Time Travel IS Possible...

<div class='quotetop'>QUOTE(TonyPSchaefer @ Jul 9 2006, 03:00 PM) [snapback]283504[/snapback]</div>

Sometimes I fly paper airplanes, and when I was 17 I flew a real plane (a Piper Tri-Pacer). But I have never flown a fish. Were they big enough to ride on, or were they just radio controlled? I'd love to see someone flying a fish. It would be fun. The fish probably wouldn't like it, though. Fish out of water, and all that. Don't worry, though. I won't report you to PETA.

 

<div class='quotetop'>QUOTE(daniel @ Jul 10 2006, 09:39 AM) [snapback]283773[/snapback]</div>

I also have never flown a fish, but I have seen fish fly. "But,I’ve never seen an elephant fly". :lol: :lol: :lol:

 

If you really want to do some serious time travel. Tonight after dark, look up at the sky. You'll be looking at a scene that took place millions of years ago, depending upon where you look... B)

 

There are parts of (my home) Washington State that are living in the 1950's; I'm sure you can find places in the country where people are living in the 19th century. Some religious leaders are living in the 15th century. We are surrounded by time travelers!!

 

<div class='quotetop'>QUOTE(grasshopper @ Jul 10 2006, 06:58 AM) [snapback]283786[/snapback]</div>

Ah, yes. Groucho. This made me imagine an elephant sky-diving. Or better yet, hang-gliding.

As for the comments about star-gazing, I'm not sure looking into the past constitutes time-travel. And I'm quite sure that living "in the past" does not constitute travelling through time.

I repeat, though, that we are all travelling through time all the time. It's impossible not to.

 

<div class='quotetop'>QUOTE(Mystery Squid @ Jul 10 2006, 07:35 PM) [snapback]284218[/snapback]</div>

Time is not a man-made concept. It is a fundamental dimension of reality. Space-time (see Einstein) is the "place" where we and everything else in this universe exist. You may re-name it if you like. Every language has its own words for things. But time itself is real, and you cannot prevent yourself from moving through it. The measurement of time is relative to the frame of reference of the observer. But we are all still moving through it.

I admit to being a pessimist.

But "absolution" is a religious concept, so you are far off the mark there.

 

<div class='quotetop'>QUOTE(Mystery Squid @ Jul 11 2006, 02:11 PM) [snapback]284515[/snapback]</div>

What is the universebut more importantly, how was it created - explain that one first to me and then we can start working on subsequent small stuff you guys are discussing like time, space, and relativity.

 

Relativity is absolute! The speed of time isn't constant, because the speed of light is. On a practical basis, everybody knows time goes faster as we age. When we're ten years old, a year is 10% of our life. When we're fifty, that same year is only 2% of our life. No wonder the years seem shorter and shorter!

 

<div class='quotetop'>QUOTE(hyo silver @ Jul 11 2006, 02:48 PM) [snapback]284533[/snapback]</div>

I am pretty sure the speed of light is not constant.

The Speed of Light - A Limit on Principle?
A physicist's view on an old controversy
Last modification 3rd February '98 - new update currently in preparation
by Laro Schatzer <[email protected]>
(comments and criticism welcome)

Conclusion: If our universe has a Newtonian background, ie. if there is an absolute time underlying the space-time continuum, then there is no threat on causality by superluminal processes, because time travel and its paradoxes are excluded a priori. And thus, within this framework, faster-than-light travel is possible, at least in principle.

Remark: It may be a surprise for many physicists that even within the framework of general relativity faster-than-light speed is allowed, provided that the space-time metric of the universe is globally hyperbolic [14]. This condition simply implies that closed time-like paths in space-time (and thus time-travel) are excluded, so that causality is again preserved. (In this framework, the cosmological time parameter can be again interpreted as the absolute time of the universe. However, in order to construct a propulsion mechanism for faster-than-light travel, exotic matter (with imaginary mass) would probably be needed in order to produce negative energy densities in space. Unfortunately, exotic matter is not known to exist, although negative energy densities have been shown to appear in quantum field theory. But, of course, such a hypothetical propulsion mechanism just provokes to be given the familiar name of the warp drive.



<div class='quotetop'>QUOTE(hyo silver @ Jul 11 2006, 02:48 PM) [snapback]284533[/snapback]</div>

Sorry - here is the more appropriate article:

Speed of light may have changed recently
19:00 30 June 2004


The speed of light, one of the most sacrosanct of the universal physical constants, may have been lower as recently as two billion years ago - and not in some far corner of the universe, but right here on Earth.

