The Alcubierre faster than light warp drive

a reply to: AlienBorg

The 'exotic matter' capable of generating a distortion of spacetime like the one discussed above, is only found in one place. Where the sun don't shine!!!

originally posted by: rounda

originally posted by: Arbitrageur

originally posted by: rounda
"Which it isn't" means the speed of light is not a constant. Because it's not.

What makes you think the speed of light in a vacuum is not constant?

Scientists proving it isn't.

Can you explain this a little?
Who has proven what?

The speed of light is constant within a given medium.

There are research papers discussing variable light speeds or in few words the speed of light could be a function of time. Interesting papers but we don't know and can't find out. But our knowledge, experiments, and tests, have shown so far the speed of light is a constant of nature.

originally posted by: AlienBorg
Can you explain this a little?

There are research papers discussing variable light speeds or in few words the speed of light could be a function of time. Interesting papers but we don't know and can't find out. But our knowledge, experiments, and tests, have shown so far the speed of light is a constant of nature.

Speed of light in a vacuum is constant, but you can find numerous papers about scientists manipulating the light to create group velocities or phase velocities traveling at speeds other than the speed of light, either faster or slower. But group velocities and phase velocities traveling at different speeds does not mean the speed of light is not a constant, as was discussed on the previous page.

Rounda posted a link to an article about one of those group velocity results except the science writer didn't even mention group velocity so he may not have known it was talking about group velocity. You had to read the actual paper by the scientists (that rounda didn't link) to see they were talking about group velocity of a manipulated wave form, traveling at some other speed.

www.abovetopsecret.com...

originally posted by: Arbitrageur

originally posted by: AlienBorg
Can you explain this a little?

There are research papers discussing variable light speeds or in few words the speed of light could be a function of time. Interesting papers but we don't know and can't find out. But our knowledge, experiments, and tests, have shown so far the speed of light is a constant of nature.

Speed of light in a vacuum is constant, but you can find numerous papers about scientists manipulating the light to create group velocities or phase velocities traveling at speeds other than the speed of light, either faster or slower. But group velocities and phase velocities traveling at different speeds does not mean the speed of light is not a constant, as was discussed on the previous page.

Rounda posted a link to an article about one of those group velocity results except the science writer didn't even mention group velocity so he may not have known it was talking about group velocity. You had to read the actual paper by the scientists (that rounda didn't link) to see they were talking about group velocity of a manipulated wave form, traveling at some other speed.

www.abovetopsecret.com...

I wasn't talking about this. I know what it was posted.

I was talking about the hypothesis of variable light speed which regards the speed of light as being a function of time c=c(t)

VLS is the actual name given.

a reply to: AlienBorg

So called tired light... but once again if this was the case we could measure, and constantly at that. People have postulated that this is what causes redshift at long distances.

One mechanism can be via scattering, but this is disproven due to the lack of cosmological blurring. The effect should also be equal at all wavelengths as a function of distance, which it doesn't appear to be. The background brightness of the universe also is difficult to fit out using a tired light hypothesis compared to what we see today. Basically the CMB should be way more energetic

originally posted by: AlienBorg

originally posted by: Arbitrageur

originally posted by: AlienBorg
Can you explain this a little?

There are research papers discussing variable light speeds or in few words the speed of light could be a function of time. Interesting papers but we don't know and can't find out. But our knowledge, experiments, and tests, have shown so far the speed of light is a constant of nature.

Speed of light in a vacuum is constant, but you can find numerous papers about scientists manipulating the light to create group velocities or phase velocities traveling at speeds other than the speed of light, either faster or slower. But group velocities and phase velocities traveling at different speeds does not mean the speed of light is not a constant, as was discussed on the previous page.

Rounda posted a link to an article about one of those group velocity results except the science writer didn't even mention group velocity so he may not have known it was talking about group velocity. You had to read the actual paper by the scientists (that rounda didn't link) to see they were talking about group velocity of a manipulated wave form, traveling at some other speed.

www.abovetopsecret.com...

I wasn't talking about this. I know what it was posted.

