The Alcubierre faster than light warp drive

originally posted by: Arbitrageur

originally posted by: AlienBorg
According to this paper. But everything so far is highly speculative and you can come up with a modification which can give you more stable warp drive geometries. We can't conclude that warp drives don't work at this point.

Right, we can't predict new discoveries and insights, but what we can say is, they don't work, until they do.

Whether someday someone might make one or not in the future is unknown, but my guess is nobody alive today will ever see one.

Most likely

It’s the “exotic material” that seems to be the cornerstone of turning envisioning things into being able to do them.

The exotic material, I would assume, is not of this planet. The moon? Mars? Outside our solar system? Outside our galaxy? Outside our local group?

Even if an ET craft, with said exotic material onboard, happened to crash, in the most pristine of environments, and a government got to it first, and was able to extract the material without catastrophic results, then, how would we get more? Or “enough” for testing and R&D to actually use it?

That’s a lot of crashed ETs.

a reply to: AlienBorg

Ok, forgive me because I don't remember where I read this, but I think i remember reading that the temperature inside a hypothetical warp bubble would conceivably be a million degrees or so, and to generate the bubble would take all the energy in the observable universe. In other words, they have a lot of bugs to work out of it.

a reply to: AlienBorg

So in order to use this hypothetical method of space travel, we also need some sort of hypothetical energy capable of manipulating space time.

Hypothetical math is hypothetically fun.

originally posted by: rounda
a reply to: AlienBorg

So in order to use this hypothetical method of space travel, we also need some sort of hypothetical energy capable of manipulating space time.

Hypothetical math is hypothetically fun.

a reply to: AlienBorg

It sounds like theoretically it's there, but how can you create what amounts to exotic matter at will? How do you create something that can move in causally violating ways, that seems like a paradox worth exploring.

Like a major chronology problem that would always invalidate using exotic particles. I'm no physicist, but that doesn't seem right.

And I'm usually wrong, so looking up creation of negative energy density now.

In the Casimir effect, two flat plates placed very close together restrict the wavelengths of quanta which can exist between them. This in turn restricts the types and hence number and density of virtual particle pairs which can form in the intervening vacuum and can result in a negative energy density.

I still think there's some major paradox lurking in creation of exotic and antiparticles that move in violation of space/time to manipulate space/time.

originally posted by: rounda
a reply to: AlienBorg

So in order to use this hypothetical method of space travel, we also need some sort of hypothetical energy capable of manipulating space time.

Hypothetical math is hypothetically fun.

It's not hypothetical math...
It's called theoretical physics which relies heavily on maths and mathematical models. And yes we need exotic matter that we don't have at the moment. Even if we did there no guarantee it would work.

If you could travel at the speed of light, you would reach your destination instantly. No time would pass for you. You could go anywhere in the universe faster than the blink of an eye.

originally posted by: 00018GE
If you could travel at the speed of light, you would reach your destination instantly. No time would pass for you. You could go anywhere in the universe faster than the blink of an eye.

If another star is 300 light years away from us then you wouldn't reach your destination instantly. You will die on your way to the star as it will take you 300 years to get there. But we can't travel at the speed of light as we will need infinite amount of energy to accelerate to this speed.


imagine.gsfc.nasa.gov...#:~:text=It%20is%20traveling%20away%20from,take%204.22%20years%20to%20arrive!

a reply to: AlienBorg
It's a bit surprising to hear you say that it will take you 300 years to get there, considering we just had discussions about how relativistic muons experience time dilation in your recent thread about the G-2 muon experiment here:

5th force muon experiment thread-Time Dilation discussion

You're right that we can't travel at light speed, but we accelerate subatomic particles to 99.99999% the speed of light. We probably can't accelerate a human in a space ship to that speed, but if we could...then the trip to a star 300 light years away would take 300 years from the reference frame of the Earth and the destination star, but from the astronaut's reference frame aboard the space ship, the trip would only last 45 days (a similar time dilation effect allows muons to reach earth despite their short lifetime). So conceptually we can imagine that 300 light year trip seeming to last 45 days per the astronaut's clock, according to relativity, but that's not realistic.

A more realistic trip might be from 10% to 50% of light speed, because going over about 50% of light speed causes death from lethal radiation.

