# Can a starship moving at warp 9.999 be hit from behind by a torpedo?

I always see torpedoes follow Newtonian physics even at Warp speeds. They always hit the targeted vessel from behind even if it's at warp speed. This means their own speed beat the speed of the targeted vessel. So can I say that before hitting a starship moving at warp 9.999, they will enter subspace?

Technically, they can still hit us as their presence occupies every point of our starship too. But, how will they be guided? And, how is their programming supposed to work?
Do you have any explanation or any evidence from Star Trek movies, TV shows, comics, etc.?

WARNING: Yes, this is long. I include quotes I think are relevant and necessary and also need to explain the one mathematical concept I'm using. Sorry for the length.

Since you're using warp 9.99 as a upper limit, I'm going to assume you're working with the revised warp scale used from Star Trek: The Next Generation and onward, where the limit is warp 10, which would be infinite speed and unreachable.

As I understand it, you're basically asking, "If my starship is going as fast as is possible in the universe, could a photon torpedo still hit it?" And I assume, when you refer to it going into subspace, that you're asking or implying that there's some reason for it to stop using warp the instant before impact.

I'm going to clarify a few points by referring to Star Trek: The Next Generation; Writer's Technical Manual (Fourth Season Edition). This is the technical manual given to all writers and directors (and others who needed to know) who would work with Star Trek: The Next Generation. This is the one sent to me as part of a pitch package by Lolita Fatjo, the Script Supervisor for that show. In other words, it's what the writers were told was the word and what held authority over whatever kind of technobabbly situations a writer might want to create.

On page 14, we have:

## Weapons - Photon Torpedoes

In brief: An energy weapon in which a small quantity of matter and antimatter are bound together in a magnetic bottle and launched at warp speed at a target. Photo torpedoes are the weapons of choice when the ship is at warp drive, because their speed is not limited by the speed of light.
Torpedo Launchers: There are two torpedo launchers on the Enterprise, one at the front and one at the rear of the engineering hull. Photon torpedoes are "smart" weapons and are capable of tracking a moving target. Torpedoes are usually launched in clusters, each independently targeted.

So there's no issue with warp speed or targeting or tracking a vessel.

And on page 7, under Warp Drive:

WarpTen. This is the absolute speed limit of the universe. As Warp Factors approach 10, speed increases dramatically (sort of like the Richter Scale) and so does the required power. Warp 9.9 is over 50% faster than Warp 9.6 and Warp 9.99 is nearly triple Warp 9.9. (Supspace radio signals propagate at about Warp 9.9999, about 100 times faster than Warp 9.6.). Warp Ten is effectively infinite, and an object at that "speed" would occupy all points in the universe simultaneously.

So Warp 10 is asymptotic. The chart on page 8 says, for Warp factor 10, "This speed is meaningless..."

(For anyone reading this who does not understand asymptotic, remember when you were in Algebra I classes and drew those curves on a graph that your teacher said would come closer and closer to the line but would never touch it? That line it can never touch is an asymptote and the curve that never reaches it is an asymptotic curve.)

It seems you are trying to say, "If you're going at the fastest speed possible, can a photo torpedo catch up and still hit you?" The answer is, "Yes." There is no fastest speed possible. No matter how fast you go, the speed limit is asymptotic, so there will always be a speed that's a little bit faster and if the torpedo can reach that faster speed, it can hit your starship.

Now, if by the reference in your question where you say, "as their presence occupies every point of our starship too," you are asking, "At the limit of warp drive, since you're occupying every point in space, can a torpedo still hit you?" then there are two answers:

1: The first is that this speed, as defined in the Writer's Guide, is not possible, so that situation cannot occur.

2: But if we push that and say, "What if...?" then the answer would be, "Yes, because the torpedo is in space, and we cover every point in space, so it can hit us and when it destroys us, it would destroy the universe as well, because we occupy every point of the universe." (However, again, according to the series bible, this is not possible. I know that's not the answer you want, but it's the answer from the series bible.)

As to if this is canon or not, in Star Trek, as I understand, novels and, essentially, all media other than the TV shows and the movies, are not canon. Canon comprises only the 5 live action TV shows and the 10 movies. If that is the case, then this source is what is given to screenwriters to tell them what they can and cannot do, so, in a sense, it is even above canon.

