Thursday, December 18, 2014

Black Hole --Rabbits have commandeered this post!--

Weeee! We finally got a hold of the computer! Hmm, what to post? It looks like the dog was going to write about black holes? Haha, how funny! Black holes aren't real, are they? Silly dog. We should play Parcheesi! Or, even better, make up rules on how black holes work. Won't that be fun?

Hmm, so we don't know what black holes are, so we'll have to make them up. Think of a black hole like a cartoon hole that you can place anywhere:
https://www.youtube.com/watch?v=_PYPfJyIFrA
This is what a black hole is, a small flat portable hole you can carry in your pocket. Dashedly useful for when your caught cheating in Parcheesi, wot wot?

*All right, bunnies go back to your game! Silly wabbits!*

*Ahem* As I was saying, black holes are nothing at all like that. They have to do with gravity, and are often super massive. What's more, they wouldn't fit in your pocket. :P  A black hole is a region of space-time where gravity is so strong that nothing, not even light can escape. As a special treat, I've invited Shadow, a small black cat with extra-ordinary knowledge of black holes, to share what he knows.

Good Morning everyone. My name is Shadow. I've spent a lot of time traveling with Schwarzschild the mouse. He first introduced me to the theory of wormholes and black holes. Since then, I have been investigating in my own quiet way, the subject of black holes. As Sheepdog stated, they have a massive gravitational pull, which sucks everything around it into its center. The point where objects first begin to be pulled, and cannot escape is called the event horizon. Remember that term, I'll use it later. Anyways, this theory was first considered in the 18th century by a pair of outrageous squirrels by the name of Michell and Laplace. Their work was expanded by my friend the mouse. He really is quite bright! Black holes are what I call an observable enigma, they actually exist according to our top scientists. For example, they theorize a super-massive black hole is at the center of our galaxy, keeping all the stars rotating around it in orbit. Another fascinating feature of black holes, is even though they are by all accounts invisible, any particles including light will accelerate as they approach the black hole, giving off a blinding light until they are swallowed up. This light surrounding the black hole is perhaps the brightest objects in the universe. The center of a black hole, also called the singularity is theorized to have infinite density. Any object sucked in is compressed, and added to the total mass of the black hole. Black holes can be formed through the collapse of a star, or other giant object. Once formed, black holes were originally though to last indefinitely. 

However, a recent discovery by a very intelligent hawk by the name of Stephan showed that black holes emit a kind of radiation. In short, it releases certain particles while gobbling up all other particles. If the black hole has not other particles to swallow, it will eventually release enough hawking particles that it will evaporate. A small black hole the size of a car would evaporate in an instant due to this radiation. A black hole the size of a star would take significantly longer. 

Thanks Shadow. Sorry about the rabbits...

No worries. If the lesson is over for the day, I may go join them actually. A cup of cocoa sounds pretty good. 

 

Wormholes (A big adventure for a small mouse)

Happy Thursday everyone!

Today we will be taking a look at wormholes (continuing discussion from our dimensions). Now currently we know nothing about wormholes except what we have seen from star trek. :P After some poking around however, I found a pair of experts on the subject; EinsteinTail, and RosenEar, a pair of white mice. They have started a science club which meets on the great golden bridge every 5th Tuesday. A smarter pair of mice you have never seen. They even managed to beat the rabbits at Parcheesi last night! And as any observer will tell you, rabbit-Parcheesi with its Calvin-ball-rules and card swapping is no easy feat. Through these lengthy discussions at the golden gate bridge (sometimes lasting for hours at a time) led to the discovery of wormholes, or is as formally known by the club: the Einstein-Rosen Bridge.

This time I traveled to the golden gate bridge to talk to these two mice, and decided to meet with their club a few days ago. They lost me in their debating and endless chattering, but the cheese buffet was delicious!

