For Anonymous: Passing the Bug

First an announcement: For the next two months, I'm forgoing tarot questions. Up until recently, I was getting a steady supply of those and, truthfully, they're generally not very interesting for anyone but the questioner. On October 1, I'll open it back up to tarot questions, but I'm going to limit the number to two per month so people can still come here to learn more general stuff.

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Anonymous asked: that if someone gets rid of their bug, someone else can still get it of them a couple of days later?

I'm glad you asked because I only have a vague idea of the answer and love to learn new things. So, off to do research.

Wow, cool. OK, here are some of the answers (because this is biology and there are lots of answers).

First off, people don't necessarily get sick as soon as their exposed to a "bug." Many diseases have an incubation period that can range from hours to days to even years (though the latter is very unusual). What that means is that, if you were exposed to a "bug" (or other pathogen), it could very well take days, weeks, even longer before the disease manifested. That makes tracking down where (and when) you actually got it much more complicated. Long incubation periods (and asymptomatic individuals) can spread disease unknowingly as infectious people pass the bug around without realizing they are "sick." One reason why AIDS is so challenging to control is that people can be infected without realizing it for years - in turn passing it around to others through the use of needles and unprotected sex. So, if you get a bug long after the person you think infected you has recovered, it may be because you were infected much earlier than you thought you were.

This can be particularly tricky when someone is healthy but infected with something, particularly something nasty, as Typhoid Mary was. She had every reason to feel she was healthy and unable to communicate a disease, but managed to infect more than 50 people cooking for them, and was infectious even when she died in quarantine. There are other examples of this kind of thing, but she was somewhat celebrated. And that leads me to another possible answer:

It could also be that the source remained infectious after the symptoms receded. Which meant they were carrying the bug, even if they didn't look like it. With so many over the counter and prescription drugs to treat symptoms, someone could be still quite sick without it appearing so. Though, for some reason, that never seems to happen to me. When I'm sick, I'm miserable no matter what drugs I take. Some diseases manifest in visible ways, like herpes, but can be transmissible even when in "remission." So that's two rather readily available answers to your question.

But wait, there's more. Some diseases can survive for long periods of time on surfaces, like smallpox and tuberculosis and staff bacteria. It's a concern for hospitals who need to ensure surfaces (and hands) are cleaned between patients so that diseases aren't spread between people who never even see each other.

And there's more than one way to become sick: contaminated water or food, exposure to a toxin or radiation, bites of animals (rabies) or insects (malaria, Black plague, lyme disease, etc.), exposure to contaminated fluids or surfaces, parasites . . . any of these can look like a disease you got from a friend without actually being one.

Science, what fun!

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For Shakespeare: How Hot Is the Sun?

Shakespeare asked: How hot is the sun, how did it get this way, and how does it stay hot without burning up?

Good questions. First off, whenever I get a question about the solar system, I stop off first at Nineplanets.org. Great educational stuff about about the planets, their moons and, of course, the sun. Wikipedia's a good source, too. The temperature of the Sun is actually a tricky question. Like the gas giants, the sun isn't a solid mass but a tightly packed gaseous mass (though it is very very massive - 99.8% of the solar system mass is contained within it's "boundaries).

At the core, where the heat is generated, the temperature is 15.6 million degrees Kelvin (and about the same Centigrade - when you get that hot the 270 odd degree difference in scale really doesn't matter). I can't think of an analogy to tell you how hot that is, but it's hotter than anything we can make (or at least sustain) here on earth. The core is also under so much pressure (from the gravitational weight of all that mass) that the core of superheated hydrogen gas is actually 150 times denser than water. Think of that, gasses that weigh more than water.


Near the boundary's of the sun, the so called "surface of the sun" the heat and pressure are much less, 5800 degrees Kelvin (which is still unbearably hot) with sunspots that can be 2000 degrees cooler. However, above this level, there is another level, called the corona that extends far out from this solar "surface" and can be hotter than the surface itself, ~1 million degrees K. You can see the corona in this photograph during a solar eclipse.


Solar flares and limbs and also shove out streaks of fire from the surface. Is this a cool picture or what (taken by Hinode's Solar Optical Telescope)?

The way we understand things, the sun was formed when a dense molecular cloud of hydrogen collapsed. The weight of the mass caused tremendous pressure and heat in the core triggering a nuclear reaction. The heat and energy from the nuclear reaction keep the fire going. Now, that may not make much sense, so let me explain, step by step.

