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Posted: 7/29/2015 2:31:53 PM EDT
[#1]
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You seem very convinced that this is valid technology. I'm not sure your optimism is justified by the experimental results so far. Quote HistoryQuoted:
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"Davis noticed some problems in the experiment as well. “I noted in [the study’s] conclusion paragraphs that [Tajmar’s] apparatus was producing hundreds of micro-Newtons of thrust when it got very hot and that his measuring instrumentation is not very accurate when the apparatus becomes hot,” Davis told io9. “He also stated that he was still recording thrust signals even after the electrical power was turned off which is a huge key clue that his thrust measurements are all systematic artifact false positive thrust signals.”" 1: Lagging and lingering thrust is hardly proof the device does not function. Go turn a nuclear reactor off and observe the result. 2: There's an easy solution to the "it's just thermally induced magic thrust!" claim of the critics. Repeat the experiment with the device unpowered, then heat the device using a laser to the same operating temperature. Then turn the laser off and observe for thrust. No thrust = not thermal. Thrust = thermal. You seem very convinced that this is valid technology. I'm not sure your optimism is justified by the experimental results so far. 1: Four separate teams in four nations have observed positive results with the device. This is extremely encouraging. 2: Most (though not all) of the nay-sayers quickly prove themselves quite ignorant of the device, the testing, and the competing theories involved. There is little reason to give those voices any weight. I will not be "convinced this is valid technology" until the microsat demonstrator is tested in a heliocentric orbit and demonstrates delta-v. Fortunately, that is a fairly easy task. |
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Posted: 7/29/2015 2:44:36 PM EDT
[#2]
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. 
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Posted: 7/29/2015 2:47:15 PM EDT
[#3]
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. |
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Posted: 7/29/2015 2:47:49 PM EDT
[#4]
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1: Four separate teams in four nations have observed positive results with the device. This is extremely encouraging. 2: Most (though not all) of the nay-sayers quickly prove themselves quite ignorant of the device, the testing, and the competing theories involved. There is little reason to give those voices any weight. I will not be "convinced this is valid technology" until the microsat demonstrator is tested in a heliocentric orbit and demonstrates delta-v. Fortunately, that is a fairly easy task. Quote HistoryQuoted:
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"Davis noticed some problems in the experiment as well. “I noted in [the study’s] conclusion paragraphs that [Tajmar’s] apparatus was producing hundreds of micro-Newtons of thrust when it got very hot and that his measuring instrumentation is not very accurate when the apparatus becomes hot,” Davis told io9. “He also stated that he was still recording thrust signals even after the electrical power was turned off which is a huge key clue that his thrust measurements are all systematic artifact false positive thrust signals.”" 1: Lagging and lingering thrust is hardly proof the device does not function. Go turn a nuclear reactor off and observe the result. 2: There's an easy solution to the "it's just thermally induced magic thrust!" claim of the critics. Repeat the experiment with the device unpowered, then heat the device using a laser to the same operating temperature. Then turn the laser off and observe for thrust. No thrust = not thermal. Thrust = thermal. You seem very convinced that this is valid technology. I'm not sure your optimism is justified by the experimental results so far. 1: Four separate teams in four nations have observed positive results with the device. This is extremely encouraging. 2: Most (though not all) of the nay-sayers quickly prove themselves quite ignorant of the device, the testing, and the competing theories involved. There is little reason to give those voices any weight. I will not be "convinced this is valid technology" until the microsat demonstrator is tested in a heliocentric orbit and demonstrates delta-v. Fortunately, that is a fairly easy task. I'm not sure positive results is an accurate description, the observed thrust is near the margin or measurement error and I don't believe that system artifacts are properly accounted for. |
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Posted: 7/29/2015 2:51:02 PM EDT
[#5]
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My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. |
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Posted: 7/29/2015 2:52:02 PM EDT
[#6]
I hope it's true. Lots of good SF stories to be written if it is...