A wormhole, or Einstein-Rosen Bridge, is an unobserved hypothetical phenomenon that is basically a tunnel or shortcut from one location to another. Picture a 2-dimensional world, where the observer can only see in 2 dimensions. a wormhole would be a 3-dimensional tunnel from one spot to another. To the observer, an object would seem to disappear from sight, then re-appear in another location entirely. Now picture this in our world, only the tunnel would have a sphere as the opening, pull the object out of our 3-dimensional space, and into a different dimensional space where the distance from any one point to any other point could easily be much shorter. This is what a wormhole is. Although one has never been observed, the math behind these wormholes is sound, and many thought-experiments have developed. A senior mouse of the club, Schwarz, would often begin these thought-experiements, which included lots of paper, hard thinking, and plenty of erasers. Sadly, he was unable to come up with anything helpful. His child, a very tiny mouse, was perhaps the first to to discover a solution to a wormhole problem. He hypothesized that a wormhole in the center of a black hole meets the required properties to exist without violating natural law. A black hole has the densest matter in the universe. This gravitational pull could create, then collapse a wormhole in such a way that the entrance to the wormhole and the exit to the wormhole are in exactly the same spot. If you can picture that, imagine that because one can observe particles entering the black hole from either side, one must be able (potentially) to see them exit either side. Thus, the black hole has two sides if you will, one for the entrance of the wormhole, and one for the exit of the wormhole. These would enter and exit in to locations, or possibly in two universes. Needless to say, the small mouse was immediately praised and given a cup of hot chocolate for his efforts. Upon further examination the club discovered that such a phenomenon would almost immediately collapse in on itself. But it gave opened the door for traversable wormholes which were discussed during a very cold winter when the mice lit their fire. 

It was a cold day, and the mice lit a small fire for the first time that season. They noticed that there were still 2 logs left over from last year. While the small mice began to build the fire, two older mice, known as Thorne and Morris, began theorizing about a wormhole allowing space and time travel. They wondered if the two logs represented a stable wormhole (which they conceded is impossible without some form of undiscovered exotic negative-energy), then the wormhole would start and finish at the same time in the fireplace. However, if the wormhole were created, and the 2nd log was placed in a spaceship, sent to mars and back, then by the laws of time dilation, the 2nd log would have aged 1 minute less than the 1st log which had stayed in the fireplace the whole time. Therefore, by jumping through the wormhole from the 2nd log, they would likely have traveled back in time by 1 minute. They then extended the analogy to a close-to-light-speed travel by the 2nd log. Suppose they were able to accelerate it much faster. Why then, there might be a 2 year difference between the two. While they could not travel back in time further than the creation of the wormhole, they could certainly travel back to the time it was created. Very please with themselves, they forgot all about the fire, and began eating the cheese plate because they were so hungry from all their hard thinking. 

The group as a whole, with their fire finally lit, began talking about the possibility of wormholes which existed in space for hundreds of years. If such a stable wormhole already existed, why it was possible to travel to a fixed point in the past, whenever the other end of the wormhole was created, or any time between depending on the speed and trip the second portal may have taken since it's creation. Their small group gradually grew as more mice began coming to this small meeting, including Deutsch and Raychaudhuri, both mice from Harvard, who added their ideas to the masses. 
 Schwarzs' Child didn't come often after that. It was soon noticed that he had disappeared, and the club believed that he, getting tired of endless talk, went out and found a wormhole on his own and may be anywhere in the universe by now...


*squeak squeak*
 

Wednesday, December 17, 2014

Relativity

Albert Einstein is most well known for his general theory of relativity. Today we are going to tackle as best we can, this theory of relativity. To do this, we have phoned in the best source we could find: Chico the 7th. Chico was Einstein's dog. Although Chico disliked Einsteins work, (and would frequently bite the mailman in efforts to cut off Einsteins correspondence) he nevertheless learned quite a bit from his master. This knowledge of relativity (in dog lingo) he passed down to his offspring. Chico the 7th has had no formal college training, but has attended several lectures on the subject, and has been working on a theory of why cats are so annoying (corollary, why cats' bones tend to disappear when they sleep). But I digress.

