I do not think that many would disagree with the statement that there is dispute on the subject of sexuality. I've started several posts related to the subject, but in all cases I find that I need to lay some groundwork first (as I best think about things from basic principles, as you've surely noticed if you've read my thoughts before). So I begin with underlying principles.
The doctrine to which I subscribe and the belief which I have about sexuality is full of a sense of the sacred. People are sacred. Their bodies are sacred. Sexuality is sacred. The parts of the body associated with sexuality are sacred. All of these things are tied to the very purpose of life, and our potential to grow and to become all that we are meant to become.
The moral principles of chastity are fundamentally tied to this sacredness. We are to be chaste because God so commanded, but also because, in doing so, we honor our own sacredness, the sacredness of those around us, the sacredness of the body, the sacredness of sexuality, the sacredness of sex organs, and the sacredness of life and godhood. These things are not to be treated lightly, and this sacredness is so great that God has given very direct commandments about what is required in our respect for them. These things are not to be mocked, displayed and so opened to mockery, made use of except in a context equal to their sacredness, or otherwise treated lightly. This sacredness is, so far as I am aware, the underlying principle by which we may understand the Law of Chastity and associated commandments.
This conception of sexuality and chastity is clearly at odds with some other ideas that one might have about the topic. By subscribing to it, I obviously reject the idea of "free love": it is not morally right to act on all sexual impulses simply because we have them, we cannot in righteousness sleep around as we wish, and indeed this respect for the sacred requires us to exercise self-control in abstaining from sexual activity except in very particular circumstances. At the same time, I reject the notion that sexuality is evil: Chastity exists not because sexuality is evil, but because it is so very good. I believe that God wants us to enjoy sex, that it is supposed to be pleasant and to build sacred bonds between husband and wife, beside the fact that its role in producing life is a key part of His plan for this life. Yet these things, pleasant though they are, and though God intends that men and women should enjoy them, must not be indulged in except in His way.
One more piece of theology, in order to suggest the great depth of this sacredness. One of God's great roles, indeed, among the things that defines His Godhood, is His role as creator. Sex is the means by which men and women can act as co-creators with God in this life. And it is not only a creative act in a very divine sense, it is the creative act by which the pinnacle of creation, a very child of God embodied in the flesh, is brought into the world. In sexuality, properly respected, we work with God for the very fulfillment of His work and glory, the growth, progression, perfection, and eventual immortality and eternal life of His children. At the same time, it looks forward to God's plan for us, to grow and to become as He is, creators and parents as He is a parent. In sexuality, there is a microcosm of godhood, and a foreshadowing of what God, in His mercy and power, will make of us if we will allow Him. This idea is so glorious, beautiful, sacred, and divine, that with all the care, awe, and respect that I might give, I am fully aware of my inadequacy in approaching the subject; yet I hope that this account of things gives at least some sense of the level of respect which sexuality deserves.
I hope that this may serve as a guide in considering related topics, and I hope that as I approach them, I am in clear in illustrating how they are tied to both this sacredness of sexuality which I have considered tonight, as well as the sacredness of other things which may be implicated (particularly people).
Tuesday, September 24, 2013
Wednesday, August 21, 2013
Improving Relationships
Like everything, there's a complicated side to this subject, and there's lots of advice that one could give. But I'd like to make this a very quick post and simply point out two obvious things today:
1. Find out what other person likes. Do it. Repeat.
2. Find out what the other person doesn't like. Don't do it.
1. Find out what other person likes. Do it. Repeat.
2. Find out what the other person doesn't like. Don't do it.
Sunday, June 9, 2013
The Steward and the King
Today I'm going to discuss something different. I've been re-reading Lord of the Rings, and I discovered several new things on this reading, and today I wanted to think about one of the things that I noticed. SPOILER ALERT! (Oh, and this has become quite the long post)
So, one thing that I noticed was the parallels between the House of Eorl and the House of the Stewards. There are some things about this that seem obviously juxtaposed which prompt this thought. To name just a few:
-The lord of each house, Denethor and Theoden, loses his heir during the action of the story to Saruman's Uruk-Hai
-Gandalf arrives shortly after each discovers the loss of his son
-A hobbit swears fealty to each of them near the beginning of "The Return of the King"
Yet these events, and other similarities, allow us to see the contrast between these lords and houses.