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Posted: 7/29/2015 2:55:24 PM EDT
[#7]
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I'm not sure positive results is an accurate description, the observed thrust is near the margin or measurement error and I don't believe that system artifacts are properly accounted for. Quote HistoryQuoted:
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"Davis noticed some problems in the experiment as well. “I noted in [the study’s] conclusion paragraphs that [Tajmar’s] apparatus was producing hundreds of micro-Newtons of thrust when it got very hot and that his measuring instrumentation is not very accurate when the apparatus becomes hot,” Davis told io9. “He also stated that he was still recording thrust signals even after the electrical power was turned off which is a huge key clue that his thrust measurements are all systematic artifact false positive thrust signals.”" 1: Lagging and lingering thrust is hardly proof the device does not function. Go turn a nuclear reactor off and observe the result. 2: There's an easy solution to the "it's just thermally induced magic thrust!" claim of the critics. Repeat the experiment with the device unpowered, then heat the device using a laser to the same operating temperature. Then turn the laser off and observe for thrust. No thrust = not thermal. Thrust = thermal. You seem very convinced that this is valid technology. I'm not sure your optimism is justified by the experimental results so far. 1: Four separate teams in four nations have observed positive results with the device. This is extremely encouraging. 2: Most (though not all) of the nay-sayers quickly prove themselves quite ignorant of the device, the testing, and the competing theories involved. There is little reason to give those voices any weight. I will not be "convinced this is valid technology" until the microsat demonstrator is tested in a heliocentric orbit and demonstrates delta-v. Fortunately, that is a fairly easy task. I'm not sure positive results is an accurate description, the observed thrust is near the margin or measurement error and I don't believe that system artifacts are properly accounted for. Stick one in orbit around the sun and turn it on for a year with an anti-normal orientation. Observe orbital characteristics. Should answer the question to everyones satisfaction. |
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Posted: 7/29/2015 2:57:02 PM EDT
[#8]
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You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? |
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Posted: 7/29/2015 3:03:42 PM EDT
[#9]
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I'm not sure positive results is an accurate description, the observed thrust is near the margin or measurement error and I don't believe that system artifacts are properly accounted for. So you're more educated on the subject than the scientists working on it in multiple countries who are saying they are getting positive results and are very excited? |
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Posted: 7/29/2015 3:04:26 PM EDT
[#10]
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At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. and if done right, you have earth-gravity the entire trip. |
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Posted: 7/29/2015 3:25:07 PM EDT
[#11]
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I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? It's difficult to post formulas on ARFCom due to formatting, but you're looking for the uniform motion formula with time and acceleration as variables and distance (displacement) as the result. Understand that this does not factor in the orbital mechanics, which are far more complicated. It simply demonstrates how wrong 2,700gs of acceleration is. In two hours of constant acceleration at 1g, you will travel 157,932 miles from your point of origin. Turn the ship around and accelerate in the opposite direction for two hours and you have traveled another 157,932 miles. Total distance traveled in four hours, accelerating at 1 g half of the way and decelerating (oxymoron) at 1g for the second half, you will cover 315,864 miles. The distance to the moon is merely ~239,000 miles. In reality orbital mechanics laughs at such calculations, but "hours to the moon" with human survivable acceleration is certainly plausible, thousands of g's are not required. |
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Posted: 7/29/2015 3:28:50 PM EDT
[#12]
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I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? You forgot to add 6000 to the final results. |
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Posted: 7/29/2015 3:31:19 PM EDT
[#13]
Quoted: The EMDrive has yet again been proven to work by an independent study in Germany.. |
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Posted: 7/29/2015 3:31:30 PM EDT
[#14]
Quote HistoryQuoted: I hope it's true. Lots of good SF stories to come true be written if it is... |
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Posted: 7/29/2015 3:36:47 PM EDT
[#15]
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Some of these replies sound like electricity skeptics from 150 years ago. LOL You must be super old. Hasn't the .mil made you retire yet? |
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Posted: 7/29/2015 4:24:53 PM EDT
[#16]
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So you're more educated on the subject than the scientists working on it in multiple countries who are saying they are getting positive results and are very excited? Quote HistoryQuoted:
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I'm not sure positive results is an accurate description, the observed thrust is near the margin or measurement error and I don't believe that system artifacts are properly accounted for. So you're more educated on the subject than the scientists working on it in multiple countries who are saying they are getting positive results and are very excited? I'm just as excited as the subject matter experts who are calling into question the methodology of the people who are trying to generate funding from their non-peer reviewed results. |
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Posted: 7/29/2015 4:31:39 PM EDT
[#17]
I really hope this turns out to be something.