Chico, it's good to hear from you. What can you tell us about all this relativity nonsense?
Well, it's not nonsense, if you go in for this sort of thing. :) Now lets see, where to begin. The theory of relativity has been around since before Einstein. He just improved it. Simply put, any law of nature should be the same at all times, that is, any person observing a tree falling will see just that, a tree falling. To this we will add the dimension of time. Suppose one sees a tree falling, and then 5 minutes later, another person sees a different tree falling in the same way. By comparing these two instances, we can record and observe the results, and begin to calculate the energy involved. It is in this way scientists can make testable predictions on the laws. 
Okay, I can picture that. I spend a lot of time outside and around trees. :)
Now lets look at the theory of general relativity. Einstein did most of his most famous work with the general (and special) theory of relativity. The theory of special relativity states that these laws of physics (like the tree falling) should be the same in every inertial frame of reference.
What's that mean?
It means assuming where you are standing is a non-moving entity. Technically, you would be standing in a forest, on earth. Now the earth is moving around the sun, but for our purposes, we assume the earth is standing still in reference to the tree. So, special relativity states that the laws must remain the same (the tree will fall toward the earth and emit a loud THWUMP). This allows special cases, like a non-inertial frame of reference to have a different set of laws. For example, the light from a distant star is traveling at the speed of light. How can we still see it? Because even though we seem to be standing still, the earth is traveling pretty fast, the sun is moving about our galaxy, and the light is traveling not away or across the earth, but directly towards the earth. So, we can see particles traveling at the speed of light. 
You're very smart for a dog, did you know that?
Thanks fluffy. Like I said, I attended a few lectures, and the subject fascinates me. As I was saying, the theory of special relativity allows for special cases to be made. Now then, in special cases, physics professors would historically attack the problem (*gobble snarf*) using a coordinate transformation, first to an inertial reference frame (back to our tree problem), calculate it, and move it back to the special case (absolute inertia). Our star problem above would be a little more difficult. But since it would use strictly non-inertial reference frames, it is not constricted to our regular laws of nature. 
Thanks...I think. Now lets move on to the question we have been dying to ask. According to Einstein, is time travel and faster-than-light travel possible?
This is a question I am often asked. This question deals with a branch of relativity called time dilation. Time dilation has been proven and tested with astronauts and the ISS. Time dilation, simply put, is an actual difference of elapsed time between two separate events relative to gravitational pull. A dog on earth with a pocket watch, and a dog in space with the same pocket watch may observe that after a day apart, their watches would be about 42 minutes off from one another. This is not due to a mechanical failure of the watch, rather the nature of space time itself. Here's another example: place a cat in a spaceship for a little over 2 months. Place another cat on earth. At the end of the time period, the cat on earth will have waited spent 81 days watching tv and taking naps. The cat in space will have only spent 80 days watching tv and taking naps. This 1 day difference is due to the space time/gravitational difference between earth and the first layer of space around our planet. furthermore, the further away from gravity you go, the slower time will appear to pass for you. The same theory holds true for velocity. The faster you are going, the slower time will pass for you. The ISS space station, for example, is moving much faster than most of our commutes to work. They are also further away from the gravitational pull of the earth. They age more slowly, (e.g. 0.007 seconds less than we do for every 6 months they are in space). The difference isn't earth shattering, but it is a marked change.
I see. So you can alter the speed you travel through time using speed, and force.
That is correct. Some scientists theorize that if you are able to move fast enough (many times the speed of light), then time will slow to a crawl, then a stop, then move backwards. At a practical level, scientists hope one day to create a strong enough propulsion system to send humans to the far reaches of the galaxy without the dramatic aging. A human may travel 8 years in space, but for them, only 1 year may have passed. Likewise, you can also travel very slowly in space, and near a dense object with a heavy gravitational pull. This would speed up your clock, and slow everyone else clock. For example, if you traveled to the center of the earth, you may emerge having spent 5  years there, only to find the earth has only spent 1 year. However, the effect of reversing it becomes a much more difficult problem to solve. 
So you cannot travel backward in time?
According to our current understanding of time dilation, we can travel forward into the future, but cannot travel backwards. We have proved that traveling ahead is possible, we just lack the technology to jump forward years or decades. Einstein also proposed a universal speed limit on the universe. He believes the speed of light is the fastest possible particle. In other words, the star trek enterprise would be stuck at warp 1. :(
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Tuesday, December 16, 2014

Diminsions in Time and Space

Dimensions can be disputed, both how many they are, what each one is, and how they apply to our lives. A physics professor may disagree with a math professor on the details of the number and explanation of each dimension, which we will get to in a little while. Just to see what will happen, we have invited one of each to attend today's lecture:

I will begin with my rudimentary definitions of dimension:

1st Dimension: a point or line. The point or line has no width, or thickness, and can only exist in one direction.

2nd Dimension: Think about area. the second dimension is like a square or circle; flat, but with 2 directions: width and length. Circles, squares, basic shapes, and even complex shapes can all be 2 dimensional.

3rd Dimension: Now think about volume: cubes, spheres, swimming pools all have 3 directions: width, length, and height. Most of what we interact with on a daily basis is 3 dimensional. Actually, even a piece of paper has 3 dimensions, it is just very thin.

