It all comes down to infinity. Theoretically, if we could build a ship strong enough, we could fly at 99.99999999999% the speed of light. Forever getting closer, but never actually achieving it. Infinity is a hard concept to grasp, but once you achieve the speed of light, everything becomes infinite. (At least according to relativity). That means your mass would be infinite. You would have length contracted to zero (Infinitly thin 2 dimensional object). You would appear as if time had stopped completely for you (Frozen infinitly). we cant get to infinity as far as our mental capability is concerned. Someone on here even said something else though I cannot remember who. It was a good point. Your gravity would become infinite, therefore everything would accelerate into you at an infinite rate. You would become a singularity. A black hole the size of an infinitely small point.

Originally posted by Kano
Hrm, I think the mass flowrate would stay the same. As the mass of the fuel (or whatever you are flinging out the back of the engines) increases. The amount by which it can be accelerated by the engines decreases, as the engines extract no more power from a fuel by it being more massive. This rate of slowing should be inversely proportional to the rate the mass of the fuel/reactionary mass is increasing. Thus the flowrate should remain the same?

No, no, no. The engines are going to "burn" (and we're just going to have assume a combustion type for now) whatever it was they could burn, but the EFLUX would increase, and hence the thrust.

Same thing happens on a BUFF. They USED TO (don't know if they still do this now or not), injected water just at the exit of the combustion chamber to increase the mass flowrate out of the engine, and increase the thrust. The water didn't have anything to do with the combustion effeciency of the engine, it just increased the mass of the eflux. That's why when you would see a B52 taking off...it would look like it's engines were on fire and belching out thick black smoke...that was from the water binding with the unspent hydrocarbons.

So, what I am saying is, if you have an engine that burn a certain amount of fuel, and you increase the mass of that fuel, your EFLUX will increase and hence your thrust. It's already proven.

Originally posted by greenkoolaid
I would think that eventaully you wouldn't even be able to fling the fuel out the back. The weight of the ship and the fuel itself would be so large that the energy from the combustion wouldn't even be able to move either one. I am not sure what would happen, maybe the fuel would simply get blocked up in the rocket.

Okay, you have a good point on moving "liquid" fuel, but what if it is solid fuel? Then it doesn't matter. The ignition and combustion process doesn't care what the mass of the solid is it is burning. And since the energy released is associated with the mass-dependent latent energy of the fuel, as it burns you get more energy out than you would prior to the mass increasing.

A few interesting points. As the mass of the fuel increases, the energy released by it does not increase in line with the mass. There are still the same amount of molecular reactions occuring, thus the same energy being released.

Now the mass of the spent fuel exhaust (and any other reactionary mass we add to the efflux) is increasing, but the energy released by this fuel is not increasing. As such the velocity of the efflux would decrease. However the kinetic energy imparted to the ship would remain the same, as the reactionary mass is larger and larger.

On a side note, I'm not particularly familiar with the engines on the B-52, but I'd imagine that due to aerodynamic factors it is more efficient to have a slower heavier efflux than a faster light one. Hence adding the water to the outflow, the total kinetic energy remains the same.

William,

I said everything,

the rest of you said nothing.

Originally posted by Kano
A few interesting points. As the mass of the fuel increases, the energy released by it does not increase in line with the mass. There are still the same amount of molecular reactions occuring, thus the same energy being released.

Now the mass of the spent fuel exhaust (and any other reactionary mass we add to the efflux) is increasing, but the energy released by this fuel is not increasing. As such the velocity of the efflux would decrease. However the kinetic energy imparted to the ship would remain the same, as the reactionary mass is larger and larger.

On a side note, I'm not particularly familiar with the engines on the B-52, but I'd imagine that due to aerodynamic factors it is more efficient to have a slower heavier efflux than a faster light one. Hence adding the water to the outflow, the total kinetic energy remains the same.

Okay, first off, have you address any potential increases in enthalpy due to the molecular/atomic increase of the fuel?

Second, the kinetic energy of the eflux increases with the mass == > 1/2 m v^2 < = = no getting around it.

Third, the BUFF had to have water injection because its original engines were under powered for the ultimate take-off weights it experienced...so they increased the mass of the eflux ==>1/2 m v^2<== to increase the thrust.

Originally posted by THENEO
William,

I said everything,

the rest of you said nothing.

Actually, neo, of all the posts on this thread, yours lacked the most substance, and said the least per word count of any other post.

so what's your problem? do you want to be called an asshole? or did you not realize that's what you're acting like?

First of all I get slammed as though I said nothing in this thread,

when I pointed out that human knowledge is actually quite limited despite what some here are trying to indicate otherwise,

then I get a so called courtesy warning.

I don't care if everyone in this thread is a rocket scientist.

Who wants to tell me that my intial post was:

A. Wrong?
B. Off topic?

and regarding subsequent posts by me I am asking this:

1. Do I not have a right to stand up for myself?
2. If comments are directed to me then they are on topic are they not?

Neo.

