Resources on the "Scientific Unrealism" of Trek

[Bounty]

An article ike that one has popped up once a month, every month, for the past forty years. It's interesting research but it's in the same category as "Star Trek predicted cellphones"; a stylistic link that makes for a nice headline.

[bz249]

Anyone see this article today? Star Trek's Warp Drive "not impossible":
http://news.yahoo.com/s/space/20090506/ ... impossible

Faster than light maybe possible... Star Trek warp definitely impossible

[Darth Wong]

Anyone see this article today? Star Trek's Warp Drive "not impossible":
http://news.yahoo.com/s/space/20090506/ ... impossible

Science journalists are not scientists. They take things scientists say and absurdly distort them.

[Kurgan]

Okay, but I bet if you put a science journalist on the shoulders of a scientist and move them around, they'd go where the scientist went and people might think what the science journalist was saying was what the scientist said!


Or something...

[JGregory32]

For the powered orbit, would it make sense if the mass-lightening field was left on the whole time? I.e. if the field makes the ship mass 1% of its normal mass, then if something happens to the field, the ship 'gains' its original mass back, and slows to 1/100 of its original velocity.

Small problem with that. Removing the mass-lightening field would not slow the ship because no momentum has been gained or lost. The ship would continue foward at its present speed and heading but changes in velocity or heading would require much more energy than they did before.

This was brought up on another threat somewhere and some one noted that you either have to obey the conservation of momentum or the conservation of energy when dealing with a Trek style mass-lightening field.

When a trek ship in orbit loses power it begins to deorbit rapidly. I'm not an expert on orbital mechanics (in fact I know very little.) but could this not be becasue the orbit they choose when the ship weighed only 1% of its mass is insufficent for a ship weighing the full mass?

On another note is it possible that they need to frequently change orbits to dodge debries, satelites, or space stations?

[Isolder74]

For the powered orbit, would it make sense if the mass-lightening field was left on the whole time? I.e. if the field makes the ship mass 1% of its normal mass, then if something happens to the field, the ship 'gains' its original mass back, and slows to 1/100 of its original velocity.

Small problem with that. Removing the mass-lightening field would not slow the ship because no momentum has been gained or lost. The ship would continue foward at its present speed and heading but changes in velocity or heading would require much more energy than they did before.

This was brought up on another threat somewhere and some one noted that you either have to obey the conservation of momentum or the conservation of energy when dealing with a Trek style mass-lightening field.

When a trek ship in orbit loses power it begins to deorbit rapidly. I'm not an expert on orbital mechanics (in fact I know very little.) but could this not be becasue the orbit they choose when the ship weighed only 1% of its mass is insufficent for a ship weighing the full mass?

On another note is it possible that they need to frequently change orbits to dodge debries, satelites, or space stations?

Momentum is m x v. If one of those terms(mass or velocity) changes momentum has to be conserved. If the mass goes up the velocity has to drop to compensate. So if the magic mass lightening field goes down then the mass has just gone up so the velocity HAS to drop.

[Darth Wong]

I think JGregory32 interpreted those discussion of conservation of momentum in precisely the opposite way from their intended meaning. Perhaps he needs up upgrade his CPU and become JGregory64 before he can understand

[Isolder74]

I think JGregory32 interpreted those discussion of conservation of momentum in precisely the opposite way from their intended meaning. Perhaps he needs up upgrade his CPU and become JGregory64 before he can understand

That's really funny.

i think the problem was he didn't grasp why that if the magic field making the ship appear to have less mass would affect the speed, in lay terms, of an orbital object. Since momentum is an multiplication term system small changes in mass or velocity can have a huge affect on the other when the answer they make can't change.

[Patrick Degan]

Hmm...

I think some people have rather overthought the problem. The object of the exercise is not to try to rationalise a patently ridiculous idea away but to point out just why it's a patently ridiculous idea in the first place. And indeed, the several attempts at rationalisation only pointed out more reasons why it's a patently ridiculous idea.