4rth Dimension: Although this can be disputed, Time is the generally accepted 4rth dimension. While time is not a spatial dimension, it can interact with the previous 3 dimensions. Water for example, when placed in a freezer will turn to ice. Was it always ice? As it progresses through time, it will change depending on its environment.

Our mathematician however, loves to complicate things: (and he loves graph paper)

     The dimension of a mathematical object is informally defined as the minimum number of coordinates needed to specify any point within it.
Huh? Lets ask him more slowly to define this:
     When drawing any object on a set of axis (graph paper), if you can refer to a point in your object using a single coordinate (such as 1,2) then the object is in the 1st dimension. Any object which requires 2 coordinates, will be in the 2nd dimension. A box for example, has area, and would need at least 2 points to define it. A sphere, would need 3 points to define it. And so on and so forth. 
Ahh, that makes a little more sense. This sounds very much like our informal definition above. Oh wait, I don't think he's done:
     However, there are strange cases of objects like a unit circle, which are 2 dimensional, but can be defined as being 1 dimensional! A point in a unit circle can be specified by two coordinates, but on a polar (circle graph) you only need one polor coordinate! Thus, it exists in 1 and 2 dimensional space.
 Hmm, I didn't know that. Oh, he's still talking:
     In vector analysis/matrices mathematics there can be many more than 4 dimensions. While these dimensions do not exist as we see, and they do not even define nth dimensional objects, they are used simply to compare points, figures, and sets to one another. 
Okay, I think he lost me in there somewhere...
     Fractal dimension is another example of a unique set of mathematics. Fractal dimension implies some objects may be between dimensions. For example, the perimeter of the Koch Snowflake we examined a month or two ago. The perimeter is a line, which by our definition, is 1 dimensional. However, that line weaves and swerves, and continues expanding indefinitely. This is too complex to be 1 dimensional, and yet has no area like a 2 dimensional object should have. Fractal dimensions have been put to use to define these unique case.
Ack! Okay, lets move on to the physist's, maybe he'll have some straight answers for us. Oh good, our physist is much more practical about all this: well for the time being anyway. 
     There are 3 dimensions which are clearly defined. The first dimension is a point or line, the second has area, the third has volume. Time is often referred to as the 4rth dimension, but is viewed as different in nature to the first 3.  We can *currently* only move through time in one direction.
He agrees with our basic definitions, and will consent that time is often referred to as the 4rth dimension. He can observe things changing over time, has no problem with this. 
He then launched into a 45 minute lecture about string theory and superstring theory, which involved 10 spacetime dimensions. Basically speaking, each new dimension is another force acting on our object. Gravity, for example can be a dimension, or the sun pulling on the planets, or the galaxy pulling on our solar system. This is a very rough introduction, but it led to a 90 minute argument between the mathematician, and our physicist. In the end, they both stormed out, but not before eating all the snacks. :P





Thursday, December 4, 2014

Cold and Wet (Brrrrrr)

Woof woof!
Good Morning everyone. I apologize for not posting last week, I admit I took a week off to enjoy stuffing, pies, Turkey, and all those wonderful things. Yessiree, it was a week to be thankful for! We began our week with some Holiday baking, (this included flour fights with the bunnies of course! Our masters weren't too happy, but it was fun!). However, they were both in good moods, having all of Thursday off work to enjoy our company, and family of course. We took a car trip to visit family, and had an awesome thanksgiving dinner! There was cranberry sauce, fresh crecent rolls, orange salad, stuffing, mashed potatoes, and of course a large Turkey! Then afterwords, we played some games, enjoyed 3 kinds of pie, chocolate bars, and ice cream! It was a great night.

The next morning however...
One of my masters went out Black Friday shopping at O-Dark Thirty. I crawled into bed and took his spot. :) He seemed to have good luck though, and came home with plenty of bags to stimulate the economy with. It was fun seeing what all he picked out, and I'm excited for Christmas! By Sunday, both masters were ready to start off the Christmas season with a bang. They decorated the place and played Christmas tunes all day. I jumped up on the couch to stay out of their way. They have been slowly adding decorations this week, and may put up the outside lights this weekend. Oh! And last night the bunnies and I made banana bread, and chocolate covered rice crispie balls.

Say...anyone up for a Christmas party? :D