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I WANT TO BELIEVE

26 (41.9%)

I WANT OFF PLANET NINE'S WILD RIDE

14 (22.6%)

I WARNED YOU ABOUT PLANET X BRO

22 (35.5%)

Total Members Voted: 62

[exdeath]

Which thing in particular do you have a problem with?

I assumed it would be easy to spot stuff at our solar system, a thing I assumed because all those guys complaining about stealth in soft scifi space battles.

[Telgin]

It's mostly that planets don't have rocket engines on them.  And it's super far away.  As far away as the planet is, it reflects so little sunlight that it's going to be hard to resolve it with a telescope.

The stuff we can see elsewhere in the universe is generally emitting light directly or occluding it.  Otherwise it's usually inferred to exist because of gravitational perturbations of other things we can see, kind of like this prospective planet.

[Graknorke]

There's differences between a spaceship and a planet. Even assuming you can somehow bend visible light around the hull or something, a vehicle is going to be generating heat which has to be transferred away in some way in order to stop it melting, and some of that is going to be as EM radiation. That can be detected and measured pretty easily.
On the other hand this planet would be both cold and very far away from us and the sun, which means there's not a lot of reflected light, and the thermal radiation would be difficult to distinguish from random fluctuation without a very intensive search.

[exdeath]

thanks

[Loud Whispers]

One of these days we'll notice there's a gigantic cthulhu maw drifting on the periphery of our solar system

[Reelya]

Which thing in particular do you have a problem with?

I assumed it would be easy to spot stuff at our solar system, a thing I assumed because all those guys complaining about stealth in soft scifi space battles.

Cloaking devices are sorta BS, but that misses the point that it's actually much harder to spot ships at a distance in space than sci-fi would lead you to believe. Basically, you don't need a cloaking device, you just need a non-reflective hull and to not emit too much EM radiation.

For this hypothesized planet it's around 200 AUs from the suns, so let's say we want to view it via reflected sunlight. Brightness is distance-squared however, so the sun's brightness out that far is 1/40000th of the light that hits us. It's bigger than Earth, so we can say the raw brightness of this object is around 1/10000th of Earth. But then we need to remember that we're also viewing this object from 200 AUs away (assuming that it's at it's closest point), so it would be 1/40000th as bright as something that was 1 AU away. The net effect would be an object that's literally millions of times fainter than viewing e.g. Mars. It'd be drowned out by interstellar bodies that actually emit light, such as stars and galaxies.

To detect something like that involves more than a little luck. An example is Sedna, a 1000km-wide rock (almost as big as pluto) which we detected in 2003 about 100 AUs from Earth. But it turns out that it was detected near it's nearest point to the sun, and it's orbit takes it almost 1000 AUs from the sun. It's orbital period is 11000 years. When you consider that this is just the one we got lucky and saw when it was close, it's likely that there are 100,000 Sednas out there - e.g. 100000 things the size of Pluto. A few bigger ones out there is almost a certainty.

[Shadowlord]

To detect something like that involves more than a little luck. An example is Sedna, a 1000km-wide rock (almost as big as pluto) which we detected in 2003 about 100 AUs from Earth. But it turns out that it was detected near it's nearest point to the sun, and it's orbit takes it almost 1000 AUs from the sun. It's orbital period is 11000 years. When you consider that this is just the one we got lucky and saw when it was close, it's likely that there are 100,000 Sednas out there - e.g. 100000 things the size of Pluto. A few bigger ones out there is almost a certainty.

This planet was detected by its gravitational effects, though. And by detected, I mean "their math says it must be there, it explains the orbits of these other bodies that we know about," and stuff.

[Graknorke]

exdeath is talking about seeing things though.

[Flying Dice]

Which thing in particular do you have a problem with?

I assumed it would be easy to spot stuff at our solar system, a thing I assumed because all those guys complaining about stealth in soft scifi space battles.

Cloaking devices are sorta BS, but that misses the point that it's actually much harder to spot ships at a distance in space than sci-fi would lead you to believe. Basically, you don't need a cloaking device, you just need a non-reflective hull and to not emit too much EM radiation.

And TBH a "cloaking" device for a starship would (assuming no Clarketech) essentially amounts to "release all excess energy in the same direction as the drive plume and occlude that point to a degree sufficient to prevent detection from the forward arc of the ship". Star Trek style visual cloaking is absurd unless your ships are efficient enough to not be detected at significant ranges by their waste energy or your ECM is strong enough to make your general presence blatantly obvious.

[BlackHeartKabal]

We should call it Pluto.

[Bohandas]

EM Drive is still on ~it somehow works except nobody can rly explain why STAR TREK WHEN~ territory, me thinks.

It's more "We haven't proved it doesn't work yet, but there's no good model for why it would" territory. All the experiments have other possible sources for the measured thrust, but getting a good enough measure is looking super-expensive - and that means that, even if it works, I wouldn't expect a practical system for decades, at least, given how low the forces we're talking about are. And that's me trying to account for technology advancing faster than I can really anticipate.

Yeah, it seems to work, but not very well.

[PyroDesu]

Which thing in particular do you have a problem with?

I assumed it would be easy to spot stuff at our solar system, a thing I assumed because all those guys complaining about stealth in soft scifi space battles.

Cloaking devices are sorta BS, but that misses the point that it's actually much harder to spot ships at a distance in space than sci-fi would lead you to believe. Basically, you don't need a cloaking device, you just need a non-reflective hull and to not emit too much EM radiation.

In other words, if you want to stealth in space, you're going to roast yourselves to death. You've gotta get rid of the excess heat to keep your life-support supporting you, and that's going to stand out like a beacon against the 3 Kelvin background (Example: using the surface of the craft to maximize surface area without building radiators (something like the Shuttle did), something the size of, shall we say, an Oscar-class submarine (a good ballpark estimate for a small combat spacecraft), looking at it from an angle. Nose-on surface area's 250m², broadside's 2770m², so call it 1510m² facing what's looking for you. What's say you know you're being looked for and don't mind irritating your crew a bit and have life support set to 275 Kelvin (a bit above freezing). You can still be seen from a little over 2 light-minutes away (Math: R_d = 13.4 * sqrt(A) * T², where R_d is the range at which you can be seen in kilometers, A is exposed surface area in m², and T is surface temperature in Kelvin)).

-snip-
Yeah, it seems to work, but not very well.

Kinda like a photon drive. Yeah, they work, but you have to put ungodly amounts of power in them to do anything worthwhile.

[Shadowlord]

The only selling point is that the emDrive doesn't need fuel, if it works.

[penguinofhonor]

Some people used to believe our solar system had many dark planets, potentially bearing life. I'm glad a little of that mystery has been restored.

[Bohandas]

The only selling point is that the emDrive doesn't need fuel, if it works.

Yes it does. At least in the sense of needing an energy supply for the em radiation source