At 10% the speed of light, the astronaut's clock would show the journey took 298 years.
At 50% the speed of light, the astronaut's clock would show the journey took 260 years.

How fast could humans travel safely through space?

Although only present at a density of around one atom in a cubic centimetre, the cosmos’s ambient hydrogen would translate into a bombardment of intense radiation. The hydrogen would shatter into subatomic particles that would pass into the ship, irradiating both crew and equipment. At speeds around 95% of light, the exposure would be near-instantly deadly. The star ship would heat up, too, to melting temperatures for essentially any conceivable material, while water in the crew’s bodies would promptly boil. “These are all nasty problems,” quips Edelstein.

He and his father roughly estimated that barring some sort of conjectural magnetic shielding to divert the lethal hydrogen rain, star ships could go no faster than about half of light speed without killing their human occupants.

So if that approximately 50% light speed limit for humans holds, humans will never be able to make the 300 light year trip in a human lifetime, since they will still experience 260 years of time at 50% of light speed. (Acceleration and deceleration omitted for the sake of simplicity)

,

originally posted by: Arbitrageur
a reply to: AlienBorg
It's a bit surprising to hear you say that it will take you 300 years to get there, considering we just had discussions about how relativistic muons experience time dilation in your recent thread about the G-2 muon experiment here:

5th force muon experiment thread-Time Dilation discussion

You're right that we can't travel at light speed, but we accelerate subatomic particles to 99.99999% the speed of light. We probably can't accelerate a human in a space ship to that speed, but if we could...then the trip to a star 300 light years away would take 300 years from the reference frame of the Earth and the destination star, but from the astronaut's reference frame aboard the space ship, the trip would only last 45 days (a similar time dilation effect allows muons to reach earth despite their short lifetime). So conceptually we can imagine that 300 light year trip seeming to last 45 days per the astronaut's clock, according to relativity, but that's not realistic.

A more realistic trip might be from 10% to 50% of light speed, because going over about 50% of light speed causes death from lethal radiation.

At 10% the speed of light, the astronaut's clock would show the journey took 298 years.
At 50% the speed of light, the astronaut's clock would show the journey took 260 years.

How fast could humans travel safely through space?

Although only present at a density of around one atom in a cubic centimetre, the cosmos’s ambient hydrogen would translate into a bombardment of intense radiation. The hydrogen would shatter into subatomic particles that would pass into the ship, irradiating both crew and equipment. At speeds around 95% of light, the exposure would be near-instantly deadly. The star ship would heat up, too, to melting temperatures for essentially any conceivable material, while water in the crew’s bodies would promptly boil. “These are all nasty problems,” quips Edelstein.

He and his father roughly estimated that barring some sort of conjectural magnetic shielding to divert the lethal hydrogen rain, star ships could go no faster than about half of light speed without killing their human occupants.

So if that approximately 50% light speed limit for humans holds, humans will never be able to make the 300 light year trip in a human lifetime, since they will still experience 260 years of time at 50% of light speed. (Acceleration and deceleration omitted for the sake of simplicity)

Yes we can't accelerate humans to the speed of light as we need an infinite amount of energy to achieve such speed. My estimation was made with non-relativistic speeds which will take the astronaut around 300 years (although a little less). For example if you move with 1% of the speed of light, that is 3,000km per second (still an incredibly high speed) the astronaut will record a time of around 299.98 years (close to 300 years as I said in the other post). But still I can't see how we achieve these speeds.

My explanation in the reply above was a bit sloppy. I should have been more careful in adding some numbers and further explanations but I did say we can't travel at the speed of light as we need an infinite amount of energy. That should have been the first point made and then what happens when we reach non relativistic speeds. Still impossible to travel at 1% of the speed of light or even a fraction of it.

If another star is 300 light years away from us then you wouldn't reach your destination instantly. You will die on your way to the star as it will take you 300 years to get there. But we can't travel at the speed of light as we will need infinite amount of energy to accelerate to this speed

At the speed of light, you would experience ZERO time passing. a reply to: AlienBorg

originally posted by: 00018GE
At the speed of light, you would experience ZERO time passing. a reply to: AlienBorg

You can't accelerate to the speed of light or even anywhere near as you need infinite amounts of energy. But in theory in your frame of reference the Lorentz factor is the square root of zero which is zero (for speeds equal to the speed of light).

But...

