in the interim

No real post tonight. I'm getting ready for school. Oh that was fun to say. But I shall report the happenings of our class back to you and I might even get some of my classmates in on it. Oh I'm so excited! In the meantime here have an lolcat...err...loltiger!

General Relativity

Ok so I’m getting the general sense that I’m in over my head, with this stuff. But I have terrific news! I’ve been enrolled in a cosmology class! Imagine me an old man in a class with a bunch of young college students. But I hope to learn so much! And I shall report it all to you. But I think I need to finish up this discussion of time and metrics first. So when Minkowski came up with his space time, Einstein had a new setting for trying to figure out gravity. So what he decided (and it took him quite some time to figure it out too) he decided that gravity warped space, it sort of bends the metric. Where there was a straight line now that line has been bent by the object that has been placed there. Just like in the picture. This is what creates gravity. This is why we feel pulled towards the sun. We aren’t actually pulled towards the sun we are falling into it. And that is the basis of general relativity.

Metrics 2

So the first spacetime I would like to talk about is the Minkowski spacetime. It was first invented by the German mathematician Hermann Minkowski soon after Einstein came out with special relativity. Minkowski came up with it to supplement Einstein’s theory. It’s a 4D space consisting of 3 spatial dimensions and 1 time dimensions. A lot of rules that we are used to in 3D space apply but there are some differences. And they are very important differences. But the problem is that these difference only make sense if you know a good deal of linear algebra and differential equations and in all honesty I don’t understand all of it. So I’m not really sure who to proceed from here. I guess to make it very simple when you take a 4D vector in Minkowski space and multiply or add it to another one it doesn’t work the same way as another sort of space. It sorta has magic math. I know, that sounded stupid. Oh well. I guess that’s all I can say…like I said I don’t really understand it either so, yeah.

Metrics

There are more relationships like this one but I won’t take the time to explain them all…mainly cause I don’t really understand them all/don’t care that much. Let’s move on to bigger and better things, The Metric. Now we know about the metric system, right? You know that thing that America reuses to use with meters and kilometers? Well that is a metric of sorts. In math a metric is a sort of…well it’s like Middle Earth. It a place that has its own set of rules and laws. You can do magic there. And there are elves. It’s a lot different from here. And that’s what a metric is. It’s a space that exists outside our own, like scifi, with its own set of rules and laws and things like that. So for LOTR we would call it Tolkien’s metric. Other metrics you might be familiar with include Rowling’s metric (Harry Potter), Roddenberry’s metric (Star Trek) and the Blizzard Entertainment metric (WOW). Some which you may not be familiar with but which we will be using include the Riemannian metric, the Euclidian metric and the Minkowski metric. And we will talk more about those tomorrow.

Time 10 warning math included (but it's not that bad)

So now we get to deal with the classic sci-fi topic of causality. Now let’s pick two events and since we are dealing with sci-fi and I recently watched the movie I pick wolverine and deadpool causing the meltdown of the three-mile island reactor. Ok, I know that didn’t really happen but let’s say it did. So we have two distinct events wolverine fighting deadpool (we’ll say the instant that they start fighting) and the reactor meltdown (we’ll say they instant that the people monitoring it call the military). Now these two events are separated by a time-like interval. Because we know this and that one event causes the other, we know the above equation applies. What it says is that the square of the spatial distance between the events must be less than the speed of light multiplied by the time between the two events. The second equation therefore says that the spacetime interval (or ‘distance) between the two events must be greater than zero. All this says if that if the instant wolverine took a step forward to fight deadpool a light sensitive trigger went off, tripping, by electrical signal the phone that was to call the military it would take at least as much time as a beam of light to be shot from the warehouse opening to the phone. I know it really doesn’t tell you anything important does it. Well I suppose the most important thing is that wolverine won.

GOD! ?

ok so i continued reading the wikipedia article on spacetime and i am currently feeling like penny in the presents of sheldon. so i'm gonna try again tomorrow night. but in the mean time have some pictures of god, gods and the like. the last one is called a flower for god if that helps.

Time 9 warning math included

Ok I ended up not seeing him today but when I do see him I’ll get back with you on that stuff. So everyone know that the shortest distance between two points in space is a straight line. In math that straight line is designated the distance between the two objects and we use a lovely little formula to derive it which I’ve included in figure one it’s the first equation, it’s sort of the extension of the Pythagorean theorem(I’m really gonna have to find another way to write equations in there, any ideas???) but in space time this equations changes to the second equation where c is the speed of light and t is time. I think since this post has some math in in…as will most the consecutive posts on time, I’ll make it a little shorter and go at a slower rate.

