Timetravel

Relativity Visualized - Lewis Carroll Epstein
Maxwell's Conundrum: A serious but not ponderous book about Relativity - Walter Scheider
Entanglement - Amir D. Aczel
Any of Stephen Hawking's 4 or so books that he has out now.

Time is inherent to reality and is a part of it. I was just stating that Time as life percieves it differs from how matter is affected by it.

Thalion

Can time exist without matter or energy?

Was there real time or virtual time before the big bang from say the point of view of other possible membranes of reality as per M-Theory?

/my head hurt writing that

I meant that Time is inherent to matter, or necessary to it. I consider what is Reality to be matter. Matter cannot exist or have existed if it didn't exist for a given time (heh, that sounds pretty stupid, but true. It didn't exist if it never existed....)

Agreed - I see matter and energy as being different states of some elementary thing that has a relationship to time. I visualise matter as a standing ocean wave (like where the tidal current equals the waves speed but in the opposite direction) and energy as a moving wave.

But take away energy, matter and space - is time still left - who know - certainly not in our reality. We can only speculate about other dimensions or membranes until we have a theory about them that links to time as a valid element of their dimensional structure.

To me that's like asking if a tree fell in a forest, and no one was around, would it make a sound? Without matter or energy, there would be nothing to define time, but it's principles woudl still be in effect. For example, if there were only one atom in the entire universe, would motion still exist? There would be nothing else by which to define motion.

The begining of the universe began in a Singularity as Hawking proved. Here all of our laws of physics break down. It is therefore pointless to ask questions about what happened before then; we just assume that it is the beginning of time. Therefore, I don't think that time exists independently of matter.

Again, something G__day has emphasized several times in discounting "time" in preference of "spacetime." Time is an aspect of matter, just as density, velocity, color, i tak dalye.

Cyracuz, First of all, a hearty Welcome to A2K. I like the twist you put into our perception of time. I wonder what Einstein would say.

I don't think it's pointless at all. How can you be sure there was nothing before this singularity? In my opinion there has to be something.

sorry to sidetrack from timetravel. :wink:

Well Hawking's "A Universe in a Nutshell" looks at a concept he calls "imaginary" time that runs on until the big bang happened. At this point imaginary time translates into real time - or spacetime as we know it.

The point being just as matter and energy are equivalnet and inter-convertable, imaginary time and spacetime where converted by the big bang event.

So I could rationalise a fundamental attribute that can manifest in a membrane of existance that we call a property of time.

So I envisage a concept say I call metatime - which exists across infinite membranes. Within any membrane a time function of metatime can be plausibly postulated.

So theoretical lets say all membranes are either 10 or eleven dimensional. Well theoretically a membrane could have as one or more of its 10 or 11 dimensions a zero, one, two, three etc dimensional time function that is a subset of metatime.

Scientif America last year did a good article on What is time and Universe or realities with different physical variables as to our own. So concepts such as could life exist in a Universe with only 2 dimensional space or 2 or 3 dimensional time.

Life in a twodemensional world? Is that dismissing time as a dimension, or is time the relative second dimension off that system? The definition of life doesn't work without time, and therefor a truly 2d system would have to include time AS one of those dimensions to support life. That limits things further, but is of course a side note.

Our concept of time only works for our universe. The billions (factored by itself) of stars "out there" has different time dimensions than the one we experience here on earth. I'm not so sure we'll ever find out the answer to what's beyond our time zone. We talk about some stars being billions of light yeas away from earth, but once we move outside this universe, our concept of time will have no meaning.

I beg to differ - an infinite number of universes could have our type of time function.

Two or three dimensional time is mind bending to try and imagine, intelligent life would require a far different conciousness to interact and explore a reality with multi-dimensional time axes. Its as wierd as envisaging a Universe where Bill Gates actually writes good software that doesn't crash

For life to exist you probably have to allocate several of you 11 dimensions a certain way - like 3 to space (x, y, and z co-ordinates) 1 to mass and one and only one (Big Arse Guess) to time etc. Then you have to edefinie tehplanck constant, speed of light, total amount of matter/energy in your system, weak and strong nuclear force constants etc with exacting precision.