The controversial finding is turning up the heat on an already simmering debate, especially since it is based on re-analysis of old data that has long been used to argue for exactly the opposite: the constancy of the speed of light and other constants.

A varying speed of light contradicts Einstein's theory of relativity, and would undermine much of traditional physics. But some physicists believe it would elegantly explain puzzling cosmological phenomena such as the nearly uniform temperature of the universe. It might also support string theories that predict extra spatial dimensions.

The threat to the idea of an invariable speed of light comes from measurements of another parameter called the fine structure constant, or alpha, which dictates the strength of the electromagnetic force. The speed of light is inversely proportional to alpha, and though alpha also depends on two other constants (see graphic), many physicists tend to interpret a change in alpha as a change in the speed of light. It is a valid simplification, says Victor Flambaum of the University of New South Wales in Sydney.

It was Flambaum, along with John Webb and colleagues, who first seriously challenged alpha's status as a constant in 1998. Then, after exhaustively analysing how the light from distant quasars was absorbed by intervening gas clouds, they claimed in 2001 that alpha had increased by a few parts in 105 in the past 12 billion years.

Natural nuclear reactor
But then German researchers studying photons emitted by caesium and hydrogen atoms reported earlier in June that they had seen no change in alpha to within a few parts in 1015 over the period from 1999 to 2003 (New Scientist, 26 June) though the result does not rule out that alpha was changing billions of years ago.

Throughout the debate, physicists who argued against any change in alpha have had one set of data to fall back on. It comes from the world's only known natural nuclear reactor, found at Oklo in Gabon, West Africa.

The Oklo reactor started up nearly two billion years ago when groundwater filtered through crevices in the rocks and mixed with uranium ore to trigger a fission reaction that was sustained for hundreds of thousands of years. Several studies that have analysed the relative concentrations of radioactive isotopes left behind at Oklo have concluded that nuclear reactions then were much the same as they are today, which implies alpha was the same too.

That is because alpha directly influences the ratio of these isotopes. In a nuclear chain reaction like the one that occurred at Oklo, the fission of each uranium-235 nucleus produces neutrons, and nearby nuclei can capture these neutrons.

For example, samarium-149 captures a neutron to become samarium-150, and since the rate of neutron capture depends on the value of alpha, the ratio of the two samarium isotopes in samples collected from Oklo can be used to calculate alpha.

A number of studies done since Oklo was discovered have found no change in alpha over time. "People started quoting the reactor [data] as firm evidence that the constants hadn't changed," says Steve Lamoreaux of Los Alamos National Lab (LANL) in Los Alamos, New Mexico.

Energy spectrum
Now, Lamoreaux, along with LANL colleague Justin Torgerson, has re-analysed the Oklo data using what he says are more realistic figures for the energy spectrum of the neutrons present in the reactor. The results have surprised him. Alpha, it seems, has decreased by more than 4.5 parts in 108 since Oklo was live (Physical Review D, vol 69, p121701).

That translates into a very small increase in the speed of light (assuming no change in the other constants that alpha depends on), but Lamoreaux's new analysis is so precise that he can rule out the possibility of zero change in the speed of light. "It's pretty exciting," he says.

So far the re-examination of the Oklo data has not drawn any fire. "The analysis is fine," says Thibault Damour of the Institute of Advanced Scientific Studies (IHES) in Bures-sur-Yvette in France, who co-authored a 1996 Oklo study that found no change in alpha. Peter Moller of LANL, who, along with Japanese researchers, published a paper in 2000 about the Oklo reactor that also found no change in alpha, says that Lamoreaux's assumptions are reasonable.

The analysis might be sound, and the assumptions reasonable, but some physicists are reluctant to accept the conclusions. "I can't see a particular mistake," says Flambaum. "However, the claim is so revolutionary there should be many independent confirmations."

While Flambaum's own team found that alpha was different 12 billion years ago, the new Oklo result claims that alpha was changing as late as two billion years ago. If other methods confirm the Oklo finding, it will leave physicists scrambling for new theories. "It's like opening a gateway," says Dmitry Budker, a colleague of Lamoreaux's at the University of California at Berkeley.

Horizon problem
Some physicists would happily accept a variable alpha. For example, if it had been lower in the past, meaning a higher speed of light, it would solve the "horizon problem".