Recall that Denethor had long stood in the defense of Gondor, and near the beginning of "The Return of the King," when we first meet him, and even before that, when Faramir is telling Frodo and Sam about Boromir, we learn something about Denethor's nobility, strength, and wisdom, with which he had long ruled and labored for his people, awaiting the return of the king, according to his charge as steward. When we first meet him, Denethor is still fighting; though we may detect some decay in his greatness (he inspires no great love in Pippin), still he is carrying on nobly.
In contrast, when we first meet Theoden, we have heard rumor of the goodness of the Rohirrim (primarily from Boromir, though somewhat also from Aragorn), yet he sits on his throne, old, inactive, deceived, convinced that he has no strength left; indeed, we might say that he is broken. He has imprisoned his new heir, Eomer, for defying his command to stay and guard Edoras, Eomer having pursued the Uruk-Hai that had ambushed the Fellowship (possibly to the salvation of all, because of what Merry and Pippin might have revealed, unwittingly or under torture, when it was discovered that they did not have the Ring).
Yet all of this changes. The events when Gandalf, Aragorn, Legolas, and Gimli arrive at Meduseld would take scarcely an hour, yet in that time, Theoden arises from his throne, breathes the free air again, takes up his sword, remembering his own strength, finds out about the treachery of Wormtongue, reinstates Eomer, and resolves to lead his men in battle. In a mere hour, the dying embers in the old king's heart are reignited into a blaze and a strength which inspires his men to great deeds. Just a few days later, he leads the charge out of the Hornburg against an army of thousands with just a handful of the men of his house, to be saved by the help of the Huorns and the men of Westfold, led by Gandalf. And not two weeks after his healing by Gandalf, Theoden arrives at Minas Tirith at the head of the host of the Rohirrim, saving the city from destruction, slaying the Southron chieftain and scattering the enemy cavalry, and, as he lay dying during the Battle of the Pelennor, he declares, "I go to my fathers. And even in their mighty company I shall not now be ashamed. I felled the black serpent. A grim morn, and a glad day, and a golden sunset!"
In contrast, Denethor, who was clad in armor and carried a long sword so that his arm would not forget its strength, was broken shortly after the wounding of Faramir. He lost hope, and would not let healers tend to his son, nor continue the defense of the city, leaving Gandalf in command by the simple fact that none other would lead. Even while Theoden was leading his riders on the last leg of their march, preparing for a desperate battle to save the city of Minas Tirith, Denethor sat in that same city, giving up on it and saying, "My line too is ending, even the House of the Stewards has failed. Mean folk shall rule the last remnant of the Kings of Men, lurking in the hills until all are hounded out." He will not hope for his son, nor remember that he yet has kin even beside Faramir in which the blood of Numenor runs true (as is said of Prince Imrahil of Dol Amroth). And then he is broken, and waits for a time for his son to merely speak before his death, and finally even gives up on that. Indeed, perhaps at the same moment that Theoden lay dying without shame, Denethor burned himself alive, and would have burned his son had Gandalf not prevented it.
But this isn't all that lies between these two lords. We see a difference in faithfulness as well. When the Red Arrow comes, Theoden is waiting for the summons, having marshaled his forces already, and sets out the next morning to Gondor's aid with 6,000 spears, according to the oath which his fathers had made long before. In contrast, when he learns through the palantir of the impending return of Aragorn, Isildur's heir, Denethor the Steward calls him the "last of a ragged house long bereft of lordship," and refuses to turn over his charge, as is his duty (though he is never an obstacle to Aragorn's return because of his self-immolation). This statement is in defiance not only of an oath taken by his fathers, but of what he taught his own son and heir, Boromir, when asked, "How many hundreds of years needs it to make a steward a king, if the king returns not?" To which Denethor replied, "Few years, maybe, in other places of less royalty. In Gondor ten thousand years would not suffice."
