Page 7 of 8 [ 120 posts ]  Go to page Previous  1 ... 4, 5, 6, 7, 8  Next


How do you feel about the subject of UFO's and Aliens??
Earth is the only planet in the universe that supports life. 3%  3%  [ 2 ]
I believe that there is probably life out in the universe, but UFO's and alien abductions are false. 53%  53%  [ 37 ]
I believe that there is life out in the universe and that UFO's and alien sightings are real. 33%  33%  [ 23 ]
I'm not sure. 11%  11%  [ 8 ]
Total votes : 70

Haliphron
Veteran
Veteran

User avatar

Joined: 28 Jan 2008
Age: 39
Gender: Male
Posts: 1,980

27 Jul 2008, 3:22 pm

Speaking of causality, have a look at This twoshots:

Quote:
Researchers in Switzerland have succeeded in breaking the cosmic speed limit by getting light to go faster than, well, light.

Or is it all an illusion?

Scientists have recently succeeded in doing all sorts of fancy things with light, including slowing it down and even stopping it all together. Now a team at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland is controlling the speed of light using simple off-the-shelf optical fibers, without the aid of special media such as cold gases or crystalline solids like in other experiments.

"This has the enormous advantage of being a simple, inexpensive procedure that works at any wavelength," said Luc Thevenaz, lead author of the study detailing the research.

Using a technique called Stimulated Brillouin Scattering, the researchers were able to slow down or ratchet up the speed of light like the gas pedal on a car. They succeeded in reducing the speed of light by almost a factor of 4 (although that's still plenty fast at 46,500 miles per second), but even more dramatically, the team was also able to speed up the speed of light.

Light in a vacuum travels at approximately 186,000 miles per second, but a popular misconception is that, according to Einstein's special theory of relativity, nothing in the universe can travel faster than this speed.

This seeming paradox can be resolved because a pulse of light is actually made up of many separate frequency components, each of which moves at their own velocities. This is known as the pulse's phase velocity. If all the frequency components have the same phase velocity, then the overall pulse will also appear to move at that velocity.

However, if the components have different phase velocities, then the pulse's overall velocity will depend on the relationships between the velocities of the separate components. If the velocities differ, the pulse is said to be moving at the group velocity.

By tweaking the relationship between phase velocities, it's possible to adjust the group velocity and create the illusion that parts of the pulse are traveling faster than the speed of light.

One area where such an advance could be enormously beneficial is in the telecommunications industry.

Although information can be channeled through fiber optics at the speed of light, it can't be processed at this speed because with current technologies, light signals must be transformed into much slower electrical signals before they are useful.

Thevenaz's technique would essentially allow light to be processed with light without a costly electrical conversion.

The group's research will be published in an August 22nd issue of the journal Applied Physics Letters.



Now it seems you and Fnord have a pretty understanding of Special Relativity but Im dismayed to see no acknowledgement here of General Relativity; in which the causality issue is considerably more complex and uncertain(as it is in QM). So you see, at the moment it appears that nothing can travel faster than light by brute force, but effective FTL actually CAN be achieved by means of warping spacetime.


here's the link BTW: http://www.livescience.com/technology/0 ... light.html



twoshots
Veteran
Veteran

User avatar

Joined: 26 Nov 2007
Age: 35
Gender: Male
Posts: 3,731
Location: Boötes void

27 Jul 2008, 6:49 pm

I haven't reviewed that kind of thing yet, but I'm pretty sure the overall conclusion is still that you can't send info faster than light (especially with this method).

Yes, the situation becomes much more complicated when you take into account GR (you did specifically question SR). Which brings up the question of the practicality of time space warping methods. As I have pointed out, wormholes are not even sure to be possible, Alcubierre Drives even if they were physically possible are pretty much certain to be impossible to actually implement, and they both require things like exotic matter, which may or may not exist. If you can think of any other known solutions to GR which allow us to circumvent the speed of light, similar objections probably apply.


_________________
* here for the nachos.


Doc_Daneeka
Pileated woodpecker
Pileated woodpecker

User avatar

Joined: 3 Jul 2007
Age: 47
Gender: Male
Posts: 195
Location: Toronto. But we call it Tarana.

27 Jul 2008, 8:28 pm

Larree wrote:
Doc_Daneeka wrote:
Larree wrote:
Moon-walker claims alien contact cover-up
July 24, 2008 12:01am

FORMER NASA astronaut and moon-walker Dr Edgar Mitchell - a veteran of the Apollo 14 mission - has stunningly claimed aliens exist.