Time 8

Wow. Yesterday’s post was really long wasn’t it? Sorry. Anyway so hopefully today we can start getting at some of the detail’s of time and in particular the physical approach used by most physicist today with regard to time. In other words, spacetime. Ok first some vocabulary. A worldline is a path or line type thing in 4-D space that specifies the path of an object. I’ve included a picture that is much like the one from yesterday but has a worldline mapped out on it, the one of your hoverboard perhaps. If it is a ‘straight’ line, unlike the one in the picture, it is sometimes called a geodesic. And now for the units physicists use when talking about spacetime. Oh…wait…I don’t think I really understand these. I know we express velocities as a percentage of the speed of light. But even that doesn’t really make sense. But you know what I think I’ll be visiting one of my professor friends tomorrow and I’ll ask about that and report back.

Time 7

Before Einstein and the theory of relativity time was considered the one constant in the universe. It was absolute and everybody measured it the same way. So when Newton used the analogy of a giant clock for the universe, he met a very accurate consistent clock. But with Einstein that is not so. For Einstein the thing that is the same for everyone is the speed of light. It doesn’t matter where you are (save perhaps parallel universes or something like that) or how fast you are going if you measure the speed of light it is always the same. And now I would like to spend a few days on spacetime. We’ve already went over that briefly in past posts but I would like to go a bit more in depth. And we shall start with the horrible little picture I’ve included. It’s a 2-D picture that looks like it’s in 3-D and represents a 4-D phenomena. It starts by locating your point in space. That’s the arrow that points to the origin and says observer. Now let’s say on this hypersphere of the present, the observer arrow happens to find you in a very dark place for example a very large cavern. A very large cavern. And let’s say you have a flashlight. Now if you were to stand in that one spot and turn your flashlight on then you would produce a cone of light not unlike the one in the picture. You like would be moving away from your location in the hypersphere of the present as fast as is physically possible, and any action you do, say hop on your super-jet-powered-hoverboard and follow your flashlight’s light, would have to take place inside that cone of light. Now, but what does this tell us about you or more importantly how you are going to get out of the cavern in time to see tomorrows football game? Nothing it tells you nothing. That’s why it’s a horrible little graph. But it is a good way to think about the present and the past and the future and to incorporate time into the picture.

Time 6

The trick to measuring time is to find something repetitive that always takes the same amount of time. We just guessed at first. we said hey I think that the sun is there for the same amount of time each day so we used that to tell time with. Of course it wasn’t’. then we used the stars. And of course they weren’t quite right either, now the second is defined by the radiation emitted by caesium atoms. Which in another hundred years or so we will discover is not quite right either. To be more precise Now the SI (the people who define these sorts of things) has declared that a second is 9,192,631,770…well let me explain exactly what the periodic thing that caesium does is. Ok first you have all the electrons right? And they are in their little orbital. Have I ever explained about spin? Well it’s a property of electrons and protons and stuff BUT they don’t really spin. This confused me for a long time. Anyway electrons only have two ‘spins’. They can either spin up or spin down. And if you take a ceasium atom and look at the electrons on its lowest energy level you will it (they?) flip spin in a very period way. In fact 9,192,631,770 flips occur in our traditional second. So now this is what we use to define a second.

lolcat!

so i have bronchitis...which won't be so bad except that i am apparently allergic to antibiotic they gave me (you would think that wouldn't happen to an alchemist who specialized in medicine). anyway no real post today. but here have an lolcat. i don't have time to explain this...it's about quarks...but they're really cute so it's ok.

Time 5

As much as I don’t like philosophers I think it might be helpful to hear what they have to say about the subject. The first view is that time is a real tangible thing that is part of the fundamental structure of the universe. It’s pictured like a film strip where each cell is a moment and if you string all the cells together they form the reality that we are used to. So basically time makes up just another dimension. This is the point of view that physics holds (or at least the majority of physicists).The second view says basically the opposite thing, that time is not a physical think and can’t really be measured. Instead, it says that time is part of a fundamental intellectual structure that humans operate out of. To dumb this view-point down, it’s all in our heads. If I were to come to any conclusions on this one I would side with the physicists. But I do think there is something big we must be missing in the nature of time. Whenever I’m looking at something I can’t figure out it’s usually because I’m not looking at it in the right way. Unusually if I look at it from a different perspective then I can see the answer right away. I’m hoping this is the case with time. We’re just not looking at it from the right perspective. Once we figure out how to look at it, what it is will become clear.

