ST VI: TUC torpedo calculations...

[Praeothmin]

In relations to this thread a few months back:
http://www.starfleetjedi.net/forum/view ... highlight=

I finally found my post-its.
I will post the calculations this week-end, but the reason I mention it is that, on SB, a few months ago, Vivftp posted a link to a video showing voyager getting hit by a 8472 Bioship's beam.

Voyager's shields were brought down to 82%, an 18% drop in one shot.
But what interested me more in that video was that the beam brought Voyager from a still position to spinning out off control.
Yes, spinning!
Voyager had enough momentum imparted to itself to do almost 2 full turns before finally regaining control.
And they did one full turn in less then 2 seconds.

Keeping in mind that Voyager masses 700 000 metric tons, even with a mass lightning that left it with 10% its original mass, I imagine the energy needed for such a feat would be staggering.

[Mr. Oragahn]

Woah, we almost posted those two torpedoe related threads at the same time!
We're lucky that they adress subjects which are different enough. :)

On topic: How far goes mass lightening for Voyager, and where did the alien beam hit the shields exactly?

[Praeothmin]

Mr. Oragahn wrote:

How far goes mass lightening for Voyager, and where did the alien beam hit the shields exactly?

As far as the mass lightening goes, I have no clue just how far we could take it.
I wasn't the one who brought it up in the above-mentioned thread.
But even if it's only 10% of the original mass, it has to be powerfull.

I just rewatched the scene, and the shot hit Voyager from the back, and we only see voyager do about two thirds of a cartwheel in about 1 second.
Still impressive.
We then cut to inside the ship, we see a few things being done, and then when we come back to the outside view, we see the ship still spinning, at least half a turn, then it regains control.

[l33telboi]

Keeping in mind that Voyager masses 700 000 metric tons, even with a mass lightning that left it with 10% its original mass, I imagine the energy needed for such a feat would be staggering.

I've was thinking about the same thing in one of those god-awful 8472 threads on SB some time ago. But largely didn't try to do anything because of mass-lightening.

Where did the figure 700 000 000kg come from btw?

[AFT]

I've was thinking about the same thing in one of those god-awful 8472 threads on SB some time ago. But largely didn't try to do anything because of mass-lightening.

Isn’t mass-lightening a part of the Impulse drive? If so, it only operates when the ship is moving at impulse speeds, right? During this example Voyager was standing still, I mean it wasn’t moving, so the mass-lightening was not functioning, maybe you can work out something, whatever you wanted to do anyway.

Where did the figure 700 000 000kg come from btw?

From the show itself. Voyager was quoted several times of having a mass of 700,000 metric tons.

[Mike DiCenso]

The dialog in the episode suggests that the bioship was still in the stages of powering up when it fired. On top of that, Tuvok at an earlier point notes that the same ship suffered damage from a Borg disruptor fire. So this is what a powering up, damaged S8472 vessel can do.

Also, even if the mass-lightening effect reduces Voyager's apparent mass by a thousand times, it would still mass out at 700 tonnes. Even a 10,000 x reduction still leaves Voyager at 70 tonnes.
-Mike

[Jedi Master Spock]

For a variety of reasons, it is best to model neglecting any inertial dampening first, and see what exactly we are dealing with. Assume that the biobeam is hitting an inert object, and that Voyager does not begin to stabilize until after the initial shot.

I would take Voyager as a uniform 150x50x341m ellipsoid (it isn't, of course, but we're ballparking here.) This gives our moment of inertia as 3.5-19.4 x 10^12 kg m^2 depending on axis of rotation. 2/3 of one rotation is roughly 2 radians per second, meaning that we have a rotational energy of 7-41 terajoules and an angular momentum of 7-41 x10^12 kg m^2/s.

Exactly what that means in terms of beam energy is in turn dependent on both what the beam is composed of, where it impacted, whether the beam was reflected or absorbed, and at what angle the beam impacted (and, if reflected, what angle(s) it was reflected at). It is highly sensitive to all of those figures, adjusting further by several orders of magnitude depending on these parameters.

For example, if the beam was comprised of photons, flipped Voyager nose-over-tail (i.e., about a line drawn through the front of the nacelles), and impacted ~41 meters from the center at a perpendicular angle, my napkin says "3e20 J," which should be right if I haven't made any silly mistakes.