It's probably worth noting that there is no reason to take his view more seriously than that of a random person. The fact that he has been in space is irrelevant. When it comes to an area in which we have no real knowledge, an astronaut is as good a source as a carpenter.


Well, even so, what reason would he even have to make these statements? Perhaps he always wanted to shout "fire" in a crowded theater? I get a kick out of it. I personally know that we, I mean "they," do travel through space using concepts and technologies that are way beyond our wildest scifi theories! Yeah, Beam me up!


I can't read his mind, but I would guess that he makes such statements because he believes them to be true. I merely wished to point out that his statements aren't more credible than those of my neighbour simply because Mitchell been to the moon.


_________________
------------------------
ubi dubium ibi libertas


Haliphron
Veteran
Veteran

User avatar

Joined: 28 Jan 2008
Age: 39
Gender: Male
Posts: 1,980

27 Jul 2008, 11:14 pm

twoshots wrote:
I haven't reviewed that kind of thing yet, but I'm pretty sure the overall conclusion is still that you can't send info faster than light (especially with this method).

Yes, the situation becomes much more complicated when you take into account GR (you did specifically question SR). Which brings up the question of the practicality of time space warping methods. As I have pointed out, wormholes are not even sure to be possible, Alcubierre Drives even if they were physically possible are pretty much certain to be impossible to actually implement, and they both require things like exotic matter, which may or may not exist. If you can think of any other known solutions to GR which allow us to circumvent the speed of light, similar objections probably apply.


What makes you focus so fervently on wormholes BTW? Yes they have not been proven to exist but the Alcubierre Drive is only ONE possibility. I agree that its feasibility is VERY sketchy but that does not mean that it would be impossible to warp spacetime in a (rather)small region of space to get around the light barrier.But as you can see, there is some VERY Reasonable Doubt that travelling faster than light and/or travelling vast distances in outer space by means of shortening the actual distance is totally impossible. Wormholes may not exist in nature, they may have to be created.



Fnord
Veteran
Veteran

User avatar

Joined: 6 May 2008
Age: 63
Gender: Male
Posts: 46,528
Location: Stendec

28 Jul 2008, 10:54 am

Larree wrote:
I personally know that we, I mean "they," do travel through space using concepts and technologies that are way beyond our wildest scifi theories! Yeah, Beam me up!

Evidence, Please?


_________________
*TRE45ON!!*
Lock Him Up!


Fnord
Veteran
Veteran

User avatar

Joined: 6 May 2008
Age: 63
Gender: Male
Posts: 46,528
Location: Stendec

28 Jul 2008, 10:56 am

Quote:
Researchers in Switzerland have succeeded in breaking the cosmic speed limit by getting light to go faster than, well, light.

Or is it all an illusion?

Scientists have recently succeeded in doing all sorts of fancy things with light, including slowing it down and even stopping it all together. Now a team at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland is controlling the speed of light using simple off-the-shelf optical fibers, without the aid of special media such as cold gases or crystalline solids like in other experiments.

"This has the enormous advantage of being a simple, inexpensive procedure that works at any wavelength," said Luc Thevenaz, lead author of the study detailing the research.

Using a technique called Stimulated Brillouin Scattering, the researchers were able to slow down or ratchet up the speed of light like the gas pedal on a car. They succeeded in reducing the speed of light by almost a factor of 4 (although that's still plenty fast at 46,500 miles per second), but even more dramatically, the team was also able to speed up the speed of light.

Light in a vacuum travels at approximately 186,000 miles per second, but a popular misconception is that, according to Einstein's special theory of relativity, nothing in the universe can travel faster than this speed.

This seeming paradox can be resolved because a pulse of light is actually made up of many separate frequency components, each of which moves at their own velocities. This is known as the pulse's phase velocity. If all the frequency components have the same phase velocity, then the overall pulse will also appear to move at that velocity.

However, if the components have different phase velocities, then the pulse's overall velocity will depend on the relationships between the velocities of the separate components. If the velocities differ, the pulse is said to be moving at the group velocity.

By tweaking the relationship between phase velocities, it's possible to adjust the group velocity and create the illusion that parts of the pulse are traveling faster than the speed of light.

One area where such an advance could be enormously beneficial is in the telecommunications industry.

Although information can be channeled through fiber optics at the speed of light, it can't be processed at this speed because with current technologies, light signals must be transformed into much slower electrical signals before they are useful.

Thevenaz's technique would essentially allow light to be processed with light without a costly electrical conversion.

The group's research will be published in an August 22nd issue of the journal Applied Physics Letters.

The phrase I put in bold type, and the word in italics say all that needs to be said.

