Do you guys believe in aliens?
If yes, where do they come from? Have you ever think that they are actually human-being, like us, the mankind....but their appearance are evolved from what we are right now? and of course they have the capability of travelling through time due to their higher intelliegent technologies or inventions. We could look like them maybe zellion of years later...and we could actually travel thought time by means of to the past or to the future...

It could be......who knows...

eh? i was just looking at the title of the thread... and then these posts... ???

well, here goes what i think (i don't claim to be an authority on these things, just my opinion here):

time is a human abstraction, a social construction... we calculate the movement of time today through a regular electrical impulse. this used to be done by looking at the position of shadows when technology meant using a wooden club against your enemy while he tried to scratch your eyes out with his fingers...

the term 'time passes'... it is a work of abstraction, a kind of imaginative metaphor. what actually happens is that planetory movements causes more or less light to fall on each part of the earth. what i think is time does not 'pass'. it is not a linear measure of the passing of a medium. rather we live in a kind of stasis where time is concerned. in this case, i think it easier to say that time exists only as a concept, as a perspective. the reality is that it does not exist (philosphers, pardon me. i know that something must first exist before one can refute it, but read my post once again and try to grasp the debunking of that pre-assumption. thanks!)

if time does not exist, then it cannot 'pass'. if this holds true, then how do you go back in time?

once again, i'm just thinking off the fly... u don't have to agree with me. neither do i claim that i am right nor omniscient. treat this post like an alternative view. then again, i didn't get to read all the posts here (no time! ) so if i'm repeating someone else's post, forgive me.

Theoretical physicist, I specialize in quantum theory.

Re: Gui10,

Time is *not* abstract. Ever heard of space-time? Gravity warps time. Electrical fields warp time. The space-time continuum is GR, not fantasy.

Physics is not reality. It's just an abstract model used for describing and predicting behavior.

I would like to hear you explain how the concept of "space-time" proves that time exists, that it is not abstract.

If a second is a constant than a year is too. A second is determined by recording the time it takes an object (in this case light) to travel from one point to another. This same method is used for determining a year, although it changes ever so slightly due to certain circumstances, it is still a constant, and you can put a year in terms of a seconds. If one were able to travel into the future it would mean that the "constant" of the second would have to be warped for that individual, or their seconds would have to be shorter, something which cannot happen, no matter how fast something is moving. If it were true that one would have lived through less seconds after going .99c (c= speed of light for all those trying to read along) than it would also be true for someone going the speed of sound or any speed for that matter, as there can not be a cutoff.

wow, i didn't realize my saturday morning thinking after my long drive from dallas to austin would actually cause a debate.

but we will never travel at the speed of light.. we won't survive to see that day happen as the sun will swallow the earth.

all i do know is that we will never time travel, we couldn't tell a machine to go back to 1950, cause that exists only in our heads, a machine would not no any difference.

what your explaining iceman does make sense.. i am just saying that time travel is not possible due to that affect.. yes if we could travel at light speed then come back, it would probably be like the persons traveling go into the future or whatever.. but while they are traveling, i do believe that the people here on earth will be doing their everyday thing.. still spinning around the sun on the earth, so technically it wouldn't be time travel, more like a jump in time...

i am not sure i believe in aliens, but i do think we're not alone or not the only living organisms in the universe.

Sausage,

How many seconds in a year, then?

glock19,

Actually, physics is reality. Our laws of physics are based loosely on probability, true, but probabilities so precise that in a finite universe they are deemed impossibilities. Our laws of physics are by no means reality. Our laws of physics, however, are by no means the natural laws of physics. We cannot actually determine such laws due to problems with infinities (ever heard of infinite subtractions?) and whatnot. Regardless, there are universal natural laws of physics, regardless of whether they are printed in your physics book or not.

lol, 31557600 as an approximation albeit it can be calculated in more exact terms for any given "year", at least as exact as we can get the speed of light in a vacuum. If moving at slightly below c were to result in seconds becoming faster than would the light that we see here on earth not be traveling into the future because it does not age through as many seconds as other things? If this were true, wouldn't the results of experimentation with fizeau's technique be skewed, and the measurement of the speed of light in air not possible? v=D/t if going just under c results in these pseudo-seconds (lesser than a real second) then the velocity would end up being greater than that of c.

31557600 seconds is the time it takes the Earth to revolve around the Sun? That's a universal unit?

You can't actually *see* light, but you are technically seeing into the fast and therefore you are technically in the future.

Iceman:
i know we can argue till the cows come home. and i'm sure theoretical physicists, much like the masters of other specialized fields, claim to hold the key to the truth. or at least the key to reality. i respect what you have learnt and how u have come to learn them. however, i hope that u also learn to be humble. before you become defensive, please don't take offense, because none is given. let me explain.

to you, physics is reality. or rather, what u have learnt to this point has caused you to believe that it is reality. to most of us(to me at least) what we know of physics could hardly constitute the entirety of what we know or believe is reality. i stopped studying physics as a form of formal education 10 years ago. i could not talk to you about how gravity or electrical fields or space-time warps time. for firstly, i don't know much about those fields to carry a conversation of sufficient content(although i am very sure that it would be very interesting to find out!). secondly, if we did, we would have to go down to the nitty gritty of agreeing/disagreeing on basic definitions of many many things based on different pre-assumptions. we'd be dead by the time we're ready to talk about time or reality. we might even have become enemies over such trivial things.

i just gave my opinion to share what i have been musing. not to invite someone with an absolute view based on several pre-assumptions to lord his/her opinion over me. i asked for your kindness to indulge me, to pursue a train of thought with me. are u so confined to quantum physics?

Interesting discussion for sure. I'm by no means an expert in quantum mechanics (though I with I had heard about this before I started going into computers...) but I vague remember something like this:

time particules move at the speed of light (okay time's not a particle I guess so perhaps a image from a time frame? I'm not making sense anymore and I haven't even finished my sentence...). If you would exceed light speed, wouldn't you be 'catching up to time' and thus effectively see the past? I have doubts myself about actually traveling back into time and participate but couldn't you see past images, say the image of a planet when a start reflected off of it in the past?

Now would be a good time to ask what people think of the idea of quantum computers..I've read up on what they are supposed to be and its mind bogling..not sure if they'd be great for games tho

elaborate?

any url's regarding this subject?

It's the height of human hubris to assume that the universe works the way we see it through our own limited perceptions.

The idea of time is a useful abstraction. Time appears to be real, but it's only an illusion coming from after-effects that emerge from the fundamental elements of the universe at play.

Gravity is the same way. There is no graviton, or gravity particle. That's because gravity is not a real force, it doesn't exist. Gravity is only an illusion coming from the bending of space due to the presence of quantities of mass/energy. On our limited level, it appears that gravity is a real force, yet it's only an after-effect of what happens when space gets curved by certain quantities of matter/energy.

Centre for quantum computation
http://www.qubit.org