[Mike DiCenso]

l33telboi wrote:

Where did the figure 700 000 000kg come from btw?

The figure of 700,000 metric tons is quoted in "Phage" [VOY1] and "Relativity" [VOY5].
-Mike

[Mike DiCenso]

This isn't the exact instant of being hit:


http://voy.trekcore.com/gallery/display ... 56&pos=165


But it does show Voyager knocked upwards about 40-60 degrees or so from her former relative horizontal position. You can see from the beam's impact position on her shields that she was struck or clipped on the dorsal shield facing, then flipped by the force of the beam.
-Mike

[Mike DiCenso]

Jedi Master Spock wrote:
For example, if the beam was comprised of photons, flipped Voyager nose-over-tail (i.e., about a line drawn through the front of the nacelles), and impacted ~41 meters from the center at a perpendicular angle, my napkin says "3e20 J," which should be right if I haven't made any silly mistakes.

If I'am not making any mistakes in my conversion, that would be the equivalent of about 71 gigatons....
-Mike

[SailorSaturn13]

Jedi Master Spock wrote:
For example, if the beam was comprised of photons, flipped Voyager nose-over-tail (i.e., about a line drawn through the front of the nacelles), and impacted ~41 meters from the center at a perpendicular angle, my napkin says "3e20 J," which should be right if I haven't made any silly mistakes.

If I'am not making any mistakes in my conversion, that would be the equivalent of about 71 gigatons....
-Mike

Not bad for a tributary beam, but then the energy to blast a planet has to come from just 9 ships, so even a stray hit must be powerful..

[Mr. Oragahn]

Jedi Master Spock wrote:
For example, if the beam was comprised of photons, flipped Voyager nose-over-tail (i.e., about a line drawn through the front of the nacelles), and impacted ~41 meters from the center at a perpendicular angle, my napkin says "3e20 J," which should be right if I haven't made any silly mistakes.

If I'am not making any mistakes in my conversion, that would be the equivalent of about 71 gigatons....
-Mike

Not bad for a tributary beam, but then the energy to blast a planet has to come from just 9 ships, so even a stray hit must be powerful..

They do it through technobabble. It can be reliable to try to translate that for raw firepower applied to ship to ship engagements.

[Jedi Master Spock]

Jedi Master Spock wrote:
For example, if the beam was comprised of photons, flipped Voyager nose-over-tail (i.e., about a line drawn through the front of the nacelles), and impacted ~41 meters from the center at a perpendicular angle, my napkin says "3e20 J," which should be right if I haven't made any silly mistakes.

If I'am not making any mistakes in my conversion, that would be the equivalent of about 71 gigatons....
-Mike

~70 gigatons indeed. Geometric parameters may vary somewhat from that ballpark.

However, the most important parameter to plug in is not the geometry, but the ratio of transmitted beam energy to momentum. Which, this not being the case of photons being absorbed, is probably not going to turn out to be within an order of magnitude of c.

Anything qualitatively known about the biobeams, or in particular how fast they propagate?

[Praeothmin]

It seems my calculations weren't needed after all... :)

Jedi Master Spock wrote:

70 gigatons indeed. Geometric parameters may vary somewhat from that ballpark.

And lets not forget that this 70 Gigatons didn't even bring Voyager's shields down.

[Mr. Oragahn]

http://www.youtube.com/watch?v=xUVbu4-U_80

Shows the ship getting hit.

A few questions now.

What's the composition of the bioship's beams?
Are we sure the hit didn't disrupt some of the engines (Voyager was trying to flee a bioship on impulse drives, likely full throttle)?
How long did it take for the crew to nullify the spinning?
What's the real mass lightening factor?
Is the hull able to withstand tens of gigatons (~70 GT) of firepower (see this clip, at 2:21, to view the unshielded Voyager getting hit by a bioship's beam)?

If I get it correctly, the idea is that the beam imparted like 70 GT of kinetic energy, right.
Well, then there might be a problem, because of the impact angle. The beam's coming from behind, and is almost horizontal to Voyager's horizon plate. It hits the superior hemisphere of the shield, above the stern, off axis on the left, actually above the portside nacelle.
Considering the ship's center of gravity, with a hit coming kilometers away from behind, wouldn't that make the ship spin the other way round, and slower?
Shouldn't the ship nosedive and rotate towards the right, instead of the exact contrary?