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Posted: 7/29/2015 4:59:43 PM EDT
[#18]
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Posted: 7/29/2015 5:15:34 PM EDT
[#19]
The article was lacking in key details. What was the ethnic, gender, and sexual-orientation of the researchers? We shouldn't accept any idea as scientific unless it has a diversity makeup which is approved by the Politbureau.
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Posted: 7/29/2015 5:41:47 PM EDT
[#20]
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At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. 1G is 9.8m/s squared? Ok, I get it. Thanks. |
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Posted: 7/29/2015 5:44:52 PM EDT
[#21]
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So if it can make it to the moon in 4 hours, how long would it take to go 1400 light years to earth 2? Would a solar powered ship survive a trip that far? It would have to be pretty much shut completely off for a majority of the trip then turned back on when it got close enough to a star to generate power again wouldn't it? But how do you do that without some kind of timer running so you could periodically check if you are near a sun? I imagine you would also need to periodically power up and perform checks to make sure you are still on course and make corrections along the way. Where do you get the power to do all those things? I dont think a nuclear powered ship would run long enough would it? |
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Posted: 7/29/2015 5:46:28 PM EDT
[#22]
Quote HistoryQuoted: Some of these replies sound like electricity skeptics from 150 years ago. LOL  Comments like yours always about in discussions about scam machines "all you naysayers are stupid". The reality is, experimental errors and attributing mechanisms to those errors is a common mistake in science, and its actually the first thing any scientist looks for in any experiment, so sorry that the skeptics are just trying to apply scientific reasoning and intuition that holds true 99.9999999% of the time. Test the thing is space, measure the change in velocity (if it works), and it will be proven to work on some level. Until then everyone is going to be wondering what effects of the experimental setup and the lab are causing this rather then assuming it must be violating the laws of physics. |
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Posted: 7/29/2015 5:50:45 PM EDT
[#23]
Quote HistoryQuoted: Get your ass to Mars What you did there, I see it...  |
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Posted: 7/29/2015 5:53:16 PM EDT
[#24]
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My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. Apollo covered the same distance in 36 hours and it was coasting 35 hours and 50 plus minutes of that. I think your calculations are a bit off. |
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Posted: 7/29/2015 5:56:45 PM EDT
[#25]
I read somewhere that Ion engines, as they exist today, take awhile to build up speed.........I wonder how long it will be before they overcome that limitation
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Posted: 7/29/2015 6:21:24 PM EDT
[#26]
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I read somewhere that Ion engines, as they exist today, take awhile to build up speed.........I wonder how long it will be before they overcome that limitation Ion still needs reaction mass. What makes the EM drive so attractive is it breaks the rocket equation. Most of a rocket's power is used to push fuel to burn to push fuel to burn to push fuel.......(about 23 more times)........to push the payload. Of the Saturn V's that went to the Moon, a couple percent was the lander and the command module dry. 98 percent was fuel and fuel structure. So you can make something that does the same job that is a couple percent the mass of a Saturn V. That is revolutionary. |
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Posted: 7/29/2015 6:30:35 PM EDT
[#27]
Quote HistoryQuoted: At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. Quote HistoryQuoted: Quoted: I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. |
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Posted: 7/29/2015 6:49:24 PM EDT
[#28]
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And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. You either put a lot of weight into physical shielding, streamline the ship or use electromagnetic shielding of some kind. Or all three. |
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Posted: 7/29/2015 6:51:47 PM EDT
[#29]
