science tumbled

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Who Can Name the Bigger Number?

Ah! Sometimes I need to be reminded why I love science in the first place. The answer is simple curiosity, and the extraordinary sensation of satisfying it. A child-like wonder at the world is a great thing. It can lead in two directions: either to the mystic, who so clings to that wonderful feeling that any attempt to dissolve it by explanation is seen as a threat; or to the scientist, who enjoys the wonder for what it is, but who sees it rather as a motivation to explore, invent, discover, and seek the equally extraordinary sensation of satisfying curiosity. That is the phenomenology of science in a nutshell, the science of what it feels like to do science, or learn science, or at least my idealized version of it.

Scott Aaronson is the kind of rigorous modern scientist who hasn’t lost touch with his child-like curiosity and wonder at the world. He asks an innocent question—who can name the bigger number in fifteen short seconds—and goes on to explore how this question connects to a series of incredible discoveries in the history of mathematics and science. And he’s funny, too. Read it. I’m surprised I haven’t linked this essay before.

While we’re on the topic of quantum physics, here is a nifty illustration from Wikipedia of the elementary particles of the Standard Model. “Atom” means indivisible, as atoms were originally thought to be the smallest parts of the universe, the bits that compose everything else but are not themselves composed of smaller particles. As physics advanced, scientists found that atoms consisted of even smaller particles, and these are the smallest, atomic (indivisible) parts of reality as far as we know today, according to the most accurate and experimentally verified theory of physics as of 2014. Notably missing is the graviton, a particle hypothesized to be the carrier of the elementary force of gravitation, but as of today physicists have been unable to create a theory that unifies the three forces of the Standard Model—the electromagnetic force, the strong and the weak nuclear force—with gravity.
The fact that these particles are regarded as elementary doesn’t necessarily mean that they aren’t composed of even smaller particles. It could be that in the future, likely when we can study even higher energies than those in our most powerful particle accelerators—big machines that collide particles at enormous velocities, generating extreme energies in order, basically, to see what happens, what comes of the collision—we will discover that these particles are composed of even smaller constituents. But as it stands right now, these are the smallest things we know exist, and as of now, based on the information we possess from experiments and mathematical theories, we think they’re indivisible. Nothing, as far as we know, is smaller than those particles up there.
Many hypotheses have been put forth which bring further or smaller elementary particles into the fray, notably string theory, but these are so far only mathematical fantasies, hypotheses which have yet to be tested and verified. Science is a process, not an end goal.
If you’re missing the familiar protons and neutrons, they are composed of quarks, held together by the strong nuclear force, which is mediated by the gluon. The electron, however, swirling about the atomic nucleus, is believed to be elementary. Perhaps one day we’ll peek further into the depths of the quantum world and discover smaller things, but that’s where it stands right now.
The pre-Socratic philosopher Democritus is often credited as the father of atomism, the theory that everything is composed of tiny, tiny things that are themselves indivisible and indestructible. This view is, on the face of it, a lucky guess that hints at modern physics; on the other hand, Democritus imagined atoms as solids; some of them could lock together with hooks and become very durable, like iron, while others were slippery and constantly in motion, like water or air. Of course, the Ancient Greeks had no way of investigating this; modern technology and high energies are required to observe the atomic and subatomic world.

While we’re on the topic of quantum physics, here is a nifty illustration from Wikipedia of the elementary particles of the Standard Model. “Atom” means indivisible, as atoms were originally thought to be the smallest parts of the universe, the bits that compose everything else but are not themselves composed of smaller particles. As physics advanced, scientists found that atoms consisted of even smaller particles, and these are the smallest, atomic (indivisible) parts of reality as far as we know today, according to the most accurate and experimentally verified theory of physics as of 2014. Notably missing is the graviton, a particle hypothesized to be the carrier of the elementary force of gravitation, but as of today physicists have been unable to create a theory that unifies the three forces of the Standard Model—the electromagnetic force, the strong and the weak nuclear force—with gravity.

The fact that these particles are regarded as elementary doesn’t necessarily mean that they aren’t composed of even smaller particles. It could be that in the future, likely when we can study even higher energies than those in our most powerful particle accelerators—big machines that collide particles at enormous velocities, generating extreme energies in order, basically, to see what happens, what comes of the collision—we will discover that these particles are composed of even smaller constituents. But as it stands right now, these are the smallest things we know exist, and as of now, based on the information we possess from experiments and mathematical theories, we think they’re indivisible. Nothing, as far as we know, is smaller than those particles up there.

Many hypotheses have been put forth which bring further or smaller elementary particles into the fray, notably string theory, but these are so far only mathematical fantasies, hypotheses which have yet to be tested and verified. Science is a process, not an end goal.