One more contrast still is apparent between these two lords. To both of them a Halfling swears fealty, Pippin to Denethor and Merry to Theoden. Both are short in their service to these lords, but even so the difference in their service is obvious, perhaps even more obvious because they're so closely juxtaposed (Pippin and Merry offer their swords within a chapter of one another). We see a difference from the very start, in how each comes into the service of his lord. Each offers it, unprompted, yet when Peregrin does so, it is in speaking of the death of Boromir, who fell defending Merry and Pippin from many foes, and saying, "Little service, no doubt, will so great a lord of Men think to find in a hobbit, a halfling from the northern Shire; yet such as it is, I will offer it, in payment of my debt." In contrast, of Merry before Theoden it is said, "Filled suddenly with love for this old man, he knelt on one knee, and took his hand and kissed it. 'May I lay the sword of Meriadoc of the Shire on your lap, Theoden King?' he cried. 'Receive my service, if you will!'" And of course this is not the end to the differences in their service, for Theoden speaks of sitting with Merry in his hall at Meduseld and speaking of herb-lore, while Denethor does sit with Pippin in his hall in the Citadel, but interrogating him more than anything else. And then each hobbit acts against his lord's wishes before the end, yet Pippin does so in working to deliver Faramir from his own father's fey mood, while Merry does so to ride with Theoden and stand with him in battle. And each one saves a near and beloved kinsman of his lord by his disobedience, Pippin saving Faramir, and Merry helping Eowyn to defeat the Witch King, cutting the Nazgul as he stood over Theoden's niece and prepared to kill her, so that she had a chance to stand and slay the wraith. Indeed, when all was said and done, both halflings did a far greater service than could have been expected before the end, both in defiance of their lord's orders, yet Theoden loved and forgave Merry at the last, and was glad of his service (and would have been even more glad had he known the extent of it), while Denethor ignored Pippin and cursed the good which he did.
Several more things we can note which stand between the House of Eorl and the House of the Stewards, beside the contrast between these two lords. The first is a matter which long predates the events of "The Lord of the Rings." The Stewards are a house of greater nobility: they are descended from the Faithful of Numenor. The House of Eorl is a house of kings rather than stewards, it is true, but they are of the "middle men," as Faramir notes, rather than the "high" men. Aragorn speaks no unkind words of this: in describing the Rohirrim to Legolas and Gimli he says, "They are proud and wilful, but they are true-hearted, generous in thought and deed; bold but not cruel; wise but unlearned, writing no books but singing many songs, after the manner of the children of Men before the Dark Years." Yet perhaps this can be seen as a backward extension of the change that happens in the lives of Denethor and Theoden. Whereas the Stewards had been true men of Numenor, they are in decay by this time, so that Faramir notes that they may hardly be called "high" anymore, and perhaps the nobility of the House of Eorl has been rising. Indeed, over the past 500 years it had risen from that of mere chieftains of the north to true kings of a great people. And this continues, at least on the part of the House of Eorl. For the highest king living, Aragorn son of Arathorn, true king of Gondor, speaks to Eomer, the new king of the Rohirrim, heir to Eorl, saying, "Between us there can be no word of giving or taking, nor of reward; for we are brethren."
And so both houses, the Stewards and that of Eorl, are established once more, to continue so long as their realms shall last. Yet one thing more remains between them: Faramir weds Eowyn, and so unites the two houses forever. And though she is not of Numenor, it may be questioned whether this at all reduces the standing of the House of the Stewards. More ancient perhaps it was, and a line of Numenor, with Elvish blood, yet it would seem to me that rather it was renewed in the great deeds and nobility of both Faramir and Eowyn.
So, one thing that I noticed was the parallels between the House of Eorl and the House of the Stewards. There are some things about this that seem obviously juxtaposed which prompt this thought. To name just a few:
-The lord of each house, Denethor and Theoden, loses his heir during the action of the story to Saruman's Uruk-Hai
-Gandalf arrives shortly after each discovers the loss of his son
-A hobbit swears fealty to each of them near the beginning of "The Return of the King"
Yet these events, and other similarities, allow us to see the contrast between these lords and houses.
Recall that Denethor had long stood in the defense of Gondor, and near the beginning of "The Return of the King," when we first meet him, and even before that, when Faramir is telling Frodo and Sam about Boromir, we learn something about Denethor's nobility, strength, and wisdom, with which he had long ruled and labored for his people, awaiting the return of the king, according to his charge as steward. When we first meet him, Denethor is still fighting; though we may detect some decay in his greatness (he inspires no great love in Pippin), still he is carrying on nobly.