FTL is an illusion, at best.


_________________
*TRE45ON!!*
Lock Him Up!


Haliphron
Veteran
Veteran

User avatar

Joined: 28 Jan 2008
Age: 39
Gender: Male
Posts: 1,980

28 Jul 2008, 11:01 am

Fnord wrote:
Quote:
Researchers in Switzerland have succeeded in breaking the cosmic speed limit by getting light to go faster than, well, light.

Or is it all an illusion?

Scientists have recently succeeded in doing all sorts of fancy things with light, including slowing it down and even stopping it all together. Now a team at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland is controlling the speed of light using simple off-the-shelf optical fibers, without the aid of special media such as cold gases or crystalline solids like in other experiments.

"This has the enormous advantage of being a simple, inexpensive procedure that works at any wavelength," said Luc Thevenaz, lead author of the study detailing the research.

Using a technique called Stimulated Brillouin Scattering, the researchers were able to slow down or ratchet up the speed of light like the gas pedal on a car. They succeeded in reducing the speed of light by almost a factor of 4 (although that's still plenty fast at 46,500 miles per second), but even more dramatically, the team was also able to speed up the speed of light.

Light in a vacuum travels at approximately 186,000 miles per second, but a popular misconception is that, according to Einstein's special theory of relativity, nothing in the universe can travel faster than this speed.

This seeming paradox can be resolved because a pulse of light is actually made up of many separate frequency components, each of which moves at their own velocities. This is known as the pulse's phase velocity. If all the frequency components have the same phase velocity, then the overall pulse will also appear to move at that velocity.

However, if the components have different phase velocities, then the pulse's overall velocity will depend on the relationships between the velocities of the separate components. If the velocities differ, the pulse is said to be moving at the group velocity.

By tweaking the relationship between phase velocities, it's possible to adjust the group velocity and create the illusion that parts of the pulse are traveling faster than the speed of light.

One area where such an advance could be enormously beneficial is in the telecommunications industry.

Although information can be channeled through fiber optics at the speed of light, it can't be processed at this speed because with current technologies, light signals must be transformed into much slower electrical signals before they are useful.

Thevenaz's technique would essentially allow light to be processed with light without a costly electrical conversion.

The group's research will be published in an August 22nd issue of the journal Applied Physics Letters.

The phrase I put in bold type, and the word in italics say all that needs to be said.

FTL is an illusion, at best.



In that case, why dont we Ramp up the speed of light! :D
But like I said in the last few posts. The way to get around the light barrier on the classical leve is Not to use quantum entanglement but to exploit General Relativity.



Chaotica
Veteran
Veteran

User avatar

Joined: 28 Jun 2008
Age: 38
Gender: Female
Posts: 714
Location: Hyperborea, buried under the ice and snow

28 Jul 2008, 11:57 am

I assume that somewhere in the Universe aliens exist, but what we or our friends see, or mass-media tell us about the UFO is really not worth attention. It might be an optical illusion like Aurora Borealis :tongue:



Haliphron
Veteran
Veteran

User avatar

Joined: 28 Jan 2008
Age: 39
Gender: Male
Posts: 1,980

28 Jul 2008, 12:47 pm

Chaotica wrote:
I assume that somewhere in the Universe aliens exist, but what we or our friends see, or mass-media tell us about the UFO is really not worth attention. It might be an optical illusion like Aurora Borealis :tongue:


The skepticism surrounding UFOs and aliens by rationalists strikes me as very odd. There really are NO obstacles in physical law precluding extraterrestrial life AND extraterrestrial intelligence.



greenblue
Veteran
Veteran

User avatar

Joined: 25 Mar 2007
Age: 44
Gender: Male
Posts: 7,896
Location: Home

28 Jul 2008, 12:55 pm

Fnord wrote:
Quote:
Researchers in Switzerland have succeeded in breaking the cosmic speed limit by getting light to go faster than, well, light.

Or is it all an illusion?

Scientists have recently succeeded in doing all sorts of fancy things with light, including slowing it down and even stopping it all together. Now a team at the Ecole Polytechnique Federale de Lausanne (EPFL) in Switzerland is controlling the speed of light using simple off-the-shelf optical fibers, without the aid of special media such as cold gases or crystalline solids like in other experiments.

"This has the enormous advantage of being a simple, inexpensive procedure that works at any wavelength," said Luc Thevenaz, lead author of the study detailing the research.

Using a technique called Stimulated Brillouin Scattering, the researchers were able to slow down or ratchet up the speed of light like the gas pedal on a car. They succeeded in reducing the speed of light by almost a factor of 4 (although that's still plenty fast at 46,500 miles per second), but even more dramatically, the team was also able to speed up the speed of light.