For instance, just what would be the reason for the Enterprise to use it's subspace mass-lightening field to aid it's orbit around a planet? The main reason for employing the forcefield is to make the ship's acceleration and movement in space easier than it normally would be, but if the ship is going to be at rest in a stable orbit around a planet, there really is no reason to power a forcefield which the ship doesn't need to employ when plain, ordinary gravity and momentum will do the job quite nicely. And why wouldn't Data or Sulu (depending upon your preference), in bringing the Enterprise into orbit, ramp down the subspace forcefield as the ship is making its final approach until it has "reacquired" it's original rest-mass and velocity at the moment of gravitational capture? Presumably, the intrinsic velocity would be that of a planetary orbit to begin with if the Enterprise began her journeys from an orbiting spacedock or in free Earth orbit before powering up the forcefields for travel, and this would be sufficient to maintain the orbit around the planet she's visiting just on momentum.

Besides which, we have seen several instances of the Enterprise in spacedock, or docked with Deep Space Nine, or at rest within a formation of junk ships in high orbit around a planet —all situations in which it's quite apparent that the ship is not using forcefields of any sort to facilitate a stable orbit. Breaking the orbit, on the other hand, is simply a matter of powering up the subspace fields to facilitate acceleration by employing the mass-lightening effect, as Miles O'Brien does to move the DS9 station from it's orbit around Bajor to the Denorius asteroid belt in "Emissary (2)"; which when deactivated, the station at the periphery of the wormhole zone assumed again it's original velocity and rest-mass as it had in Bajor orbit.

By way of illustration, let's examine the behaviour of another entity which acts very much like a Star Trek ship surrounded by it's subspace mass-lightening field: Glinda, the Good Witch from The Wizard Of Oz. Glinda, when she wants to travel, conjures up her magickal soap-bubble forcefield, within which she is at-rest but is able to move at any speed and in any direction at any altitude regardless of the gravity, wind direction, or the intrinsic velocity of Oz at ground-level. And when she wants to land amongst her Munchkin subjects, she is able to slow the bubble until it comes into contact with the ground and dissolves, leaving Glinda standing perfectly steady on the stones of the Yellow Brick Road —or more accurately, at-rest with respect to the intrinsic velocity of Oz through space, which was the state she must have started out in to begin with. She does not need the soap-bubble to remain in place, however, and wishes it up again only when she's ready to travel someplace else.

Similarly, there is no real necessity for the Enterprise to employ forcefields to remain in an orbit or even to enter one, and no real reason to enter a needlessly close orbit and thus put the ship in an unstable condition except through arbitrary writers' fiat. In short, power-orbiting is a patently ridiculous idea.

And no, the Enterprise does not have to change orbits to avoid debris. Sweeping away micrometeorites from the ship's pathway is, after all, the purpose of the navigational deflectors.

[Darth Wong]

Frankly, I feel a twinge of nausea every single time I am forced to type "mass-lightening field". It dignifies the pretentious Star Trek fanboys' technobabble, even if we have no choice but to occasionally use it. As a general rule, we should keep in mind that these are writers' copouts, and as copouts, we should endeavour to resort to them only with great reluctance.

To listen to the hardcore Trekkie is to listen to a person who is eager to use the most complex and "advanced" technology to solve any problem. If you asked him to design a 24th century refridgerator, his idea would probably involve "subspace". It's like the kind of person in real-life whose solution to every industrial design problem involves robotics, even though most of the machines in real factories operate reliably and cheaply with simple devices like cams, limit switches, and simple brackets and linkages.

[JGregory32]

Allow me to lay out my understanding of the issue.
Take a mass of say 100 kilograms( yes I know mass and weight arn't the same, work with me here). We engage the mass-lightening field and it now has a real world mass of 10 kilograms with 90 kilograms hidden in subspace. To accelerate the mass to say 10 meters per second would require (F=1/2(m*v*v)) 500j of energy. Once the object is traveling at 10 m/s we turn off the mass-lightening field and the object now has a mass of 100 kg. However it's velocity does not change. Changes in velocity must be acompanied with by changes in energy, it must either lose energy or gain energy to change it's velocity.
Becasue the act of switching off the mass-lightening field neither imparts nor removes energy from the object it would remain at it's current velocity.
If it changes its velocity then energy would have to be imparted from somewhere.
That's my understanding of the subject, if it is error please let me know and explain what's wrong with it.

