Can someone explain Time to me in its scientific form?

[LonnieFisher]

Since time doesn't really exist, time travel isn't possible.

[Duncan]

Let's say you're on Mars looking in a telescope at Earth and you see a murder take place. Lets say it takes 5 minutes for the light from Earth to travel to Mars. If it were possible to travel faster than light you could travel to earth and get there before the murder took place and save the person.

The laws of the universe don't permit anything traveling faster than light, but it illustrates how inconsistent time is, I think.

I thought this was interesting:

"Hong Kong physicists say they have proved that a single photon obeys Einstein's theory that nothing can travel faster than the speed of light -- demonstrating that outside science fiction, time travel is impossible."

"The study, which showed that single photons also obey the speed limit c, confirms Einstein's causality; that is, an effect cannot occur before its cause," the university said.


Time Travel Impossible, Say Scientists : Discovery News

[johnmiic]

Time is perhaps the wrong way to refer to the concept. Space-Time might be more accurate, (I think). Time and Space exist together and to our knowledge never exclusive of one another. We have compartmentalized the concept of time into clocks, watches, calendars, seasons because we are observing and counting the effects of change and movement in the universe. That is an indication of time but maybe not the whole picture.

As far as Time Travel goes many scientists have theorized it *is* possible, (many theories use wormholes as a roadmap to the past); more than scientists who theorize FTL travel is possible, (Faster Than Light). Einstein's theory of Relativity allows for the favorite particle of Science Fiction to exist: Tachyons. Light, Photons, should not be able to move faster than light but on the other side of the light barrier a Tachyon cannot move slower than light. If a Tachyon exists it should also be moving backwards in time, (anything moving faster than light would be moving backwards in time according to relativity).

So how do you detect a particle that moves faster than light yet backwards in time-at the same time? The caveat is a lot of scientists don't believe in Tachyons. There is a general prejudice against them. No one is really looking for them because they don't believe in them, (tho they believe in guons, muons, and many other odd particles). I would also not trust things the Chinese say. They outlawed Time Travel back in the winter. They have a vested interest in propaganda proving Time Travel isn't possible.

I think Carl Sagan once said, "We are all time travellers. We travel forward in time one day at a time."

Other Links:

Great Scott! Scientists Claim Time Travel Is Possible | PCWorld

Theorists get us closer to believing time travel is possible via the Large Hadron Collider -- Engadget

Stephen Hawking says time travel should be possible - Technology & science - Space - Space.com - msnbc.com

Scientists Explain Why Time Travel Is Possible - ABC News

[Brazoo]

Our understanding of the universe is not complete - and science acknowledges that.

We've basically organized the rules of the universe into two major groups, Classical Mechanics (which includes the Theory of Relativity, for example) and Quantum Mechanics (which shows how some of the rules of Classical Mechanics seem paradoxical and contradictory on the atomic and sub-atomic scale.)

We theorize that a unified theory to explain everything exists, it may not. The universe may just obey different laws on different scales.

Theories like String Theory are highly complex mathematical models using the framework of what we know about the universe to try and unify the two major sub-fields of physics. They're compelling because they attempt to unlock everything we know about the universe and apply it to physics on both scales. It's somewhat controversial because we can only model these things mathematically, and math is not science, mathematics is just a tool of science. Science requires testing - and no one has come up with ways to effectively test these models yet.

Some scientist (from what I understand, a fairly small faction) don't consider these theories to be true scientific theories because they can't be tested. It's not prejudice though, that's just based on the strict concepts of the way science works.

In fact most of the cutting edge research and media attention in physics is focused on wild ideas right now, so I'm not sure where you're getting that there's a prejudice against these ideas. Arguing and controversy is a necessary part of science. The issue with Tachyons is the same thing - tachyons are often part of string theory models. I don't think it's fair to say that scientists aren't looking for them, nobody knows how to look for them. They're theoretically not observable, so "belief" doesn't seem like the real issue.

Also, the problem Adam West mentioned about the Twin Paradox is not really effected by anything on the quantum scale and it doesn't need to involve any aspect of string theory because he's asking about time as we experience it on our scale.

I would also not trust things the Chinese say. They outlawed Time Travel back in the winter. They have a vested interest in propaganda proving Time Travel isn't possible.

I'm also skeptical of any cutting-edge science coming out of China right now. There's a lot of governmental interference and pressure - though this article has been peer reviewed in the US. It will be interesting to read more about this.

[MegoMark71]

Great thread guys

[emeraldknight47]

Great thread guys

One could even go so far as to say "timely" if one were so inclined.

Consider me inclined.

