There are 13 comments.

Become a member to join the conversation. Or sign in if you're already a member.
  1. FredGoodhue Coolidge
    FredGoodhue
    @FredGoodhue

    I still want interstellar colonization. 

    • #1
  2. StoughtonObserver Member
    StoughtonObserver
    @Bruce W Banerdt

    Dark matter doesn’t exist.

    • #2
  3. Taras Coolidge
    Taras
    @Taras

    StoughtonObserver (View Comment):

    Dark matter doesn’t exist.

    A minority view among physicists, I think!

    • #3
  4. OccupantCDN Coolidge
    OccupantCDN
    @OccupantCDN

    Taras (View Comment):

    StoughtonObserver (View Comment):

    Dark matter doesn’t exist.

    A minority view among physicists, I think!

    No, I think its the majority opinion.

    Dark Matter only exists as a mathematical kludge to make the equations work – it has never been observed, there is no evidence that it actually exists.

    • #4
  5. Taras Coolidge
    Taras
    @Taras

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Tyson is far too quick to dismiss it.

    For one thing, there is no physical law that prevents the drastic extension of the human lifespan.  Our distant descendants may take thousand-year voyages in their stride — even setting aside future methods of suspended animation.

    As our descendants establish space colonies across the solar system, it will no doubt occur to some of them to simply add a propulsion unit, and lay a course for the “second star to the right and straight on till morning”.

    • #5
  6. Taras Coolidge
    Taras
    @Taras

    OccupantCDN (View Comment):

    Taras (View Comment):

    StoughtonObserver (View Comment):

    Dark matter doesn’t exist.

    A minority view among physicists, I think!

    No, I think its the majority opinion.

    Dark Matter only exists as a mathematical kludge to make the equations work – it has never been observed, there is no evidence that it actually exists.

    The neutrino was also such a “mathematical kludge” from Wolfgang Pauli’s proposal in 1930 to its eventual detection in 1956.

    According to Wikipedia, “most experts” think dark matter is real, abundant, and had a major influence on the evolution of the cosmos.

    • #6
  7. OccupantCDN Coolidge
    OccupantCDN
    @OccupantCDN

    Taras (View Comment):

    OccupantCDN (View Comment):

    Taras (View Comment):

    StoughtonObserver (View Comment):

    Dark matter doesn’t exist.

    A minority view among physicists, I think!

    No, I think its the majority opinion.

    Dark Matter only exists as a mathematical kludge to make the equations work – it has never been observed, there is no evidence that it actually exists.

    The neutrino was also such a “mathematical kludge” from Wolfgang Pauli’s proposal in 1930 to its eventual detection in 1956.

    According to Wikipedia, “most experts” think dark matter is real, abundant, and had a major influence on the evolution of the cosmos.

    There is something out there – or we’re completely wrong on gravity…. I say its 50/50….

    I like the theory of quantum inertia – that gets rid of dark matter completely.

    • #7
  8. OccupantCDN Coolidge
    OccupantCDN
    @OccupantCDN

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    • #8
  9. Taras Coolidge
    Taras
    @Taras

    OccupantCDN (View Comment):

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    What about at the speed of Musk, Branson, and Bezos?

    • #9
  10. OccupantCDN Coolidge
    OccupantCDN
    @OccupantCDN

    Taras (View Comment):

    OccupantCDN (View Comment):

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    What about at the speed of Musk, Branson, and Bezos?

    Getting to Mars is one thing – getting beyond Saturn or Jupiter – is at least an order of magnitude harder.

    Because the voyages will be much longer – they’ll be much heavier – and in order to stay in the free return trajectory, you need to travel at a much higher velocity.

    • #10
  11. Taras Coolidge
    Taras
    @Taras

    OccupantCDN (View Comment):

    Taras (View Comment):

    OccupantCDN (View Comment):

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    What about at the speed of Musk, Branson, and Bezos?

    Getting to Mars is one thing – getting beyond Saturn or Jupiter – is at least an order of magnitude harder.

    Because the voyages will be much longer – they’ll be much heavier – and in order to stay in the free return trajectory, you need to travel at a much higher velocity.

    I’m puzzled.  The Wikipedia article on “Free-return trajectory” suggests that the faster you get there, the longer duration is the free return trajectory (in case of an abort).

    The usual saying is, when you’re in Earth orbit, you’re halfway to anywhere in the solar system.

    No question deep space manned missions will require improvements in shielding and recycling.

    • #11
  12. jonb60173 Member
    jonb60173
    @jonb60173

    OccupantCDN (View Comment):

    Taras (View Comment):

    OccupantCDN (View Comment):

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    What about at the speed of Musk, Branson, and Bezos?

    Getting to Mars is one thing – getting beyond Saturn or Jupiter – is at least an order of magnitude harder.

    Because the voyages will be much longer – they’ll be much heavier – and in order to stay in the free return trajectory, you need to travel at a much higher velocity.

    Obviously we’ll need to discover a different propulsion system or method of movement than we have now.

    • #12
  13. OccupantCDN Coolidge
    OccupantCDN
    @OccupantCDN

    jonb60173 (View Comment):

    OccupantCDN (View Comment):

    Taras (View Comment):

    OccupantCDN (View Comment):

    FredGoodhue (View Comment):

    I still want interstellar colonization.

    Me too… But at the speed of NASA it’ll take us longer to leave than to arrive.

    What about at the speed of Musk, Branson, and Bezos?

    Getting to Mars is one thing – getting beyond Saturn or Jupiter – is at least an order of magnitude harder.

    Because the voyages will be much longer – they’ll be much heavier – and in order to stay in the free return trajectory, you need to travel at a much higher velocity.

    Obviously we’ll need to discover a different propulsion system or method of movement than we have now.

    Actually no. We already have a propulsion system that would work just fine.

    Its called a thermal nuclear rocket. Its a nuclear reactor that heats hydrogen from a liquid state to 2200c, then ejects it out a nozzle to generate thrust. Projects Rover and NERVA ran in the late 50s and 60’s. Tests were conducted at Jackass Flats NV (why always Nevada? Poor Nevada!) that proved the viability of the technology.

     

    • #13
Become a member to join the conversation. Or sign in if you're already a member.