Imagination

This is a discussion on Imagination within the A Brief History of Cprogramming.com forums, part of the Community Boards category; >>"The mass of the fuel does increase, but why do you forget that the mass of your rocket also increases ...

  1. #106
    train spotter
    Join Date
    Aug 2001
    Location
    near a computer
    Posts
    3,856
    >>"The mass of the fuel does increase, but why do you forget that the mass of your rocket also increases with it, hence, more fuel is required for it's acceleration.

    Overall, the relative proportion remains the same."


    Relative to the crew, the rockets proportions have not changed, so why should its ability to accelerate? What stops it reaching light speed?

    EDIT: Now I see Clyde has changed the 'not enough energy in the universe to reach light speed post'.
    Last edited by novacain; 06-05-2002 at 10:56 PM.
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  2. #107
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    "EDIT: Now I see Clyde has changed the 'not enough energy in the universe to reach light speed post'."

    I have? I don't follow.

    There is not energy in the universe to accelerate an object to lightspeed. Because an infinite amount of energy would be required to do so.

    Say you go from 0 - half the speed of light, your mass doubles, then you go from 1.5 *10^8 to 2.25, your mass doubles again, then to 2.625 your mass doubles again....

  3. #108
    train spotter
    Join Date
    Aug 2001
    Location
    near a computer
    Posts
    3,856
    Sorry Clyde.
    Missed this in re reading. Thought you had edited out. My bad.

    >>Say you go from 0 - half the speed of light, your mass doubles

    Not relative to me in the rocket, to me there is no change. The rocket to fuel ratio (therefore the ability to accelerate) remains in proportion.

    What if I create a power station rocket.
    Put it in orbit, 'sling shoting' it round the planets, using their gravity, to get its speed up to half light speed.
    Then the mass of fuel I have will double.
    Then I can burn it in the power plant and beam it back to earth.
    Half of the power would be from the increase in mass and so free.

    In other words I can create energy from nothing.
    "Man alone suffers so excruciatingly in the world that he was compelled to invent laughter."
    Friedrich Nietzsche

    "I spent a lot of my money on booze, birds and fast cars......the rest I squandered."
    George Best

    "If you are going through hell....keep going."
    Winston Churchill

  4. #109
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    "Not relative to me in the rocket, to me there is no change"

    No thats not true, relative you your time dilation is unobserved, however your increase in mass is very much observed.

    "The rocket to fuel ratio (therefore the ability to accelerate) remains in proportion. "

    The rocket to fuel ration will remain in proportion BUT you acceleration will decrease, because your mass will have increased.
    Rocket fuel is oxidised to create high temperature gas, that shoots out the back of the rocket pushing it forward, increasing the mass of the rocket fuel does not increase the energy released by burning it, so your acceleration decreases.

    "Then the mass of fuel I have will double.
    Then I can burn it in the power plant and beam it back to earth"

    Your fuel with twice as much mass will release the same amount of energy as your fuel at normal mass.

    "In other words I can create energy from nothing"

    Even if your rocket fuel trick worked it would not be producing energy from "nothing", because your sling shot technique doesn't create energy from nothing, using the sling shot technique you still need fuel, it can however allow use of less fuel because it makes the process more efficient.

  5. #110
    *
    Guest
    Actually, you can do anything in your imagination, because your mind is unfettered by physical laws.

    Real life is different.

    As far as actually being able to do anything at all... we are limited by the constraints of the physical universe. Laws which are immutable.

    There most certainly are things we cannot, and never will be able to, do.

  6. #111
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    "Actually, you can do anything in your imagination"

    Your imagination is constrained by your experience, blind people cannot imagine colour, deaf people cannot imagine sound, people living in 3 dimensional space cannot imagine >3 dimensional space, etc. etc.

  7. #112
    Registered User
    Join Date
    Apr 2002
    Posts
    132
    It is possible to imagine >3 dimensional space. Here is an article I found describing how to imagine higher dimensions.

    "To visualize higher dimensions, consider a Japanese tea garden, where carp spend their entire lives swimming on the bottom of a shallow pond. The carp are only vaguely aware of a world beyond the surface. To a carp "scientist," the universe only consists of two dimensions, length and width. There is no such thing as "height." In fact, they are incapable of imagining a third dimension beyond the pond. The word "up" has no meaning for them. (Imagine their distress if we were to suddenly lift them out of their two dimensional universe into "hyperspace," i.e. our world!)

