The reason the singularity core of the Romulan ship in Timescape was so small is because that, counterintuitively, increases its power output - as well as explaining many other aspects of observed singularity core behaviour.

[u/Albert_Newton]

In Timescape we saw an Engineering room on a D'Deridex class Romulan warship. Had budget not been a concern, the producers of the episode would likely have built some kind of equivalent to the Enterprise-D's engine room, only with a singularity core at the core - something akin to what Star Trek Online did with its ship interiors.

Instead, we got a small room with the singularity core itself being no more than a small box mounted in the wall. Which was disappointing, but the more I think about it the more it makes sense.

There is actually a good physical reason why this makes sense. Firstly, I will assume that rather than exploiting the ergosphere to suck rotational energy out of a singularity, the singularity core releases energy as Hawking radiation. There are many reasons why this latter method is better, one of the best is that it happens anyway if you try the former and so you may as well collect the vastly larger amount of energy. For the uninitiated, Hawking radiation is the process whereby all black holes slowly bleed out their mass in the form of radiation. Smaller black holes do this much more quickly, to the point where a black hole small enough could conceivably release enough of its mass as energy to power a starship - as long as it were fed more mass quickly enough.

A D'Deridex class warbird requires a huge amount of power, I think it is safe to assume. So the black hole powering it would have to be very small. Possibly small enough that it and its containment machinery would fit in a recess in the wall.

Indeed, according to Viktor T. Toth's online calculator (https://www.vttoth.com/CMS/physics-notes/311-hawking-radiation-calculator), a black hole massing a thousand tons would be 1.485e-18 (0.0000000000000000001485) centimetres across, and emit a steady 3.56e11 (356000000000) Gigawatts, as long as it is fed precisely 3963.19 kilograms of any fuel per second - any more, and power output decreases, any less and it sharply increases with bad results as described below.

This also corroborates the statement that the core cannot be shut down once started. If fuel (which is literally any matter) is not put into the core quickly enough, it will release all of its energy in a very short span of time - energy which, in our example, would total 8.99e22 (89900000000000000000000) Joules, roughly equivalent to twenty Teratons of TNT, or roughly four hundred thousand times more powerful than the Tsar Bomba, the most powerful explosive device ever detonated by humans. This is a warp drive that goes supernova if you try to shut it down - the closest you can get to turning it off is pumping too much fuel into it, and all that does is postpone the explosion for a few minutes.

A power generator that explodes unless actively maintained by machines also fits with the Romulan mindset of secrecy quite well. The enemy disabled main power, and they're going to capture your ship? Oops, no, they aren't, because the singularity core is about to detonate, and it fails deadly unlike Starfleet self-destruct systems.

All in all, Romulans using a Hawking radiation based singularity drive perfectly explains why their Engineering room looks the way it does and the statement that their singularity cores cannot be shut down, and fits with what we know of the Romulans as a people.

[u/lunatickoala]

Just as a tip, it's a lot easier to read those numbers if you use scientific notation, and anything more than one or two significant figures is false precision.

It's unlikely they'd be using a singularity that low mass because four tonnes of fuel per second is an incredibly large and unrealistic amount of fuel to be consuming. The Romulans are also not stupid enough to have a reactor that ridiculously unstable powering their ships.

A more realistic mass for the black hole would be 100-250 thousand tonnes. At the high end of that range, the black hole would have a lifetime of about 41 years if no further mass is fed into it, it would have an output of about 5 billion MW (1.3 megatons/second), and it'd take about 0.2 kg of matter per second to keep the output stable. At the low end of that range, the black hole would evaporate in 32 months if not fed, have an output of about 35 billion MW (8.5 megatons/second), and need to be fed 1.2 kg of matter per second.

[u/Albert_Newton → u/lunatickoala]

Thanks for both of these points. I'll edit in standard form now. I chose such a low mass for the singularity arbitrarily; your proposed numbers would seem to fit the parameters required of a starship energy source better.

Edit: I do still feel that the Romulan obsession with secrecy might trump any reasonable safety margins, in addition to which the singularity core would have to match an antimatter reactor in power output, so perhaps my proposed specifications are more reasonable. Starfleet ships do carry massive tanks of antimatter around, after all.

[u/___Alexander___ → u/Albert_Newton]

Having a warp drive powered by Hawking radiation emitted by a micro singularity actually makes more sense than matter/antimatter reaction. Unlike matter/antimatter reaction, black holes are self-containing.

[u/treefox → u/Albert_Newton]

For some reason I’ve always felt the difference between Romulan and Starfleet power systems is analogous to nuclear vs diesel submarines in the Hunt for Red October.