Light in a vacuum travels at approximately 186,000 miles per second, but a popular misconception is that, according to Einstein's special theory of relativity, nothing in the universe can travel faster than this speed.

This seeming paradox can be resolved because a pulse of light is actually made up of many separate frequency components, each of which moves at their own velocities. This is known as the pulse's phase velocity. If all the frequency components have the same phase velocity, then the overall pulse will also appear to move at that velocity.

However, if the components have different phase velocities, then the pulse's overall velocity will depend on the relationships between the velocities of the separate components. If the velocities differ, the pulse is said to be moving at the group velocity.

By tweaking the relationship between phase velocities, it's possible to adjust the group velocity and create the illusion that parts of the pulse are traveling faster than the speed of light.

One area where such an advance could be enormously beneficial is in the telecommunications industry.

Although information can be channeled through fiber optics at the speed of light, it can't be processed at this speed because with current technologies, light signals must be transformed into much slower electrical signals before they are useful.

Thevenaz's technique would essentially allow light to be processed with light without a costly electrical conversion.

The group's research will be published in an August 22nd issue of the journal Applied Physics Letters.

The phrase I put in bold type, and the word in italics say all that needs to be said.

FTL is an illusion, at best.

Yes, something that I find paradoxical about this issue is that, if FTL was possible then I don't see the point of space and time bending when getting close to the speed of light, according to the special relativity theory, which that aspect itself suggests the speed of light being the limit.


_________________
?Everything is perfect in the universe - even your desire to improve it.?


Haliphron
Veteran
Veteran

User avatar

Joined: 28 Jan 2008
Age: 39
Gender: Male
Posts: 1,980

28 Jul 2008, 1:07 pm

Good point greenblue. But the structure of spacetime on the Quantum level is VERY different than on the astronomical level. twoshots gave the 2 assumptions of SR that prohibit FTL, but the discovery of Quantum Entanglement casts some SERIOUS doubt on quantum-scale causality.



greenblue
Veteran
Veteran

User avatar

Joined: 25 Mar 2007
Age: 44
Gender: Male
Posts: 7,896
Location: Home

28 Jul 2008, 1:12 pm

Haliphron wrote:
Tis true. The first assumption has been tested experimentally and appears to be accurate. The second assumption though, is increasingly being questioned by modern physics. Especially on the quantum level. But if you are familiar with General Relativity, such a theory does provide a means of travelling to distant parts of the Cosmos in a MUCH shorter amount of time than it would take to travel to them directly which is effectively superluminal but does not violate causality. The way this would be done would be *Warping* spacetime and shortening the physical distance between them. The whole concept of Wormholes is derived from general relativity.

This is an area I find interesting, but I don't have proper knowledge about it, wormholes could be used not only to inmediate travel to space but also to become time machines, although not so much likely I think. As it is an interesting theory, and it seems there are mathematical models for it, not sure if this has been actually tested in labs at quantum level? Some claim to be this true, I have heard some UFO fans to claim and seem to be sure about it, that this is the way aliens travel through space to visit earth.


_________________
?Everything is perfect in the universe - even your desire to improve it.?


Fnord
Veteran
Veteran

User avatar

Joined: 6 May 2008
Age: 63
Gender: Male
Posts: 46,528
Location: Stendec

28 Jul 2008, 2:25 pm

greenblue wrote:
... wormholes could be used not only to inmediate travel to space but also to become time machines, although not so much likely I think. As it is an interesting theory, and it seems there are mathematical models for it, not sure if this has been actually tested in labs at quantum level? Some claim to be this true, I have heard some UFO fans to claim and seem to be sure about it, that this is the way aliens travel through space to visit earth.

No wormhole has ever been created in a laboratory. Wormholes are mathmatical constructs used to explain (or 'fudge') certain other quantum-level theories and observations.

UFO Fans? About as reliable in explaining the origins of UFOs as anime otaku are at explaining classical literature.


_________________
*TRE45ON!!*
Lock Him Up!


greenblue
Veteran
Veteran

User avatar

Joined: 25 Mar 2007
Age: 44
Gender: Male
Posts: 7,896
Location: Home

28 Jul 2008, 2:39 pm

Fnord wrote:
greenblue wrote:
... wormholes could be used not only to inmediate travel to space but also to become time machines, although not so much likely I think. As it is an interesting theory, and it seems there are mathematical models for it, not sure if this has been actually tested in labs at quantum level? Some claim to be this true, I have heard some UFO fans to claim and seem to be sure about it, that this is the way aliens travel through space to visit earth.