If you compress a gas suddenly, you will increase pressure and temperature. Release it, suddenly, the gas will cool and pressure drops. This is adiabatic heating and cooling and it happens from the work done on the gas without any additional heat added from the outside. There was a lot of pressure, a lot of compression and that meant a lot of heat, which is how the reaction was triggered.

Nuclear reactions aren't like burning the way most of us know it. When something is "burned" we are really breaking down the structure of a mass, combining some of it with oxygen (which is required for fire) and sending much of it into the air. The mass of an object if one could capture all the byproducts from combustion, is the same. Matter can't be created or destroyed without nuclear reactions.

For example, if you burn hydrogen gas in an oxygen atmosphere, you'll get water in return. But the hydrogen's still there, as part of the water, H2O. You can extract it back out because it can't be destroyed with simple combustion.

However, with nuclear reactions, elements are changed into other elements, combined or reduced, and the extra mass those elements shed are released as energy, a lot of energy: e=mc^2 which means the mass times the speed of light squared. That's a lot of energy for a little bit of mass. With fission, the extra mass comes from changing a heavy element, like uranium, into something less heavy like Xenon or Barium. However, even more powerful than a nuclear fission reaction is a nuclear fusion reaction, where hydrogen atoms (the smallest, lightest element) combines to form helium atoms (the second smallest lightest element). The extra mass from the two atoms to form the one larger atom is released as heat and radiation. A great deal of both.

That's what heats up the sun.

And, it is burning up its fuel. It just has so much of it that it takes a really really long time. The sun has used up a great deal of its hydrogen and has a great deal of helium from this reaction. In about another five billion years, it will use up all the hydrogen and start causing helium fusion which makes carbon. The sun will expand, out past where our planet is now, until it's used up all the helium, when it will throw off its outside layers and collapse into a little tiny star.

Fortunately, five billion years is quite a bit of time yet, so no nightmares.

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For Shakespeare: Why Two Arms?

Shakespeare asked: Why do we only have two arms, instead of 3 or 4, since that would make doing things easier?

Why indeed. Well let me preface my "answer" with a few comments. First, I don't know the answer. I can speculate, but I'm not a biologist and, if I were, my answers would likely be educated speculation anyway. Science has a few hard facts associated with it, but the answer to why questions are rarely among them.

Having said that, I'm going to tell you what I think is the answer to "why." Evolution, the development and adaptation of life over long periods of time to make the species we know today, depends on several things: environment that weeds out traits that are not optimal for survival and the originating species itself. Although the environment can force tremendous changes over time, the underlying species often retains key characteristics.

What struck me, when I began thinking of this, is that, though are untold animals that have more than four limbs (tails, I'll get to them in a minute), but I couldn't think of a single one that had a spine. Invertebrates (exoskeletons like bugs/spiders or squishy stuff like jellyfish/octopi) are far less restricted. However, when I think of vertebrates (birds, mammals, fish, reptiles, and amphibians), I realize there's a consistency: two forelimbs, two rear limbs, perhaps a tail.
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On birds, that becomes wings and feet. On mammals, the four limbs and, perhaps, a tail or the legs are melded together into a tail and the arms are flippers (like dolphins). Limbs for reptiles and amphibians (though sometimes the limbs are more pronounced than others and sometimes they disappear like snakes). Fish with vertebrae fairly consistently have two main side fins and a tail - not a stretch to see a comparison to the two sets of limbs. But, even with the fish, you don't see six or seven arms on a fish with a spine.

So, my answer to why is that whatever first animals started out with spines, the ones that seeded our species and the rest of the vertabrae, apparently had four limbs. Perhaps that (those) vertabraed survived because the set of four limbs is so versatile, adapting admirably to water and air and land, even walking upright. But it could be a fluke, too, the luck of the draw. In Avatar, James Cameron played with a notion that the animals had an extra set of limbs between forelimbs and hind limbs. The flying creatures had two sets of wings instead of one (and still had fore/hind limbs). Only the N'avi didn't.

But, would the extra arms really be that useful? Would they be just like the other arms only below them on the ribs? If so, you couldn't move them like your top arms - there's no place to put a shoulder joint, or, in fact, any stable bone structure (like a collar bone) to tie to. The ribs, the only bones through there, attach to the spine in one place. You'd have to have muscles there, too, where there aren't any now and it wouldn't be able to move like a regular arm, probably only restricted to two directions for the joint (like legs attach to the hips). That means you could move them forward and backward, but probably not up and down. Pretty limited.

Any way, I wouldn't take anything I've said here as gospel (ha ha!), but that's my two cents on why we only have two arms instead of three or four.