The mathematics of Special Relativity tells us that as a reference frame moves at ever higher speeds, its space contracts ever smaller and its time becomes ever slower, relative to the stationary observer. In the limit that its speed approaches the speed of light in vacuum, its space shortens completely down to zero width and its time slows down to a dead stop. Some people interpret this mathematical limit to mean that light, which obviously moves at the speed of light, experiences no time because time is frozen. But this interpretation is wrong. This limiting behavior simply tells us that there is no valid reference frame at the speed of light. A reference frame that has exactly zero spatial width and exactly zero time elapsing is simply a reference frame that does not exist. If an entity is zero in every way we try to describe it, how can we possibly say that the entity exists in any meaningful way? We can't. Space and time simply don't exist at and beyond the speed of light in vacuum. Therefore, taking the limit towards c simply reaffirms the two postulates.

wtamu.edu...

originally posted by: AlienBorg

originally posted by: rounda
a reply to: AlienBorg

So in order to use this hypothetical method of space travel, we also need some sort of hypothetical energy capable of manipulating space time.

Hypothetical math is hypothetically fun.

It's not hypothetical math...
It's called theoretical physics which relies heavily on maths and mathematical models. And yes we need exotic matter that we don't have at the moment. Even if we did there no guarantee it would work.

Theory means your idea is based on real world data.

Hypothesis is the precursor to theory... an assumption being made before you have real world data.

Since we can't actually travel faster than light, or anywhere near the speed of light, and do not have the capability to accumulate real world data of light speed travel; and since we don't have the ability to test this magic material that would enable us to break the speed of light...

This is all completely hypothetical.

originally posted by: 00018GE
If you could travel at the speed of light, you would reach your destination instantly. No time would pass for you. You could go anywhere in the universe faster than the blink of an eye.

No, that's not how light, distance, speed, and travel work.

It takes one earth year for light to travel one light year. Or rather, one light year is measured as the time and distance light travels in one earth year.

If you were traveling at the speed of light, it would take one year to travel one light year.

a reply to: rounda

Of course, but you don't experience it as one year.

Basically if we were to construct a ship that went 99.999999% the speed of light and traveled 10 light years you experience only .0014 years, or a little over 12 hours. 100 light years, you experience 5 days. Travel light speed or faster would be experienced instantly no matter how far it was.

Fun time dilation calculator

The only Einstein-Approved method of time travel, excluding Einstein-Rosen bridges.

But to that stationary observer back on earth, they died of old age on hour 68 of your 120 hour hundred light year voyage.

a reply to: Degradation33

The problem with that theory is, we can actually see light, and measure it's speed.

And we can determine how long it takes to travel distances.

If light can't travel instantaneously, what makes you think you can?

a reply to: rounda

If we could build a ship to travel at 99.999999999999% the speed of light, with 12 decimal places, a person could travel the 2.5 million lightyears to Andromeda and only experience .35 TIME DILATED years.

Back on earth 2.5 million years passed. The continents are different. Everyone is dead. But to a person travelling that velocity they are only 17 weeks older than when they left.

At C or faster, no matter the distance, you experience the trip instantaneously regardless of how long that is for the observer.

Theoretically, moving faster than light can only cut down on the stationary observer time. At 5000C, observer time for 100 light years is cut to about 8 days. It's negligible to the person travelling C or faster.

Like the reason every long term space station occupant is slightly younger (microseconds) than their earth counterparts. Even an added 17500 mph dilates a little.

This is actually a thing satellite programmers have to deal with, particularly in GPS.

en.wikipedia.org...

To that, I can't say anything other than take it up with relativity.

One fatal problem with Alcubierre drives is that at the very instant you exceed the speed of light, your warp drive becomes a warp bomb. The reason for this is that event horizons would form at both ends of the warp bubble, with these horizons producing Hawking radiation. This radiation would set off a runaway feedback loop due to the near-infinite blueshifting it experiences where it becomes so energetic it causes its own warping of spacetime, which causes further blueshifting, which then causes additional warping of spacetime, and so on. The resulting maelstrom of radiation destabilizes and collapses the warp bubble, releasing all of the energy in an apocalyptic explosion that at best would sterilize any nearby planets, and at worst vaporize the whole local star system with a supernova-like blast...

a reply to: AlienBorg

It Canna Hold ! We Need More Power Captain !