In contrast, when we first meet Theoden, we have heard rumor of the goodness of the Rohirrim (primarily from Boromir, though somewhat also from Aragorn), yet he sits on his throne, old, inactive, deceived, convinced that he has no strength left; indeed, we might say that he is broken. He has imprisoned his new heir, Eomer, for defying his command to stay and guard Edoras, Eomer having pursued the Uruk-Hai that had ambushed the Fellowship (possibly to the salvation of all, because of what Merry and Pippin might have revealed, unwittingly or under torture, when it was discovered that they did not have the Ring).
Yet all of this changes. The events when Gandalf, Aragorn, Legolas, and Gimli arrive at Meduseld would take scarcely an hour, yet in that time, Theoden arises from his throne, breathes the free air again, takes up his sword, remembering his own strength, finds out about the treachery of Wormtongue, reinstates Eomer, and resolves to lead his men in battle. In a mere hour, the dying embers in the old king's heart are reignited into a blaze and a strength which inspires his men to great deeds. Just a few days later, he leads the charge out of the Hornburg against an army of thousands with just a handful of the men of his house, to be saved by the help of the Huorns and the men of Westfold, led by Gandalf. And not two weeks after his healing by Gandalf, Theoden arrives at Minas Tirith at the head of the host of the Rohirrim, saving the city from destruction, slaying the Southron chieftain and scattering the enemy cavalry, and, as he lay dying during the Battle of the Pelennor, he declares, "I go to my fathers. And even in their mighty company I shall not now be ashamed. I felled the black serpent. A grim morn, and a glad day, and a golden sunset!"
In contrast, Denethor, who was clad in armor and carried a long sword so that his arm would not forget its strength, was broken shortly after the wounding of Faramir. He lost hope, and would not let healers tend to his son, nor continue the defense of the city, leaving Gandalf in command by the simple fact that none other would lead. Even while Theoden was leading his riders on the last leg of their march, preparing for a desperate battle to save the city of Minas Tirith, Denethor sat in that same city, giving up on it and saying, "My line too is ending, even the House of the Stewards has failed. Mean folk shall rule the last remnant of the Kings of Men, lurking in the hills until all are hounded out." He will not hope for his son, nor remember that he yet has kin even beside Faramir in which the blood of Numenor runs true (as is said of Prince Imrahil of Dol Amroth). And then he is broken, and waits for a time for his son to merely speak before his death, and finally even gives up on that. Indeed, perhaps at the same moment that Theoden lay dying without shame, Denethor burned himself alive, and would have burned his son had Gandalf not prevented it.
But this isn't all that lies between these two lords. We see a difference in faithfulness as well. When the Red Arrow comes, Theoden is waiting for the summons, having marshaled his forces already, and sets out the next morning to Gondor's aid with 6,000 spears, according to the oath which his fathers had made long before. In contrast, when he learns through the palantir of the impending return of Aragorn, Isildur's heir, Denethor the Steward calls him the "last of a ragged house long bereft of lordship," and refuses to turn over his charge, as is his duty (though he is never an obstacle to Aragorn's return because of his self-immolation). This statement is in defiance not only of an oath taken by his fathers, but of what he taught his own son and heir, Boromir, when asked, "How many hundreds of years needs it to make a steward a king, if the king returns not?" To which Denethor replied, "Few years, maybe, in other places of less royalty. In Gondor ten thousand years would not suffice."
One more contrast still is apparent between these two lords. To both of them a Halfling swears fealty, Pippin to Denethor and Merry to Theoden. Both are short in their service to these lords, but even so the difference in their service is obvious, perhaps even more obvious because they're so closely juxtaposed (Pippin and Merry offer their swords within a chapter of one another). We see a difference from the very start, in how each comes into the service of his lord. Each offers it, unprompted, yet when Peregrin does so, it is in speaking of the death of Boromir, who fell defending Merry and Pippin from many foes, and saying, "Little service, no doubt, will so great a lord of Men think to find in a hobbit, a halfling from the northern Shire; yet such as it is, I will offer it, in payment of my debt." In contrast, of Merry before Theoden it is said, "Filled suddenly with love for this old man, he knelt on one knee, and took his hand and kissed it. 'May I lay the sword of Meriadoc of the Shire on your lap, Theoden King?' he cried. 'Receive my service, if you will!'" And of course this is not the end to the differences in their service, for Theoden speaks of sitting with Merry in his hall at Meduseld and speaking of herb-lore, while Denethor does sit with Pippin in his hall in the Citadel, but interrogating him more than anything else. And then each hobbit acts against his lord's wishes before the end, yet Pippin does so in working to deliver Faramir from his own father's fey mood, while Merry does so to ride with Theoden and stand with him in battle. And each one saves a near and beloved kinsman of his lord by his disobedience, Pippin saving Faramir, and Merry helping Eowyn to defeat the Witch King, cutting the Nazgul as he stood over Theoden's niece and prepared to kill her, so that she had a chance to stand and slay the wraith. Indeed, when all was said and done, both halflings did a far greater service than could have been expected before the end, both in defiance of their lord's orders, yet Theoden loved and forgave Merry at the last, and was glad of his service (and would have been even more glad had he known the extent of it), while Denethor ignored Pippin and cursed the good which he did.