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For Soubriquet: Reconciling the Mystical and Science

Soubriquet asked: How does a rocket-scientist reconcile Science with Tarot and Palmistry, and other mystical phenomena? It's a serious question. Do you believe that tarot cards can predict the future, that a person's fate is written in the lines of their palm?

I think it's an excellent question (though I've touched on it before). I actually thought I could do some searches and provide examples, but I probably didn't label it well. I rarely do.

What I've said before, and I hold by this, is that there is no conflict for me.

I understand and accept that data and facts are required, as well as rigid adherence to the scientific process, for something to be scientifically valid, to be science, whether it's a "fact" or a theory (which is subject to challenge). Reality is not forgiving and doesn't give partial credit. When someone says they "believe" something will be strong enough or powerful enough or reliable enough for human lives to depend on, they better have the data to back it or I'll be asking some hard questions and, on a few occasions, providing a formal protest.

But I'm also a living breathing person with imagination and feelings and all that goes with it. I dream. I envision. And I don't disbelieve in anything that can't be readily disproven.

Does that conflict with my scientist persona? Absolutely not! Why would it? The world is a fascinating and amazing thing. People do things no one could imagine. I'd be twenty times the fool thinking I know so much that, if I can't explain it or prove it, it can't be. I'm not that arrogant. And most of the good scientists I know are equally slow to discount something out of hand.

Some of the mystical things I believe, some I don't. But I don't disbelieve any of them. I, personally, believe in reincarnation and the potential for psychic power - or magic if you prefer -, a higher power or deity, souls and magic. I don't personally believe in heaven or hell, Satan, demonic possession or Santa Claus. I don't take the Bible as a literal translation of anything but the words of other people (and even that is doubtful). I don't believe in anything that argues treating others with hatred and fear.

I don't insist or expect anyone to share my beliefs. I'm perfectly satisfied with my beliefs as they are and, in fact, will discard one if it can be disproven. I don't discount the possibility that things I don't believe in to be true; I just don't personally believe they are. However, in either case, my beliefs and my what I don't believe, neither is fact and I'm careful not to let what I believe put myself and others at risk. I don't confuse it with science. Why would I?

I believe my children are wonderful. I love them dearly. Neither of those are scientifically derived, yet they are both true. By which example, I can demonstrate that what we have accepted as science does not encompass all that is true. I don't know what else is true.

Now, I don't hold with things that are demonstrably false and, therefore, potentially dangerous, such as anti-vaccine nonsense or that people have no appreciable effect on the climate. Others aren't potentially dangerous, like the lunatics who believe we never landed on the moon, but I don't see any reason to pander to them either.

The mystic, however, can neither be proven or disproven. I am an advocate of freedom of religion and/or belief as long as those beliefs harm no one else. I have frequently (but don't remember to on every post) encouraged people not to take tarot readings too seriously. Do I think they truly tell the future? Well, I don't know. I discount the possibility. It could be that, at best, you see what you already knew to be true in the cards whatever turns up. It could be more than that. Originally, I didn't think they could do anything. Now I'm not so sure. I do believe people can understand each other, communicate on some unexpected wavelength that allows one person to discern truths a person has not even acknowledged themselves, but I believe it comes the questioner. But it's a belief, not science, and I've never tested it and would never recommend anyone build their lives based on what a tarot reading told them.

People who refuse to have their children treated for treatable illnesses, like diabetes, I have no respect for. Pray all you want, have whoever you want put their hands on her, try any non-dangerous mystic cure you care to - but don't fail to take advantage of modern science while you're at it. If my child were in danger, I wouldn't turn my back on any solution that could help (as long as it did no harm).

Apparently, many people have a hard time with separating the two. I have to admit, that just confuses me. My openness to what hasn't been proven or disproven, I consider part and parcel with being a scientist. Many a great scientist was also a great mystic or deeply religious. After all, part of being a scientist is admitting what you don't know...

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For Sparkle: What's Really Out There?

Sparkle said: So i have a few questions most i dont think you will be able to answer since no one really has an answer which is why they trouble me so much but i just want your opinion on the matters. Sorry if my writing isnt very good im use to texting so not very good punctuation. Anyway i havent had the chance to read books from great minds like Newton or Einstein but i have read up alot of others summaries and comments about them but im fascinated with things like gravity,light, and the size of the universe along with how it works. Hmm how should i start off...