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Test the thing is space, measure the change in velocity (if it works), and it will be proven to work on some level. Exactly. I don't get why we are even testing these things on Earth anymore. Any result will be tainted with doubt. This device, as is, lends itself perfectly to a tiny microsat testbed. Something literally the size of a toaster oven, weighing almost nothing, using very cheap and readily available components could test this. It would be so small that, with a small payload booster, it could be put into a heliocentric orbit as a piggyback payload on a larger mission or satellite launch. It's time to stop screwing around and just see if the damn thing works. It either will or it won't. |
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Posted: 7/29/2015 6:53:51 PM EDT
[#30]
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And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. Within the context of exploring and colonizing our own solar system, that isn't a real problem. The "25% of the speed of light" example is just to show how impressive a mere 1g of acceleration is. Just because you could, doesn't mean you should. |
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Posted: 7/29/2015 6:56:22 PM EDT
[#31]
Quote HistoryQuoted: You either put a lot of weight into physical shielding, streamline the ship or use electromagnetic shielding of some kind. Or all three. Quote HistoryQuoted: Quoted: Quoted: Quoted: I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? At 1g of constant acceleration, you will reach ~1,300mph in one minute, ~79,000mph in an hour, ~1,900,000mph in a day, ~13,000,000mph in a week and ~25% of the speed of light in three months (that last figure is probably low as I'm not going to bother doing the real math on near relativistic velocities at this time). Constant acceleration allows for extreme velocities well within the limits of human survival. And when you're going 1/4th the speed of light and your spaceship hits a marble sized piece of rock, THEN WHAT? We have to solve THAT problem too.... but that's a subject for another thread. You either put a lot of weight into physical shielding, streamline the ship or use electromagnetic shielding of some kind. Or all three. I think a strong static-electric field could do well to deflect micrometeorites and such. Of course that could have an effect on the vector of the ship though? Physical armor can only do so much at those velocities, even cone/sloped armor. |
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Posted: 7/29/2015 8:05:20 PM EDT
[#32]
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However scientists still have no idea how it actually works. Nasa suggested that it could have something to do with the technology manipulating subatomic particles which constantly pop in and out of existence in empty space. Um -
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However scientists still have no idea how it actually works. Nasa suggested that it could have something to do with the technology manipulating subatomic particles which constantly pop in and out of existence in empty space. Um -
There was a doctor in the mid 1850's who suggested that jf doctors would wash their hands, it would reduced infant mortality. This is what people thought about him until well after his death and being locked up in an insane asylum. Some doctors were offended at the suggestion that they should wash their hands and Semmelweis could offer no acceptable scientific explanation for his findings. He was right, documented the results, just couldn't explain how it worked, but nevertheless, he was right. |
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Posted: 7/29/2015 8:30:54 PM EDT
[#33]
first we have to get it into orbit....
there are a few challenges to building it in space....
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Posted: 7/29/2015 8:40:41 PM EDT
[#34]
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first we have to get it into orbit.... there are a few challenges to building it in space.... The think the ultimate versions might have enough thrust to lift-off from the surface. Orbit will be unnecessary as you can directly ascend and descend at the moon or mars. And the one that needs a boost is still small. One SLS launch can launch a complete Mars expedition. One Saturn V class launcher gives us Mars, a couple gives us Saturn. Both, mass-wise are a fragment of the completed size of the ISS. |
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Posted: 7/29/2015 8:57:59 PM EDT
[#35]
Please visit the nasaspaceflight advanced concepts subforum for intelligent discussion on this matter.