If you’re missing the familiar protons and neutrons, they are composed of quarks, held together by the strong nuclear force, which is mediated by the gluon. The electron, however, swirling about the atomic nucleus, is believed to be elementary. Perhaps one day we’ll peek further into the depths of the quantum world and discover smaller things, but that’s where it stands right now.

The pre-Socratic philosopher Democritus is often credited as the father of atomism, the theory that everything is composed of tiny, tiny things that are themselves indivisible and indestructible. This view is, on the face of it, a lucky guess that hints at modern physics; on the other hand, Democritus imagined atoms as solids; some of them could lock together with hooks and become very durable, like iron, while others were slippery and constantly in motion, like water or air. Of course, the Ancient Greeks had no way of investigating this; modern technology and high energies are required to observe the atomic and subatomic world.

The Higgs Boson

Someone asked me to explain the Higgs Boson. This will be the last question I answer in a while. I’ll let the ask function stay open, but I’ll be collecting the questions and answering some of them at a later date. To clarify my earlier post, I do not consider any of the questions I answered to be dumb. The comment about dumb questions was intended to discourage people from asking me to help them with their schoolwork. I have no interest in that. But if you have a question about science inspired by genuine interest and curiosity, that is the sort of question I am interested in answering on this blog. This blog isn’t just about Q and A, though: more posts about science inspired by my own curiosity are forthcoming.

So, the elusive and mysterious Higgs boson. On this subject I am hopelessly out of my depth, as acquiring a good understanding of it requires a background in mathematical physics which neither I nor most of my readers possess. I will try to defer to better informed authorities. Here is John Baez, a mathematical physicist I really admire for his productivity both in producing cutting-edge theoretical science and also cranking out one educational piece after the other. This was written before CERN confirmed that the particle they detected in 2012 was indeed a Higgs boson:

The Standard Model predicts the existence of a spin-0 particle called the Higgs boson, which comes in two isospin states, one with charge +1 and one neutral. (It also predicts that this particle has an antiparticle.) According to the Standard Model, the interaction of the Higgs boson with the electroweak force is responsible for a “spontaneous symmetry breaking” process that makes this force act like two very different forces: the electromagnetic force and the weak force. Moreover, it is primarily the interaction of the Higgs boson with the other particles in the Standard Model that endows them with their masses! The Higgs boson is very mysterious, because in addition to doing all these important things, it stands alone, very different from all the other particles. For example, it is the only spin-0 particle in the Standard Model. To add to the mystery, it is the only particle in the Standard Model that has not yet been directly detected! [ed. note: now it has]

On the 4th of July, 2012, two experimental teams looking for the Higgs boson at the Large Hadron Collider (LHC) announced the discovery of a previously unknown boson with mass of roughly 125-126 GeV/c2. Using the combined analysis of two interaction types, these experiments reached a statistical significance of 5 sigma, meaning that if no such boson existed, the chance of seeing what they was less than 1 in a million.

However, it has not yet been confirmed that this boson behaves as the Standard Model predicts of the Higgs [ed. note: at this point, many signs point to the particle behaving roughly as predicted]. Some particle physicists hope that the Higgs boson, when seen, will work a bit differently than the Standard Model predicts. For example, some variants of the Standard Model predict more than one type of Higgs boson. LHC may also discover other new phenomena when it starts colliding particles at energies higher than ever before explored. For example, it could find evidence for supersymmetry, providing indirect support for superstring theory.

So what is up with this boson, anyway? Bosons are a kind of elementary particles, the other kind being fermions. You may have heard about the Pauli exclusion principle, which says that no two particles (such as neutrons) can occupy the exact same quantum state. Fermions are particles that obey this principle, as well as other laws found by Paul Dirac and Enrico Fermi (principal discoverer of the neutron). Bosons do not, however, obey these laws. The Higgs particle is a boson.

As mentioned above, the Higgs is important for several reasons. For one, it is the missing piece in the Standard Model of physics. This is the model that constitutes what is colloquially only known as quantum physics. Using a variety of laws operating on a variety of particles, it explains three of the fundamental forces of nature: the electromagnetic force, and the weak and strong nuclear forces. Einstein’s General Relativity explains the last force, gravitation, and famously we have yet to find a good theory of quantum gravity, a theory that can explain all four forces in a common framework. Finding the Higgs, predicted more than forty years ago, goes a long way towards confirming the standard model.