Might as well start out with the best i suppose. What do you think about white holes and about the chance that our universe isnt the only one. I mean how can we know for sure yet or ever know that there arent other universes at there other small condensed matter waiting to become a universe like ours and if so where and what kind of area are those other universes in is their time different than ours? Im sorry i know im asking unanswerable questions but like i said i just want your view on the matter. I will ask more questions based on your response to this one :) [sic]

Well, Sparkle, that's quite the question. Like many of the questions I get, I'll give you a short answer first: I don't know. That's people like me do for questions where the answer is, at best, speculative.

See, there's a great deal out there in the wide wide universe that doesn't fit neatly into the world was we understand it, which is incompletely. Models, particularly when delving into the world of quantum physics, only work part of the time or for part of the range or sometimes give different answers than, sigh, reality under certain circumstances. And there are still disconnects between what quantum particles (really really small things) and regular-sized stuff do that many a scientist has scratched his head over.

That's where theoretical physics come into it. Scientists try to devise explanations for what doesn't fit in with the physics as we know it, but does fit in what we can see. And, in science, reality trumps theory. In other words, if scientists think the world runs a certain way but reality demonstrates that's not true, science has to change because reality won't. These scientists come up with hypotheses to explain reality and then test it against what we can measure. Hypotheses that seem to fit with reality become theories. Hypotheses that fail get tossed during peer review. A single fact can kill a theory.

But these aren't theories like evolution and plate tectonics, which are well grounded, demonstrable and have literally piles of data to support them. Those are theories that give every indication of being fact, with only a few details still being bandied about. No, when we get into theoretical physics, we're getting more into speculative physics where the data is so sparse and limited that the hypotheses and theories that emerge sound like fantasy. Proving any of these theories might be hundreds of years in the future.

Some of the theories involve things like multiverses (as you mentioned), black or white holes, string theory, dark matter, gravitons, tachyons, in fact, many different ideas to explain what otherwise wouldn't be explainable. None can be proven. Many can't be disproven. So far, though, none of them explain everything, just some stuff here and some stuff there.

But there are a few things to remember. The first is that our ability to detect what we need to find the answers might be very limited. 100 years from now, the data we have might be lightyears beyond what we have today.

Secondly, just because these are the only explanations we've thought of doesn't mean that they are the only ones out there. Reality has thrown us a few curve balls.

So I don't know what's out there. But I don't disbelieve anything until proven impossible. Are there white holes and universes you can fit in your pocket? Are there multiverses and wormholes and tachyons flying through us as we speak? Possibly.

If you limit your disbelief to what can be readily disproven, your mind won't be closed to all the wonders that lie before you.

I like to keep an open mind, but not so open my brains fall out.
-- Arthur Sulzberger

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For Kathy: A Rainbow of Explanations

Kathy said: Yesterday a friend and I were admiring some beautiful clouds on a perfectly sunny and lovely day. We noticed that one very large, oblong cloud was surrounded by not one, but two rainbows. It hadn't rained a drop all day. How is this phenomenon possible without rain?

Such a good question and so many cool things to say and show you. Most people know that rainbows are the refraction of light through water droplets (like rain) in the sky with the water droplet acting like a prism. The full spectrum being seen is a result of seeing light reflected in many water droplets as an individual watching could only see the light refracted at a particular wavelength through a particular droplet. Wikipedia (damn, I love that site) has an excellent write-up of the physics/optics of it as well as some slick pictures.

Here's a key factor: droplets don't have to be falling on you for them to be seen. In fact, if you're standing in the sun and looking on rain in the distance, you stand a much better chance of seeing one. Rainbows can be caused by seaspray (or other water spray), dew, and other mists, basically any water droplets in the atmosphere. Some other cool things about rainbows I gleaned looking into it was that the light below the primary rainbow is lighter than just above it. Look at the picture below and you'll see what I'm talking about.

By Eric Rolph taken at Wrangell-St. Elias National Park, Alaska

You can see the lovely arc of the primary and, above it, the dim vision of the secondary. Notice it's not raining. The Wikipedia link shows rainbows on seaspray and in the spray of a geyser

However, there are other cool types of rainbows even than these like moonbows, rainbows from the light of the moon. How cool is that. Here's a picture.

Photo of a Lunar Rainbow taken from the Zambia side of Victoria Falls. The constellation Orion is visible behind the top of the moonbow. Taken by Calvin Bradshaw.

And there are more cool phenomena, including apparent rainbows in the ice crystals of cirrus clouds like this little lovely. It's called a circumhorizontal arch and there are some cool pictures here, too. And a real stunner taken over Idaho here.

Circumhorizontal arc, photographed in Idaho, June 3, 2006, by Gavin Anderson

So, hope that helped. It's cool stuff.

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