# Thread: Can a terminator swim?

1. Hey all,
Interesting topic that has popped up in the IMDB forum. (Actually not so interesting just amazed at how many people don't seem to understand what seem like basic principles of physics to me – I could be completely wrong that’s why I am posting here).

Before I go on, let’s make a few assumptions.
• Terminators exist and are coming to get us all :-)
• A terminator is very heavy, let’s say for arguments sake 300kg +
• A terminator has extremities that are able to generate a very large amount of thrust. Let’s say 1000 X a human extremity.

Briefly, on this week’s episode of Terminator Sarah Connor chronicles the terminator couldn’t swim, sank to the bottom of the ocean and had to walk out.
Now a huge argument has burst out on the IMDB forum with the logic that a terminator weights X amount (usually quoted in the hundreds of KG), has no oxygen within their body and therefore is not buoyant and therefore could not swim under any circumstances.

Now the majority of people on the forum subscribe to this opinion and infact only a poster or two has argued that this is not correct. To me this sounds like complete rubbish.

Firstly, my understanding is that it’s not oxygen that makes us (humans) float but the fact that per X area (sorry meant volume), we are lighter then water of the same area (again meant volume) – that is what allows massive tankers to float right?

Secondly assuming these things have superhuman strength (which obviously we do assume) then the thrust that they could generate using their arms and legs would be able to overcome the force of gravity, the friction of the water and whatever other forces I am forgetting about – again assuming we are talking about them being able to generate 1000 X a humans thrust.

In conclusion they would weight X and would need to generate Y amount of thrust (based on their weight) to be able to swim. Provided that these conditions were met there is nothing that would stop them or any other object from “swimming”, correct?

Could someone please provide a more scientific explanation of how this can be correctly proven? or correct me if I am wrong!

2.

3. Originally Posted by maximg
Firstly, my understanding is that it’s not oxygen that makes us (humans) float but the fact that per X area, we are lighter then water of the same area – that is what allows massive tankers to float right?
You are absolutely right that it's not the oxygen, except that oxygen is part of the air in our lungs, and this air does help increase our buoyancy. But if the oxygen were replaced with any other gas, the buoyancy would be the same up to the very small difference in the weight of the gas. Needless to say, the person would suffocate.

But the term you are looking for is not area; it's volume. Check the good old Archimedes' law. A human weighs nearly the same as an identical volume of fresh water; I am not sure, but I think just breathing in or out can tip the balance in favour of floating or sinking.

A terminator the same size as a human but weighing 300 kg would displace the same amount of water, say 80 kg. This leaves about 220 kg to lift by active swimming movement, or thrust as you call it.

You said a terminator can generate 1000 times more thrust than a human. I am not a good swimmer at all, but 220 g of lead at my belt would not make me sink immediately. So a terminator 1000 times stronger than me, and presumably with better sporting skills, would easily lift its 220 additional kilograms.

Assuming its limbs are of similar size as mine, the terminator's enormous muscle strength would need to move them very quickly to get the powerful thrust. The swimming terminator would look a bit like a dolphin standing on its wiggling tail fin, except it would be more submerged, and it would also be working hard with its hands.

4. First let's consider what it takes to do the easiest form of swimming; treading water.

You move your hands back and forth and kick your feet in order to displace water downward to keep yourself afloat. Being stronger in itself does not help in doing this (other than the fact that you'll tire less quickly). If I tied an extra weight to you and increased your strength to compensate and changed nothing else, you'd sink.

How much water you displace to produce the thrust needed to keep you afloat depends on how fast you can move your arms and feet. To keep afloat with the extra weight you have to kick faster and move your arms faster.

For a terminator weighing 300kg with a medium frame, he would have to develop about 5 times the thrust to keep afloat than a human would. This means kicking and moving the arms at least 5 times faster (probably more, as moving faster also creates more turbulence which will decrease your effective thrust.)

A terminator swimming would have to look like a whirling dervish. So the question becomes: Can a terminator generate the kind of speed of limb movement needed to swim?

5. My own body with a half lung-full of air does sink. Which is annoying. I must constantly exert energy to keep my face above water.

A very dense terminator would have to exert that much more energy. But water has inertia and if the terminator forces the water too hard, water cavitates. This means where there is low pressure (high suction) gas is kinda ripped out of the water, forming short lived but violently imploding bubbles (these commonly destroy steel propellers) or even a standing bubble, rendering the terminators added effort very inefficient (it is swimming in air).