Expecting most arftards to make sense of this (or most anything else) is preposterous. |
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Posted: 7/29/2015 9:07:07 PM EDT
[#36]
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Please visit the nasaspaceflight advanced concepts subforum for intelligent discussion on this matter. Expecting most arftards to make sense of this (or most anything else) is preposterous. Shh...don't tell them about Nasa Space Flight............... |
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Posted: 7/29/2015 9:18:42 PM EDT
[#37]
I think that the "controversy" of this topic is as much a exercise in bad science as the Fleischmann–Pons cold fusion experiment. As has been said before, multiple credible sources have claimed measurable thrust from these devices, and the outrage over the so called "reationless" properties of such a device are unfounded. Color me skeptical, but the math works and apparently so does the machine.
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Posted: 7/29/2015 9:35:04 PM EDT
[#38]
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You forgot to add 6000 to the final results. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? You forgot to add 6000 to the final results. *sigh* If we're going to apply high-school kinematics to a melodramatic journalist's nescience, we may as well do it right. x = 1/2at^2 + v_o*t Assume that the moon is 384000000 meters away and that 4 hours is 14400 seconds and the initial velocity is zero. 2*x = at^2 a = 2x/t^2 - 2v_o/t = 0.377673 g or 3.703707m/s^2. |
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Posted: 7/29/2015 9:49:06 PM EDT
[#39]
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Exactly. I don't get why we are even testing these things on Earth anymore. Any result will be tainted with doubt. This device, as is, lends itself perfectly to a tiny microsat testbed. Something literally the size of a toaster oven, weighing almost nothing, using very cheap and readily available components could test this. It would be so small that, with a small payload booster, it could be put into a heliocentric orbit as a piggyback payload on a larger mission or satellite launch. It's time to stop screwing around and just see if the damn thing works. It either will or it won't. Quote HistoryQuoted:
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Test the thing is space, measure the change in velocity (if it works), and it will be proven to work on some level. Exactly. I don't get why we are even testing these things on Earth anymore. Any result will be tainted with doubt. This device, as is, lends itself perfectly to a tiny microsat testbed. Something literally the size of a toaster oven, weighing almost nothing, using very cheap and readily available components could test this. It would be so small that, with a small payload booster, it could be put into a heliocentric orbit as a piggyback payload on a larger mission or satellite launch. It's time to stop screwing around and just see if the damn thing works. It either will or it won't. I agree entirely. In fact, it's projects like this that comprise a majority of the waning scientific value of the ISS. |
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Posted: 7/29/2015 9:53:12 PM EDT
[#40]
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I think that the "controversy" of this topic is as much a exercise in bad science as the Fleischmann–Pons cold fusion experiment. I started out at UT Austin in physics. I remember the 'cold fusion' debacle (~1989), with all the other universities "replicating" their results. What a joke. At some point you people need to understand that "scientists" are just like you and me: stupid, greedy, small minded, and egotistical, and not just the "anthropogenic global warming" climatologists. This magic drive is just un-magic crap. 
