3 ms·

I really do not understand how people could say something like this (and also things like "GR is one of the most confirmed theories ever"). "Theoretically" 95%

by nonbel 8y ago

I really do not understand how people could say something like this (and also things like "GR is one of the most confirmed theories ever"). "Theoretically" 95% of the universe is made of invisible, unexplained stuff...

db48x 8y ago
Dark matter and energy are irrelevant, no matter what percentage of the "stuff" in the universe are made of them. Greater than 99% of the things you or I experience from day to day are the result of the electromagnetic force. We experience gravity pulling us down all the time, but that's like one continuous note contained within a symphony. Some of our electricity is produced by nuclear power, but that's hard to pick out from anything else. A few people have lived through a nuclear explosion, which probably had a profound emotional impact on them. Perhaps you've seen the glowing, radioactive paint that they used to use on watch-hands to make them glow in the dark (probably from behind glass in a museum, if you have). But everything else, all of the things you can detect with your senses, comes from the interactions between electrons and photons. Dark matter doesn't interact with either electrons or photons, and neither does dark energy. So they're irrelevant; they can't be used to explain the behavior of the EMDrive, because the EMDrive is made of matter.
gmueckl 8y ago
Then you do not know and/or understand the huge body of work around these theories that support them. These are hard to understand for people not familiar with physics. But especially for GR there are experimental confirmations that are absolutely spectacular (Mercury's apsidal precession computed precisely, time delation by gravity measured by placing atomic clocks on mountaintops and airplanes, etc., observed gravitational waves, gravitational lensing...). And noone was so far able to create an experiment that managed to falsify that theory (it is a perfectly falsifiable theory), but not for lack of trying.
- nonbel 8y ago
  >"And noone was so far able to create an experiment that managed to falsify that theory (it is a perfectly falsifiable theory), but not for lack of trying." It was falsified by the aberrant rotation curves way back in the 1930s, the "dark matter" save was allowed for awhile but still no other evidence has been found for that. The only evidence is that GR predicts the wrong thing. It doesn't matter how many successes your theory has when we are talking about taking it as fact, only whether there is a single fail. Regarding your individual examples: >"Mercury's apsidal precession computed precisely" - GR was designed to fit this, which is great.. but doesn't count as a confirmation. >"time delation by gravity measured by placing atomic clocks on mountaintops and airplanes" - Looks like they had to modify the original predictions to fit the data, ie Einstein didn't anticipate accounting for the rotation of the earth: http://www.conspiracyoflight.com/Hafele/HafeleKeating.html http://www.conspiracyoflight.com/Hafele/HafeleKeating.html So, like the case of mercury's precession it is more a post-diction. > "observed gravitational waves" - There still hasn't been one independently verified, they need to detect a GW, calculate the coordinates, then tell other people where to find a GRB, kilonova, etc. So far this has not happened. >"gravitational lensing" - This idea predates GR: https://arxiv.org/abs/1206.1165 https://arxiv.org/abs/1206.1165. Also, don't the quantitative predictions here rely on the dark matter fudge factor?
  - gmueckl 8y ago
    >>"Mercury's apsidal precession computed precisely" > >- GR was designed to fit this, which is great.. but doesn't count as a confirmation. How can you claim this? GR is derived from first principles only. It also does not need any new physical constant to describe Mercury's apsidal precession. There are no adjustable parameters. It fits precisely even without the cosmological constant which you seem to hate with a passion. >- This idea predates GR: https://arxiv.org/abs/1206.1165 https://arxiv.org/abs/1206.1165 What?! How can you possibly claim that work published in the 1930s predates GR, which was published in 1915 (Hilbert) and 1916 (Einstein himself). An incomplete version of the theory was published by Einstein in 1912.
    - nonbel 8y ago
      >"How can you claim this? GR is derived from first principles only. It also does not need any new physical constant to describe Mercury's apsidal precession." You can derive many theories from first principles but they need to be checked against observation to be useful physics... explaining the orbit of mercury was one of the main checks of any theory. All theories that could not explain that better than Newton were filtered out. My point is only this does not count as a prediction, which needs to be on new data. >"What?! How can you possibly claim that work published in the 1930s predates GR" This is something you've made up? The source I provided quotes Henry Cavendish on this from ~1800: "To find the bending of a ray of light which passes near the surface of any body by the attraction of that body"