If the terminator flaps its arms very quickly, can it fly?

Powerful swimmers like dolphins are subject to cavitation, and limit their movement to minimize that. Cavitation is a sort of wall they can't surpass, like the sound barrier. Surely a terminator, with its flipperless limbs would hit that wall far far sooner than a dolphin.

So, assuming limb speed and power are unlimited, does the terminator keep churning water, and eventually reduce to even less efficient skeleton (probably just the flesh at limb extremities would strip off), or does it give up and sink?

***

As a macho-science aside, I wonder if you can cook a chicken breast by duct-taping it to an outboard motor propeller, running in a barrel of water? Or would the meat just erode to bones before it cooked?

6. I took it for granted that the given data tell us the terminator's maximum thrust (and not just muscle strength) is 1000 times that of a human.

But I'll take exception with this statement of yours:

Originally Posted by Janus
For a terminator weighing 300kg with a medium frame, he would have to develop about 5 times the thrust to keep afloat than a human would.
I understand "thrust" means the upward force generated by active swimming, as distinguished from purely hydrostatic (Archimedean) buoyancy. If that is so, 5 times the human thrust is definitely not enough.

A swimming human's movements just generate enough thrust to keep his (or her) head above the water. A similar effect can be achieved by supporting yourself on, say, an empty plastic canister of something like 2 to 5 litres volume. Which means that many kilograms of buoyancy. Without this makeshift lifebuoy, you need the same amount of active thrust: something of the order of a one-digit number of kilograms.

Now if you weighed 220 kg more while not being any larger in volume, you would need not 5 times but between 50 and 100 times (approximately) more thrust. Still safely within the 1000x margin, but I agree you'd have to move those iron (?) limbs real fast.

BTW whirling dervish is not the right comparison - contrary to popular belief, their dancing does not resemble an aircraft propeller. It's more like a graceful waltz.

7. Warning: I have had enough science for today. I am getting sleepy and in the mood for some silly joking. So don't take it personally, Pong, your questions are very much to the point, but I just have to do some misinterpretation.

Originally Posted by Pong
My own body with a half lung-full of air does sink.
Ever tried sinking someone elses body? Did they find it?

Originally Posted by Pong
A very dense terminator
Hey, I know a place where you can see some of those! Not very nice...

Originally Posted by Pong
As a macho-science aside, I wonder if you can cook a chicken breast by duct-taping it to an outboard motor propeller
Nope. Duck tape is for ducks. To fix a chicken breast to anything, use chicken wire.

Good night,
Leszek.

8. Thanks allot all, your input is much appreciated, have posted a link to this forum on the IMDB site.

Its funny how even science fiction can make you think about real science.

9. Pong: I only just noticed your post....

You cant compare flying and swimming and even if you could I would argue that provided you (the terminator) generated sufficient lift, it could infact fly.

The point is, all of these things, flying and swimming are a basic ability to generate sufficient thrust to overcome the resistant forces such as gravity etc...
Now I am not aware of this water cavitations effect you have discussed and you may very well be correct as to problems with efficiency however it seems a moot point to me unless you can provide a more specific explanation that due to this effect would prevent such a machine/object from accomplishing this task.

Am I forgetting something? I dont think I am!

10. Originally Posted by maximg
Pong: I only just noticed your post....

You cant compare flying and swimming and even if you could I would argue that provided you (the terminator) generated sufficient lift, it could infact fly.

The point is, all of these things, flying and swimming are a basic ability to generate sufficient thrust to overcome the resistant forces such as gravity etc...
Now I am not aware of this water cavitations effect you have discussed and you may very well be correct as to problems with efficiency however it seems a moot point to me unless you can provide a more specific explanation that due to this effect would prevent such a machine/object from accomplishing this task.

Am I forgetting something? I dont think I am!
Hey, I never said the terminator can't attain lift in air by flapping its limbs.

For sure though it's going to generate significant cavitation. Even animals and machines built to swim or pump in water suffer cavitation. The gravelly noise from cheap aquarium pumps is of cavitation bubbles oscillating around the impeller. And when cavitation grows to nearly envelop a fin or impeller, we really can say we're working in air as opposed to water, i.e. flying not swimming. The latest generation of torpedoes, note, literally fly underwater within a "supercavitation" bubble. The bubble is generated by a very unstreamlined nose. That works great with missile propulsion but it's totally incompatible with swimming by fins or, worse, terminator legs.

