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> Ouch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics. I disagree. That's the fun thing about

by croon 6y ago

> Ouch, that’s one of those painfully bad ideas that makes it obvious most people lack a basic understanding of physics. I disagree. That's the fun thing about scifi. As long as your idea could theoretically work (which you seem to agree), you can decide whether the theoretical risks manifest or not, or handwave uninvented solutions to those. Scifi is about dreaming within our universe beyond our current knowledge or limitations. At least that's my two cents. Edit: Not familiar with this specific book, but just in general terms.

Retric 6y ago
> Which you seem to agree Well no their are a host of issues beyond safety and energy requirements. You’re not going to be able to contain that much virtual mass moving at near light speed. We also don’t know if virtual mass produces gravity, etc etc.
- ars 6y ago
  > We also don’t know if virtual mass produces gravity Yes we do. It does. Gravity is produced by energy, of which mass is only one type.
  - Retric 6y ago
    Last I checked there was zero experimental support for this. Unless you have a citation?
    - ars 6y ago
      See my other post here: https://news.ycombinator.com/item?id=25793668 https://news.ycombinator.com/item?id=25793668 Basically any other answer would be a violation of a whole bunch of conservation laws. In short: It's easy to convert velocity energy to rest energy, rest energy obviously has gravity, so velocity energy must as well.
      - Retric 6y ago
        The issue as I understand it is neutron stars would form black holes in some reference frames. It really breaks relativity for all forms of energy to produce gravity. Which is completely ok as long as there is some experimental support.
        ars 6y ago
        That's a flaw of the theories of black holes, not relativity. > It really breaks relativity for all forms of energy to produce gravity. It does not, quite the opposite: It's a fundamental feature of it. > Which is completely ok as long as there is some experimental support. There is no experimental support for black holes either, it breaks physics far less for black holes not to exist. (Note black holes are not the same as super massive objects, which do have experimental support. An event horizon has never been observed, just assumed.)
        Retric 6y ago
        The existence of black holes is part of the general consensus at this point. It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have. I don’t mean this as an appeal to authority, just a suggestion you likely have some fundamental misunderstandings. Especially if you never worked through the actual equations.
        ars 6y ago
        > The existence of black holes is part of the general consensus at this point. Yes it is, but the lack of understanding of black holes is also part of general understanding. Physicists know quite well they don't fully understand what happens in every black hole situation. > It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have. We don't have any evidence, only conjecture and [incomplete] math. Two things that might prevent black holes: Quark degeneracy pressure (unknown, not even the magnitude is known), and time dilation, which leads to "frozen stars" which hover just before becoming black holes, but never do because that last bit of mass that takes them over the edge takes an infinite time to arrive. Neither of those two are "fringe" theories mind you, they have both been discussed by prominent theorists (I also get to appeal to authority :)

by croon 6y ago

Retric 6y ago

> Which you seem to agree Well no their are a host of issues beyond safety and energy requirements. You’re not going to be able to contain that much virtual mass moving at near light speed. We also don’t know if virtual mass produces gravity, etc etc.

ars 6y ago
> We also don’t know if virtual mass produces gravity Yes we do. It does. Gravity is produced by energy, of which mass is only one type.
- Retric 6y ago
  Last I checked there was zero experimental support for this. Unless you have a citation?
  - ars 6y ago
    See my other post here: https://news.ycombinator.com/item?id=25793668 https://news.ycombinator.com/item?id=25793668 Basically any other answer would be a violation of a whole bunch of conservation laws. In short: It's easy to convert velocity energy to rest energy, rest energy obviously has gravity, so velocity energy must as well.
    - Retric 6y ago
      The issue as I understand it is neutron stars would form black holes in some reference frames. It really breaks relativity for all forms of energy to produce gravity. Which is completely ok as long as there is some experimental support.
      - ars 6y ago
        That's a flaw of the theories of black holes, not relativity. > It really breaks relativity for all forms of energy to produce gravity. It does not, quite the opposite: It's a fundamental feature of it. > Which is completely ok as long as there is some experimental support. There is no experimental support for black holes either, it breaks physics far less for black holes not to exist. (Note black holes are not the same as super massive objects, which do have experimental support. An event horizon has never been observed, just assumed.)
        Retric 6y ago
        The existence of black holes is part of the general consensus at this point. It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have. I don’t mean this as an appeal to authority, just a suggestion you likely have some fundamental misunderstandings. Especially if you never worked through the actual equations.
        ars 6y ago
        > The existence of black holes is part of the general consensus at this point. Yes it is, but the lack of understanding of black holes is also part of general understanding. Physicists know quite well they don't fully understand what happens in every black hole situation. > It’s fine to suggest they don’t exist, just realize you’re disagreeing with the vast majority of physicists and evidence we have. We don't have any evidence, only conjecture and [incomplete] math. Two things that might prevent black holes: Quark degeneracy pressure (unknown, not even the magnitude is known), and time dilation, which leads to "frozen stars" which hover just before becoming black holes, but never do because that last bit of mass that takes them over the edge takes an infinite time to arrive. Neither of those two are "fringe" theories mind you, they have both been discussed by prominent theorists (I also get to appeal to authority :)