About time there was someone that spotted one of the main points. It takes time to travel distance, which is why one of the usual reason people identify it as improbable is basing a long journey on the time it would take with their own period of existence.
We can apply some Darwinism to this, we can state that some animals on the planet can live for centuries (Tortoises) and obviously Plantlife even longer (Like Tree's, Just waiting for John99 to ask "if Tree's can pilot UFOs?")
Some people might raise ideas in regards to Cryogenics, however this might keep a life form lasting a little longer in theory it still serves no practical use, after all if you travelled many light years to meet an alien race, you'd probably want to return to your home world and tell your "friends". Not turn up centuries later to a planet that's as alien as the one you've just found because of all the social changes and loss of friends and family from the time you were away.
Other people might offer a conclusion suggesting "Wormholes" however to be totally honest they have just been theory and something to get Science fiction audiences to be able to identify with how something is suppose to have occurred. Creating some sort of nexus between two points in space requires a lot more than pushing a piece of paper into folding. The other point here is if it was proven to be physically possible then we would already be observing instances of this phenomena, since it's not just distance that would potentially be spanned by this method but time itself. (Considering instantaneous travel between two points would mean you would arrive at a destination potentially before you left. Lets say you were observing a planet in distance from where you arrive at about the same distance as our sun. Light takes 8 1/2 minutes to travel to earth, so for circa 8 minutes you would see a world that you were still on through a telescope)
But this just of course takes it a little further, you see if Wormholes allow time travel who's to say that it would be alien visitors that wouldn't want to be seen and not time travellers concerning themselves of the ripples they could create through interaction. To me it actually kind of makes sense that if we could push our physics boundaries, we would more likely interact with our past than attempt to travel to star systems in the search of life. We'd already be able to reference any attempts, work out where we are attempting to go and plan in regards to that, rather than just picking an interstellar lottery for the "potential chance" to discover another civilization.
What is time in the eyes of physics? Apart from the clocks on the wall and the watch around your wrist, time has a very interesting description by physicists. The strange thing about time, is that you cannot see it, touch it, or feel it. We can sense it to some degree - but there is a reason why we sense time; that is because it all exists inside of us. The clock of the universe, is simultaneously and paradoxically a mental clock; time is a product of our minds.
When considering time, we ask questions like, 'what is time?' And other questions like, 'why can't we live forever?' And, 'can we make the hand of the clock move anti-clockwise?' Let's investigate these for a second. We often wonder why our skin ages. What causes my body to age...? Is it simply a process of time?
Yes, and no. Obviously, it takes time to do it. However, scientists think they can locate the subject that causes ageing, the 'free radical' - a deteriate molecule, eating electrons. However, there is no scientific technology as yet that can stop these free radicals from self-destructing. This is just a fact about nature.
The whole world is governed by specific times, in a day or even in a year. The flower will close its petals over night, and re-open in the morning. The trees in autumn will shed its leaves, and sheep in springtime give birth to their lambs. Even humans, females that is, have an 'in-built' maternal clock. In fact, we have several clocks. One is our 'sleep clock.' It is around 24.5 hour sleep clock. Scientists have discovered the gene that causes this perception, and called it the 'Suprachiasmatic Nucleus.'
Time is the 4th dimension of time, physicists call, 'the imaginary dimension of space.' Quantum physics points to a startling conclusion when regarding time - and that is that the human mind is somehow, the same thing as it! It makes us inextricably linked with space, matter and energy. Somehow, through the presence of time, everything is dependant on each other. It is our perceptions of time that interests scientists. Certain times of the day can go faster than other times. Even certain narcotics can play an influence on the human perception.
So can we slow down the molecular process of ageing?
Some scientists think that it is possible. The molecular structures of quantum systems can be tinkered with to alter their life spans. In the Buck Institute in Novato, California, they have been able to increase the lifespan of the Nematode Worm; This is by cataloging its individual genes, the thousands of them. A human being has about 80,000 genes. By locating certain genes inside of humans, we can alter disease, and, in the case of the Nematode - triple their life spans. Given that humans have a considerable amount more cells than the 959-cell nematode worm, we have around 50,000 billion cells, and a great deal more genes, about 60,100 more; can we alter human life expectancy in mapping and cataloging the human genetic makeup?
There is a tree is Bristlestone National Park, near Death Valley in Sunkist California that is 4785 years old! It was given the most appropriate name of the 'Methuselah,' named after the biblical character in Genesis, father of Lamech and oldest man to be recorded, as 969 years. Being as old as the pyramids themselves, older than Christ, It has lasted this long because it has an amazingly slow metabolism.