But its most publicized property is its ability to give (certain) particles mass; without the so-called Higgs mechanism, we don’t know how to explain the mass of some particles. As it turns out, if you look closely, by which I mean at the subatomic level—like the researchers at the Large Hadron Collider—you find that the electromagnetic and weak nuclear forces can be unified to one force. But why then do they behave as if they were two, how come this one force seems to act like one force in certain circumstances and another under different circumstances? This is where the Higgs boson comes in. It “spontaneously breaks symmetry” and cleaves the electroweak force into the weak and electromagnetic forces. Interacting with the Higgs field, a field that can be described by four numbers that permeates space—so the theory goes—also endows the W and Z bosons, carriers of the weak nuclear force, with a mass they would otherwise not have. Thus we have in principle four particles involved with the electroweak force, produced by the Higgs symmetry breaking: the positively charged W+ boson, its antiparticle the negative W- boson, the electroneutral Z boson, and finally the familiar, massless photon.

This symmetry breaking, the cleaving of one force into two apparent ones, can only be seen at very large energies, hence the need to build the expensive particle accelerator at CERN.

Various analogies have been proposed to explain how particles gain mass by interacting with the Higgs field, but none of them really hit the mark; all of them, while partially accurate, are prone to misinterpretation. In reality, what goes on in the quantum realm has no easily explainable analog in the macroscopic world we live in. I won’t even pretend to make an analogy. To fully understand it, you need a physics background.

This has been a layman’s attempt at explaining the Higgs boson. It is undoubtedly not wholly accurate, precisely because I lack the necessary scientific background. Those of you who are physicists will likely object to some of what I’ve said, and that is fine. I am perfectly aware that I am not entirely qualified to speak about this, but for the sake of my own understanding and that of my readers, I’ve given it a shot. If someone reblogs this with a better, more accurate explanation that is nevertheless accessible to the layman, I’ll share it. Maybe a physicist among you would like to do a guest post? I haven’t forgotten the early days when this was a group blog.

Anyway, the takeaway, which is one thing I am fairly certain is entirely accurate, is this: the discovery of the Higgs boson is very important in that it presents strong confirmation of what we already suspected based on previous evidence, namely that the Standard Model is, while not perfect, a very good description of reality at the subatomic level, as good as any we have today. The Higgs mechanism also solves important problems with the Standard Model involving how certain particles gain mass, particles which without this mechanism would be massless—and we know from experiments that they do have mass.

Q & A Hour

Although I have never publicized this possibility, a number of you have taken the opportunity to send questions to this blog. Instead of responding to each individually, I will answer some in a bunch. It’s always encouraging when the silent masses make the effort to tell you, either directly or indirectly that they appreciate something you have put a lot of effort into over the years. But before I answer any questions, let me just make one thing crystal clear: there is such a thing as a dumb question. Dumb questions are not what you think. You need not be dumb in order to ask an ignorant question. Ignorance is neither a sin nor a sign of low intelligence: it simply means that there is something you don’t know at this moment in time. We are all ignorant in one aspect or another. I myself have many embarrassing holes in my knowledge, and even top-flight scientists make their ignorance known on a daily basis when they entertain the misguided idea that their expertise in their field grants them domain-specific knowledge in another.

But some questions really are dumb. Particularly questions that amount to poorly veiled attempts to get someone else to do your homework for you. Now that’s dumb. The educational system has two purposes: it is there to teach you things you need to know—and as in any imperfect system, inevitably it will also attempt to force you to learn some things you don’t need to know, and it will occasionally even teach you things that are wrong—but it is also there to teach you how to learn things for yourself, without a curriculum, a required reading list, a teacher, and a confirmation that “this will be on the test.” Trying to cajole others to do your homework for you is self-sabotating. It is a form of learned helplessness. Those are dumb questions.

That out of the way, onto the questions.

Did giraffes come from dinosaurs?

No, giraffes are mammals. This is what some might call a dumb question, but I don’t consider it to be so dumb. Ignorant perhaps, but not dumb. I don’t know why you would come to think that giraffes evolved from dinosaurs, but I guess the long neck has something to do with it. Which leads to us to an interesting facet of evolution: the fact that some traits have evolved independently numerous times. When a scientist sees the same trait in different living creatures, it is natural to ask whether they have a common descent. But sometimes, this is not the case. Similar evolutionary forces have led some traits to evolve independently in different lineages and at different times. Reaching high up in the treetops to feed was useful to long-necked dinosaurs, and it was useful to giraffes. The most prominent and interesting example, however, is the eye. Being able to respond to light is useful to any kind of life that lives, feeds and procreates in an environment filled with light, and the eye is believed to have evolved independently maybe fifty or even a hundred times.

Could it be that the universe will keep expanding so long as light keeps traveling?

