5 ms·

I'm reminded of the "sailing downwind faster than the wind" fiasco. One guy had an intuition that said it could be done, but everyone pooh-poohed it on energy c

I'm reminded of the "sailing downwind faster than the wind" fiasco. One guy had an intuition that said it could be done, but everyone pooh-poohed it on energy conservation grounds until he built a full-scale machine and actually did it. Perpetual motion machines (and unethical behavior, another good example in this thread) really do need to be shot down fast, but they're rarer than they might appear, and sometimes an idea that looks like PMM-level fantasy can be brought to reality by modest changes in its assumptions. I like the idea of literally saying "what about energy conservation?" If you say that and actually have an open mind, maybe you can figure out how the energy budget really does add up, and even help figure it out. You still need to be prepared to deliver a hard TWW when needed. When? No blog post can answer this. It's a judgment call. As usual, there are no shortcuts.

masklinn 5y ago
> Perpetual motion machines (and unethical behavior, another good example in this thread) really do need to be shot down fast, but they're rarer than they might appear They really are not, a stint at (or getting chummy with) the nearest patent office demonstrates it quickly. The machine you mention is pretty much the exception that proves the rule, and unintuitive enough that yes it did really need a proper model. > One guy had an intuition that said it could be done There are dozens of guys waking up with the intuition that a PMM can be done every day.
- exporectomy 5y ago
  Better to keep quiet than to criticize it without bothering to study it though. Unless your criticism is simply "most inventions that look like this are PPM so yours probably is too."
- andrewflnr 5y ago
  > They really are not Ok, but in the context of work conversations, though. I still think more of them can be recovered than our instincts first tell us.
benhurmarcel 5y ago
Relevant video: https://www.youtube.com/watch?v=jyQwgBAaBag https://www.youtube.com/watch?v=jyQwgBAaBag
exporectomy 5y ago
Another story of the same type was somebody trying to recover waste heat from shower drain water to put back into the shower water. It was poo-pooed for violating the 2nd law or something. But the poo-pooer neglected the fact that hot shower water is made from a mixture of hot and cold water, so the cold water could be heated by the warm waste water.

masklinn 5y ago

> Perpetual motion machines (and unethical behavior, another good example in this thread) really do need to be shot down fast, but they're rarer than they might appear They really are not, a stint at (or getting chummy with) the nearest patent office demonstrates it quickly. The machine you mention is pretty much the exception that proves the rule, and unintuitive enough that yes it did really need a proper model. > One guy had an intuition that said it could be done There are dozens of guys waking up with the intuition that a PMM can be done every day.

exporectomy 5y ago
Better to keep quiet than to criticize it without bothering to study it though. Unless your criticism is simply "most inventions that look like this are PPM so yours probably is too."
andrewflnr 5y ago
> They really are not Ok, but in the context of work conversations, though. I still think more of them can be recovered than our instincts first tell us.

benhurmarcel 5y ago

Relevant video: https://www.youtube.com/watch?v=jyQwgBAaBag https://www.youtube.com/watch?v=jyQwgBAaBag

exporectomy 5y ago

Another story of the same type was somebody trying to recover waste heat from shower drain water to put back into the shower water. It was poo-pooed for violating the 2nd law or something. But the poo-pooer neglected the fact that hot shower water is made from a mixture of hot and cold water, so the cold water could be heated by the warm waste water.