Several more things we can note which stand between the House of Eorl and the House of the Stewards, beside the contrast between these two lords. The first is a matter which long predates the events of "The Lord of the Rings." The Stewards are a house of greater nobility: they are descended from the Faithful of Numenor. The House of Eorl is a house of kings rather than stewards, it is true, but they are of the "middle men," as Faramir notes, rather than the "high" men. Aragorn speaks no unkind words of this: in describing the Rohirrim to Legolas and Gimli he says, "They are proud and wilful, but they are true-hearted, generous in thought and deed; bold but not cruel; wise but unlearned, writing no books but singing many songs, after the manner of the children of Men before the Dark Years." Yet perhaps this can be seen as a backward extension of the change that happens in the lives of Denethor and Theoden. Whereas the Stewards had been true men of Numenor, they are in decay by this time, so that Faramir notes that they may hardly be called "high" anymore, and perhaps the nobility of the House of Eorl has been rising. Indeed, over the past 500 years it had risen from that of mere chieftains of the north to true kings of a great people. And this continues, at least on the part of the House of Eorl. For the highest king living, Aragorn son of Arathorn, true king of Gondor, speaks to Eomer, the new king of the Rohirrim, heir to Eorl, saying, "Between us there can be no word of giving or taking, nor of reward; for we are brethren."
And so both houses, the Stewards and that of Eorl, are established once more, to continue so long as their realms shall last. Yet one thing more remains between them: Faramir weds Eowyn, and so unites the two houses forever. And though she is not of Numenor, it may be questioned whether this at all reduces the standing of the House of the Stewards. More ancient perhaps it was, and a line of Numenor, with Elvish blood, yet it would seem to me that rather it was renewed in the great deeds and nobility of both Faramir and Eowyn.
Tuesday, April 9, 2013
"Anything will lase if you pump it hard enough"
Okay, leaving behind controversy, philosophy, and such for a moment, I'm going to approach something simpler, and something I know a bit about. Tonight, I'm going to write about how a laser works.
There's one basic thing that you have to understand about Quantum Mechanics in order to understand lasers. You see, in quantum systems, you often have discrete energy levels: the electron in the hydrogen atom can have -13.2 units of energy (we'll call it eV... don't worry about what that unit means, just know it's a unit of energy that physicists use when dealing with atoms and stuff) or -3.4 eV, but it can't be between those two energy levels. The difference between these two energy levels is 9.8 eV. So if you've got a hydrogen atom, and its electron is sitting in the lower energy level, it needs to get exactly 9.8 eV from... somewhere... if it's gonna go up to the higher level. Maybe you shine a light on your atom, and it takes 9.8 eV out of the light. But there's a catch: it turns out that light comes in discrete packets (that's the idea of a "photon," really), and the amount of energy in a photon is directly related to the frequency/wavelength of the light. So you need to choose just the right color of light (in this case, it turns out that it's ultraviolet light) to give your electron the energy it needs. If you do that, your electron absorbs a photon of light to jump up to the higher energy level, and you have an event that is called "stimulated absorption."
