[Aesaar]

The Indus was in an elliptical orbit that would have brought it to an altitude where it could not survive.  For convenience's sake, we'll call that a decaying orbit, because it gets the point across perfectly well.

Happy?

[Herra Tohtori]

Many explanations for a decaying orbit, one would be that it's an elliptic orbit that intersects with the photosphere, another would be that the Indus may be venting something in the retrograde direction, causing it to end on a downward spiraling orbit... the science of it is mostly irrelevant for the storytelling perspective.

The surface of the sun is plenty hot enough. The temperatures of Sun's visible surface (photosphere) are about the same as you get from the tungsten wire in incandescent bulbs. Incandescent bulbs have a really small radiative area, yet you can clearly feel the heat of the small radiating piece of wire. Now imagine a square metre surface of glowing hot tungsten, and you being seated about 0.5 metres away from it (in that situation, the tungsten plate has apparent diameter of 90 degrees, which is close enough to what Indus experienced (depending on exact orbital altitude, but close enough for an approximation).

The radiation flux is quite overwhelming; a black body with surface temperature T has surface flux of

F = σ T⁴ , which gives out Watts per square metre when σ = 5.67 x 10^-8 W/m²K⁴  (Stefan-Boltzmann constant).

When temperature is 5800 Kelvins, you get a radiation flux of 64.169×10⁶ watts per square meter.

Therefore a metre by metre plate of tungsten heated to 5800 Kelvins would radiate at the power of 64 Megawatts, which you wouldn't exactly want to sit right next to.

As far as black body temperature balance goes, it would be rather trivial exercise to calculate the terminal temperature of Indus at different distances from the Sun. After that it would just be a matter of looking at what sort of temperatures the environmental controls can deal with - or, what kind of thermal energy output the shadow-side radiators can establish at maximum coolant flow.

However since none of this is exactly critical information, we never really calculated any actual values, settling for a simple cover-all definition of the situation: The Indus is screwed.

[newman]

However, that scene is already inaccurate: you can't be in a "decaying orbit" unless you're actually inside the atmosphere of the thing you're orbiting, and the Indus would be slag long before getting that close.

Yes you can. I'm about to niptick, but you're not exactly in a position to complain about that

A ship of Indus's size and complex hull configuration might be susceptible to tidal forces, and it's orbit might actually gradually change over time as a result. If it's in a retrograde elliptical orbit I do believe it likely it would gradually transfer tiny amounts of angular velocity to the Sun. How many orbits it would actually take for the orbit to decay completely into collision isn't something I find particularly relevant in this case (given the differences between Indus's and Sun's mass, I'd estimate it would take extreme amounts of time before the effect was even noticeable, and is by and large negligible in any sort of realistic time frame), but if you want to nitpick about right or wrong, "decaying orbit" might actually be a perfectly accurate term to describe Indus's situation, even if it would take a 100,000 years for the ship to actually crash into the sun. Like I said, irrelevant, as is the entire argument - my point is there are forces other than friction capable of causing orbital decay. The only thing the player needs to take away from that scene is "Indus is toast". And technically, if it'll crash in some 100,000 years it is in a decaying orbit

[Buckshee Rounds]

However, that scene is already inaccurate: you can't be in a "decaying orbit" unless you're actually inside the atmosphere of the thing you're orbiting, and the Indus would be slag long before getting that close.

Yes you can. I'm about to niptick, but you're not exactly in a position to complain about that

A ship of Indus's size and complex hull configuration might be susceptible to tidal forces, and it's orbit might actually gradually change over time as a result. If it's in a retrograde elliptical orbit I do believe it likely it would gradually transfer tiny amounts of angular velocity to the Sun. How many orbits it would actually take for the orbit to decay completely into collision isn't something I find particularly relevant in this case (given the differences between Indus's and Sun's mass, I'd estimate it would take extreme amounts of time before the effect was even noticeable, and is by and large negligible in any sort of realistic time frame), but if you want to nitpick about right or wrong, "decaying orbit" might actually be a perfectly accurate term to describe Indus's situation, even if it would take a 100,000 years for the ship to actually crash into the sun. Like I said, irrelevant, as is the entire argument - my point is there are forces other than friction capable of causing orbital decay. The only thing the player needs to take away from that scene is "Indus is toast". And technically, if it'll crash in some 100,000 years it is in a decaying orbit

I'm just spitballing now, but assuming the Indus exited subspace with negligible velocity of any kind, wouldn't the Sun's rotation put her into a prograde, elliptical orbit (looking sort of like an arc coming out of the Sun)? The only way it could be counter to the Sun's rotation would be if the Indus exited subspace in that direction (which would have to be a lot of speed right?).