Yes and no. Light is not the driving force of the universe’s expansion. In the extremely short period just following the Big Bang, the universe expanded at an incredible rate. This expansion happened in a time frame so short even if we played it a trillion times in slow motion, the time frame would still be incomprehensible to humans except as numbers on a blackboard. The cause of this inflation is believed to be a natural force called by various names such as the inflaton field, analogous to the gravitational and electromagnetic fields. The exact nature of this period and the inflation is still unclear. After this initial period of cosmic inflation, the universe continued to expand at a much slower rate. But recent observations indicate that the universe is expanding at a faster rate, and the hypothetical force responsible for this acceleration is called dark energy. We have a lot to learn yet about the universe.

It’s worth noting that the universe is, as far as we know, everything that exists; there is nothing “on the outside” of the universe. The universe is not expanding like inflating a balloon; the balloon is only a small part of the universe expanding into a larger part of it. The universe itself is experiencing metric expansion: the fabric of space itself is stretching. Only on very large distance scales is this important: distant galaxies are getting further apart, not because they are moving in opposite directions, but because the space between them is stretching. This does not apply inside our own galaxy or even nearby galaxies, because our galaxies are dense (relative to the rest of the universe) collections of matter held together by their own gravitational fields. You and I are in no danger of expanding apart from ourselves anytime soon.

If a USB drive weighs 20 grams when empty, will it gain weight when you add files to it? And if so, do the files constitute weight?

This is the kind of question that sounds a little like a homework question, but I’ll give it the benefit of the doubt. The short answer is no. Here we need to get into the difference between representation and actuality. Information is weightless, because information is immaterial: it is imaginary. But to bring information out of the realm of imagination and into reality, we need to represent it by something physical. But this distinction isn’t academic. If you have a box, and you put a book full of information into it, it stands to reason that the box will get heavier. The book has mass. But since information is simply an abstract pattern, it need not be represented so crudely. We can just as well represent it by rearranging preexisting matter, without changing the object’s mass. Picture a Rubik’s cube. You could store information simply by turning it around in a special manner, representing a particular pattern distinct from other patterns. The cube wouldn’t gain any weight.

In flash memory, the information is stored in the form of electrons. Now, electrons aren’t massless, unlike photons. They do have less than a thousandth of the mass of neutrons and protons, the building blocks of atomic nuclei that make up most of the mass of a USB stick. So even if you had to add some electrons to the stick to add information to it, the weight increase would be negligible. But as it happens, that’s not how they work. To read out USB memory, you don’t simply count how many electrons are in there. Instead, you measure the conductivity of channels within the stick, and whether or not they conduct a current you send through determines the readout. You might think that the default state of a new drive is all zeroes, 00000…. but it’s actually the opposite: the default state is on, or 1. When you want to write something, you apply a current that, through magical quantum trickery—any sufficiently advanced technology is indistinguishable from magic, and to us non-hardware engineers, it might as well be—moves electrons back and forth within the memory cells, altering the conductivity and therefore the readouts.

So just like rearranging a Rubik’s cube to encode a different pattern doesn’t change its mass, adding files to a USB drive doesn’t increase its mass.

Hey my name is Jason! I have a few questions. So I study musicology but my other love is astronomy. I have a pretty good telescope but I haven’t made any progress in the field of amateur astronomy other than watching the stars, planets and the moon with my telescope. I want to be able to do more, maybe even contribute in the community of astronomy. Where should I begin?

You probably possess a telescope far superior to Galileo’s. With the proper training, you could discover things with it he never saw. The problem is that all those things have already been discovered. Long gone are the days of the polymath: the man who makes significant advances in chemistry, linguistics, painting, astronomy, botany and mathematics all in the course of one life (it was usually a man, back then, which is not the to say it couldn’t be a woman, today). We are so far advanced and specialized that if you seriously want to advance any scientific field, you need to dedicate yourself to it.

There is a good story somewhere in Surely You’re Joking, Mr. Feynman about how Feynman participated in a biology-related startup, working with cell cultures and such if you memory serves me. But he was Richard Feynman, Nobel winner in physics and one of the greatest scientists of the 20th century, and even he couldn’t just jump into a semi-related field willy-nilly. I’m afraid if you actually want to advance astronomy scientifically, you need to lay off the musicology and dedicate yourself to years of study in physics.

But there are other ways to advance the cause of science, if not the state of scientific knowledge itself. I have no scientific training, but I like to think I play a tiny part in advancing science—although I have no pretensions of bringing any new knowledge into the fray—by running this blog. Educating, inspiring, spreading the Good Word of The Lord Science is one way you can contribute.

One word of advice though: never try to give the impression that you’re something you’re not. I’m not a scientist, and I don’t pretend to be one, and all my posts must be read with the caveat that I’m just an interested amateur who must defer to better qualified sources for more authoritative and trustworthy information. This blog, just like Wikipedia—did I just compare myself to Wikipedia, oh my Darwin, I did, didn’t I—is only a starting point, not an end point for knowledge.