At the same time, if your electron is sitting in the higher energy level, and a photon with that same 9.8 eV happens to come by, the photon can actually do the opposite, it can make the electron jump from the higher energy level to the lower one, and in the process, the electron emits another 9.8 eV photon, identical to the first. So, you start with one photon and an "excited" atom (one with its electron in the higher energy level), and you end up with two identical photons and a non-excited atom. This is called "stimulated emission," and it happens at the same rate as stimulated absorption. So if you had, say, 1,000 atoms, and 500 of them started in the lower energy level, and 500 in the higher energy level, and you shined a light on all of them, you'd end up with your excited atoms and your non-excited atoms sort of switching places, at exactly the same rate, so that you always have 500 atoms in each energy level. Also, because every stimulated absorption event takes a photon (its energy is used up in exciting the atom), and every stimulated emission event creates a new photon, the number of photons remains constant.
But what if we could put all 1,000 atoms in the excited state? Well, then, when you shine your light on them, they all emit light instead of absorbing it... so, when all is said and done, you get an extra 1,000 photons. And each extra photon emitted is identical to the photon that stimulated its emission.
Okay, let's make this bigger. Instead of 1,000 atoms, let's have a reasonable number... like a mole of atoms. Then we put them all in the excited state. Then we wait. Eventually, with so many atoms around, something called "spontaneous emission" is going to happen, which basically means that an atom can't just hold onto extra energy forever, at random the electron is going to go back to the lowest energy level and emit a photon at exactly the right wavelength. Then that photon is going to go flying... until it runs into an atom. And with 10^23 around, that won't take long. And when that happens, since the atom it runs into is also in the excited state, you're going to have stimulated emission, and then you'll have two identical photons flying together inside your collection of atoms ("gain medium" is the technical term). And then your two photons run into another atom. And another. Soon, your single photon has become millions and billions of identical photons, all flying together in a big, concentrated beam of light. Eventually, the beam leaves the gain medium. But you put a mirror at the end of your gain medium, so your beam bounces back and goes through your trillions and quintillions of atoms again, and as it does so, your beam gets even bigger. It exits the gain medium again. But you put another mirror there, so your beam bounces back and forth, and you get even more atoms emitting light, until you have this awesome beam of laser light. At this point you might ask how you ever get the light out from this pair of mirrors, and there are a few ways, maybe the easiest is that you make one of the mirrors so that it only reflects most of the light (say 90%), and the rest goes through. But, regardless, you have a laser: a beam of coherent light, made up of identical photons in a concentrated beam, made by amplifying just a tiny little seed through stimulated emission by millions of atoms (incidentally, LASER is an acronym: Light Amplification by Stimulated Emission of Radiation).
And this brings me back to the title. The only tricky part is that you have to get at least the majority of your atoms in the excited state. But, in general, things don't like sitting in the excited state. So you have to find a way of "pumping" your gain medium: putting the atoms in the excited state. Some things are easier to pump than others, and that's one of the reasons that certain types of lasers are easier to find than others. But every material has quantum transitions, so if you work hard enough, pump it hard enough, you could put more atoms of any material in the excited state, and then it would "lase" (because with a noun like "laser," it's just so convenient to verb that noun). Doesn't mean you'll have a good laser (if your gain medium is opaque, or if air is opaque at the wavelength of the light it emits, you might not have much of a beam), but at least inside your gain medium, you can make lasing happen.
There is a logical fulfillment of this fact: the Jello Laser. Yes, that's right. You can make a laser from any transparent material, and it's usually convenient to work with solids (because, you know, you can put mirrors around them and they keep a nice shape and stuff), so people made a laser from Jello. The Jello laser (bonus points in Utah if it's green, I'm sure).
Title: Attributed to Theodore Maiman, who demonstrated the first laser.
There's one basic thing that you have to understand about Quantum Mechanics in order to understand lasers. You see, in quantum systems, you often have discrete energy levels: the electron in the hydrogen atom can have -13.2 units of energy (we'll call it eV... don't worry about what that unit means, just know it's a unit of energy that physicists use when dealing with atoms and stuff) or -3.4 eV, but it can't be between those two energy levels. The difference between these two energy levels is 9.8 eV. So if you've got a hydrogen atom, and its electron is sitting in the lower energy level, it needs to get exactly 9.8 eV from... somewhere... if it's gonna go up to the higher level. Maybe you shine a light on your atom, and it takes 9.8 eV out of the light. But there's a catch: it turns out that light comes in discrete packets (that's the idea of a "photon," really), and the amount of energy in a photon is directly related to the frequency/wavelength of the light. So you need to choose just the right color of light (in this case, it turns out that it's ultraviolet light) to give your electron the energy it needs. If you do that, your electron absorbs a photon of light to jump up to the higher energy level, and you have an event that is called "stimulated absorption."
