This is really cool - A real physical theory for non-superluminal warp drives.

[Freesia.Cutepearl]

Even if we never figure out how to make them superluminal, the fact you only needed negative energy to do so, and travel below light speed is within the realm of possibility opens up huge potential avenues for space travel.

 

[Assurbanipal_II]

A perpetuum mobile is also possible on paper, but that does that mean it can be realised? Not really.

Chances are high we will never achieve superluminal travel, but such is not necessary to colonise the galaxy. Relativistic speeds are sufficient.

 

[Freesia.Cutepearl]

A perpetuum mobile is also possible on paper, but that does that mean it can be realised? Not really.

Chances are high we will never achieve superluminal travel, but such is not necessary to colonise the galaxy. Relativistic speeds are sufficient.

That's what this video is about, or at least, my understanding.

We might be able to make real warp drives that can do relativistic speeds, at least, it's possible without exotic energy or matter.

 

[UYScuti]

Even if we never figure out how to make them superluminal, the fact you only needed negative energy to do so, and travel below light speed is within the realm of possibility opens up huge potential avenues for space travel.

I originally wrote a space opera on here that introduced negative mass(which for the most part is theoretical so far) to stabilize wormholes, but it didn’t gain traction. It was mostly hard science that took a ton of work to write, but after nearly three months I only had 7 followers, so I discontinued it. However, I did not use negative mass as a power source for ships. The amount of energy required is incredible and not something truly feasible on a small ship.

Constant acceleration with Aneutronic fusion drives is something I can see happening. Perhaps not as sexy as warp bubbles, but generational ships to neighboring star systems might be a realistic possibility.

 

[Freesia.Cutepearl]

Constant acceleration with Aneutronic fusion drives is something I can see happening. Perhaps not as sexy as warp bubbles, but generational ships to neighboring star systems might be something possible.

Do you by chance watch Issac Arthur on Youtube?

 

[UYScuti]

Do you by chance watch Issac Arthur on Youtube?

I don’t. Why?

 

[Assurbanipal_II]

That's what this video is about, or at least, my understanding.

We might be able to make real warp drives that can do relativistic speeds, at least, it's possible without exotic energy or matter.

As far as I understand, the video proposes an Alcubierre warp drive, which doesn't provide FTL. The drive distorts the space-time around the object thus shortens travelling time. So it is not a FTL and doesn't require infinite energy as no object exceed the speed of light.

But the drive requires negative energy, something that was conceptualised, but doesn't exist.

 

[Freesia.Cutepearl]

I don’t. Why?

I think you might like his content.

And so many more!

 

[Freesia.Cutepearl]

But the drive requires negative energy, something that was conceptualised, but doesn't exist.

My understanding was the negative energy/mass requirement only exists if you intend to CROSS the superluminal barrier but is not to be on either side of it.

 

[UYScuti]

My understanding was the negative energy/mass requirement only exists if you intend to CROSS the superluminal barrier but is not to be on either side of it.

Sorry, I didn’t watch the video, but if it’s talking about distorting space and creating a bubble, then from my understanding, negative mass is required no matter how fast that bubble of space “moves” relative to a fixed point.

And as stated, negative mass is theoretical, with (I’m not 100% certain of this) the Casimir Effect being the closest we’ve seen. Expansion in space caused by “dark matter” was proposed as a negative energy source for a while, but that’s all up in the air as well.

Don’t be discouraged, though. Who knows what discoveries lie just beyond our lifetimes

 

[Freesia.Cutepearl]

then from my understanding, negative mass is required no matter how fast that bubble of space “moves” relative to a fixed point.

To quote one short segment around the 7 minute mark(using closed captions to help):

The real question is therefore not, whether a space-time solves einstein's equations but whether the distribution of mass and energy required to make the solution to the equations is physically reasonable.

And for the alcubierre drive the answer is multiple NOs.

First, as I already said it requires negative energy, second, it requires a huge amount of that, third, the energy is not conserved.

Instead, what you actually do when you write down the alcubierre space time is that you just assume you have something that accelerates it beyond the speed of light barrier.

That it's beyond the barrier is why you need negative energies and that it accelerates is why you need to feed energy into the system.

Please check the info below the video for technical comment about just what I mean by energy conservation here.

 

[Freesia.Cutepearl]

To quote one short segment around the 7 minute mark(using closed captions to help):

To add to it, from a later section, around 9 minutes.

Question is then what does the wall of the passenger area have to be made of?

Is this a physically possible distribution of mass and energy?

Bobrick and Martire explain that if you want superluminal motion you need negative energy densities if you want acceleration you need to feed energy and momentum into the system.

And the only reason there could be a drive moves faster than the speed of light is that one simply assumed it does.

Suddenly it all makes sense, I really like this new paper because to me it has really demystified warp drives.

Now you may find this somewhat of a downer because really it says that we still don't know how to accelerate to superluminal speeds.

But, I think this is a big step forward because now we have a much better mathematical basis to study warp drives.

For example, once you know how the warped space-time looks like, the question comes down to how much energy do you need to achieve a certain acceleration?

 

[UYScuti]

To quote one short segment around the 7 minute mark(using closed captions to help):

I haven’t read the paper she’s quoting, it hasn’t passed peer review yet as she says, so perhaps they put forward a reasonable theory. However, she doesn’t provide an energy source outside of negative mass that is capable of moving a warp bubble. Nothing can move faster than light through space, except space itself. That’s the concept. You are creating a ripple in space and riding on it. From what I understand, the only way possible to expand space outward from a fixed location is negative mass. For a warp bubble to move, no matter the speed, you need to contract space in front of it and expand space behind it.

 

[Freesia.Cutepearl]

We know normal matter and energy distort space. So, my hope, is, based on the wording, and my limited understanding, that it's possible to bend space in ways to allow relativistic travel. She mentions momentum, but I am not sure how that plays into it but perhaps that's where movement can come from?

I just find it exciting and wait with bated breath to see what happens after peer review!

 

[UYScuti]

We know normal matter and energy distort space. So, my hope, is, based on the wording, and my limited understanding, that it's possible to bend space in ways to allow relativistic travel. She mentions momentum, but I am not sure how that plays into it but perhaps that's where movement can come from?

I just find it exciting and wait with bated breath to see what happens after peer review!

Yes, normal matter can warp space. It can contract it. The most extreme cases being black holes. One of the theories (which may have been shown to be obsolete recently) was that “dark matter” was the reason for the universes expansion at rates faster than light. This was proposed as negative mass for a while. I know there’s been some work trying to discredit the idea of “dark matter” and showing it’s not necessary to explain the expansion, but I haven’t followed it in a while.

These are all theories, though.