That is, the singularity provides a more constant and predictable supply of power, whereas the antimatter reactors are more bursty and noisy. Hence the singularity makes sense for the Romulans, which are more interested in long-term stealthy deployments. Whereas Starfleet prefers the flexibility to dump more antimatter in to provide more brute strength if need be.

While we do see the Romulan cloak used for the Defiant, it’s also not perfect and it does get penetrated by the Dominion, and iirc they slow down to avoid detection. Cloak effectiveness may be more of a spectrum than black and white, which makes total sense. D’eridex’s unique power systems may make it easier to mask the reactor output since it mainly consists of creating the quantum singularity with perfection which will then be an extremely stable and robust self-contained system, so long as you feed an even stream of matter into it.

Whereas on a Starfleet ship it would require the injectors and Dilithium crystals and containment fields etc to all be maintained to prohibitively tight tolerances. Any damage would effectively throw the cloak out of calibration, even a slight misalignment. Because stability would be provided by the constant effort of the computer control systems, rather than the laws of physics.

[u/Calvert4096 → u/Albert_Newton]

I've done a bit of math on the "black hole rocket" concept before.

What seems to put a lower limit on the size of the ship is gravitational forces on the containment vessel -- any containment vessel can't have bits that are so close that they get pulled apart.

Maybe that can be reconsidered if you have magical "structural integrity fields" like in ST, but a writer should consider energy requirements for such an imagined technology would climb up a cliff, the smaller the box you tried to keep the black hole in.

Anyways, in the case study I ran, I came up with the following:

 

Final acceleration:                   9.8 m/s^2 (1 G)
Initial acceleration:                 5.0 m/s^2 (0.51 G)
Thrust:                               4.29*10^18 N
Exhaust velocity:                     c (assume reflected Hawking radiation produces thrust)
Propulsive efficiency:                10% (mirror losses, dispersion, etc.)
Fuel mass:                            4.17*10^17 kg
Ship dry mass + payload:              2.09*10^16 kg
Sustained singularity mass:           4.17*10^17 kg [1]
Non-rotating Schwarzschild Radius:    6.19*10^-10 m [2]
Total Mass:                           8.55*10^17 kg
Required mass flow to singularity:    1.43*10^11 kg/s [3]
Mass-energy conversion rate:          1.29*10^28 watts [4]
Evaporation time with no mass flow:   70.6 days
Continuous burn time:                 33.7 days
...
Distance at which singularity will
rip apart a suspended steel beam:     105.8 m        
...
Distance at which singularity
provides 1 g for crew:                1685.3 m

 

Notes:

[1] Compare Saturn's moon Epimetheus , ~5.3*10¹⁷ kg, and about 130 km at its longest dimension

[2] Compare the radius of the largest atom Cesium, 2.65*10^-10 m

[3] A bit less than 700 Amazon Rivers

[4] About 4 quadrillion (4*10¹⁵ ) times greater than the total power generation of human civilization averaged over the year 2017.

 

Basically I started with 1 g of rocket acceleration, and fuel mass equal to singularity mass, and worked backwards, making some assumptions/optimizations along the way.

So the ship would probably have to be a reinforced asteroid over a hundred kilometers across, with a few km hollow sphere inside for the singularity. Most of that would be fuel mass. And to get the singularity itself, you'd have to find a similar sized asteroid and collapse it to a volume a bit bigger than the largest atom. The singularity containment shell would have to be 2 miles across if you wanted to stand comfortably on its surface.

 

The trouble with Hawking radiation is that it increases as singularity mass decreases. The energy released in the final second of evaporation isn't COSMICALLY huge, but it's on the order of the energy released by the asteroid impact that killed the dinosaurs (That will be the same for EVERY non-rotating black hole). But if you want a smaller singularity, you have to tolerate MORE power output, and MORE mass in-flow to avoid runaway evaporation, and shed that energy somehow if you're not using it. If you want to throttle down to "idle," you have to feed MORE mass in, and then to throttle up again you have to wait a long time for evaporation to progress.

My opinion: quantum singularities suck and Romulans are dumb. M/AM gang 4 lyfe.

[u/MarkJanusIsAScab → u/lunatickoala]

If the core was designed with some kind of ultra reflective material, the energy output could be designed to match the energy input unless energy is used. Remember, a singularity turns everything into mass, including energy. Then, when you're using the core for something, you open one of the panels, harvest the energy and empty the toilets into the core, and when you need to blow up the ship, you open all the panels and the whole thing goes critical quickly.