Irregardless of whatever it is that makes the Indus' orbit grow smaller (tidal deceleration, atmospheric friction) her orbit *will* get smaller at some point therefore "decaying orbit" is an accurate description imho.

[Herra Tohtori]

Nope, the rotation of the central body typically has negligible effects on its surroundings (on a short time scale).

Technically you're right, assuming the exit-point is stationary in ecliptical coordinates the Indus would be put on an orbit around the Sun depending on its emergence vector. The Sun's rotational period at equator is 24.47 days, so most objects in the Solar system orbit the Sun much slower than the Sun itself rotates. However, prograde or retrograde orbits in this case has little meaning since Sun's surface is fluid rather than a solid reference point.

Actually, you can get absurd effects when you have a rotating supermassive black hole, because all rotating objects twist the space-time around them to some extent, but with normal celestial objects and normal astronomical distances, these effects typically don't appear.

And yeah, tidal forces can cause all sorts of complex effects. If we consider the Earth-Moon pair, one object (Moon) is tidally locked (which would probably not be the case with Indus) on prograde orbit. In this case, the tidal forces do work to slow down Earth's rotation, so Earth's rotational energy and angular momentum are decreased.

However, both the mechanical energy and angular momentum of the Earth-Moon system conserve; the conservation of angular momentum actually means that while the Earth's angular momentum decreases, the Moon's angular momentum increases, which means the Moon is being pushed to higher orbit. As far as energy is concerned, most of the reduced rotational energy is converted to heat, but about 1/30th of it is converted to the Moon's potential energy as it slowly climbs to higher orbit.

Tidal forces on the Indus would probably not be observable in the time scale of Sunglare; the actual problem they are having must be something more acute.

Personally I would put a wager on two possible (and one so-so) causes:

1. Indus is simple descending too low on elliptical orbit
2. Indus is venting something to retrograde direction, causing their orbit to decay.
3. Indus' magic antigravity systems are damaged and thus it has become subject to Newton's laws of motion as well as the universal gravitational law, unlike in all other appearances.

We've seen stations hold stationary altitude at orbits that are clearly not geostationary... the ships are firing their thrusters all the time yet experience no constant acceleration... a "decaying orbit" in this environment can mean whatever is required to make the situation as dire as possible.

[Phantom Hoover]

can i just interject that irregardless is a horrible word and you should be ashamed for using it

[Luis Dias]

IMHO the "decaying orbit" jargon thrown at you just means that the vessel is falling (the elipse crosses the surface at some point in the future - and in the past if you are so inclined to be precise). To prevent falling at that altitude the Indus should be orbiting at really high speed. Herra's right.

Or it could mean that it is crossing the corona's particles, which are slowing down the vessel.

[perihelion]

Or it could mean that it is crossing the corona's particles, which are slowing down the vessel.

This would be my vote.  The solar atmosphere (aka corona) is huge.  It wouldn't be much of a stretch to say that the Indus was experiencing coronal drag.  Not to mention what direct interaction with the solar magnetic field would do.

[Darius]

It's a decaying orbit because the hull is decaying!

[redsniper]

Yeah, I think "decaying" is a good choice of word from a literary perspective too. It just makes the whole situation sound bad. The ship is decaying, the situation is decaying, the UEF is decaying.

Spoiler:

Simms is decaying.

[Colonol Dekker]

However, that scene is already inaccurate: you can't be in a "decaying orbit" unless you're actually inside the atmosphere of the thing you're orbiting, and the Indus would be slag long before getting that close.

Yes you can. I'm about to niptick, but you're not exactly in a position to complain about that

The Suns atmosphere (Heliosphere in particular) extends past pluto.

[redsniper]

Can we get a "Conversations from Act 3" or would that be too spoilery at this point? I want hype like the WiH R1 hype!

[General Battuta]

The machinery is in motion.

[General Battuta]

Act 3 discussion goes here! Conversations from Tenebra is here!

[Gray113]

Downloading the new release now
Just wanted to say thank you guys for this incredible gift

[Aesaar]

I love you guys.

I said it on IRC, but I'll say it again: That intro is godly.

[Ravenholme]

Will donate children for that awesome remix of Aney Aney that you have as the new campaigns menu music.

[headdie]

opening the vp files not working for you?

[Colonol Dekker]

Wait....

Act 3's released?

[Ravenholme]

Also, Battuta - Kovacs, Vidaura and Falconer? The nods to Richard Morgan just got a bit more overt, methinks


And, I could open the VPs, but I am fundamentally lazy and they might have a higher quality version hanging around before compression etc.