I was talking about the hypothesis of variable light speed which regards the speed of light as being a function of time c=c(t)

VLS is the actual name given.

You mean the hypothesis that the speed of light is constant.

www.livescience.com...

Two papers, published in the European Physics Journal D in March, attempt to derive the speed of light from the quantum properties of space itself. Both propose somewhat different mechanisms, but the idea is that the speed of light might change as one alters assumptions about how elementary particles interact with radiation. Both treat space as something that isn't empty, but a great big soup of virtual particles that wink in and out of existence in tiny fractions of a second.

And everyone likes to talk about how time moves slower at lower elevations, right? "Gravitational Time Dilation," right?

Well, it turns out, this not only happens with normal atomic clocks, but also with OPTICAL CLOCKS.

Which means:

Light moves slower than it's constant rate of speed.

Something Einstein had to figure out. General relativity.

Volume 7: The Berlin Years: Writings, 1918-1921 (English translation supplement) Page 140
einsteinpapers.press.princeton.edu...

Second, this consequence shows that the law of the constancy of the speed of light no longer holds, according to the general theory of relativity, in spaces that have gravitational fields. As a simple geometric consideration shows, the curvature of light rays occurs only in spaces where the speed of light is spatially variable. From this it follows that the entire conceptual system of the theory of special rela- tivity can claim rigorous validity only for those space-time domains where gravita- tional fields (under appropriately chosen coordinate systems) are absent.

originally posted by: rounda
And everyone likes to talk about how time moves slower at lower elevations, right? "Gravitational Time Dilation," right?

Well, it turns out, this not only happens with normal atomic clocks, but also with OPTICAL CLOCKS.

Which means:

Light moves slower than it's constant rate of speed.

No it doesn't mean that. Light is still traveling at c various elevations. It's time that slows down (called time dilation) at lower elevations. The frequency of the light also changes at various elevations as in the Pound-Rebka experiment, and this is how light can still travel at c when clock speed varies in a gravitaitonal field.

Is the Speed of Light Changed by Gravity?

the speed of light that you measure locally is unchanged by gravity.

Something Einstein had to figure out. General relativity.

Volume 7: The Berlin Years: Writings, 1918-1921 (English translation supplement) Page 140
einsteinpapers.press.princeton.edu...

Second, this consequence shows that the law of the constancy of the speed of light no longer holds, according to the general theory of relativity, in spaces that have gravitational fields. As a simple geometric consideration shows, the curvature of light rays occurs only in spaces where the speed of light is spatially variable. From this it follows that the entire conceptual system of the theory of special rela- tivity can claim rigorous validity only for those space-time domains where gravita- tional fields (under appropriately chosen coordinate systems) are absent.

What that's basically saying is, special relativity is not a complete theory because it doesn't account for what happens in a gravitational field. Once you apply general relativity which does account for gravitational fields, light still travels at c, the speed of light in a vacuum, including for optical clocks at various elevations. So of course if you apply the wrong theory such as special relativity to a case where it's not intended to be used (in a gravitational field), you'll possibly get the wrong answer, but you can't do that and then claim the speed of light is not a constant as you seem to be trying to do, though you're sort of all over the place, it's hard to pin down your thought process here.

originally posted by: combatmaster
a reply to: AlienBorg

The 'exotic matter' capable of generating a distortion of spacetime like the one discussed above, is only found in one place. Where the sun don't shine!!!

And where about is this?

originally posted by: Arbitrageur

originally posted by: rounda
And everyone likes to talk about how time moves slower at lower elevations, right? "Gravitational Time Dilation," right?

Well, it turns out, this not only happens with normal atomic clocks, but also with OPTICAL CLOCKS.

Which means:

Light moves slower than it's constant rate of speed.

No it doesn't mean that. Light is still traveling at c various elevations. It's time that slows down (called time dilation) at lower elevations. The frequency of the light also changes at various elevations as in the Pound-Rebka experiment, and this is how light can still travel at c when clock speed varies in a gravitaitonal field.

Is the Speed of Light Changed by Gravity?

the speed of light that you measure locally is unchanged by gravity.

Something Einstein had to figure out. General relativity.