    However, if it rains, then the surface of their pond becomes rippled. Although the third dimension is beyond their comprehension, they can clearly see the waves traveling on the pond's surface. Likewise, although we earthlings cannot "see" these higher dimensions, we can see their ripples when they vibrate. According to this theory, "light" is nothing but vibrations rippling along the 5th dimension. By adding higher dimensions, we can easily accommodate more and more forces, including the nuclear forces. In a nutshell: the more dimensions we have, the more forces we can accommodate."

  8. #113
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    The article says nothing about imagining 4d space, is merely points out that fish who only concieve of 2d space, cannot imagine 3d space, likewise we who live in 3d space cannot imagine 4d space.

    It is fundamentally impossible to imagine 4d space (this is spacial dimensions not temporal incidently).

    You can't picture something in your head, that is fundamentally different to anything you have ever experienced.

  9. #114
    Registered User
    Join Date
    Apr 2002
    Posts
    132
    ok... imagine higher dimensions as if they were to us what three dimensions were to the fish
    Last edited by mike_k; 06-07-2002 at 01:51 PM.

  10. #115
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    "ok... imagine higher dimensions as if they were to us what three dimensions were to the fish"

    That is exactly my point you CAN'T imagine them so you have to use something you can imagine and then say, if we treat it like this, then ..... What you're doing is drawing a parrallel NOT actually imagining (IE. picturing in your head) a 4th dimension.

    In the same way, you could try and explain colour to someone who was blind, by saying there was another sense just "like" the other 4 sense, as different to them as they are to each other. It allows you to work out the position of everything around you, and just as somethings that FEEL the same, can SOUND different, in the same way things that feel and sound the same can look different.

    With that explanation the blind person may have a fair idea what sight is, but he still cannot imagine it.

    Your article expresses the point well:

    "To a carp "scientist," the universe only consists of two dimensions, length and width. There is no such thing as "height." In fact, they are incapable of imagining a third dimension beyond the pond"

    We are incapable of imagining a fourth dimension.
    Last edited by Clyde; 06-07-2002 at 02:12 PM.

  11. #116
    Registered User
    Join Date
    Apr 2002
    Posts
    132
    i·mag·i·na·tion Pronunciation Key (-mj-nshn)
    n.

    The formation of a mental image of something that is neither perceived as real nor present to the senses.

    Therefore, the blind man, even if he does not actually understand color the same way we do, has still imagined it, for he has formed a mental "image" that is not known by his senses.

  12. #117
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    Are you being deliberately obtuse?

    The blind man CANNOT get a mental picture of red, he CANNOT imagine it. He has been told its LIKE something he can imagine.

    He can think about the concepts involved, but he cannot imagine red. The article YOU cited describes the same occuring with fish who only percieve in 2 dimension.

    "To a carp "scientist," the universe only consists of two dimensions, length and width. There is no such thing as "height." In fact, they are INCAPABLE OF IMAGINING a third dimension beyond the pond"
    Last edited by Clyde; 06-07-2002 at 07:09 PM.

  13. #118
    Registered User
    Join Date
    Apr 2002
    Posts
    200
    Wow...what a beautiful argument. I'm not going to take sides, because it is rather difficult to distinguish them anymore. So I'll stick to correcting inaccuracies...
    It's pedantic time, baby.
    [pedantic]
    By Clyde, I think
    Mathematics cannot by definition have "limits", it can be impossible to predict phenomena with maths (Chaos theory), but maths itself cannot reach a point where it no longer "works". And don't give me this "assertation" nonsense either, if you think maths has "limits", explain how maths can POSSIBLY HAVE "limits".
    That is false in the sense that there are true theorems in a system that cannot be proved within the system.

    By Clyde
    but i do know that they can track the universes age back to a billionth of a billionth of a billionth of a billionth of a billionth of a billionth......... of a second.
    Wouldn't that be (10^-9)^6=10^-54? That is 10^12 times less than the Planck time, so unless I haven't heard about new research that is wrong.