Time 4

100th post!!!!

If you hadn’t noticed, the pop physics excerpt played in with our current theme, time. Now we’ll take a more fundamental look at it. What is time? According to Wikipedia,

“Time is part of the measuring system used to sequence events, to compare the durations of events and the intervals between them, and to quantify the motions of objects.”

The first definition (of 19) that Merriam-Webster is the same as Wikipedia’s. In other words it’s a really really hard thing to define. If I were to be asked to give a definition of it I would be a smart-ass and something like time is velocity times distance. But of course I can’t do that because in physics time is considered a fundamental unit from which we derive all other units, such as force or speed. Physics has 7 fundamental units: kilogram, meter, candela, second, ampere, kelvin, and mole. These correspond to mass, length, luminosity, time, current, temperature and a specific (6.22X10^23) number of atoms/molecules of something. All other units and quantities in physics can be broken down into a combination of these units.

Pop physics

You remember the pop physics think I started to do, well here’s another one: The Space-Time Continuum! (insert sci-fi music here) Now this is strictly my interpretation and my spin on it, this isn’t necessarily accurate. I imagine space-time like a graph (I’ve included a homemade copy). At one end of the continuum we have light, which is the fastest thing in the universe and doesn’t experience time. And at the other end we have something that is not moving (relative to some universal standard, I’m not sure how one would get this…but oh well). The person who is not moving experiences time the quickest. For them time is much faster than it is here on earth and they would grow old faster and everything. But for someone near the other end of the line (near light) time is experienced very slowly and it would seem like earth is on fast forward. And that’s how it works. If you increase your speed, time slows down for you and if you decrease your speed your time speeds up. And now you know what to do to get time to speed up and snow down. But good luck increasing your speed by 20% the speed of light during a business meeting.

Time 3

Why do I know this? Well, believe it or not I’ve worked on a physics experiment before, not cosmology but still. It was a particle physics experiment. And I chiefly worked on electronics. But we had a problem (well we had a lot of problems but this was a big one). The timing was off. We were trying to synchronize the computer and the electronics, but they were off by a couple of milliseconds. We can’t (at least I can) imagine what a millisecond feels like. But it was a big problem. We were getting different amounts of data in different sets. This threw the whole experiment off. And it was just a matter of milliseconds. That is way all this crazy timing stuff in important, it’s really important. And I know for a fact that there are other experiments where the timing counts even more and even smaller. Nanoseconds matter, they really do!

Time 2

I say it is arbitrary because, like all other forms of measurement we define it. We say, ok here, this is a second. For a long time (far beyond what my lifetime should have been) everybody knew time was arbitrary. Only in big cities did anybody have any right to say their time was right. Most of us, myself included had no way of measuring the time outside of the church bells. I once knew a man who claimed that the Babylonians were far more intelligent about their time system and so he followed theirs. Instead of 24 parts he divided the day up into 60 and I daresay he was never on time for anything (even his own funeral, but don’t ask how that happened). But we had absolutely NO concept of what a second was. Now everybody knows what a second is. Oh don’t worry I’m not going to start lecturing; I’m old enough to know that nobody ever listens. In fact I do see a need for things to speed up. The definition of a second (and you know, I keep waiting for somebody to change the second and make time run on intervals of 10 just like meters and liters) may be arbitrary, but it is also very necessary. Physics, at very least, needs it.

Time 1

Hey! I’m not dead (yet). But like I said our internet got messed up and then we had more snow and it got even more messed up. But this time it took a while to fix it. Yes, I could have gone to the library, but hey what can I say, I’m old. Anyway my posting should be regular again. And I think I’ve found a new topic. That tangent I went on during the Randall series got me thinking about time again. It’s always been something I’d hoped to study so I checked out a book about it. It’s a book called “Faster” by James Gleick. It was in with the other science books but from what I’ve read there’s a lot besides science in it. For example in the first chapter he records his visit to the Directorate of Time. Yes, there is such a place and it’s part of the United States Government under the Department of Defense. They make time. Well, I should say they set it. They, along with the time input from other nations set the global time. They have this system of atomic clocks (don’t they have those in watches now?), and they consult each other and form a consensus and send that time to the global time … place, just outside of pairs, and then the input from other places comes in and they form a consensus and that’s the time. It’s amazingly arbitrary.