Volume 7: The Berlin Years: Writings, 1918-1921 (English translation supplement) Page 140
einsteinpapers.press.princeton.edu...

Second, this consequence shows that the law of the constancy of the speed of light no longer holds, according to the general theory of relativity, in spaces that have gravitational fields. As a simple geometric consideration shows, the curvature of light rays occurs only in spaces where the speed of light is spatially variable. From this it follows that the entire conceptual system of the theory of special rela- tivity can claim rigorous validity only for those space-time domains where gravita- tional fields (under appropriately chosen coordinate systems) are absent.

What that's basically saying is, special relativity is not a complete theory because it doesn't account for what happens in a gravitational field. Once you apply general relativity which does account for gravitational fields, light still travels at c, the speed of light in a vacuum, including for optical clocks at various elevations. So of course if you apply the wrong theory such as special relativity to a case where it's not intended to be used (in a gravitational field), you'll possibly get the wrong answer, but you can't do that and then claim the speed of light is not a constant as you seem to be trying to do, though you're sort of all over the place, it's hard to pin down your thought process here.

I don't think you know how a clock works.

a reply to: rounda

Im pretty sure you dont know how an atomic clock works

originally posted by: rounda
I don't think you know how a clock works.

Not enough to build one myself, but I understand the general principles of atomic clocks from reading articles like this.

What you said: "this ("Gravitational Time Dilation") not only happens with normal atomic clocks, but also with OPTICAL CLOCKS. Which means: Light moves slower than it's constant rate of speed."

That "Gravitational Time Dilation" is just more confirmation of general relativity, which scientists will tell you has also been confirmed by numerous other experiments. General relativity says the local observer inside the gravity well, measuring the local speed of light inside the gravity well with time dilation, will measure the same speed of light as another observer outside the gravity well, measuring their local speed of light outside the gravity well.

I'm not exactly sure where your misunderstanding lies, but I don't think you have any better understanding of clocks than I do. Perhaps you don't understand general relativity as well, but there's no shame in that since it's a difficult topic to understand. If you think general relativity is wrong, you're going to have a tough time convincing people of that, given how many experimental confirmations of GR have been performed.

originally posted by: Observer19
No. No! Don't pose that old chestnut about "you need to know science" to understand....

Actually, you do. You need to have the basics to understand the energies and masses involved.

And I'll repeat something I assumed would be clear: The various UFOs we see for over seven decades now are clear evidence that null-mass motions are available to many other civilizations.

How do you know that's what they use? 'null-mass motions'? You don't. No one does. And again, the 'clear evidence' statement goes to show what happens when ill-informed people make nonsensical, blanket statements about technology and science they don't understand.

a reply to: AlienBorg

I know a man who doesnt leave his home much. He spends most of his days meditating deeply in sacred texts. Hardly even bothers with eye contact with anyone. I have met him. This man can astral travel with seemingly minimal effort. There was no question that this is what was happening as he knew things he couldnt have known otherwise.

My thought was, if all humans knew how to apply this inherent but hidden potential ability, would we really invest our time and energy into material warp drives and such?

originally posted by: Arbitrageur

originally posted by: rounda
I don't think you know how a clock works.

Not enough to build one myself, but I understand the general principles of atomic clocks from reading articles like this.

What you said: "this ("Gravitational Time Dilation") not only happens with normal atomic clocks, but also with OPTICAL CLOCKS. Which means: Light moves slower than it's constant rate of speed."

That "Gravitational Time Dilation" is just more confirmation of general relativity, which scientists will tell you has also been confirmed by numerous other experiments. General relativity says the local observer inside the gravity well, measuring the local speed of light inside the gravity well with time dilation, will measure the same speed of light as another observer outside the gravity well, measuring their local speed of light outside the gravity well.

I'm not exactly sure where your misunderstanding lies, but I don't think you have any better understanding of clocks than I do. Perhaps you don't understand general relativity as well, but there's no shame in that since it's a difficult topic to understand. If you think general relativity is wrong, you're going to have a tough time convincing people of that, given how many experimental confirmations of GR have been performed.