How do you run a successful science blog?

This is a question that allows me to pat myself on the back and speculate like some sort of guru. That is not a role I’m comfortable in, but I rarely pat myself on the back anyway, so I’ll indulge myself slightly. I know most of you don’t want to hear about how great I’m doing here. Some of you may laugh at my puny follower count, others might be envious, but apropos of that: we just passed 200,000 followers a few days ago. I guess that is pretty successful. Certainly I’d never expected this when I started this blog six years ago.

Snagging a good URL has probably helped a good deal in establishing a name and a following. But I won’t be so insecure as to give all credit to external factors. I have to believe the quality of the writing and the various other things I share has played a part in building a reputation and following. This is a labor of love, and I hope that shines through. I try to spend time preparing before I post; I don’t just go to Wikipedia and call it a day. Nor do I follow any set posting schedule: I think having a deadline, a set number of posts you feel you need in order to maintain your readers’ interest is simply going to dilute the writing. Look at me: I can go months between posts, interspersed with periods where I’ll post almost every day, and people still follow along.

Patience and diligence pay dividends. As does humility: like I repeat until the point of nausea, I am no scientist, only an interested amateur and a decent writer after years of practice. The person who asked this question, whose name has been withheld, styled herself “a neuroscientist” who had been studying the subject since she was “like, thirteen?” She was fifteen and presumably in high school. Girl, you are not Richard Feynman. You are not a prodigy, you have not been studying neuroscience—reading Wikipedia and pop culture books, by the looks of it—and you are no scientist. Adjust your self-image a bit and you may go on to achieve great things. I wish you all the best, both in blogging and in science. If I am harsh, it is only because I’m speaking the truth, and for that reason I’ve withheld your name. I am not in the business of publicly shaming teenagers. Teens be teens. I was one not so long ago. I know what it’s like. You alternate between knowing everything and having the world before your feet and soul-crushing despair. Both are normal. Both are expected. Neither, perhaps, are fertile soil for a good science blog.

godclouds said: So I have to make a presantation for chemistry class. I will choose the subject but I havent choose it yet. Do you know any subject that easy and easy to find gifs abou it. Could you recommend me?

If you limit yourself to things that are easy to learn enough about to repeat it half-convincingly to a teacher who will subsequently grant you a B+ out of a sense of obligation while sighing inwardly and mumbling under their breath about kids today who can’t learn or present anything without those fancy animated picture things, you will never learn anything truly worth learning.

I recommend trying to learn something about chirality, which is a very important concept in organic chemistry, and biochemistry in particular. In pharmacology, right- and left-handed molecules can have radically different effects. An interesting example is dextromethorphan, which is found in cough syrup sold over the counter in many countries, and which in larger doses has dissociative effects sometimes—by which I mean all the time—used for recreation, and levomethorphan, which is a scheduled narcotic for its potent opioid activity. My favorite part about not being a high school teacher who needs to give out B pluses while sighing inwardly and so on is that I get to talk about how to get high on cough syrup and the irony of scheduling one stereoisomer for its narcotic effects while selling another equally power mind-altering drug over the counter because in lower than recreational doses it happens to reduce coughing.

Chiral molecules are named for the way they rotate light. Prepare to have your mind blown by the mere fact that light can be rotated. In fact the polarization of light is a property to which we are as blind as someone who sees only black and white would be to color—note that I didn’t say color blind, as most color blindedness leads to an inability to distinguish only certain colors, most commonly red and green, not to the complete lack of color vision—but to the magnificent mantis shrimp, light polarized in different directions looks as different as light of different colors looks to us.

Chiral molecules are abundant in nature because life depends on carbon, which is tetravalent, meaning it has four free electrons available to bond with. Most biological processes depend on molecules of a particular handedness—one apocalyptic science fiction scenario involves all the biological molecules of the correct handedness suddenly—by an impossible mechanism which is hand-waved away by the author for the sake of the story—being turned into their other-handed cousins. Thus life as we know it on Earth couldn’t survive.

See what happens when you look further than what is easily available in GIF form? You just learned how to get high on cough syrup, that light can be polarized and that polarized light can be rotated and that many important medicines and biological molecules come in right and left-handed versions—frequently, but not always, on account of a “chiral center” around some carbon atom—and that the handedness is named originally after the direction in which they rotate such polarized light, and that the mantis shrimp can perceive this rotation, and in fact has vision superior vision to all of us. Oh, and how to write a killer science fiction novel.

Celsius

I read through previous posts about temperatures and pressure and got to thinking about something I’d never considered: why Celsius? And what’s up with Fahrenheit, anyway?