Please make note of the sequence of events:

1. You made a post that was completely genius in pointing out the obvious...kudos.

2. Nobody pointed out that your post was basically....pointing out the obvious.

3. You come back and act like an asshole and say everybody else...who actually is discussing the topic, has contributed nothing.

4. Some one gets pissed at you for your attitude.

5. You start whining.

What is wrong with you?

You don't like hearing truth about Rennes?

so you have to lash out at me here?

William started this,

read the threads!

regarding everyone else's comments in this thread,

let us apply logic here:

if what I originally postulated is correct,

then how much that was said before or after is correct or even relevant to the original idea for the thread?

at best less than 100%.

that is fact,

I am no scientist,

but I do know bad science.

the purpose of science is to learn and explore and grow,

NO ONE KNOWS IT ALL!

thank you.

Originally posted by Valhall

Okay, first off, have you address any potential increases in enthalpy due to the molecular/atomic increase of the fuel?

Second, the kinetic energy of the eflux increases with the mass == > 1/2 m v^2 < = = no getting around it.

Third, the BUFF had to have water injection because its original engines were under powered for the ultimate take-off weights it experienced...so they increased the mass of the eflux ==>1/2 m v^2<== to increase the thrust.

Why would the enthalpy increase? There is no increase in the number of molecules. Their mass increases, so the specific enthalpy would decrease. The energy stored in the fuel would remain the same.

The velocity of the efflux from the engine is not a constant, increasing its mass will just lower the velocity to keep the same kinetic energy.

Regarding the BUFF engines, it seems the water injection assisted in the transfer of the energy from the fuel into kinetic energy for the plane by a much simpler method than I first suspected. When it vapourises it absorbs excess heat in the engine that would otherwise be wasted.

[Edited on 29-11-2003 by Kano]

Originally posted by Kano

Regarding the BUFF engines, it seems the water injection assisted in the transfer of the energy from the fuel into kinetic energy for the plane by a much simpler method than I first suspected. When it vapourises it absorbs excess heat in the engine that would otherwise be wasted.

[Edited on 29-11-2003 by Kano]

no, no, no...you're hurting me!

the velocity from the engine - v - of the eflux is dependent on the engine efficiency - the only thing the water injection does is increase the m which is moving at the engine's v...that's it, nothing more.

BUT, I will give you that since what we are talking about is the mass ENTERING the engine - instead of being added past the combustion point - your argument is correct. Because the engine can only impart so much energy to the fuel it takes in...so if the mass increases, the velocity imparted by the engine decreases. If it were being increased past the point that the eflux velocity is being achieved...THEN we would approach infinite thrust.

So basically, now that we have righted that logic, this would say that the flow through a conventional engine would completely stop....hmmm. circles within circles...

So in theory, if a single atom was travelling at-or near- the speed of light and hit a planetary body, it would hit with a kinetic force unlike any explosion seen on Earth?

I just took a moment to discuss this with someone and decided that an atom would be much to small and would most likely go through the planetary body.

Perhaps a ball of highly dense material about the size of a basketball and fired at a much slower speed would be useful as a planetary defense weapon.
Basically a huge modern gun. lol.

Since we have discovered that the speed of light is not a constant any longer, doesn't this throw a wrench into Einstein's law of general relativity?

1:no...not flawed.
2: the speed of light is the max. it is physically impossible to improve on it, quote: a particle physisist of unknown source at a UNI attendance from last year.

nothing can stay in one peice, not even electrons..at the speed of light.
however
research is currently being done on reflecting photons fast enough upon a metal surface, it is possible to concentrate more than one photon upon a reasonable surface, in turn pushing the emmitted electron from the metal surface at twice the speed(this does not mean the electron will remain in tact at speed of light).
Cyrus


Cyrus

Okay, so you can get light to go slower then 186,000 miles per second, but not faster, correct?
However, if mass increases to infinity at the speed of light, then why can photons go the speed of light and still remain relatively massless. If infinity is truly infinity, then even something as small and light as a photon multiplied by infinity would be pretty heavy...

All we need to do get around physics....Shouldn't be that hard ey?

Of course not...WE have 6+ billion people on this planet. I'm sure we can think of something or already have.


Electromagnetism can interfere with space/time. If we can distort space, time, we dont need to be travelling at the speed of light.

Int he future we will have technologies that will be out of this world completely. Things you cant even imagine.

Imagine this. Something on a UFO looking ship....that can make it go from one spot int he universe to another spot in the universe, instantly.

if i can imagine it....All that needs to happen is for the sciences, discoveries, and technological achievements to happen, and it will be so.

I guarantee it.

Imagine a Black hole....being created in front of your space vehicle, the ship being sucked towards it but the black hole moving forawrd with tthe ship.....faster than the speed of light?

I was wondering about gravity as well. Gravity increases as mass increases. So how does light go at its speed without sucking in the person to the flashlight? Answer: it doesnt.

Black holes probably have a light that goes higher and does achieve infinite mass, thus it sucks everything into it. As for me, I dont believe that light is the fastest speed possible.