Theoretically, a human can add an extra 5-10yrs onto their life spans by eating less (this ensures we don't use up too much energy - this is semi-starvation treatment, and they perform this on chimps), and exercise less (also to retain as much energy.) This of course happens because of a conservation of energy, by doing a lot less than the average human my metabolism will run much slower. Thus my cells use up less energy, then needing less energy.
The speed of time can fluctuate and change as moments pass around large cosmological dense bodies (even the earth produces time warps), but it cannot simply disappear from the fabric of space, because it is a universal 'invariant'. There are many 'invariant' relationships in physics. Invariance is a constant that shall remain, therego, despite if something changes. A good example is a tree. It will bud in spring, bloom in summer, but will shed its leaves in autumn. Now in winter it is bare; the invariance here is the tree. So, it is no surprise that scientists are perplexed by the brains ability to warp time senselessly - and in some extreme cases, even makes time disappear - it defies all current scientific understandings.
Baring all of this in mind, speed causes a time warp as well, so time can be effected drastically from a local point of view, when travelling large distances very quickly. Even if you are moving just a fraction short of c.
Some galaxies in the universe, will be moving already at relativistic speeds short of c, left over from the inflationary period of the universe. Without inflation, all parts of the galaxies would be moving at the same speeds, but since they are observed to be moving at very different speeds, inflation seems to be a very acceptable model in physics and cosmology.
If there is a galaxy moving relative to us at near light speed, with an alien civilization in its midst, (an advanced one at that), then it is possible according to the known laws of physics that they can move out of their galaxy at exactly the same speed, so it is theoretically possible to have the advantage of that speed, without the necessery energy requirements to accelerate up to that speed, from slower speeds.
Not only that, but relativistically speaking, their clock was always running slower than ours. And even better: The cosmos could have evolutionary created them very early on in the univeses history, possibly millions of years before us. This would have given them also the advantage of becoming very smart, so much quicker than expecting ourselves to show up on this infinite map of spacetime.
Wormholes are a good idea, as Stryder mentioned. A few technological problems arise however. After mathematical studies, it seems that to create a wormhole, you need an energy device something like the size of the entire solar system!!
The problem with a time machine is that it would require such an enormous amount of energy to do what i want. Dr. Michio Kaku, a well renown physicist just completed a series on channel four TV. called ‘Time’, and he was asked to build a time machine.
His idea was to have a gigantic atom collider, the size of the solar system to accelerate a beam of particles equal to amazing speeds, until it reaches a point called the 'Planck Energy' were space and time become unstable, and a rip can be caused in the fabric of space. This is because the particles focus an intense beam at a certain region in space and time, and the temperatures force the universe to link up with another place in that universe, or if theory is correct, to parallel universes. The wormhole gateway into another time and place would be very small. However, the presence of exotic matter could blow it up to a more reasonable size, fit for a human.
Wormholes inside of black hole are threaded with this 'antigravity' substance called 'exotic matter.' physicists aren't able to make this in labs today, but, it is believed to be a main proponent in the rapid acceleration of our universe, as it is thought to pervade our universe. One mouth of the wormhole is then taken to a 'Neutron Star.' This is a 'superdense' remnant of a dead star. One spoonful of the material weighs as much as all the cars and vans in the world put together! It will create a high gravitational field - and it is here, time becomes distorted and slowed down.
Thus, leaving one end of the wormhole at the neutron star, will slow the age of it. Let's say that he left it there until it was a year younger, than the other end. Then, entering very carefully one end of the wormhole, i can come out the other end a year back in the history of the universe. Though, i must stress, as grand as Dr. Michio's idea is, it is still science fiction, and he is aware of this. The amount of energy required is astronomical - in fact, the energy we can produce in colliders today is around a quadrillion time less than what would be required.
Then, if we where able to travel freely in time, what about the paradox's that come with it all? Einstein gave us some examples of these paradox's and riddles, where a time traveler goes back in time and kills his father before he reaches puberty; but this is where the inconsistency arises. If he killed his father before he met his mother, then that would suggest that [he] was never born, hence the paradox. If he never existed, how could he go back in time to kill his father?
Though, some physicists get around this problem with parallel universe theory. If one travels through the time barriers, according to theory, one travels into other universes. Einstien’s relativity, explains that time is not fixed. Time can be traveled through, just like space. With time not being absolute, must mean that our past time can be someone’s present or someone’s past...
In fact, contained time travel (as in, time travel soley in this universe), may be entirely impossible, with the existence of other universes. The idea, is that you move through time, but act more like a graviton, ending up in a similar universe to this one, at a specific designated time. By theory, you could travel forever, and never ever return back to the original universe, but only by fluke.
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