An Explanation of why TIME TRAVEL does not work

by Terry 110 Replies latest jw friends

• 

  BurnTheShips

  An Explanation of why TIME TRAVEL does not work

  I prefer to not rule anything out. It limits the imagination, and that is where it all starts. It makes all other things possible.

  BTS
• 

  Razziel

  A reason energy can be difficult to understand is that it is not a natural unit of measure. Energy is a derived concept. It can be derived from the fundamental units of mass, length, time, charge and temperature, but it is not a base measure in itself.

  The reason energy definitions contain the concept of "doing" something, such as the ability to do work, is because that's what the human concept of energy is.

  There are two ways I can try to explain energy, the top-down approach and a bottom-up approach. I'll use the bottom-up here.

  The concept of energy arises from the four fundamental forces in nature.

  We know there are four fundamental forces in nature: gravity, electro-magnetism, and the strong and weak nuclear force. There are 3 things that can occur resulting in a difference in force. 1. The force can change strength over a spacial distance. 2. At any particular point in space, the force can change strength with respect to time. 3. Two or more forces can be present on the same point in space.

  If you've had calculus, you'll recognize quickly that energy is just the derivative of force strength with respect to position, time, another force, or even all three. For those who haven't had calculus, energy is the rate of change of force strength when position, time, or the strength of another force remain constant.

  So energy is a consequence of changing force strengths. It isn't something that exists by itself. That's why it's a concept and can be difficult to understand.

  Is energy the motion of particles? In most cases yes, the interactions of forces with time, distance, and each other generally cause energy to be seen in the form of particle movement or vibration. Not in all cases though. Electric charge and electron spin are two examples. (Spin is a misnomer because it doesn't mean an electron spinning on an axis at all.)

  There are generally two ways energy is quantified. The first is a measure in comparison to the surroundings or environment. The second is in comparison to some ground state where no forces are present.
• 

  OnTheWayOut

  I ain't no rocket surgeon, but I read an article in early February in the issue of Discover Magazine that was on the shelf (don't know which month was on the cover) that carefully showed that known laws of the universe made time travel impossible. It basically said that the only way it was possible is if everything that happens is rigid and unchangeable. In other words, if we will ever travel in time, we already did/will do it. Anything we did in the past is a permanent part of the past (from the first time around). There is no going back in time and shooting your grandfather before your father was born. If you didn't do it already, it never happened.

  So, you cannot go back and save Abe Lincoln or prevent Hiroshima. If anything, a time-traveler is part of why Lincoln got shot, or else it's a non-issue.
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  OnTheWayOut

  This is not the article that I read, but it contains most of the same elements to consider:

  http://blogs.discovermagazine.com/cosmicvariance/2009/05/14/rules-for-time-travelers/
• 

  cyberjesus

  So can we travel in time or not? I need to know so I plan ahead :-)
• 

  OnTheWayOut

  So can we travel in time or not? I need to know so I plan ahead :-)

  You are traveling forward in time everyday. Plan ahead. I know I have been sitting at a computer that's a time-machine. I sit down and start looking at JWN and POOF, several hours are gone.
• 

  Terry

  We know there are four fundamental forces in nature: gravity, electro-magnetism, and the strong and weak nuclear force. There are 3 things that can occur resulting in a difference in force. 1. The force can change strength over a spacial distance. 2. At any particular point in space, the force can change strength with respect to time. 3. Two or more forces can be present on the same point in space.

  If you've had calculus, you'll recognize quickly that energy is just the derivative of force strength with respect to position, time, another force, or even all three. For those who haven't had calculus, energy is the rate of change of force strength when position, time, or the strength of another forceremain constant.

  ______________________________________________________________________________________________________________

  The word "force" sneaks in there after/while you are derriving "energy". Force is another one of those dodgy terms that "seem" to mean whatever is necessary for it to mean. The definitions I've pondered over like to swap force and energy as terms without really getting down to how they differ.

  At least, in my sloppy attempts to differentiate them.

