Somes J wrote:
It also sounds like he's fallen into a classic example of the Middle World Problem. The idea that a heavy concrete block and a feather would fall at the same rate
Except that in the real world they don't, on every day earth, a heavy concrete block and a feather don't. Because a feather has a specific shape that makes it fall slower, this is due to the fact that they are affected by atmospheric conditions and buoyancy.
In vacuum, they do, but people get confused because they've SEEN feathers and bricks (or other heavy objects) fall, outside of a vacuum, at different rates.
This is why on earth two objects of different weights but the same shape (when showing this to schoolchildren they use spheres to ensure that one of the objects does not spin in a way that increases drag and muck up the 'experiment') tend to fall at the same rate, but two objects with vastly different shapes and the same weight (like a parachutist without and with his chute deployed) do not.
Which is why we never say 'a heavy concrete block and a father fall at the same rate'. We add 'in a vacuum' before or after that because otherwise we're liars. It's not a complete lie to say that they fall at the same rate, because under the right circumstances, they do. But it's a better example for my case than yours, because some physicist claiming they fall at the same rate without adding the vacuum part is confusing the theoretical math (which ignores buoyancy because it's not part of the basic formula) with observable evidence in a real-world situation (in which buoyancy will not let itself be ignored).
or that it takes just as much energy to slow down as to speed up
This one is a better example. People get intuitive dissonance on this because of things they experience in real life. In order to stop a moving car (or bicycle) you stop putting energy in it, so you get the impression that slowing down doesn't take energy. But it does. The only difference between speeding up and slowing down on earth and in space being where the energy comes from (a spacecraft in a vacuum needs to provide it's own energy to stop, while a racecar on earth stops due to energy provided by the earth).
That said
observationally it currently
does take less energy to stop in space than it does to speed up. This is because we use reaction mass for propulsion in spacecraft and thus the more you speed up, the lower the weight of your craft will be and so you
will need to use less energy over all to slow down than you did to speed up (the amount of energy per unit of weight stays the same though).
btw, this is another example of your double standard. When the math says what you want to hear, you stick to it and ignore everything else. If it doesn't, it's just stupid math with no connection to the real world.
You're confusing my rebuttal to your point based on your beliefs with my own point based on my beliefs. The reason why I know that the Alcubierre metric probably can't be used for FTL has little to do with some convoluted calculation which is just as 'not even wrong' as the Alcubierre metric itself and more to do with the fact that an 'engine' based on the principle would require MATERIALS that do not, currently, seem to exist. I never said, after all, that an Alcubierre metric will produce an FTL drive, I only said that it's not as prohibitted by physics as you seem to think it is.
The bias also goes both ways, except in this case I
am functionally more reasonable than you are. The Alcubierre metric and it's opposition are both based on purely mathematical thinking along the line of 'if these assumptions are true, this conclusion is also true'. The difference between our biasses then is that I say 'well if this metric and turns out to be true, FTL is not impossible' and you say 'but I don't want FTL to be possible and this theory says it isn't, so FTL is impossible'. Based on theoretical mathematics I'm giving the matter a 'maybe', based on equally theoretical mathematics you're giving it a solid 'no'.
Time dilation has been experimentally proven; it has been directly observed on several occasions.
Well yes. Time dilation is an OBSERVATIONAL PHENOMENON. A very basic experiment: A lightning bolt hits. You are an undetermined distance away, I am half that distance away. At what time is there light and at which time is there sound? In reality, both originate the instant the bolt hits, but observationally, both events occur after twice as much time for you as it does for me. Does that mean that I am twice as far ahead in time than you are? No.
Because Time Dilation is an observational thing and while the light and sound are moving at different speeds relative to each other, despite originating at the same point. Assuming that Time Dilation is a physical thing (i.e. Because we observe events occurring at different times, we must therefore be moving through time at different rates) is wrong.
Similarly the Hafele-Keating experiment and successive verifications haven't proven, despite this being the accepted conclusion, that time itself moves differently, only that measuring devices measure time differently, when under the influence of altered gravity and relative velocity. In order to verify Time Dilation as actually affecting time itself you'd need a clock that is not affected by gravitational or kinematic forces at all. Which requires Exotic Matter, which makes the whole thing academical any way.
It says nothing of the sort.
Yes it does. (if you can do it, so can I. Now accept my saying 'yes it does' as true without arguments, the same way you expect me to accept you saying 'No it doesn't' without argument.)