Anyway, most of a terminator's effort will be wasted in stirring water back and forth. Then stirring a boiling chaos of water vapour. At some point the terminator is going to be flapping in air.

EDIT: Just remembered the "Jesus" lizard that runs over water. And I didn't consider a terminator swimming (scampering?) along the surface. So maybe a terminator can cross water provided it doesn't get submerged?

11. Originally Posted by Pong
EDIT: Just remembered the "Jesus" lizard that runs over water. And I didn't consider a terminator swimming (scampering?) along the surface. So maybe a terminator can cross water provided it doesn't get submerged?
I guess it might look a bit like those powerful racing motorboats which seem to stand on their propeller, with the hull almost completely out of water.
When the hull of such a boat does get completely out of water, it loses stability and flips over backwards, sometimes killing the driver; a terminator would have to control its leg movements in very sophisticated ways. But yes, in principle it can be done.

12. In any case clothes and flesh would part from a furiously hyperactive mechanical skeleton. Ribbons of tissue would litter the roiling water. Skeletal limbs don't pull much, so a terminator must flail even harder.

On screen, would this seem monstrously unstoppable or just pathetic? :?

13. Originally Posted by Pong
In any case clothes and flesh would part from a furiously hyperactive mechanical skeleton.
Actually, our clothes and flesh are both made of carbon-fibre-reinforced Kevlar...

Did I say our? Damn! Now I will have to kill you.

14. lol @ Leszek.

Pong I see your point. I still would err on the side that it would likely be possible for such a machine to swim - be it inefficiently.

Id love to see a terminator running across water, that would just make my day if it happened on the show. The thing would look completely retarded. :-)

I also wish we saw one trying to fly by flapping its arms on the show. That would also be funny as hell...

On a side note, anyone wanna take a guess how long till we have self aware AI? Or if it will happen at all?

15. I am trying to think of a way to make such a water-treading machine. On miniature scale, probably powered by a twisted rubber band (like the one you use in simple model planes). Would be a great educational toy for my nephews. Ideally, I'd like them to help me build it.
But it's on the back burner for now; got a job to do.

16. Try placing a tiny amount of partially melted bar soap at one edge of a piece of plastic shaped like a half ellipse. The soap's reaction to the water also gives thrust.

17. The way I've seen that done is to carefully float a notched piece of aluminum foil or thin wood on water and then put a drop of liquid soap into the notch.

18. *laughs crazily* okok, that was fun reading the questions and replies. Here's my take on the oxygen doesn't really matter thingy: Think submarines dudes. They weight THOUSANDS of Kgs and still mange to THRUST in the sea. But then, to sink or swim, they intake or expel water in their tanks right? So yea. Maybe the terminator should just inhale alot of air with her super big.....LUNGS and also flap alot.

I suck, S-U-C-K in physics coz i can never understand why the workings and equations are the way they are. Newtonian physics anyways. Cheers :P

19. You wan to noe wether it can swim anot juz catch 1 n throw in to a deep pool simple

20. Originally Posted by oceanwave
Maybe the terminator should just inhale alot of air with her super big.....LUNGS and also flap alot.
The assumption was that the terminator has the size (and consequently volume) of a normal human. Super big lungs filled with air would make it bigger. They don't have to be lungs (have the blood oxygenating function) for this purpose; just huge plastic bags filled with air will do. You can float a lot of weight this way.
And no it's not about oxygen. Fill those bags with nitrogen, CO2, helium, hydrogen, butane, they will still float and support a lot of weight.
If you fill your bags with petrol or alcohol, they will float too, but will support less weight.
Floating is all about getting the right proportion of volume to weight.

21. hahahaha...yes yes, i do know about the oxygen part. Its not really the oxygen but the gas that increases buoyancy. Best if terminators have lungs/plastic bags filled with Hydrogen gas huh?

 Bookmarks
##### Bookmarks
 Posting Permissions
 You may not post new threads You may not post replies You may not post attachments You may not edit your posts   BB code is On Smilies are On [IMG] code is On [VIDEO] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are On Terms of Use Agreement