As a non science person but with odd imagination, is it possible that you can "force" a growth in a controlled environment (this is all pure science fiction and just throwing out random idea)
So we got couple of issues:
Heat - what about incubation chamber or something with cooling?
Food - would direct nutrient feeding the body at various entry (iv style also this might provide cooling in certain area of the growth)
Body sustainability - assuming we can trigger starting and stopping of growth I guess we use a really super computer to do this
Yes, growth can be forced. All growth is 'forced' in some way, as a response to some sort of stimulus. On its own, a cell will just keep living until its genetic material either fails (look up
telomeres for more info) or it reaches some predetermined suicide condition (something called
apaptosis). Apaptosis is (partly) the reason you don't just continually get larger and more massive until the day you die. In fact, cancer can be seen as the failure of this mechanism.
Being in a cold climate, underwater, or inside of some sort of incubation chamber (ie, an ideal environment, whether artificial or natural) will allow an organism to grow
faster by being able to
expend more energy without overheating, but still not in realtime as seen in TV/movies. The larger/more massive an organism is, the more heat it will generate that it will need to dissipate and the smaller the surface area it will have available to do so. Paradoxically, an environment which is
too cold can actually
slow growth, since metabolism/cell division is at its heart a chemical process, and chilling any chemical reaction will cause that reaction to slow down.
Feeding at certain specific key points would reduce the amount of blood vessels the body would need to create AND it would increase the amount of nutrients available to the organism, since the body would not have to rely solely on the nutrients absorbed in the digestive tract (it's not terribly efficient...which is why intestines are so long in the first place). An acquaintance in high school was in an automobile accident and was hooked up to IVs for a while, and she reported the interesting side effect that her nails grew long amazingly quickly as a result. Not exactly laboratory conditions (did they just grow because she was stuck in a hospital bed and couldn't run around and break one?), but until someone really does a scientific study, it's all anecdotal. Even if you
do deliver a highly oxygenated and concentrated supply of nutrients, though, you still haven't solved the problem of eliminating the amount of waste generated AND you will still be limited to feeding the cells themselves only as fast as they can diffuse the nutrients across their individual membranes. Unless you are injecting nutrients directly into each individual cell, they will be limited by the speed of osmosis.
Starting/stopping is already handled, your problem mainly involves discovering the specific stimulus necessary to either tickle a process into starting or rein it in. The trouble lies in getting the quantity/sequence right. Give a teenager an overdose of growth hormone and . The trouble with switching these things off and on is that you have to tell
all the cells what is going on. If only a few get the message, you don't get any changes. If I send the message "You are now an elephant!" out and successfully influence 500 million cells, that's still only 0.005% of the most conservative estimates of the total number of cells in the human body (estimates range anywhere from 10-100 trillion), or about a sixth of an ounce (4.5g) of a 200lb (91kg) adult (I've just converted approximately one teaspoon of your body into an elephant! Mwaa-hahahhahaaa!). Unfortunately, most of the chemical messengers (hormones and such) that the body uses to signal these sorts of things tend to be very fragile and short-lived, so they tend to be made onsite in order to be properly effective (this minimizes oxidation/malformation/decay). Most hormones are dumped directly into the bloodstream by whatever organ produces them. Cells then react by picking up these messengers, assuming there are enough to go around.
As a related aside, there is a big difference between hypertrophy and hyperplasia. Both of these are forms of unusual growth, but hypertrophy is the enlargement of individual cells (correct quantity of cells, just each one is larger) while hyperplasia is an unusually large proliferation of cells (each cell is the right size, but there are more of them). Both could result in, say, an abnormally large liver, but each is treated separately. This is why biopsies are so important.
Mind you, I'm no expert on the subject, it's just that you've hit on one of my (many) areas of curiosity. It was the fascination to learn more about how things grow/reproduce/die (and the cellular mechanisms involved) that led to me taking up the field of research biology in college. Too bad all the prerequisites killed that dream.
--Patrick