6 ms·

On the other hand I'm sure you could find lots of other achievements where some scientists were denying it was possible right up to the point it was achieved.

akvadrako 9y ago
That's missing the point. Until it's actually achieved it isn't "finally here".
andybak 9y ago
"If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong." https://www.brainyquote.com/quotes/arthur_c_clarke_100793 https://www.brainyquote.com/quotes/arthur_c_clarke_100793 > On the other hand I'm sure you could find lots of other achievements where some scientists were denying it was possible right up to the point it was achieved. True and I'm very aware that I'm creeping towards the age where I'm likely to be on the wrong side of these debates. (Not that I'm distinguished or even a scientist) However - the distinguished, elderly scientists are sometimes right.
- Retric 9y ago
  That only seems true with hindsight bias, as distinguished elderly scientists are most memorable when they are wrong. Being right 99.9% of the time would not be enough if there are millions of you and people only care about a few quotes. Granted, you can't be proved correct if you say some action is impossible as someone can always wait to see if you're wrong.
  - coldtea 9y ago
    Or you know, that is a BS quote, extrapolating from too few historical examples (and even them, not understood well), and not some scientific law.
rwallace 9y ago
Could you? Sure, we can all think of cases where someone said something was impossible and then eventually it was achieved. But are there any cases where the expert consensus on the physical possibility of something wasn't established until it was achieved in practice? I can't think of one off the top of my head. Nuclear energy? No, the physical possibility of this was understood in the thirties; the objection was that, as one scientist put it, you would have to turn a whole country into a uranium refinery. Which wasn't exactly wrong; the Manhattan project took engineering resources in the ballpark of a small country. Supersonic flight? No, artificial objects had been going supersonic for centuries. Spaceflight? No, the physics of this was well understood long before it was achieved. Any that I'm missing?
- OscarCunningham 9y ago
  Right, people had consensus on the physical possibility, but not on whether the engineering problems were surmountable. But I think there is a consensus on the physical possibility of quantum computing in principle. The [threshold theorem](https://en.wikipedia.org/wiki/Quantum_threshold_theorem https://en.wikipedia.org/wiki/Quantum_threshold_theorem) is very convincing.
  - rwallace 9y ago
    Be careful: there's an important distinction. There is a consensus that quantum computers can, for certain problems, perform computation exponential in the number of qubits. But the often unspoken assumption is that the difficulty of getting the computation to stay coherent, is polynomial in the number of qubits. That's currently the big unknown. If it's not, then that's what would be meant by practical quantum computers being physically impossible.
    - OscarCunningham 9y ago
      Is that not the problem that the threshold theorem solves?
      - 9y ago
posterboy 9y ago
It's reverse psychology. Surely, if they are in the field, they want it to be true. I frequently find myself invariably assuming a contrarian position in debate just to provoke more arguments, effectively contradicting myself over the course of different debates. In that sense, I just wanna know if that has a name in psychology as a normal or pathological condition. I mean, it might be purely rhetorical. Also, if it's not "crypto season", what is it actually, nano, cryo, opto, ..?
- neltnerb 9y ago
  Any good scientist should be the biggest skeptic of their own work. Though I usually poke holes in my own ideas in private ;-)

akvadrako 9y ago

That's missing the point. Until it's actually achieved it isn't "finally here".

andybak 9y ago

"If an elderly but distinguished scientist says that something is possible, he is almost certainly right; but if he says that it is impossible, he is very probably wrong." https://www.brainyquote.com/quotes/arthur_c_clarke_100793 https://www.brainyquote.com/quotes/arthur_c_clarke_100793 > On the other hand I'm sure you could find lots of other achievements where some scientists were denying it was possible right up to the point it was achieved. True and I'm very aware that I'm creeping towards the age where I'm likely to be on the wrong side of these debates. (Not that I'm distinguished or even a scientist) However - the distinguished, elderly scientists are sometimes right.

Retric 9y ago
That only seems true with hindsight bias, as distinguished elderly scientists are most memorable when they are wrong. Being right 99.9% of the time would not be enough if there are millions of you and people only care about a few quotes. Granted, you can't be proved correct if you say some action is impossible as someone can always wait to see if you're wrong.
- coldtea 9y ago
  Or you know, that is a BS quote, extrapolating from too few historical examples (and even them, not understood well), and not some scientific law.

rwallace 9y ago

Could you? Sure, we can all think of cases where someone said something was impossible and then eventually it was achieved. But are there any cases where the expert consensus on the physical possibility of something wasn't established until it was achieved in practice? I can't think of one off the top of my head. Nuclear energy? No, the physical possibility of this was understood in the thirties; the objection was that, as one scientist put it, you would have to turn a whole country into a uranium refinery. Which wasn't exactly wrong; the Manhattan project took engineering resources in the ballpark of a small country. Supersonic flight? No, artificial objects had been going supersonic for centuries. Spaceflight? No, the physics of this was well understood long before it was achieved. Any that I'm missing?

OscarCunningham 9y ago
Right, people had consensus on the physical possibility, but not on whether the engineering problems were surmountable. But I think there is a consensus on the physical possibility of quantum computing in principle. The [threshold theorem](https://en.wikipedia.org/wiki/Quantum_threshold_theorem https://en.wikipedia.org/wiki/Quantum_threshold_theorem) is very convincing.
- rwallace 9y ago
  Be careful: there's an important distinction. There is a consensus that quantum computers can, for certain problems, perform computation exponential in the number of qubits. But the often unspoken assumption is that the difficulty of getting the computation to stay coherent, is polynomial in the number of qubits. That's currently the big unknown. If it's not, then that's what would be meant by practical quantum computers being physically impossible.
  - OscarCunningham 9y ago
    Is that not the problem that the threshold theorem solves?
    - 9y ago

posterboy 9y ago

It's reverse psychology. Surely, if they are in the field, they want it to be true. I frequently find myself invariably assuming a contrarian position in debate just to provoke more arguments, effectively contradicting myself over the course of different debates. In that sense, I just wanna know if that has a name in psychology as a normal or pathological condition. I mean, it might be purely rhetorical. Also, if it's not "crypto season", what is it actually, nano, cryo, opto, ..?

neltnerb 9y ago
Any good scientist should be the biggest skeptic of their own work. Though I usually poke holes in my own ideas in private ;-)