At the same time, if your electron is sitting in the higher energy level, and a photon with that same 9.8 eV happens to come by, the photon can actually do the opposite, it can make the electron jump from the higher energy level to the lower one, and in the process, the electron emits another 9.8 eV photon, identical to the first. So, you start with one photon and an "excited" atom (one with its electron in the higher energy level), and you end up with two identical photons and a non-excited atom. This is called "stimulated emission," and it happens at the same rate as stimulated absorption. So if you had, say, 1,000 atoms, and 500 of them started in the lower energy level, and 500 in the higher energy level, and you shined a light on all of them, you'd end up with your excited atoms and your non-excited atoms sort of switching places, at exactly the same rate, so that you always have 500 atoms in each energy level. Also, because every stimulated absorption event takes a photon (its energy is used up in exciting the atom), and every stimulated emission event creates a new photon, the number of photons remains constant.
But what if we could put all 1,000 atoms in the excited state? Well, then, when you shine your light on them, they all emit light instead of absorbing it... so, when all is said and done, you get an extra 1,000 photons. And each extra photon emitted is identical to the photon that stimulated its emission.
Okay, let's make this bigger. Instead of 1,000 atoms, let's have a reasonable number... like a mole of atoms. Then we put them all in the excited state. Then we wait. Eventually, with so many atoms around, something called "spontaneous emission" is going to happen, which basically means that an atom can't just hold onto extra energy forever, at random the electron is going to go back to the lowest energy level and emit a photon at exactly the right wavelength. Then that photon is going to go flying... until it runs into an atom. And with 10^23 around, that won't take long. And when that happens, since the atom it runs into is also in the excited state, you're going to have stimulated emission, and then you'll have two identical photons flying together inside your collection of atoms ("gain medium" is the technical term). And then your two photons run into another atom. And another. Soon, your single photon has become millions and billions of identical photons, all flying together in a big, concentrated beam of light. Eventually, the beam leaves the gain medium. But you put a mirror at the end of your gain medium, so your beam bounces back and goes through your trillions and quintillions of atoms again, and as it does so, your beam gets even bigger. It exits the gain medium again. But you put another mirror there, so your beam bounces back and forth, and you get even more atoms emitting light, until you have this awesome beam of laser light. At this point you might ask how you ever get the light out from this pair of mirrors, and there are a few ways, maybe the easiest is that you make one of the mirrors so that it only reflects most of the light (say 90%), and the rest goes through. But, regardless, you have a laser: a beam of coherent light, made up of identical photons in a concentrated beam, made by amplifying just a tiny little seed through stimulated emission by millions of atoms (incidentally, LASER is an acronym: Light Amplification by Stimulated Emission of Radiation).
And this brings me back to the title. The only tricky part is that you have to get at least the majority of your atoms in the excited state. But, in general, things don't like sitting in the excited state. So you have to find a way of "pumping" your gain medium: putting the atoms in the excited state. Some things are easier to pump than others, and that's one of the reasons that certain types of lasers are easier to find than others. But every material has quantum transitions, so if you work hard enough, pump it hard enough, you could put more atoms of any material in the excited state, and then it would "lase" (because with a noun like "laser," it's just so convenient to verb that noun). Doesn't mean you'll have a good laser (if your gain medium is opaque, or if air is opaque at the wavelength of the light it emits, you might not have much of a beam), but at least inside your gain medium, you can make lasing happen.
There is a logical fulfillment of this fact: the Jello Laser. Yes, that's right. You can make a laser from any transparent material, and it's usually convenient to work with solids (because, you know, you can put mirrors around them and they keep a nice shape and stuff), so people made a laser from Jello. The Jello laser (bonus points in Utah if it's green, I'm sure).
Title: Attributed to Theodore Maiman, who demonstrated the first laser.
Sunday, January 27, 2013
"Courage Is Not the Absence of Fear, But the Mastery of It"
I wanted to draw attention to this quote for a simple reason: It's really just a special case of a more general principle.
"Virtue is not the absence of temptation, but the mastery of it."
It is true that we can sometimes act in ways which bring temptation on ourselves, and that can be a matter of foolishness or wickedness, but a great many temptations come regardless of individual action. Indeed, many temptations grow out of desires which are, of themselves good.