[Darth Wong]

Your understanding of the subject is clearly not mathematically based, because your equations aren't equal: something you would realize if you bothered to examine this situation mathematically (and by "mathematically", I am talking about actual math, not just plugging in some numbers to "before" and "after" scenarios without spending the time to write equations to describe your state changes, even though the state changes are the whole point of this exercise). Quantities are magically entering and leaving your thought experiment and you don't notice because you're treating a mathematical situation intuitively: an inherently stupid approach.

Frankly, you should try to do the fucking homework to make your equations balance before asking others to explain the flaws in your thinking to you. This is basic school stuff here.

[JGregory32]

Your understanding of the subject is clearly not mathematically based, because your equations aren't equal: something you would realize if you bothered to examine this situation mathematically (and by "mathematically", I am talking about actual math, not just plugging in some numbers to "before" and "after" scenarios without spending the time to write equations to describe your state changes, even though the state changes are the whole point of this exercise). Quantities are magically entering and leaving your thought experiment and you don't notice because you're treating a mathematical situation intuitively: an inherently stupid approach.

God Damit Darth Wong I'm a historian not a mathmatician!
That said, of course the equations don't balance, the magical trek mass-lightening field breaks fundamental laws of physics. Trek is a fantasy series with loose writing rules so any attempt to define or discuss it in scientific terms is going to be very muddy.
You might as well try to explain why a gold ring can only be melted in a particular volcano, and why the melting of that ring would cause a massive eruption and general devestation. Not to mention why the death of a single person would cause a fortress to collapse.

[Wyrm]

That said, of course the equations don't balance, the magical trek mass-lightening field breaks fundamental laws of physics.

The magical trek mass-lightening field does break the laws of physics as we know them, but not because the energy/momentum equations don't balance. You can conserve the momentum and the energy using regular physics.

Initial conditions:
velocity: v = 10 m/s
mass: m = 90 kg
momentum: p = mv = 900 kg m/s
kinetic energy: K = 1/2 mv² = 4500 J
internal energy: U = 0 J
total energy: E = K + U = 4500 J

Final conditions:
velocity: v = 9 m/s
mass: m = 100 kg
momentum: p = 900 kg m/s
kinetic energy: K = 4050 J
internal energy: U = 450 J
total energy: E = 4500 J

See what I did there?

Mass lightening fields are not kosher for other reasons.

[Darth Wong]

Dammit, Wyrm beat me to it! JGregory32, when the equations don't balance, it means you did it wrong.

It doesn't mean you can just write it off because it's sci-fi. Even in sci-fi, you must balance equations. Maybe you have to add some sci-fi term to make the equations balance, but that only helps understand which theories are better, because some rationalizations require more added terms than others.

[JGregory32]

I am trying to understand this and I really thank everybody for their help.
My problem is that several people have stated that when the field is removed the object should slow down becasue it did not expend enough energy to achieve the velocity in the first place.
That's all well and good but why would an object going at a certain velocity in a vacuum suddenly slow down just becasue it gains mass?
My understanding is an object slows down because either a force acts against it or becasue it transfers it's energy to the surounding enviroment.
Let me describe the what my thinking is.

We have a ship, with the field active now hiding most of its mass. They actvate the engines ang begin accelerating, once they reach a certain velocity they turn off the engines (coasting) and disengage the field. Their mass changes and their momentum changes but why would their velocity change?

I'm not trying to be difficult but I simply don't see where the energy required for a change in velocity comes from.

Wyrm your equations looked good, but they still don't help me in my understanding. You assume the velocity would drop to preserve momentum but why would the velocity drop? What mechanism is acting against the object?