Cosmologists have struggled to explain why far-flung regions of the universe are at roughly the same temperature. It implies that these regions were once close enough to exchange energy and even out the temperature, yet current models of the early universe prevent this from happening, unless they assume an ultra-fast expansion right after the big bang.

However, a higher speed of light early in the history of the universe would allow energy to pass between these areas in the form of light.

Variable "constants" would also open the door to theories that used to be off limits, such as those which break the laws of conservation of energy. And it would be a boost to versions of string theory in which extra dimensions change the constants of nature at some places in space-time.

But "there is no accepted varying-alpha theory", warns Flambaum. Instead, there are competing theories, from those that predict a linear rate of change in alpha, to those that predict rapid oscillations. John Barrow, who has pioneered varying-alpha theories at the University of Cambridge, says that the latest Oklo result does not favour any of the current theories. "You would expect alpha to stop [changing] five to six billion years ago," he says.

Reaction rate
Before Lamoreaux's Oklo study can count in favour of any varying alpha theory, there are some issues to be addressed. For one, the exact conditions at Oklo are not known. Nuclear reactions run at different rates depending on the temperature of the reactor, which Lamoreaux assumed was between 227 and 527°C.

Damour says the temperature could vary far more than this. "You need to reconstruct the temperature two billion years ago deep down in the ground," he says.

Damour also argues that the relative concentrations of samarium isotopes may not be as well determined as Lamoreaux has assumed, which would make it impossible to rule out an unchanging alpha. But Lamoreaux points out that both assumptions about the temperature of the Oklo reactor and the ratio of samarium isotopes were accepted in previous Oklo studies.

Another unknown is whether other physical constants might have varied along with, or instead of, alpha. Samarium-149's ability to capture a neutron also depends on another constant, alpha(s), which governs the strength of the strong nuclear attraction between the nucleus and the neutron.

And in March, Flambaum claimed that the ratio of different elements left over from just after the big bang suggests that alpha(s) must have been different then compared with its value today (Physical Review D, vol 69, p 063506).

While Lamoreaux has not addressed any possible change in alpha(s) in his Oklo study, he argues that it is important to focus on possible changes in alpha because the Oklo data has become such a benchmark in the debate over whether alpha can vary. "I've spent my career going back and checking things that are 'known' and it always leads to new ideas," he says.

 

<div class='quotetop'>QUOTE(hyo silver @ Jul 11 2006, 11:48 AM) [snapback]284533[/snapback]</div>

Physicists Slow Speed of Light
http://www.news.harvard.edu/gazette/1999/02.18/light.html

Relativity is absolute? :huh:
Heck, we as humans aren't even sure who are relatives were 3.5 million years ago.

Was it Lucy?
Or is Flat Face our long lost kin?
http://www.cincypost.com/2001/mar/26/editb032601.html

 

Squid: You're beginning to sound as loony as the creationists. Maybe they've been selling you some of whatever they've been smoking? And BTW, "absolutist" is the word you were trying to invent. Absolution is something else altogether. An absolutist is a person who believes in absolutes. An absolutionist is a person who believes in absolution (i.e., that people can be absolved of sin -- Christians are generally absolutionists).

 

When I clicked on the topic, I naturally assumed somebody in Florida had sold MS very powerful narcotics. I envisioned him laying on a beach - eyes wide open and pupils blown out - giggling and saying

"SSSSSSSSSSHHHHHHHHHHHIIIIIIIIIIIIIIIIIIIIIIIIITTTTTTTTTT!!!"

<div class='quotetop'>QUOTE(daniel @ Jul 12 2006, 12:21 AM) [snapback]284823[/snapback]</div>

Ummm ... this is something NEW about him??

 

Time is variable...in the US something that is 200-300 years old is seen as something fantastic. In a place like Italy (Pompeii) or Greece that would be thought of as fairly new.....Squid's been pretty good lately, sunshine is very beneficial to "overall" health......

 

<div class='quotetop'>QUOTE(Mystery Squid @ Jul 13 2006, 07:18 PM) [snapback]285998[/snapback]</div>

When a word has a generally-accepted definition, and you choose to use it to mean something else entirely, you are choosing to substitute obfuscation for communication. Granted, in a free country you have the right to do that, and it's very much in character for you. But I have an equal right to reject your definition and use the word as it has always been used, and as everyone else understands it.

And I've always sided with Christians. Real ones, that is, not the fake ones who claim to believe in Jesus and then oppose everything he stood for and everything he preached. (I'm not a Christian, of course. I don't believe any of it. But I side with people who live as though they believed it.)