Anders Celsius, the man behind the name, was born on November 27, 1701 in Uppsala, Sweden. Son of an astronomer and grandson of two, it’s unsurprising that he dedicated himself to higher mathematics. Before he created his famous temperature scale, he was involved in an equally interesting debate: the question of the earth’s shape. At the time, there was wide agreement among scholars that our planet is basically round: however, there was equal agreement that the earth was not a perfect sphere. The question was about the nature and degree of deformation from that imaginary ideal. Newton had calculated that our planet is flattened at the poles; as a consequence, a degree of latitude would be longer near the poles than at the equator. On the other hand, measures by the French astronomer extraordinaire Jean-Félix Picard indicated that the planet is more egg-shaped.

Anders Celsius helped resolve the dispute. The French Royal Academy of the Sciences sent an expedition to Peru, current day Equador, to measure latitude near the equator. Celsius suggested that another expedition travel to the Torne Valley, on the border of Sweden and Finland and north of the Arctic Circle, to take measures for comparison. Celsius imagined that this expedition, carried out in 1736-37, would be the final word in the dispute over the shape of the earth. Celsius couldn’t imagine, of course, that in 2014 we would all be carrying in our pockets navigation instruments based on measurements of our earth accurate to a degree only possible in his fantasies, anchored in satellite technology. Nevertheless, he makes the following prescient remark in his “Letter to N. N.,” a pedagogical brochure written to explain the purpose of his expedition:

My Lord might be puzzled that Astronomy, which claims to know the length, shape and size of planets thousands of miles removed from us, still does not know the size and shape of the planet they walk upon daily. But that is not so strange; because one who observes our planet from e.g., the moon, can much easier observe her figure; and on the other hand, that we know the moon’s shape.

If only you knew about GPS, Anders! I’m sure he’d be smiling. The Torne Valley expedition was led by Pierre-Louis Moreau de Maupertuis, the first director of the French Academy of Sciences, and it was a success. Their measurements and the measurements from Peru confirmed that Newton was right: we live on a spheroid flattened at the poles.

Onto the thermometers. In the 18th century, there were dozens of different temperature scales proposed and circulating in scientific circles. Newton had proposed a scale based on the fixpoints of water’s melting and boiling points. Celsius used a Delisle thermometer to make measurements. The deciding factor, as it often is, was scientific rigor. Celsius recognized that in order to create an international temperature scale, equal amounts of heat must measure out to the same number in Paris as it would in his hometown of Uppsala. He set out as scientists do, to separate variables. The ideal is to keep conditions exactly the same in all matters that could conceivably affect the result of an experiment except one. If you vary many different variables at once, you can’t separate them and find out which variable gave rise to the effect. So to measure temperature, you’d want every condition except heat to be equal. Celsius made rigorous measurements of how the boiling point of water varied with pressure. Thus the boiling point of water at a specified pressure would have to serve as the fixpoint.

Celsius fixed his scale at 100 degrees for the melting point of water and 0 for the boiling point.

Wait, what? Yes. Some early scales, such as Delisle’s, were reversed: the colder it got, the higher the temperature in degrees. Perhaps influenced by his Delisle thermometer, Anders Celsius also employed this reverse scale. His scale was quickly picked up and spread, but people such as Daniel Ekström, maker of Celsius thermometers, and Carl Linnaeus, the botanist, inverted the scale and gave us the familiar Celsius scale. Measurements on this scale were commonly referred to as “degrees centigrade,” but the International Committee for Weights and Measurements officially declared that the term to be used was “degrees Celsius”—in recognition of the possible confusion between temperatures and 1/100th of a degree of arc, a term also dubbed “centigrade.”

As for Fahrenheit, the scale was defined by two fixpoints: zero, the lowest temperature Daniel Gabriel Fahrenheit could cool brine, and a hundred, the average human core body temperature. Neither of these were rigorous enough, and today the scale is officially defined with reference to other temperature scales. That, perhaps, says enough, although cultural explanations would have to fill in the gap as to why a scientifically inferior—because it was lacking rigour—scale has survived in North America and to some degree Britain while most of the world has long since switched to Celsius.

Come the 19th century, the need for an absolute temperature scale became apparent. Lord Kelvin introduced the unit that was later named for him, the Kelvin, denoted °K, in 1848. It is based on the Celsius scale insofar as the temperature intervals are the same, but the zero point is instead defined as being absolute zero, the point at which all particles are at their lowest energy state, at which no further cooling is physically possible: -273.15 °C. 0 °K. Shortly thereafter, the Rankine scale was proposed, which takes the same approach, defining its zero point at absolute zero, but taking the intervals between each degree after the Fahrenheit scale, that is 9/5ths or 1.8 degrees for each degree celsius.