As evidence, sexual sin is quite severe. However, we are told that attraction, even sexual attraction, is a desire which is God-given for a purpose which is essential to His plan. Sex and the desire for sex are, of themselves, good things, and part of the reason that sexual sin is so severe is that it profanes a thing which is so sacred. So it is good and right, but only at the right time, in the right way. As Elder Jeffrey R. Holland once taught, 'When faced with that inherent appetite, a disciple of Christ must be willing to say, "Yes, but not this way."' (The Inconvenient Messiah)
So temptation cannot be taken as proof that a person is bad. Indeed, the ultimate example of virtue, Jesus Christ, "was in all points tempted like as we are, yet without sin" (Hebrews 4:15). Let us be like Him. So I say again,
"Virtue is not the absence of temptation, but the mastery of it."
Title: Usually attributed to Mark Twain, though there seems to be some doubt on the subject
"Virtue is not the absence of temptation, but the mastery of it."
It is true that we can sometimes act in ways which bring temptation on ourselves, and that can be a matter of foolishness or wickedness, but a great many temptations come regardless of individual action. Indeed, many temptations grow out of desires which are, of themselves good.
As evidence, sexual sin is quite severe. However, we are told that attraction, even sexual attraction, is a desire which is God-given for a purpose which is essential to His plan. Sex and the desire for sex are, of themselves, good things, and part of the reason that sexual sin is so severe is that it profanes a thing which is so sacred. So it is good and right, but only at the right time, in the right way. As Elder Jeffrey R. Holland once taught, 'When faced with that inherent appetite, a disciple of Christ must be willing to say, "Yes, but not this way."' (The Inconvenient Messiah)
So temptation cannot be taken as proof that a person is bad. Indeed, the ultimate example of virtue, Jesus Christ, "was in all points tempted like as we are, yet without sin" (Hebrews 4:15). Let us be like Him. So I say again,
"Virtue is not the absence of temptation, but the mastery of it."
Title: Usually attributed to Mark Twain, though there seems to be some doubt on the subject
Sunday, January 20, 2013
"Obeying, Honoring, and Sustaining the Law"
There's an interesting (and important, practically speaking) conflict that comes up at times:
"We believe in being subject to kings, presidents, rulers, and magistrates, in obeying, honoring, and sustaining the law" (Articles of Faith 1:12).
"Then Peter and the other apostles answered and said, We ought to obey God rather than men" (Acts 5:29).
Clearly we are required, as a part of our religion, to "render unto Caesar" a certain degree of respect and obedience. Yet we also believe, under certain circumstances at least, in civil disobedience. If you doubt it, consider the story of Shadrach, Meshach, and Abed-nego, which is a prime example of the practice: they willfully refuse to obey a law, accepting the consequences, because their moral values could not abide it. And their stance clearly was not frowned upon by God, judging by His miraculously delivering them.
So there is a time for obeying the law, and there is a time for disobeying it on moral principle. The question of where, exactly, to put the line of demarcation between the cases in which we should obey it and those in which we should defy it is what remains to us. To determine this, the above quotes may well give us what we need to know:
"We believe in being subject to kings, presidents, rulers, and magistrates, in obeying, honoring, and sustaining the law" (Articles of Faith 1:12).
"Then Peter and the other apostles answered and said, We ought to obey God rather than men" (Acts 5:29).
Clearly we are required, as a part of our religion, to "render unto Caesar" a certain degree of respect and obedience. Yet we also believe, under certain circumstances at least, in civil disobedience. If you doubt it, consider the story of Shadrach, Meshach, and Abed-nego, which is a prime example of the practice: they willfully refuse to obey a law, accepting the consequences, because their moral values could not abide it. And their stance clearly was not frowned upon by God, judging by His miraculously delivering them.
So there is a time for obeying the law, and there is a time for disobeying it on moral principle. The question of where, exactly, to put the line of demarcation between the cases in which we should obey it and those in which we should defy it is what remains to us. To determine this, the above quotes may well give us what we need to know:
- Generally speaking, we believe in obeying the law. So in most cases, we should obey the law.
- However, "We ought to obey God rather than men." God's laws supersede man's. If obedience to a human law directly contradicts a moral law, we ought to follow God first.
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