  What I'm saying is that I think these definitions are cheating a little. Or, is it just me?
• 

  Razziel

  Here's an example in less abstract concepts. What is velocity? It is simply how position changes with respect to time at a specified moment. For example your car speedometer reads mi/hr or km/hr. What is acceleration? It is how velocity changes with respect to time at a specified moment.

  Both velocity and acceleration are just rates of change of position with respect to time, and you can give a definition of each only describing each concept by how position is changing over time, without using the words velocity or acceleration at all.

  It's the same idea with energy. Energy is directly related to how force actively changes with respect to time, position, or another force, or has the potential to change with respect to these. Power is analagous to acceleration in the above example. It is how energy changes or is transferred with respect to time.

  If you asked a professor to explain velocity or acceleration they're going to talk about position because that's where those concepts come from. The same is true with energy, they're going to talk about force. The words aren't dodgy so much as a part of the jargon used in academics.
• 

  Rabbit

  And , then there's this:

  Quantum Physics Leaps Into The Visible World

  by Joe Palca

  March 19, 2010

  Listen to the Story

  All Things Considered

  Enlarge A. D. O’Connell / Nature

  A magnified view of the tiny hair-thin device, called a resonator, that scientists used to observe quantum mechanics in action. This is the first time that quantum properties have been recorded in anything larger than a bundle of atoms.

  A. D. O’Connell / Nature

  A magnified view of the tiny hair-thin device, called a resonator, that scientists used to observe quantum mechanics in action. This is the first time that quantum properties have been recorded in anything larger than a bundle of atoms.

  March 19, 2010

  Scientists in California have done something astounding. They've shown that physical laws thought only to rule in the mysterious realm of atoms and electrons can also apply to stuff you can actually see.

  Isaac Newton was pretty much right on in describing the physical laws of how objects in our world behave. But those laws break down when you get to the world of single atoms. So modern physicists came up with a new set of laws, called quantum mechanics, that does explain how things like atoms behave.

  Andrew Cleland of the University of California-Santa Barbara says some of the laws are ... well, the word "weird" comes to mind.

  "One of the most striking is quantum mechanics says that an object can be in two places at the same time. Or two configurations at the same time," he says.

  Cleland says at first, scientists thought the laws of quantum mechanics applied to objects on the atomic scale. Cleland says it's true — physicists have observed quantum effects in structures as large as 60 atoms. That's large for the atomic world, but totally invisible in our world.

  Cleland wanted to see if he could find the size where the laws of quantum broke down and everyday laws take over.

  A Structure Extremely Large For The Atomic World

  Technically speaking, Cleland and his colleagues used a "microwave-frequency mechanical oscillator coupled to a quantum bit." While true, that's not very informative for most of us. Let's just say that they took something very small.

  More Quantum Physics From NPR

  Not Your Father's Objective Reality: 100 Years of Quantum Weirdness Feb. 16, 2010

  "The diameter of the structure is about that of a human hair, maybe smaller," he says. But that's extremely large for the atomic world.

  They cooled their structure to nearly absolute zero, and to their surprise and delight, the structure they created still behaved in a quantum way — a structure you can see with the naked eye.

  So now the question is, how far can you go before the laws of quantum mechanics give way to the more familiar rules of our macroscopic world?

  Physicist Markus Aspelmeyer of the University of Vienna says physicists are divided on the question of whether or not there's an upper limit.

  "I don't think there will be an upper limit. I think there's something very deep and fundamental about the quantum physical laws," he says.

  http://www.npr.org/templates/story/story.php?storyId=124820013&ft=1&f=1007
• 

  Razziel

  "Cleland wanted to see if he could find the size where the laws of quantum broke down and everyday laws take over."

  You can mathematically show that Newton's laws can be reduced from, and are just special cases of Einstein's relativity equations. Many quantum equations likewise can reduce to Newton's laws. I imagine when a "theory of everything" is finally developed, it will elegantly show there is just one set of governing equations that reduce to einstein's, newton's, or quantum equations depending upon the scale of the universe they apply to.