Two other fun ones: 1. The guys who had cracked the information density problem (mid '80's), and could compress any infinite amount of data, random data at that, into a finite and consistent sized packet. 2. The physicists who had cracked Wall Street (late 80's), and set up an investment firm. Can you say, "Ponzi-crash"? |
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Posted: 7/29/2015 10:33:27 PM EDT
[#41]
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*sigh* If we're going to apply high-school kinematics to a melodramatic journalist's nescience, we may as well do it right. x = 1/2at^2 + v_o*t Assume that the moon is 384000000 meters away and that 4 hours is 14400 seconds and the initial velocity is zero. 2*x = at^2 a = 2x/t^2 - 2v_o/t = 0.377673 g or 3.703707m/s^2. Quote HistoryQuoted:
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My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? You forgot to add 6000 to the final results. *sigh* If we're going to apply high-school kinematics to a melodramatic journalist's nescience, we may as well do it right. x = 1/2at^2 + v_o*t Assume that the moon is 384000000 meters away and that 4 hours is 14400 seconds and the initial velocity is zero. 2*x = at^2 a = 2x/t^2 - 2v_o/t = 0.377673 g or 3.703707m/s^2. Double it. You need to double acceleration because you'll be decelerating during the second half of the trip. 0.75g's |
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Posted: 7/29/2015 10:52:48 PM EDT
[#42]
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I think that the "controversy" of this topic is as much a exercise in bad science as the Fleischmann–Pons cold fusion experiment. As has been said before, multiple credible sources have claimed measurable thrust from these devices, and the outrage over the so called "reationless" properties of such a device are unfounded. Color me skeptical, but the math works and apparently so does the machine. http://i.imgur.com/q0R0ezo.png While the math backing the theory of operation proposed by the Shawyer camp may appear to explain EMDrive, I am 100% certain that it is not, actually, correct, and that their theory of its basic principle is fallacious. The speculation of White's team is a much more elegant and logical explanation, when taken to its logical conclusions. Additional testing will prove which camp is right, if either. I know where my money is. |
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Posted: 7/29/2015 10:57:15 PM EDT
[#43]
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They better be able to explain it. And I'm sure they will eventually. Getting on a ship that runs on "magic" would give me the creeps.. lol Quote HistoryQuoted:
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I'm fascinated by the experimental results. I really do want to see an explanation of how this works in defiance of the conservation of momentum. And will it work scaled up to a usable drive? Nevertheless.. http://i.imgur.com/jsXkNLP.gif I don't care if they can explain it as long as it works. They better be able to explain it. And I'm sure they will eventually. Getting on a ship that runs on "magic" would give me the creeps.. lol Especially one without a Gellar field generator. The Emperor Protects... |
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Posted: 7/29/2015 11:10:22 PM EDT
[#44]
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It's difficult to post formulas on ARFCom due to formatting, but you're looking for the uniform motion formula with time and acceleration as variables and distance (displacement) as the result. Understand that this does not factor in the orbital mechanics, which are far more complicated. It simply demonstrates how wrong 2,700gs of acceleration is. In two hours of constant acceleration at 1g, you will travel 157,932 miles from your point of origin. Turn the ship around and accelerate in the opposite direction for two hours and you have traveled another 157,932 miles. Total distance traveled in four hours, accelerating at 1 g half of the way and decelerating (oxymoron) at 1g for the second half, you will cover 315,864 miles. The distance to the moon is merely ~239,000 miles. In reality orbital mechanics laughs at such calculations, but "hours to the moon" with human survivable acceleration is certainly plausible, thousands of g's are not required. Quote HistoryQuoted:
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I get the significance of thrust generated without mass expulsion. Isn't that only half the equation to a space flight? How man G's of acceleration and deceleration are necessary to go 384,000 kilometers in 4 hours? Can humans withstand them? My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? It's difficult to post formulas on ARFCom due to formatting, but you're looking for the uniform motion formula with time and acceleration as variables and distance (displacement) as the result. Understand that this does not factor in the orbital mechanics, which are far more complicated. It simply demonstrates how wrong 2,700gs of acceleration is. In two hours of constant acceleration at 1g, you will travel 157,932 miles from your point of origin. Turn the ship around and accelerate in the opposite direction for two hours and you have traveled another 157,932 miles. Total distance traveled in four hours, accelerating at 1 g half of the way and decelerating (oxymoron) at 1g for the second half, you will cover 315,864 miles. The distance to the moon is merely ~239,000 miles. In reality orbital mechanics laughs at such calculations, but "hours to the moon" with human survivable acceleration is certainly plausible, thousands of g's are not required. If you can accelerate at that high a thrust for that long, orbital mechanics is pretty much a trivial factor. You have broken Hohmann's tyranny. You can go anywhere in a close to straight line. Direct ascent, turn and direct decent, no orbiting necessary. |