GOD! ?

sorry i didn't post yesterday there was a lot of snow the internet was in and out. well i'm done with Randall's maze so now you guys have got to tell me what you want me to talk about any suggestions. anybody? anybody at all???? in the meantime here are some more pictures. have fun!

Randall's maze rapup

Ok so after that pathetic excuse for a post yesterday let’s see if I can come up with something more intelligent to say today. And today’s topic is superstring theory. Oh boy. Ok so instead of particles looking like little pool balls we say they are tiny strings. And let’s say they can oscillate in different ways, just like a guitar (or for a more accurate analogy and a way cooler interment, the one stringed Chinese Duxianqin) to make different notes. Each of these notes turns into a different fundamental particle such as a quark or an electron. So superstring theory says that the whole world is made out of nothing but strings. If you think about it this way all the issues with bringing together quantum mechanics and general relativity, which is notoriously hard to do. Extra dimensions come in when you look at the math. The theory doesn’t really make sense if you only have 3 spatial dimensions but the math works out perfectly if you have for example, 10. This may sound like a crackpot theory but only time and some more investigation will be able to say.

Randall's maze rapup

And now for our second set of applications, Large extra dimensions and the Randall–Sundrum model. Both of these theories attempt to explain the weakness of gravity in comparison with the other forces, but I think I shall summarize them separately. So first let’s look at Large extra dimensions, which is apparently also known as the ADD model. It goes something like this: all the normal laws of the weak force, the strong force and electromagnetism only work in the normal 3 spatial dimensions. But gravity works in more than that I’m not sure how many but more. As for the Randall–Sundrum model, I haven’t the faintest clue what any of this means so I think I shall take the cheap way out and just quote Wikipedia. "In physics, Randall–Sundrum models (also called 5-dimensional warped geometry theory) imagine that the real world is a higher-dimensional Universe described by warped geometry. More concretely, our Universe is a five-dimensional anti de Sitter space and the elementary particles except for the graviton are localized on a (3 + 1)-dimensional brane or branes.” Yeah…I’ve got no clue what that means, but there you have it.

Randall's maze rapup

First Kaluza-Klein theory. There’s a lot of stuff I don’t understand at all but I will try to explain it best I can. It’s a theoretical model that Theodor Kaluza came up with in the early 20th century. It was meant to take the new model of gravity (Einstein’s general relativity rather than Newton’s model) and combine it with electromagnetism (electronic fields and magnetic fields and light and the like). Kaluza, who was German, figure that if you have 4 spatial dimensions you combine gravity and electromagnetism by looking at electric fields and magnetic fields differently. Just like gravity is curved in the 3 normal spatial dimensions, the fields are a result of curving in the extra dimension. I have no idea how this allows one to combine gravity and electromagnetism but whatever. People had some problems with this extra dimensions stuff and so along came the Swedish physicist Oskar Klein who said that we hadn’t know about the extra dimension was because it was very small and curled up really tight. This (then very ) weird theory fell out of favor but of course when string theory came along it was looked at again and is now seen as a sort of predecessor of string theory.

Randall's maze rapup

We’ve spent some time going though (to be painfully honest) the first chapter of Lisa Randall’s ‘Warped Passages.’ We’ve basically been talking about coordinate systems and how to conceptualize other dimensions. I looked over the rest of the book and it has some really good things to offer but I don’t have the time or energy to finish the book but I would like to go over some of her research and some ideas about more dimensions, so I think I shall be mostly consulting Wikipedia for most of my information. (oh by the way, my vacations over so I will hopefully be posting every day again.) So let’s take a looks. When consulting Wikipedia it aperies that there are 3 main ‘uses’ or applications for extra dimensions, Kaluza-Klein theory, Large extra dimensions and the Randall–Sundrum model (these apparently have to do with each other), and superstring theory. My next proposition is that we take a quick look at each of these applications and what they have to do with extra dimensions.

GOD! ?

here! have some more pictures and leave some comments!