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Thread: Faster-than-light travel: Is warp drive really possible?

  1. Top | #31
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    Quote Originally Posted by Loren Pechtel View Post
    Quote Originally Posted by repoman View Post
    The cross sectional area seems to work against large objects speeding at huge velocities.

    Even for all the area that is NOT being bombarded, the area that is gets the heat from very few sections that are.

    However all of the volume inside is not getting hit, whereas if the same mass was put into a million projectiles there would be 100 times (N^1/3) more surface area.

    Hard to thing about this considering that this is in the near total vacuum of space compared to in the Earth's atmosphere.

    What about some sponge like material to be the shielding?
    A sponge won't make a difference--the problem is the energy being dumped from the collisions. There's no shockwave to deflect the energy like there is when a properly designed spacecraft plunges into atmosphere, it all shows up as heat in your radiation shield. To survive you are going to have to pump that heat away and radiate it to space faster than it's coming in.
    Sounds like a waste. It'd be better to harness that energy and either use it for propulsion or keep the batteries charged. Granted, the math starts really getting funky with these hypotheticals.

    SOL just doesn't seem unlikely. Yes, the same was said of trains. Photons can do it, nearly anything with any kind of mass can't. The speed of light is based on just how much resistance in spacetime there is to transmitting an electric and magnetic force. Once you add mass, there is just so much more resistance.

    Faster than light even less likely. I suppose the question might be, if you can make a ship technically go faster than light... how can you get anything on the ship to work? Can anything exist in a spacetime bubble? The subatomic elements that make up everything are tethered to what exactly? Then there is the issue of electrical and magnetic fields. How do they transmit without spacetime?

  2. Top | #32
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    Quote Originally Posted by Jimmy Higgins View Post
    Quote Originally Posted by Loren Pechtel View Post
    Quote Originally Posted by repoman View Post
    The cross sectional area seems to work against large objects speeding at huge velocities.

    Even for all the area that is NOT being bombarded, the area that is gets the heat from very few sections that are.

    However all of the volume inside is not getting hit, whereas if the same mass was put into a million projectiles there would be 100 times (N^1/3) more surface area.

    Hard to thing about this considering that this is in the near total vacuum of space compared to in the Earth's atmosphere.

    What about some sponge like material to be the shielding?
    A sponge won't make a difference--the problem is the energy being dumped from the collisions. There's no shockwave to deflect the energy like there is when a properly designed spacecraft plunges into atmosphere, it all shows up as heat in your radiation shield. To survive you are going to have to pump that heat away and radiate it to space faster than it's coming in.
    Sounds like a waste. It'd be better to harness that energy and either use it for propulsion or keep the batteries charged. Granted, the math starts really getting funky with these hypotheticals.
    You can only harness energy differentials, not energy per se. And in this case you've got a big problem getting rid of the energy in the first place, attempting to capture some of it will make it even harder to keep your ship from melting.

    SOL just doesn't seem unlikely. Yes, the same was said of trains. Photons can do it, nearly anything with any kind of mass can't. The speed of light is based on just how much resistance in spacetime there is to transmitting an electric and magnetic force. Once you add mass, there is just so much more resistance.
    Getting small craft to relativistic velocity is certainly within human capability. Surviving in that realm is a lot more problematic.

    Faster than light even less likely. I suppose the question might be, if you can make a ship technically go faster than light... how can you get anything on the ship to work? Can anything exist in a spacetime bubble? The subatomic elements that make up everything are tethered to what exactly? Then there is the issue of electrical and magnetic fields. How do they transmit without spacetime?
    Einstein clearly says you can't push a craft to FTL velocity and that's a wall that will probably stand forever. What Einstein doesn't say is that there isn't some way to avoid the wall. You won't be FTL in whatever realm you're in even if the result is you beat light to some destination in our realm.

  3. Top | #33
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    Quote Originally Posted by SLD View Post
    Quote Originally Posted by Bronzeage View Post
    Do any of these fantasydrives address to problem of time distortion?

    I imagine most SOL or NSOL travels are expected to be one way trips. The alternative is to return from a 4 year spaceflight and find your children are older than you.
    In an Alcubierre drive you don’t move, thus your clock stays the same as earth’s clock.
    There would be zero velocity of the ship with respect to the space-time within the Alcubierre bubble along with the ship but there certainly would be a significant velocity of the ship with respect to Earth. That was sorta the idea of the drive.

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    Seems too good to be true. Most likely some price to pay, impossible energy requirements, etc

  5. Top | #35
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    Quote Originally Posted by DBT View Post
    Seems too good to be true. Most likely some price to pay, impossible energy requirements, etc
    One calculation suggests that the energy equivalent of one Jupiter should suffice for a small jump. All you need to do is find a Jupiter sized planet made entirely of antimatter, steer it onto a collision course with regular Jupiter, and harness at least 50% of the energy generated in the bang that ensues. That's a rather solvable engineering problem though.

    Compared to the *other* problem, that sounds entirely plausible: the bigger problem is shielding the earth (or indeed any place within light years) from the waste heat, the excess energy you fail to harness. Even under unrealistic efficiencies, you're effectively left with a supernova in our backyard.

  6. Top | #36
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    Quote Originally Posted by Loren Pechtel View Post
    Quote Originally Posted by Jimmy Higgins View Post
    Sounds like a waste. It'd be better to harness that energy and either use it for propulsion or keep the batteries charged. Granted, the math starts really getting funky with these hypotheticals.
    You can only harness energy differentials, not energy per se. And in this case you've got a big problem getting rid of the energy in the first place, attempting to capture some of it will make it even harder to keep your ship from melting.
    We are talking about a ship going a large fraction the speed of light. Clearly technology is going to be present that can manage things better. And if we are getting such high velocities, we must be doing well with not losing energy in processes. One should never waste energy, and if something in coming and impacting, that can provide an opportunity to harness it. Not saying it is easy, but SOL isn't exactly easy either.

    SOL just doesn't seem unlikely. Yes, the same was said of trains. Photons can do it, nearly anything with any kind of mass can't. The speed of light is based on just how much resistance in spacetime there is to transmitting an electric and magnetic force. Once you add mass, there is just so much more resistance.
    Getting small craft to relativistic velocity is certainly within human capability. Surviving in that realm is a lot more problematic.
    I said SOL, not less than SOL.

    Faster than light even less likely. I suppose the question might be, if you can make a ship technically go faster than light... how can you get anything on the ship to work? Can anything exist in a spacetime bubble? The subatomic elements that make up everything are tethered to what exactly? Then there is the issue of electrical and magnetic fields. How do they transmit without spacetime?
    Einstein clearly says you can't push a craft to FTL velocity and that's a wall that will probably stand forever. What Einstein doesn't say is that there isn't some way to avoid the wall. You won't be FTL in whatever realm you're in even if the result is you beat light to some destination in our realm.
    And I'm asking what the realm is. Can light even exist in such a realm.

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