[Isolder74]

Conservation of Momentum

This states that momentum in any system must alway be conserved. Basically momentum is the Mass times the Velocity. If you add Mass to a system when it is in motion, adding nothing else, then the Velocity must go down to conserve the momentum.

[Darth Wong]

JGregory32, you are still thinking intuitively, and then asking why the equations don't match your intuition. That's exactly backwards.

[Wyrm]

Wyrm your equations looked good, but they still don't help me in my understanding. You assume the velocity would drop to preserve momentum but why would the velocity drop? What mechanism is acting against the object?

There are no external forces on the block, so the momentum of the block must remain constant by definition — momentum is conserved, always. The same amount of momentum is distributed among a greater amount of mass, so the velocity must drop. It's operationally equivalent to a 90 kg mass smashing into a stationary 10 kg target — the excess energy shows up as random molecular motion (internal energy).

[JGregory32]

Okay so I'm wrong. I'll admit to that.
Still if lowering the field does slows a ship would raising the field increase the velocity? That's assuming there are stages between full on and full off.
Could be an interesting way to get around fuel and engine requirements huh?

[Wyrm]

Okay so I'm wrong. I'll admit to that.
Still if lowering the field does slows a ship would raising the field increase the velocity? That's assuming there are stages between full on and full off.
Could be an interesting way to get around fuel and engine requirements huh?

What if you're moving along with it, so that in your frame of reference, it's not moving at all when you turn the field on? Which way does it go?

[JGregory32]

What if you're moving along with it, so that in your frame of reference, it's not moving at all when you turn the field on? Which way does it go?

I'll admit I have no idea, I would like to assume that it increases in velocity in the direction of travel but I have already been warned about making assumptions.

[Wyrm]

What if you're moving along with it, so that in your frame of reference, it's not moving at all when you turn the field on? Which way does it go?

I'll admit I have no idea, I would like to assume that it increases in velocity in the direction of travel but I have already been warned about making assumptions.

You are learning something. Making a blanket statement that the velocity increases in the direction of travel is to invite bitter argument, because different observers will disagree what direction the ship was traveling in in the first place. You need to have some standard of what "direction of travel" means.

But even if you specify the direction of travel unambiguously with a special frame of reference, you still have some headaches. For one thing, turning off the field is irreversible; internal energy includes both stored potential energy and thermal energy, and you can't count on all of that energy being in its potential form. Some of it will be as thermal energy, and you cannot recover all of that energy and put it back into kinetic energy.

Remember that we modeled the turning off field as an inelastic collision between a projectile and a stationary target. Simply separating the target from the projectile again is insufficient. To recover the old velocity, the projectile has to exert forces on the target such that the momentum is all back in the projectile. The physics has to be arranged such that everyone agrees on certain salient things about the system, such as whether the ship reaches the planet before the patient dies.

(The book Thinking Physics has a thought problem of similar vein. In one problem, you are given a hopper car running smoothly on a long track. While the car is moving, sand is dropping into the hopper. The hopper keeps its momentum but loses kinetic energy, slowing as it gained mass. In the second problem, the sand input is gone, but the plug in the bottom opens up, letting the sand drain out. This time, the car loses both the momentum and the kinetic energy in equal proportion, keeping the same speed.)

[bilateralrope]

Reference frames are a problem. For example, lets take Wyrm's equations, but start in a reference frame moving with the object.

Initial:
v = 0 m/s
m = 90kg
p = 0 kg m/s
K = 0 J
U = 0 J
E = 0

Final:
v = 1 m/s
m = 100kg
p = 100 kg m/s
K = 50 J
U = -50 J
E = 0

Now instead of the ship gaining 450 J of internal energy it loses 50 J and doesn't conserve momentum.

[Wyrm]

Which is why reactionless drives lead to madness and confusion. Had there actually been a stationary target (in the reference frame where the projectile is going 10 m/s) to smack into, the momenta and energies all work out.

(I personally am partial to the subspace mass reservoir interpretation myself.)