by nonbel 8y ago

db48x 8y ago

Dark matter and energy are irrelevant, no matter what percentage of the "stuff" in the universe are made of them. Greater than 99% of the things you or I experience from day to day are the result of the electromagnetic force. We experience gravity pulling us down all the time, but that's like one continuous note contained within a symphony. Some of our electricity is produced by nuclear power, but that's hard to pick out from anything else. A few people have lived through a nuclear explosion, which probably had a profound emotional impact on them. Perhaps you've seen the glowing, radioactive paint that they used to use on watch-hands to make them glow in the dark (probably from behind glass in a museum, if you have). But everything else, all of the things you can detect with your senses, comes from the interactions between electrons and photons. Dark matter doesn't interact with either electrons or photons, and neither does dark energy. So they're irrelevant; they can't be used to explain the behavior of the EMDrive, because the EMDrive is made of matter.

gmueckl 8y ago

Then you do not know and/or understand the huge body of work around these theories that support them. These are hard to understand for people not familiar with physics. But especially for GR there are experimental confirmations that are absolutely spectacular (Mercury's apsidal precession computed precisely, time delation by gravity measured by placing atomic clocks on mountaintops and airplanes, etc., observed gravitational waves, gravitational lensing...). And noone was so far able to create an experiment that managed to falsify that theory (it is a perfectly falsifiable theory), but not for lack of trying.

nonbel 8y ago
>"And noone was so far able to create an experiment that managed to falsify that theory (it is a perfectly falsifiable theory), but not for lack of trying." It was falsified by the aberrant rotation curves way back in the 1930s, the "dark matter" save was allowed for awhile but still no other evidence has been found for that. The only evidence is that GR predicts the wrong thing. It doesn't matter how many successes your theory has when we are talking about taking it as fact, only whether there is a single fail. Regarding your individual examples: >"Mercury's apsidal precession computed precisely" - GR was designed to fit this, which is great.. but doesn't count as a confirmation. >"time delation by gravity measured by placing atomic clocks on mountaintops and airplanes" - Looks like they had to modify the original predictions to fit the data, ie Einstein didn't anticipate accounting for the rotation of the earth: http://www.conspiracyoflight.com/Hafele/HafeleKeating.html http://www.conspiracyoflight.com/Hafele/HafeleKeating.html So, like the case of mercury's precession it is more a post-diction. > "observed gravitational waves" - There still hasn't been one independently verified, they need to detect a GW, calculate the coordinates, then tell other people where to find a GRB, kilonova, etc. So far this has not happened. >"gravitational lensing" - This idea predates GR: https://arxiv.org/abs/1206.1165 https://arxiv.org/abs/1206.1165. Also, don't the quantitative predictions here rely on the dark matter fudge factor?
- gmueckl 8y ago
  >>"Mercury's apsidal precession computed precisely" > >- GR was designed to fit this, which is great.. but doesn't count as a confirmation. How can you claim this? GR is derived from first principles only. It also does not need any new physical constant to describe Mercury's apsidal precession. There are no adjustable parameters. It fits precisely even without the cosmological constant which you seem to hate with a passion. >- This idea predates GR: https://arxiv.org/abs/1206.1165 https://arxiv.org/abs/1206.1165 What?! How can you possibly claim that work published in the 1930s predates GR, which was published in 1915 (Hilbert) and 1916 (Einstein himself). An incomplete version of the theory was published by Einstein in 1912.
  - nonbel 8y ago
    >"How can you claim this? GR is derived from first principles only. It also does not need any new physical constant to describe Mercury's apsidal precession." You can derive many theories from first principles but they need to be checked against observation to be useful physics... explaining the orbit of mercury was one of the main checks of any theory. All theories that could not explain that better than Newton were filtered out. My point is only this does not count as a prediction, which needs to be on new data. >"What?! How can you possibly claim that work published in the 1930s predates GR" This is something you've made up? The source I provided quotes Henry Cavendish on this from ~1800: "To find the bending of a ray of light which passes near the surface of any body by the attraction of that body"