Is it *time* that slows, or is it the pieces that measure the time that move slower?

What do you think you're measuring time against?

originally posted by: rounda
Is it *time* that slows, or is it the pieces that measure the time that move slower?
What do you think you're measuring time against?

In the case of the current standard atomic clock, the frequency standard is the cesium-133 atom, so that's what we measure time against. The formal definition of a second is:

"The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency, Δν(Cs), the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9,192,631,770 when expressed in the unit Hz, which is equal to s^−1."

The new standard under development will probably come out some time in the next decade and works very similarly, but it will be more accurate and stable. The main difference is that instead of using microwaves to excite the atoms, we will use a higher frequency form of electromagnetic radiation to excite a different atom that reached peak excitation at those higher frequencies. I think there are about 4 or 5 different atoms being experimented with to see which provide the best accuracy and stability. They are the so-called "optical atomic clocks" because the higher frequency EM radiation is laser in the frequency range of light.

So the new standard will read very similar to that but it will specify some atom other than a cesium atom (Al + ions in the example below), using some laser frequency instead of microwave frequency. And using those more accurate clocks, such as optical atomic clocks based on individual trapped Al + ions, we have put them at a height difference of a meter (or even less) and found the transition frequency at those two heights. . When we do that, we can see the clock that is one meter lower, runs more slowly, so in that case, we compare one clock to the other.

If you wanted to claim the lower clock was running more slowly for some reason other than time slowing as in gravitational time dilation, I'm not sure how you would prove that, but you would need a different defintion of a second and you would need to define time differently than we define it now. Theoretical physicists might have some ideas on how to do that, but if so, I would suspect their hypotheses are as yet unproven. The consensus view is that the reason the lower clock runs more slowly is that time passes more slowly at the lower elevation per relativity. Prove otherwise and you might get a Nobel prize.

a reply to: Arbitrageur

So if I gave you a mechanical clock, and it started to slow down, you would say it was "gravitational time dilation."

Not that the clock needed to be wound?

If gravity affects everything, why wouldn't it affect the moving parts in a clock? And yes, atoms are moving parts. So is light....

So again, I ask you:

Is it *time* that is slowing down, or is the time keeping mechanism that is slowing down?

What do you think you're measuring time against? What frame of reference are you measuring from? What body is that *time* relative to?

originally posted by: rounda
a reply to: Arbitrageur

So if I gave you a mechanical clock, and it started to slow down, you would say it was "gravitational time dilation."

Not that the clock needed to be wound?

If gravity affects everything, why wouldn't it affect the moving parts in a clock? And yes, atoms are moving parts. So is light....

So again, I ask you:

Is it *time* that is slowing down, or is the time keeping mechanism that is slowing down?

What do you think you're measuring time against? What frame of reference are you measuring from? What body is that *time* relative to?

You are SO close and yet not quite connecting the dots.

Firstly your mechanical clock example... is a poor one, but i think you have chosen that example because you *THINK* it gives you a gotcha! however science doesn't use mechanical clocks to measure... anything. We use crystal clocks, or other high frequency oscillators at the very LEAST. The atomic clock here is the important one as multiple atomic clocks positioned next to each other, will give you the same definition of 1 to an absolutely unbelievable accuracy.

A strontium clock will remain accurate to within 0.07ns over a YEAR of operation. So this idea of "Oh what if the clock needs winding up" is absolutely irrelevant for the accuracy required. The experiment I work for uses a 10MHz and a 50MHz clock in order to synchronize all the clocks that exist in our experiment, but, to make sure we are not loosing time, we sync it to GPS time to ensure that if we do one day have to look at supernova data... we will know within a nanosecond or two, the arrival time at the experiment... anyway... on with your questions.