    By Clyde
    No i'm not describing the properties, i'm describing the observations, you go to your wavelength machine and you measure the wavelength, you get an answer, doesn't matter who makes that measurement they will get the same answer, hence objective.
    Incorrect. If I am getting closer to a star and you are getting farther away, and we pass by each other and at that moment measure the wavelength, we will not get the same answer.

    By Clyde
    Say you go from 0 - half the speed of light, your mass doubles, then you go from 1.5 *10^8 to 2.25, your mass doubles again, then to 2.625 your mass doubles again....
    I do not think so. At 0 m/s, my mass is around 70 kg. At 1.5*10^8 m/s my mass is going to be around 80.3 kg, not 140. To my knowledge, relativistic mass is (rest_mass)/sqrt(v^2/c^2), where v is velocity and c is the speed of light.

    By Clyde
    ....... the laws of physics are the same everywhere.
    No, the laws of physics are the same in all inertial frames of reference.
    [/pedantic]

  14. #119
    The Earth is not flat. Clyde's Avatar
    Join Date
    Mar 2002
    Posts
    1,420
    Heavens you again.....

    "That is false in the sense that there are true theorems in a system that cannot be proved within the system"

    I said as much in the thread that not everything was deriveable, however that wasn't quite what i was arguing.

    "Wouldn't that be (10^-9)^6=10^-54? That is 10^12 times less than the Planck time, so unless I haven't heard about new research that is wrong"

    Yea, there are two more billions there than neccessary, hardly a big deal, i was attempting to illustrarte that the universe could be tracked back, to a tiny fraction of a second.

    "Incorrect. If I am getting closer to a star and you are getting farther away, and we pass by each other and at that moment measure the wavelength, we will not get the same answer"

    I'm aware of red and blue shifts, but that has nothing to do with humans subjective measurement. Thats a direct and predictable occurance, due to the effect differring physical environments. Furthermore, your example is somewhat irrelevant because they are using two separate measuring devices, and getting two separate answers, if you swapped the person doing the measuring in each case, you would still get exactly the same answers, which was my point to start with.

    " do not think so. At 0 m/s, my mass is around 70 kg. At 1.5*10^8 m/s my mass is going to be around 80.3 kg, not 140. To my knowledge, relativistic mass is (rest_mass)/sqrt(v^2/c^2), where v is velocity and c is the speed of light"

    It was a simplification, I wasn't attempting to give an accurate picture of what occured i was attempting to show them an example of why you couldn't just use more reocket fuel hence push harder to overcome the increase in mass. I just used a simplified scenario because it was easier, the actual values are different, but that is irreleveabt to the point i was trying to make.

    "No, the laws of physics are the same in all inertial frames of reference"

    I'm not sure about that Fyodor, please clarify.

  15. #120
    Registered User
    Join Date
    Apr 2002
    Posts
    200
    That is one of the postulates from which Einstein derived the Special Theory. There are a lot of sites on the net, here is one that's okay: http://www.phy.ntnu.edu.tw/java/rela...elativity.html

    From the mouth of the master himself, we have the slightly more impenetrable:
    We advance a step farther in our generalisation when we express the tenet thus: If, relative to K, K' is a uniformly moving co-ordinate system devoid of rotation, then natural phenomena run their course with respect to K' according to exactly the same general laws as with respect to K. This statement is called the principle of relativity (in the restricted sense).
    [I believe K in this case is any Lagrangian coordinate system, described by q, q-dot, but I doubt it matters]
    which is pretty much the same thing. A pretty good, slightly technical site on the subject is http://www.cbloom.com/physics/relativity.html
    I go to encounter for the millionth time the reality of experience and to forge in the smithy of my soul the uncreated conscience of my race.

    Windows XP consists of 32 bit extensions and a graphical shell for a 16 bit patch to an 8 bit operating system originally coded for a 4 bit microprocessor, written by a 2 bit company, that can't stand 1 bit of competition.

Popular pages Recent additions subscribe to a feed

Similar Threads

  1. Pretty Optimistic
    By mithrandir in forum A Brief History of Cprogramming.com
    Replies: 42
    Last Post: 11-06-2001, 09:27 PM

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21