• The speed limit is asymptotic, so there will always be a speed that's a little bit faster.. Can I limit it by power requirement.. Is there anything about power of torpedoes in that manual? Jan 7, 2012 at 10:36
• @SachinShekhar: Without digging up the series bible again, at the moment, I think the power curve is even steeper than the speed curve, but it's also very steep. But then, if you limit the power, that sets a different limit and the answer would be that at some point the torpedo won't have the power to move as fast as a starship can move. It just depends, considering large starship mass and small torpedo mass, which one has a bigger power plant relative to its size. Jan 7, 2012 at 16:57
• As much as I loathe stepping out of the universe to answer the question, from what I saw with the producers at ST:TNG (and statements in the Writer's Guide), story trumps technical details. If they had a starship running from a torpedo, the needs of the story would lead to technobabble that would justify the needed outcome. Maybe they fired a torpedo back at the pursuing torpedo and destroyed it or they ran out of power and got hit. There's always some technical issue that can go wrong or get fixed so what the writer wants to happen will happen, whether it's outrunning the torpedo or not. Jan 7, 2012 at 17:02
• Of course the real reason it can 'catch up' is because the photon torpedo being launched is itself contained in a warp bubble, just like all starships at warp, when it exits the warp-capable ship's own subspatial bubble, which allows it to travel fast enough to catch up to the other warp-capable ship, assuming the original ship itself is also fast enough to catch up. Relativity. Apr 2, 2014 at 19:04
• @Zibbobz: Read the excerpt I quoted from the tech manual about photon torpedoes. They're not limited by light speed, implying that they have some kind of warp drive themselves - so the issue of the warp bubble around a ship is moot. Apr 3, 2014 at 20:13

I'm probably going to duplicate some info from TangoOversway's excellent answer, but I wanted to provide a very concise explanation of the most important factor that answers your question:

So can I say that before hitting a starship moving at warp 9.999, they will enter subspace?

There is nothing magical about number 9.999 aside from the fact that it's less than magical "infinite" Warp 10 speed. There are a LOT (infinite[1] - to be precise) amount of distinct Warp speed settings greater than 9.999 but less than 10. Your torpedo can overtake the ship at Warp 9.9990000000001 or 9.99922222678768 (hopefully you see the pattern).

[1] - even more precise, there are as many numbers to represent Warp speeds between 9.999 and 10 as there are ALL of real numbers. If that's not something that's as obvious to a reader as it is to someone with a graduate Math degree, feel free to request an explanation from Math Stack Exchange

• This is already pointed out by TangoOversway. Jan 7, 2012 at 18:58
• And, you can't say it directly.... see the power threshold vs speed graph keep those random Nos. away.. Jan 7, 2012 at 19:00
• In fact, warp 15 has been achieved if not going thru revised scale of ST:TNG... Jan 7, 2012 at 19:03
• Anyway, Warm Welcome! Looks like you're here just because of this question.. ;) Jan 7, 2012 at 19:05
• Look... your precise answer is not complete. You need to tell warp 10 is not reachable too. See later part of question. Plus, keep your mathematical understanding folded as it is known by even a kid... Jan 7, 2012 at 19:21

I always see torpedoes follow Newtonian physics even at Warp speeds.

I'm not sure what you mean by this. They do follow a direct path.

They always hit the targeted vessel even if it's at warp speed. This means their own speed beat the speed of the targeted vessel.

Assuming they're aimed properly and the other ship doesn't evade them, yes.

So can I say that before hitting our starship they will enter subspace?

No. Photon torpedoes have warp-sustaining propulsion, so when they are fired at warp they do stay at warp, but if fired at sublight speeds they can't jump to warp.

Technically, they can still hit us as their presence occupies every point of our starship too.

No, I'm not sure how you got that. Perhaps you think they go at warp 10, infinitely fast? I'm afraid not, they're physical objects, they take time to travel (as you see whenever they fire one), and they don't have the infinite power required to get to warp 10. Note that, despite their name, they are antimatter weapons, not light-based.

But, how will they be guided? And, how is their programming supposed to work?

Umm... they fly as fast as they can in a straight line? I don't recall ever seeing one maneuver like a modern missile does. But maybe they do have some sort of heat or warp field-sensing guidance. I suspect this is moot given the last answer, however.

• I don't recall ever seeing one maneuver like a modern missile does. Star Trek VI; the torpedo that reveals the cloaked Bird of Prey manuvered along the impulse ion trail left by the BoP. Jan 7, 2012 at 6:39
• Don't split up my every sentence as they're inter-connected.. Jan 7, 2012 at 10:40