and in gatherings of family and friends, then get fully vaccinated. But even then, there are some situations where masks provide an extra needed layer of protection.

There are at least two important questions relating to mask wearing. The first is – do they really work? The short answer is yes, they do. But obviously there is some complexity here. When worn properly, and in the right setting, masks provide a measurable level of protection from a respiratory infection. They protect you and they protect others. The latest evidence to support this conclusion looked at countries with and without face mask policies. They found:

Average COVID-19 mortality per million was 288.54 in countries without face mask policies and 48.40 in countries with face mask policies.

Continue Reading »

Comments: 0

Next »