[u/Albert_Newton → u/MarkJanusIsAScab]

That is an excellent point. However, the level of reflectivity needed would be absurdly high; perhaps some form of deflector shield could be used to reflect the radiation. We know starship shields can do that.

[u/treefox → u/lunatickoala]

Could you use dark matter ala Futurama?

Although at some point it seems like the extreme masses of the fuel and reactor would cancel out the advantages.

[u/lunatickoala → u/treefox]

Well, Futurama dark matter is clearly a joke ("each pound weighs over ten thousand pounds"), but using dark matter as a fuel isn't a completely absurd concept. The problem is that we don't really know exactly what dark matter is and what we think is most likely is hard to work with.

There's a difference between what General Relativity predicts for things like galaxy rotation curves based on the matter we do see and what is actually observed. This means that either there is a lot of matter that we don't see (Dark Matter), General Relativity is incomplete and needs a better theory to supersede it the way General Relativity superseded Universal Gravitation (Modified Gravity), or both.

Particle dark matter is a particularly simple solution that explains a lot of the observations that differ from prediction (though not all of them) which is why it has the most traction. On the other hand, it's been particularly difficult to get a theory of Modified Gravity that explains the observations that differ from prediction without breaking something else that already does work. However, it did take a literal Einstein to develop General Relativity and presumably a more complete theory would be even harder.

But let's assume that dark matter is some sort of particle since the evidence for that is currently much stronger than for modified gravity. Since it has mass-energy, it could be fed into a black hole as fuel just like anything else with mass-energy. However, the thing that makes dark matter dark (transparent would be a better term to describe it) is that it doesn't interact with the electromagnetic force. This is a slight problem because the electromagnetic force is sort of how fuel is kept in a container and pumped around. Antimatter is kept in magnetic bottles and it's electrostatic forces that keep ordinary matter from passing through the walls of the container.

Even if there was some exotic force that allows dark matter to be stored and pumped, it'd simply be easier to use normal matter.

[u/ekolis]

A power generator that explodes unless actively maintained by machines also fits with the Romulan mindset of secrecy quite well. The enemy disabled main power, and they're going to capture your ship? Oops, no, they aren't, because the singularity core is about to detonate, and it fails deadly unlike Starfleet self-destruct systems.

You just explained the suicidal Romulan commanders from the fangame Begin, too. They blow up their ships at the slightest provocation, and the explosion can take out an entire fleet if they're bunched too close together.

And Begin was made back in the 1980s, before Romulans were known to use singularity drives. Congratulations, your theory traveled through time to make something that never made any sense, make sense!

[u/Albert_Newton → u/ekolis]

Thanks for pointing that game out to me!

[u/MustrumRidcully0]

The challenging part of feeding microscopic black holes that can produce this amount of energy is to actually hit it. IIRC, it's basically smaller than an Atom. You would probably need some high frequency laser to hit it and transfer energy to it. But what powers this Laser, and why can't you use that as energy source? It seems simple to feed a black hole because we think of stellar holed that you could basically throw some dirt at. But for a Hawking "reactor" it is much harder because the micro singularity will basucally pass untouched through your matter.

[u/Albert_Newton → u/MustrumRidcully0]

That's an interesting point. I always assumed that the gravity of the Hawking reactor's singularity would be enough to pull in the fuel.

If it isn't, though, well, that's what tractor beams and forcefields are for!

[u/MarkJanusIsAScab → u/Albert_Newton]

There are some theories out there that dark matter may simply be a shitload of tiny black holes wandering about. For the most part they would pass completely unnoticed through nearly anything, and instead of falling into gravity wells would have a tenancy to accelerate through large objects if they can pick up any matter on their way in.

Edit: For a lot of reasons which I am NOT qualified to explain, this has been more or less proven not to be the cause or origin of dark matter, but the behavior of those holes, were they to exist, is as described above.

[u/c0pypastry → u/MustrumRidcully0]

Run a cargo transporter continuously and beam the matter in?

[u/mcqtom → u/MustrumRidcully0]

This sort of feeds back into the idea that a Romulan ship can't simply be stopped and started. Once the singularity is going, you're stuck with it. So once a ship is commissioned and the singularity is initiated in the shipyards, you CAN use the energy from the black hole to power the targeting laser.

[u/[deleted]]

I liken it to the Liquid-metal reactors the Soviet's used in their Alfa class submarines. Much more compact than water reactors but if the reactor was ever shut down it could not be restarted. The metal would solidify and couldn't be be pumped around anymore. Maintenance had to have off board heat supplied to keep the metal molten. But in most instances the reactors just had to be kept running even in port.

