The solar eclipse of August 21, 1914, seen from 66 degrees north, in the town of Sandnessjøen, in Northern Norway. Solar eclipses are always cool, and this is especially interesting to me because the center of this eclipse, the point at which the Moon most completely obscured the Sun, passed over my hometown one hundred years ago. The German scientist Adolf Miethe took a huge risk traveling to Norway to build an observatorium specifically for this astronomical event. If the day had been overcast, all would have been for nought.
Many astronomers were interested in observing this event, but the outbreak of war prevented many of them. Luckily for Miethe and his team, he got to observe the event even as his country went to war. Three of his fellow expedition members had to return back home for military duty.
Miethe is an interesting character, having co-invented both an early photographic flash and a process of color photography.
Observations of solar eclipses later helped confirm Einstein’s theory of relativity, as one of his predictions, the existence of gravitational lensing, could be seen.
The locals, however, were reportedly unimpressed by the eclipse, having expected it to be darker. Oh, well.
starbuqzz said: Why is yawning contagious?
Mirror neurons, These are neurons with a curious property: they fire both when you do something, but also when you observe the same action in others. Much speculation surrounds the functional role of mirror neurons, and in particular how they might factor into developing empathy, and whether defects in the mirror neuron system could contribute to autistic spectrum disorders, which are characterized by poor cognitive empathy.
In this instance, we’re seeing a primitive kind of “motor empathy,” which might underlie cognitive empathy, our ability to understand others’ thoughts, feelings, motivations and so on from their outward behavior. Brodmann’s area 9, a part of the mirror neuron system in the brain, lit up when test subjects engaged in contagious yawning. This area of the brain has also been implicated in mentalizing, i.e., precisely in understanding other people’s mental states. Interestingly, in people with Major Depressive Disorder, we have found neurons in this area to be smaller, and glia—the support cells which are more numerous than neurons, and increasingly are understood to play more than just a passive role in thought—to be fewer and further between.
It remains to be seen exactly what role mirror neurons play in human empathy, but they’re certainly interesting. It’s fascinating that not only we can automatically do something because we saw someone else do it; this automatic act is caused by parts of our perfectly healthy brain not being able to distinguish between ourselves and our fellow human beings.
llapacas said: Is it true we don't use all of our brain??? If so, why can't we. I mean, we have a brain, why not use it all to its superlative capability?
Why not indeed. The idea that we only use a small portion of the brain, usually quantified by a very specific number, is completely false. I don’t even have a guess as to where it originated, but it has since spread and infected the public consciousness. We do, in fact, use all of our brain.
Of course, this implies that we can’t just “switch on” the rest of the dormant brain and magically become smarter and more handsome, like Bradley Cooper’s character in Limitless. If it sounds too good to be true, it probably is.
However, that doesn’t mean that the way in which our brain operates is at all times completely optimal for our goals. Increasing or decreasing activity in certain parts of the brain, or certain neurotransmitter pathways, could plausibly make at least some of us happier or more productive. Which, of course, is nothing new, since we have been using psychoactive drugs for such purposes since the dawn of medicine. As we learn more about the brain, we will come closer to the level of understanding required to really mess with it in ways that can, possibly, make us smarter or happier without risking dangerous side effects. But we aren’t really there yet. Most current drugs, or non-drug methods of altering the brain come with a long sheet of possible adverse reactions.
Obviously it would be easier if there really were large swaths of the brain going unused all the time, just sort of hitchhiking on the evolutionary trail, a sort of parasitic neural network gobbling up nutrients and energy—the brain is the part of our body that uses the most energy as compared to its volume—that we could activate to become superhuman. But that really isn’t the case.
And if you think about it, that really makes no sense at all on two levels. First, why would we have a huge organ that consumes huge amounts of precious (at least in prehistoric times) energy if we only used a small portion of it? If we could do with the brain of a baboon, we would never have retained, or evolved such a big brain in the first place. And secondly: consider the extremely implausible-even-for-a-hypothetical scenario that we all were actually carrying around a huge brain but only using a small portion of it. That would constitute normal experience. What would happen if we suddenly activated the rest? In the movies, the obvious answer is that we’d be superhuman. But maybe we’d actually become emotional wrecks, or maybe we’d become intellectually impaired because the mind could not integrate all the new activity into a coherent picture.
Luckily for us, no such dilemma faces us. The 10% or whatever number is making the rounds is completely fabricated.
However, while it’s not the case that ordinary healthy people go around not using a large chunk of their brain, it is possible to survive and even thrive with minimal loss of cognitive function with only half your brain. A procedure known as hemispherectomy involves removing or severing one hemisphere of the brain. This surgery is only performed in extreme cases of epilepsy where the source of seizures has been found to be localized to one hemisphere, due to the obvious risks of cutting out or off one half of someone’s brain. Remarkably, the brain, especially if the surgery is performed at a young age, is able to adapt and allow basically all of the functions of the other hemisphere to be taken over by the one remaining.
oneidaiscrazyforyou said: Why is carbon Dioxide Really hot?
Carbon dioxide isn’t really hot. Like other gases, it all depends on how much you heat it. The boiling point of CO2 is far below freezing. But carbon dioxide and other greenhouse gases in the atmosphere absorb heat that would otherwise be reflected off earth into space, thus increasing the average temperature on our planet’s surface. In absolute terms, global warming doesn’t amount to much warming at all—if you saw it on the weather forecast, you might shrug it off—but an increase in average temperature of only a few degrees can have dramatic and devastating consequences.
In-ear headphones were patented all the way back in 1891, when French engineer Ernest Mercadier invented his “bi-telephone”:
After extensive testing and optimization of telephone receivers, Mercadier was able to produce miniature receivers that weighed less than 1 3/4 ounces and were “adapted for insertion into the ear.” His design is an incredible feat of miniaturization and is remarkably similar to contemporary earbud headphones, down to the use of a rubber cover “to lessen the friction against the orifice of the ear… effectually close the ear to external sounds.”
Surely there’s a hip kickstarter waiting to happen in there somewhere.
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.
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.