My whole point is that a two-dimensional system, of say, width and height, is no longer 2d once you ad one or more dimensions of time. If we establish height and width respectively as the first two ordinal dimensions, a system which consists of only height and length is still 2d, and length becomes the systems relative 2nd dimension, omitting the ordinal second. Time is ordinally the fourth dimension, but a cartoon, for example, embodies only two PLUS time, which makes time it's relative third dimension. Life requires time to exist, so life could not exist in a 2D system if neither of those dimension were time. It's only a matter of termonology, and no importance, which is why I said it was a side note. I am of course assuming when you say "life in a 2d universe" you are referring to the dimension of height and width or length. So the concept of life conflicts with those confines. But hey, you're talking to someone who dismisses parallel lines as fictional.

I just can't fathom a universe of 2 demensions. You can't slice anything that thin. Even at an atomic level you'd still have a 3rd dimension.

Clarification:

Make each Universe at least 10 or 11 dimensional or say it has 10 or 11 defining characteristics if the word dimension is being confused as meaning x, y or z dimensions.

I see it practically impossible for life to exist in a 11 characteristic Universe where only 2 characteristics are allocate to spacial dimensions - meaning a flat plane.

Even if a Universe had our exact 11 characteristic but a different starting mass/energy at creation, a different mass for the hydrogen atom or planck's constant life couldn't exist. So perhaps defining characteristcs and creation energy is crucial to resolving whether or not life can exist.

Does anyone know if the Universe at creation had half or double its mass would planck's constant h = 6.626 10-34 joule-second be radically different?

/answer that for an instant Nobel prize!

g__day,

Just for reference, can you define what the 11 characteristics are please ?

Thanks

3 characteristics are spacial dimensions (x,y and z co-ordinate system)
1 characteristic is matter (mass or energy)
1 characteristic is spacetime (or gravity = function (space , time) )

So what are the missing 6 dimensions - or rather those that are too small to be detected yet by any experiment. I don't know - google searches haven't led me to any article that reveal these characteristics if we know them at all! I think scientists are developing models that cover topology first and characteristics second. But a good starting point is:
"Parallel Universes" Max Tegmark, Pages 30 - 41, Scientific America, May 2003 - page 35 is of particular importance, the box on Evidence thiwth teh graphs mapping Strength of Strong Nuclear Force vs Stength of Magentism and secondly the graph charting Number of Large Time Dimensions vs Number of large Spatial Dimensions.

But whatever they are they have to link and explain theory with all observed particles and effects e.g. http://www.fortunecity.com/emachines/e11/86/graphics/dimens/DIMENS2.gif (apologies if this direct link doesn't work in your browser) its in the small PDF below!

Why they exist are well documented http://arxiv.org/PS_cache/hep-th/pdf/9703/9703174.pdf but understanding that is about as simple as learning ancient Greek!

This has all been quite interesting but I would like to throw another idea into the time travel arena:
Paradoxes.
What if I was to get a lot of those quarks from g_day and strap them to my self,flick the on switch...And before you can say,planck's constant h = 6.626 10-34 joule-second.I'm siting at my computer a week from now.

Well the second thing I do after having a look at the lottery numbers is log on to A2K.And I read all the nice things y'all are saying about me and what a shame it is that I was killed driving my car.

So I recharge the quarks reverse the connections,hit the switch,and here I am.Back from the future. I decide to stay in bed the day of the crash and don't get mashed in my car.

The problem is I've printed of all the nice things y'all said. and I read the accident report. So I've proof that the accident happened but I was also in bed that day so clearly the accident didn't happen.

The question is what did happen?

Also when I was travelling back from the future did I get a week younger or was my body ageing forward as I was travelling back.

Lastly; and I know it's an old one. If time truly does exist and can be travelled through.where are all the time travellers?