One could again turn to cultural explanations for why the Kelvin scale, which could be said to be scientifically superior to the Celsius scale, has not seen use outside scientific circles. I suppose in daily life the boiling and freezing points of water are more relevant to our interests than absolute zero, a physical curiosity that we never encounter naturally—even in deep space, the temperature is slightly above absolute zero. One thing we can say in the Kelvin scale but not in Celsius or Fahrenheit is that twice the temperature actually means twice the thermal energy. 20 °K really is twice as hot as 10 °K, which is not the case with 10 and 20 °C.

A little funny aside that I found while researching this article: remember Linnaeus, the botanist? You might know him as the father of modern taxonomy, the classification of living things. A century before Darwin introduced his theory of evolution, which would give the right framework for such taxonomies, he gave us essentially our modern way of classifying plants and animals. One part of that method is the so-called type specimen: the particular sample of an animal or plant that has been studied and fixes a name to that particular species. And the type specimen of Homo sapiens? Carl Linnaeus.

timelordtributedetectivewizard said: Can science answer moral questions?

A wise man named David Hume once wrote that, in all the moral systems he had observed, at some point the author proceeds imperceptibly from “is” statements, statements about how things are, to “ought” statements, normative statements about how things ought to be. But they never seem to add the necessary logical step between—how one goes from those statements about the natural world as it is, to the statements about how it ought to be. In other words, morality. What has become known to some as Hume’s Law states that one cannot logically derive an “ought” statement from a series of “is” statements.

This is a philosophical question, and as philosophers are wont to do, they still argue about it, almost three hundred years later. Some claim that Hume’s Law is false. They subscribe to a theory called moral realism. Others claim that it holds, and they are called moral anti-realists. This whole philosophical field is called metaethics, and concerns questions such as what moral statements really mean, whether one can derive normative “oughts” from facts about the natural world, and related issues.

Science is in the business of describing the world as it is. As such, scientists are rarely interested in questions about how it ought to be. Or they might be interested, but they can only come with proposals, not actual, logically deduced demands about how people should treat one another. That is philosophy, not science. Science explores and teaches us about how the world works, not about how humans should behave towards one another.

In my personal opinion, science can certainly explore moral questions, but cannot conclusively answer them. We can do polls about what people think, but is it given that what the majority thinks is true? In any other field, one would say no. When people thought the world was flat, or that the Earth, not the Sun was the center of the universe—later, of course, we realized that the Sun isn’t even the center of the universe, which has no center, but merely the center of the solar system, but that’s a tangent—would that majority opinion make it true? No.

Game theorists and others try to model how one can optimally behave in various situations. But if taken as a moral theory, that could easily lead to egoism.

Some claim that what is natural is right, but they also skip the necessary logical step between “is” and “ought”. Rape happens in nature. Does that make it right? No. That is sometimes called the naturalistic fallacy.

This is a super complicated issue that has been debated since Socrates. If you are interested, you can read Plato’s dialogue Euthyphro. Or you can read about the is-ought problem on Wikipedia. The best source, however, is the Stanford Encyclopedia of Philosophy, which is a free encyclopedia peer-reviewed by philosophers. See hereherehere and here. But the Stanford Encyclopedia is rather dense and technical, and perhaps hard to read if you have no previous experience reading analytic philosophy.

Personally, I subscribe to a theory called moral quasi-realism, which was inspired by Hume and by Ludwig Wittgenstein and developed by Simon Blackburn. Blackburn has also written some books aimed at introducing people unfamiliar to philosophy to the field. Quasi-realism allows you to make moral statements without betraying Hume’s Law, but admittedly they have less force than if they could be claimed to be grounded in science.

In general, I have to say this is a very complex question to answer. It’s hard to answer properly without getting too technical, and I think most of the readers of this blog would lose track or patience or get bored quite quickly if I really got into it. Not because they’re dumb, just because this is Tumblr, they are unfamiliar, it’s technical and they might just want to look at pretty pictures or hear the latest in science explained in an understandable, but not dumbed-down way. That is my goal with this blog: to bring science to the people in a way that neither betrays the science by explaining it with half-baked metaphors or overhyping findings which are really just small developments in a field. But also to make it readable and enjoyable for as many people as possible.

Science is fantastic, people! It’s not just pretty pictures of galaxies or neurons or puppies transplanted with genes so they glow in the dark.

But to conclude: No, science can’t answer moral questions. Only explore them.

The Golden Rule, advocated by such luminaries as Jesus and Buddha, is still a good rule of thumb. It’s not scientific, it’s just a basic test to see if you’re being an asshole or not.

This is not scientific advice grounded in peer-reviewed journals, but it’s still damn important: be kind to one another, and as long as people are not hurting anyone else, tolerate them, whether they have the same skin color or the same politics or religion or musical tastes as you or not.