[johnmiic]

It's not prejudice though, that's just based on the strict concepts of the way science works....I don't think it's fair to say that scientists aren't looking for them, nobody knows how to look for them. They're theoretically not observable, so "belief" doesn't seem like the real issue.

I wish I had saved the issue of Discover Magazine handy where it said scientists were generally against Tachyons existing. I'll have to look around online and see if I can find the article. There are many particles scientists are searching for. They have ways to "try" and detect them tho they are not certain they will even see traces of them. If they thought Tachyons were real they would devise a way to try and detect them too rather than risking a missed opportunity.

[Brazoo]

I wish I had saved the issue of Discover Magazine handy where it said scientists were generally against Tachyons existing. I'll have to look around online and see if I can find the article. There are many particles scientists are searching for. They have ways to "try" and detect them tho they are not certain they will even see traces of them. If they thought Tachyons were real they would devise a way to try and detect them too rather than risking a missed opportunity.

I'd love to see it - right now the most I've read about tachyon's is just from the wikipedia article.

From that article I get that the existence of tachyon is hypothetical and the methods of trying to detect it are hypothetical, which is usually not a great combo for science sorting things out quickly. I mean, if they're not sure they'll see traces of them, let alone observe them directly then we could be in for the long haul on that theory gaining traction.

The basic theoretical groundwork for black holes started in the late 1700s and it took until the 1970s for there to be enough data collected to transform the consensus of science to general acceptance.

I don't think personal prejudice prolonged the understanding of black holes though - I just don't think of it that way. I think that collecting the data for theories based purely on mathematical concepts takes a long time to sort out. Besides that, how many ideas exist in the pure theoretical form until they go the other way and are completely eliminated?

I think some ideas have to seem better than others, or science would never progress. Sometimes the technology for testing ideas don't exist, so we have to wait. I think we've only begun collecting the most empirical confirmation of black holes in the last couple of years due to new technology.

Sometimes a lot of other stuff has to be weeded out first or the new theory might just ask more questions than it answers.

[Brazoo]

For the record - I'm not trying to make myself out to be an expert on these subjects - I doubt I could pass any college level 101 physics pop quiz.

I love this stuff. I love reading and watching science stuff. I love scientists like Carl Sagan and Michio Kaku (and my recent favorite) Phil Plait, who try to illustrate concepts in layman's terms and popularize science.

I love talking about this stuff. I try to confirm what I think is correct when I write on here - and I'll gladly correct or admit if I find I've written something that's wrong.

All I'm doing is reiterating stuff I think I've learned from these non-academic sources. On some level these concepts don't make total sense to me - but I also think on some level what we're able to visualize for these concepts also breaks down and only illustrates itself properly in the equations. I totally admit that I don't have the mental capacity or the inclination to even try and learn physics on that level.

[johnmiic]

For the record - I'm not trying to make myself out to be an expert on these subjects...

Yeah, that's what I though It's a cool thread.

Also you may have read how, a long time ago, many of Stephen Hawking's academic peers were up in arms about his theories on Black Holes. They gradually learned to accept the theories. Then he said later on he discovered X-Rays could escape the gravity of a Black Hole and they were up in arms again because he had theorized earlier nothing could escape. So scientists are not a calm bunch of people.

[emeraldknight47]

Brazoo----are you sure you're not just a Time Lord in hiding and don't want anyone to know...?

Somebody get that man a sonic screwdriver!

[Tothiro]

That time seems to be directly affected by gravity (different rate for atomic clocks at earth orbit when compared to synchronized clocks at planet surface for example) has always struck me as a strong real-world example of Einsteins space-time theory... But it still makes my brain hurt to think of the example of a planetary orbit as something like circling a drain (or an area of curved space) in outer space - which would seem like it should be an omnidirectional construct.
Yet our planets seem to have organized an orbit on a single plane instead. Has anyone seen/read anything discussing this more directly?

[Wee67]

In May, Scientific American published an article called "Is Time An Illusion?" It dealt alot with theories that say time cannot be mathmetically (and hence, also within the field of Physics) proven to exist. Our concepts of time only exists because our reltionship with our physical world. Even for a magazine which does a wonderful job of complex theories to laymen like myself, it was still a head-spinning read. I also read it on an eliptical machine which makes it a little harder to focus.

[MIB41]

My definition of "Time" - What we never have enough of, but waste looking back at the periods when we enjoyed it the most.

[Adam West]

Thanks for all the input guys. I admit my head is still spinning but a lot of what was said now makes sense to me. I knew this was the right place to ask and based on the variety of responses, see that many are very interested in this subject and also admit that it is complicated....thanks again.