No wormhole has ever been created in a laboratory. Wormholes are mathmatical constructs used to explain (or 'fudge') certain other quantum-level theories and observations.

UFO Fans? About as reliable in explaining the origins of UFOs as anime otaku are at explaining classical literature.

lol, of course, there are some that claim themselves to be investigators in the subject, which they claim to do research, and come up with the theory of how aliens travel through space. Anyway, some "research" or "proof" they might claim, have been proven false. The face on mars is one of them and some UFO videos have been proven false by ILM. (video montage).


_________________
?Everything is perfect in the universe - even your desire to improve it.?


Judith
Blue Jay
Blue Jay

User avatar

Joined: 25 Jul 2008
Age: 55
Gender: Female
Posts: 85
Location: NOVA

28 Jul 2008, 3:40 pm

Statistically speaking, the odds are that there are many planets "out there" with life on them. Some likely more advance than ours, some likely less. The chances of us recognizing any of them as life are fairly small. What makes anyone so certain that they would recognize US as life? Or that we would be so fascinating that they would really bother travelling such massive distances to observe or abduct us? Frankly, if someone could just answer for me why we bother watering the lawn to make the grass grow when we're just going to complain about mowing it, then the human race just might make sense. Maybe?

Judith



Fnord
Veteran
Veteran

User avatar

Joined: 6 May 2008
Age: 63
Gender: Male
Posts: 46,528
Location: Stendec

28 Jul 2008, 3:58 pm

Judith wrote:
Statistically speaking, the odds are that there are many planets "out there" with life on them. Some likely more advance than ours, some likely less. The chances of us recognizing any of them as life are fairly small. What makes anyone so certain that they would recognize US as life? Or that we would be so fascinating that they would really bother travelling such massive distances to observe or abduct us? Frankly, if someone could just answer for me why we bother watering the lawn to make the grass grow when we're just going to complain about mowing it, then the human race just might make sense. Maybe? Judith

Life is characterised by having all of the following:

(1) Cellular Structure

All living things are composed of one or more cells. Different types of cells have different "jobs" within the organism. Each life form begins from one cell, which then will split. These cells split, and so on. After this has happened several times, differentiation is undergone, when the cells change so that they are not the same thing anymore. Then they are used to begin to put together the final organism, some cells, for example, as the eyes, some as the heart, etc. The only arguable exception to this is viruses. They are not composed of cells, but are said to be "living."

(2) Organization and Differentiation

Complex organization patterns are found in all living organisms. They arrange themselves on very small levels, grouping like things together. On larger levels, they become visible. This also has to do with differentiation, as the cells are organized in a manner that makes sense for the organism after they change to what they’ll be in the final organism.

(3) Use of Energy

All organisms use energy. The sum of the chemical energy they use is called metabolism. This energy is used to carry out everything they do. Autotrophs (plants) use energy from the sun for photosynthesis, to make their own ‘food’ (glucose). Heterotrophs (animals and humans) must ingest food for this purpose.

(4) Homeostasis

All organisms have stable internal conditions which must be maintained in order to remain alive. These include temperature, water content, heartbeat, and other such things. In a way, this has to do with energy use, because a certain level of energy must be kept within the body at all times. For this, obviously, humans must then ingest food on a regular basis. Not all conditions are for the body to maintain itself; though most are.

(5) Growth

All organisms grow and change. Cells divide to form new, identical cells. Differentiation happens, as well, when cells mutate into other types of cells, making a more complex organism. Organisms growing, changing, and becoming more complex is called development. Single-celled organisms do grow as well, but they will only become slightly larger – this is nearly unmeasurable.

(6) Reproduction

All organisms reproduce in order to continue the species' life. This is combining genetic information (in sexual reproduction) or splitting into two organisms (in asexual reproduction) in order to create another of the same species. In sexual reproduction, the new organism will have some characteristics from the mother, and some from father. It may look like either of them, or it may not. In asexual reproduction, the new organism is an exact copy of the first. Sometimes, not every member of a species is able to reproduce. As long as others are (which we know they can, if they still exist today) then it does not threaten the species. (Except for mules, but don't worry about them, they are a bizarre anomoly.)

Note that all of these conditions must be present (with a few rare exceptions) to be classified as life.

BYW: I stopped watering my lawn more than once a month about a year ago, after putting in drought-resistant plants instead of grass. Mowing now takes about a half-hour once every three months, and nobody complains.


_________________
*TRE45ON!!*
Lock Him Up!