So the thing about relativity is that, if I was holding my mechanical clock in your (very silly example but lets roll with it) I would not witness it experiencing gravitational time dilation because i am in the same relative frame as it. If i put the clock on a tall building and looked at it, and compared it to a video i took of the same clock when it was on my desk... On earth I would not notice the difference in ticks, BUT by the theory of relativity, the clock on the tall building, as a macroscopic, large scale instrument, Would first tick more slowly if it was a pendulum clock, but lets assume its a spring loaded one for simplicity, the 'wind up clock' then yes i would observe that clock ticking faster than in the video. Would i actually though? No because the difference cannot be measured using such crude inaccurate devices. BUT we can, and HAVE proven this using atomic clocks which is the point.

The mechanism used for an atomic clock is the vibrations of the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom, for a caesium clock.

The example works for both elevation, and relative velocity. not only proving gravitational influence but velocity too, even at slow, non relativistic speeds.

originally posted by: rounda
a reply to: Arbitrageur
So if I gave you a mechanical clock, and it started to slow down, you would say it was "gravitational time dilation."

Not that the clock needed to be wound?

I can't see any situation on Earth where we could measure gravitational time dilation with a mechanical clock, but a lot of factors can affect mechanical clocks. This was already known by 19th century scientists, see below. It's better to stick with the current definition we use of the cesium-133 atom to avoid the other variables.

If gravity affects everything, why wouldn't it affect the moving parts in a clock? And yes, atoms are moving parts. So is light....

So again, I ask you:

Is it *time* that is slowing down, or is the time keeping mechanism that is slowing down?

In the case of the cesium atomic clock we use to define the unit of a second, I would say they are indistinguishable because a second is literally defined by the cesium frequency using the current international standard definition of a second. If you want to use a different definition of a second, you would have to tell me what it is. Then we can figure out if there's a way to test for a difference between the timekeeping mechanism slowing down, and time slowing down. But lacking that, under the current defintion using the cesium-133 atom, it's not possible for there to be a difference. It's literally the same by definition.

What do you think you're measuring time against? What frame of reference are you measuring from? What body is that *time* relative to?

The cesium-133 atom wasn't always the basis for the definition of a second. We have used various references in the past, so timekeeping standards have an interesting history. Back in the 19th century, some scientists already knew that mechanical clocks had limitations, but they thought atomic clocks didn't have those same limitations and would be preferred.

Second: The Past

Atoms, they explained, were identical to one another and would never change, so they would always “tick” with the same frequency and wouldn’t be susceptible to the same sorts of disturbances as mechanical clocks.

Unfortunately they didn't have the technology back then to be able to build or use atomic clocks. Fortunately, we do have that technology today.

a reply to: ErosA433

No, I'm connecting the dots just fine.

You don't seem to understand how a clock works either....

I used the example of a mechanical clock because:

No matter what kind of clock you use, there is ALWAYS a mechanical element to it. The example of a wind-up mechanical clock is the simplest example you can give. One that basically everyone on the planet can understand, because everyone is familiar with it.

Atoms get heated up with microwaves and fed through magnetic fields in order to make them oscillate so they can be measured. The mechanical piece is applying a force to the atoms to produce movement.

You can throw out all the numbers you want about "accuracy." What happens when that "accuracy" stops? Why do atomic clocks fail?

Weird how a drifting magnetic field affects atomic clocks, huh?

Now if you'd like to address the question:

Is it *time* that is slowing down, or is the time keeping mechanism that is slowing down?

What do you think you're measuring time against? What frame of reference are you measuring from? What body is that *time* relative to?

And here's another one, since you're so fond of "accuracy":

How have you determined a clock to be accurate?

WHAT ARE YOU MEASURING?

a reply to: Arbitrageur

No, it's not better to stick to something most people can't pronounce just because you think it's what we should use.

You can't even define what you're trying to measure. "The current international standard definition of a second."

A second of what? Compared to what? Defined by whom?

WHAT ARE YOU MEASURING?

Again:

Is it *time* that is slowing down, or is the time keeping mechanism that is slowing down?

What do you think you're measuring time against? What frame of reference are you measuring from? What body is that *time* relative to?


IF TIME IS RELATIVE, YOUR CLOCK CANNOT MEASURE IT.

The classic scientific conundrum.

You can't measure something until you create a device to measure it.

Doesn't mean the device is correctly measuring whatever it is you want measured; it just means you created a device to attempt to measure something.