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Posted: 7/29/2015 11:41:59 PM EDT
[#45]
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I started out at UT Austin in physics. I remember the 'cold fusion' debacle (~1989), with all the other universities "replicating" their results. What a joke. It may end up being a bit less of a joke in hindsight. Have you kept up on that at all? |
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Posted: 7/29/2015 11:51:43 PM EDT
[#46]
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While the math backing the theory of operation proposed by the Shawyer camp may appear to explain EMDrive, I am 100% certain that it is not, actually, correct, and that their theory of its basic principle is fallacious. The speculation of White's team is a much more elegant and logical explanation, when taken to its logical conclusions. Additional testing will prove which camp is right, if either. I know where my money is. Quote HistoryQuoted:
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I think that the "controversy" of this topic is as much a exercise in bad science as the Fleischmann–Pons cold fusion experiment. As has been said before, multiple credible sources have claimed measurable thrust from these devices, and the outrage over the so called "reationless" properties of such a device are unfounded. Color me skeptical, but the math works and apparently so does the machine. http://i.imgur.com/q0R0ezo.png While the math backing the theory of operation proposed by the Shawyer camp may appear to explain EMDrive, I am 100% certain that it is not, actually, correct, and that their theory of its basic principle is fallacious. The speculation of White's team is a much more elegant and logical explanation, when taken to its logical conclusions. Additional testing will prove which camp is right, if either. I know where my money is. That seems rather hasty, although I admit that his treatment of the wave group velocity is a bit reductive. A Theory of Microwave Propulsion for Spacecraft
If v is replaced with the group velocity vg of the electromagnetic wave, then equation 1 illustrates that if vg1 is greater than vg2, then Fg1 should be expected to be greater than Fg2. Eta: If it appears as though I'm trying really hard to sound like I know what I'm talking about, it is because I am. To amend the words of yesterday's idiom: Mathematics is my game, but microwave propulsion systems are not my name.
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Posted: 7/30/2015 12:12:55 AM EDT
[#47]
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If you can accelerate at that high a thrust for that long, orbital mechanics is pretty much a trivial factor. You have broken Hohmann's tyranny. You can go anywhere in a close to straight line. Direct ascent, turn and direct decent, no orbiting necessary. Quote HistoryQuoted:
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My math comes in at just under 2700 G constant acceleration. We may have to go a little slower for the meat bags on board. You did your math very wrong. Do it again. If you get the same result, show your work, so it can be corrected. I'm working on a post-it note here. Why don't you just show us the correct math and save everyone the trouble? It's difficult to post formulas on ARFCom due to formatting, but you're looking for the uniform motion formula with time and acceleration as variables and distance (displacement) as the result. Understand that this does not factor in the orbital mechanics, which are far more complicated. It simply demonstrates how wrong 2,700gs of acceleration is. In two hours of constant acceleration at 1g, you will travel 157,932 miles from your point of origin. Turn the ship around and accelerate in the opposite direction for two hours and you have traveled another 157,932 miles. Total distance traveled in four hours, accelerating at 1 g half of the way and decelerating (oxymoron) at 1g for the second half, you will cover 315,864 miles. The distance to the moon is merely ~239,000 miles. In reality orbital mechanics laughs at such calculations, but "hours to the moon" with human survivable acceleration is certainly plausible, thousands of g's are not required. If you can accelerate at that high a thrust for that long, orbital mechanics is pretty much a trivial factor. You have broken Hohmann's tyranny. You can go anywhere in a close to straight line. Direct ascent, turn and direct decent, no orbiting necessary. You still need to consider the motion of your target while plotting your course, which still requires some application of orbital mechanics. However, you are correct that it becomes amazingly simple compared to present astronavigation. I, personally, do not expect 1g of acceleration anytime soon, even if the device works. This is all thought experiment thus far, correcting misunderstandings of the benefits provided by constant acceleration. |
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