The Galle crater is a Martian crater that happens to look like a smiley face, due to the position of a curved mountain range.
Someone made a good point about our previous post about carbon dioxide melting on Mars. At normal pressure, or the very low atmospheric pressure on Mars (less than 1% of the average at sea level on Earth), dry ice does not melt into liquid. Instead, it sublimes. Sublimation is a word for the phase transition where a solid bypasses liquid entirely and becomes gas. This is what gives the familiar smoke effect you get when you expose dry ice to air. You would need a pressure of over 5 atmospheres, that is five times the pressure at sea level on Earth, or about a thousand times the average pressure on Mars, to create liquid carbon dioxide. Sublimation also occurs to a certain extent to water ice on Earth.
The point at which dry ice sublimates at normal pressure is -56 celsius, which means when the temperature goes below this, the opposite transition, from gas to solid, which is called deposition, occurs. Thus “melts” was not the right word to use in the previous post. This also gives a measure of just what spring on Mars means: the dry ice cover starts melting, sorry, sublimating when the temperature goes above -56.4 C or -69.5 F. Talk about a chilly spring!
The atmosphere on Mars is about 96% carbon dioxide. About 0.1% is oxygen. For comparison, Earth’s atmosphere is about 78% nitrogen and about 21% oxygen.
The somewhat surprising fact, at least to me, that there’s only 21% oxygen in the atmosphere lead to the invention of carbogen, a mixture of oxygen and carbon dioxide. This mixture can be used to simulate the feeling of suffocation without actually suffocating, as the brain does not monitor the oxygen levels in the blood, but rather responds as if you can’t breathe if the blood carbon dioxide levels go too high.

The Galle crater is a Martian crater that happens to look like a smiley face, due to the position of a curved mountain range.

Someone made a good point about our previous post about carbon dioxide melting on Mars. At normal pressure, or the very low atmospheric pressure on Mars (less than 1% of the average at sea level on Earth), dry ice does not melt into liquid. Instead, it sublimes. Sublimation is a word for the phase transition where a solid bypasses liquid entirely and becomes gas. This is what gives the familiar smoke effect you get when you expose dry ice to air. You would need a pressure of over 5 atmospheres, that is five times the pressure at sea level on Earth, or about a thousand times the average pressure on Mars, to create liquid carbon dioxide. Sublimation also occurs to a certain extent to water ice on Earth.

The point at which dry ice sublimates at normal pressure is -56 celsius, which means when the temperature goes below this, the opposite transition, from gas to solid, which is called deposition, occurs. Thus “melts” was not the right word to use in the previous post. This also gives a measure of just what spring on Mars means: the dry ice cover starts melting, sorry, sublimating when the temperature goes above -56.4 C or -69.5 F. Talk about a chilly spring!

The atmosphere on Mars is about 96% carbon dioxide. About 0.1% is oxygen. For comparison, Earth’s atmosphere is about 78% nitrogen and about 21% oxygen.

The somewhat surprising fact, at least to me, that there’s only 21% oxygen in the atmosphere lead to the invention of carbogen, a mixture of oxygen and carbon dioxide. This mixture can be used to simulate the feeling of suffocation without actually suffocating, as the brain does not monitor the oxygen levels in the blood, but rather responds as if you can’t breathe if the blood carbon dioxide levels go too high.

It’s spring on Mars! Dry ice is melting sublimating from the sand dunes to the North of the red planet. Image courtesy of NASA from the HiRISE camera onboard the Mars Reconnaissance Orbiter.

It’s spring on Mars! Dry ice is melting sublimating from the sand dunes to the North of the red planet. Image courtesy of NASA from the HiRISE camera onboard the Mars Reconnaissance Orbiter.

Chaohusaurus Fossil Shows Oldest Live Reptile Birth

Icthyosaurs were giant reptiles who lived in the seas at the same time as the dinosaurs ruled the land. They gave live birth to their children. A fossil newly discovered in China, dating back almost a quarter of a billion years, shows the earliest known live birth of a reptile. The fossil literally captures the moment of birth, as there was an embryo still inside the mother, a newborn just outside her, and a third halfway between, in the process of exiting the pelvis. The headfirst posture of the second baby indicates to researchers that live birth may have evolved on land, not in the water in reptiles as previously thought.

Icthyosaurs, although they lived in the same time period and could be mistakenfor them owing to their shared reptilian inheritage, were not dinosaurs. (And neither were the plesiosaurs, which, unlike the more fish-like icthyosaurs, look exactly like you’d expect water-dwelling dinosaurs to look.) Live birth is one of the things that distinguishes them.

Although not a first per se, it still amazes me that, through fossilization, we can look back at a birth in progress that started 248 million years ago.