Out of Pod Experience

0/10. Try trolling someone else, anyone with a degree knows you're an idiot now.

Didn't I just tell you to troll someone else? Are you really that needy for attention?

oh my, such frustration! such tension! how entertaining =D

let's start at the end and work our way backwards, shall we?

first, these two statements...



and



... are incorrect (the first being completely incorrect and the second being incorrect in the context the discussion concerning magnetic confinement fusion).

the force acting on a charged particle of charge q and velocity V in the presence of a magnetic field B is precisely F = qV X B where all bold face characters are vectors. there is actually much more going on in this equation, and there are other ways it can be expressed, but this is generally the most familiar to people. the value of F can be either positive or negative, and so the charged particle can experience both attractive and repulsive forces with respect to the source of the magnetic field. this confusion may be from the close relationship between electric and magnetic fields.

consider a charged particle traveling in a straight line that suddenly enters a region of space with a local magnetic field of B. when it enters this region it experiences a force proportional to its velocity and it begins to move along a curved trajectory. now, lets say we didn't know that this field was a magnetic field. knowing the mass, charge, and velocity of the particle we could still conclude that there IS a magnetic field present because of how the charge accelerates. HOWEVER, what if we decided to move with the charge, matching its initial velocity of V? from our perspective the charge now has a velocity of 0. when we enter the region of space with the field, we will see the charge begin to accelerate! because we see that the charge had a velocity of 0 from our perspective, we can measure the acceleration and conclude that it is under the effect of an ELECTRIC field!

from these two conclusions we can see that both electric and magnetic fields are related by relativity transformations (be it special or Galilean). the electric and magnetic force were the first two fundamental forces to be unified mathematically, forming the electromagnetic force.

your statement that all particles have an electric field is, presently, incorrect by simple counter example: the neutrino, which has no charge or electromagnetic moment of any kind. it is a fully neutral lepton. i included the qualifier "presently" because if the Higgs field exists, and can be successfully coupled to the EM field, then this may no longer be the case, though current evidence in so far as we can measure it, suggests otherwise.

the second statement should also be answered by the above discussion, linking the electric field, magnetic field, and v together. whether or not a system has a magnetic field is a matter of reference frame.

ooooook, there are some fairly important corrections to this statement that i feel i need to make... i mean no offense by this



i go over the details of different fusion processes (known as confinement methods) in post #307 of page 16 of this thread. Magnetic Confinement fusion using a TOKAMAK device is the current most promising method for using fusion as a source of energy. the ITER project, which is currently under construction, should, even within engineering uncertainties, produce a few percent more electrical power than it takes to run. this method is STABLE is is designed around maintaining a long term state of equilibrium within the confined plasma. the pulse reactions you are referring to are most likely Inertial Confinement, which is often used to study heavier or short lived fusion processes.

the method of fueling a ship using interstellar deuterium was first proposed in 1960 and is known as a Bussard Ramjet. the device that catches the local deuterium ions (and other fussable material) is known as a Ram Scoop, and is simply a set of two "loops" of magnetic field extending out in front of the ship. as the ship moves through the interstellar gas, the relative velocity causes the ions of the gas to accelerate along the field line into the ship. this can be done very cheaply in space if we can create super conducting materials that remain so at interstellar temperatures. the magnets can then simply be "charged" with current, which they will then hold until quenched. the feasibility of such a device is primarily reduced by the estimated deuterium densities of interstellar space, and not the technology itself. it had a great deal of support among the scientific community when it was first proposed, and was even mentioned by Carl Sagan in Cosmos. even it if cannot fuel a starship entirely on its own, the idea has merit just from an efficiency standpoint. do not cast it aside so casually.

1) a common question that i get asked a lot, which basically boils down to "what's the point?". there are many answers to this question, the most important of which is that knowledge about the past helps us predict the future. the physics we gleam from the universe by examining very distant, very old objects is still relevant because the current evidence suggests that the physical laws of the universe do not change with time. this is known as Temporal Symmetry, and i comment on this earlier in the thread. such new physics also inevitably leads to new technology though a better understanding of the universe itself.

2) to understand something like gravity is to harness and use it. without a proper understanding of gravity we wouldn't have cellphones, GPS, the Hubble Telescope, or any understanding or knowledge of the existence of Legrange points. also, because it's cool.

3) i do not understand this question. time is a dimension of the universe, while gravity is an effect on and within it. to ask "why make a difference between time and gravity?" is akin to asking "why make a difference between length and acceleration?". the only answer i can give you is "because they are different..." :p

How are charged particles repelled by a magnetic field? With a magnetic field in itself this is impossible. It does not "repel", if the magnetic field is weakened the charged particle simply moves further away but not by a force that repels it, nor does it really attract it directly towards the magnetic field line. This is suspicious. If you want to do what you mentioned in the second paragraph, fine, but the basic definition of a magnetic field is as you already said, which again, doesn't really attract or repel. In fact, a magnetic field on it's own does zero net work.

This is exactly what I meant about pulsing though, though I'm not sure what you mean by "fusion cycle". Though the TOKAMAK might have been the first to be implemented, there are many other designs out there that use a magnetic confinement method which are just as promising.

Also, I have a hard time considering that stable from a power producing point of view. From what I remember, the main method that was considered in producing power from a fusion reactor was essentially just replacing the fission reactor with a fusion reactor in a common PWR. Having a reactor that increases and decreases in power in cycles like that? That's a terrible design, when you think of the long list of problems that would create in terms of managing the power output so that it has a constant frequency, even down to thermal stresses over the life of the system, ergo in order for it to really be considered stable for power, it needs to run continuously without stopping.

Some of the first clocks humans invented were sun clocks, hour glasses and pendulums. Before then we did not talk about time and we did not measure it. At best did we look at the sun itself and its position to get a sense of time. Hour glasses and pendulums are devices that require gravity in order to work. Sun clocks use Earth's rotation and thus were independent from gravity, but if we were to improve the measurement would we possibly have to include the gravitation of the Sun and planets. The point however is that at the beginning of human time measurement were we not independent from gravity as we believe to be today.

Today we use atomic clocks for time measurement and we see time as another dimension. But we cannot move freely along this dimension. We also know from the theory of relativity that time slows down in strong gravitational fields. We only imagine moving back and forth in time just as we imagine travelling faster than light, but we know that both is not possible. It leads to the question if time actually is another dimension and how it is independent from other dimensions.

Hence the question, why do we make a difference between time and gravitation?

inducing a charge in an object is certainly possible, but it would require you to physically move the charge from the source to the object. we can create coherent ion beams, so assuming the projectile can hold the charge, then, perhaps? the result would be soft scattering; the projectile would not immediately change direction as if it hit a wall, but rather, it would slowly change its trajectory along a smooth continuous path... in order to create effective shielding it would require massive MASSIVE field strengths. the exact values would depend on the momentum of the projectile and how much it needs to be scattered.

i comment on possible FTL travel methods in post #260 on page 13. our current understanding of physical principles do not disallow FTL travel, merely the acceleration of a mass past the speed of light. Einstein is often misquoted about this. the energy required to move an object with mass at a specified velocity increases asymptotically towards infinity as you approach c. but there are ways around this through tricks wormholes and spacial compression and the like. check out the post! details are there