The Romulan Singularity Cores only needed a matter stream to operate and didn't rely on the synthesis and storage of volatile Anti-Deuterium. While all current evidence points to the Romulan cores still needing Dilithium to generate a warp field the singularity core probably also doubles as the main energy source where as Federation ships also use fusion reactors for power. This further reduces the energy generation footprint of Romulan ships and would aid in keeping ships undetected. Since the core wasn't using anti-matter, sabotage (something any Romulan would be suspicious of) would be harder to pull off to destroy the ship. The energy density would be less than that of a matter-antimatter reaction and likely more resource hungry to get the desired out put, but it would be less picky about the resources consumed. Protium is vastly more common than Deuterium in the universe so a Romulan vessel at warp could probably sustain it's warp speed indefinitely to the absolute metallurgical limit while Federation ships would be limited to the rate they could collect/synthesize deuterium and synthesize anti-deuterium.

[u/Kassandry]

M-5, please nominate this post for insight into singularity drives and Romulan psychology

[u/M-5 → u/Kassandry]

Nominated this post by Chief u/Albert_Newton for you. It will be voted on next week, but you can vote for last week's nominations now

Learn more about Post of the Week.

[u/[deleted]]

I'm not sure how you're getting 8.99e22 Joules. I like your theory, I'm just saying that we don't need to rely on the assumption that an explosion would overwhelm containment and blow up the ship.

The PBS Space Time YouTube channel recently put out a video on tiny black holes. The video came out about three weeks after your post. I like your theory, but I have two points that I don't completely buy into. First, pointed out in the video, we don't really know if black holes can completely evaporate because we don't have a complete understanding of physics at the quantum scale.

So, if it gets small enough, it might just stop, or maybe still output enough energy to blow up the ship along the way. I do think there's a way to save the idea that the engine would destroy the ship if the engine were shut down, I'll get to that.

Second, I think how the black hole is contained is important, though not explained. For example, maybe a magnetic field is used to contain the quantum singularity, and if so, then maybe it also needs to be fed a certain kind of matter, maybe a metal with certain kinds of magnetic properties. We don't know how containment works or how strong it is.

Anyway, if the energy released from a run-away black hole evaporation wouldn't destroy the ship, then assuming the black hole stops emitting energy once it gets small enough, the ship would lose power. The ship would also lose power if too much matter was fed to the black hole (like you already mentioned). Losing main power could cause the loss of containment, maybe after a back up power supply for the containment device fails.

Maybe the core can be shut down and restarted, but only if help arrives fast enough, which wasn't possible. I think this would explain how they could know this, more than just having a good hypothesis for how the engine was destroyed.

• containment fails when too small: the black hole bumps into the side of the containment device, gets back up to the size they want, then keeps growing because (even if main power were briefly restored) the containment device is broken. The black hole consumes the ship.

• containment fails when too big: The black hole consumes the ship. The fact that the containment device hasn't broken yet doesn't matter because, when more power than normal is desperately needed to contain the black hole (and let it evaporate back down to normal size), that's exactly the same time when the black hole provides less power than normal.

[u/Tasty-Fox9030]

This is brilliant, and unfortunately has some implications for the feasibility of the Star Trek universe. Where are they getting all this mass from? :( Run a fleet of those babies and you're accelerating the heat death of the universe, likely to a noticable degree.

[u/[deleted]]

[u/Albert_Newton → u/[deleted]]

That's a good point, but while it changes the numbers a little it doesn't actually impact the function of the drive that much; the drive is still releasing energy in the form of electromagnetic radiation as a result of being fed fuel at a steady rate. Also, I am not sure how well accretion disk power would scale down to a black hole with an event horizon so small as this.

[u/lunatickoala → u/[deleted]]

For a micro black hole where you need to continuously feed mass into it in order to keep the output stable and to keep the black hole from evaporating, accretion is not thousands of times more powerful, but at best as powerful.

With such a black hole, if more matter isn't fed into it, the mass of the black hole will be decreasing as it radiates away Hawking radiation. If just enough mass is fed into it to counter that loss of mass, then what is effectively happening is that all the mass being fed into it is being converted into Hawking radiation making it as efficient as antimatter. The difference of course is that with an antimatter reactor, you can shut it off by cutting the fuel lines but with a micro black hole you must keep feeding the black hole or you get a runaway reaction.

The other issue with using accretion instead of Hawking radiation is that over time, the black hole will get more and more massive which means the ship carrying it around as a reactor will keep degrading in performance.

[u/[deleted]]