a) Special and General Relativity are better approximations to what is going on than Newtonian mechanics. While it is true that Newtonian mechanics holds up well enough to be used in most cases it is a poorer approximation than relativity.
b) Special and General Relativity are 'new kids on the block' as compared to Newtonian Mechanics longevity.
Certainly one day there will be an even better approximation of what goes on in the universe than even these models, this is what scientists and specifically Theoretical Physicists work on all day long. However, just because these models are approximations does not mean that one day you will just be able to break the lightspeed barrier with impunity, the lightspeed barrier is a very real thing that has been measured to the 12th decimal place in experiment after experiment, something akin to knowing the distance between San Francisco and New York to the width of human hair.
I'm not talking about accuracy of measurement. I'm talking about accuracy of our understanding how things work. We may discover some crazy loophole that allows us to do something like instantaneously move from point a to point b. It is true that our current understanding of the universe makes this unlikely but at one time we thought that light didn't travel at all so who knows.
Thanks, Grey; I was going to reply but now I don't have to.
You're welcome? I'd still like you to issue a statement on the matter, because there may have been things I got wrong, my reply being an approximation of my views.
a) Special and General Relativity are better approximations to what is going on than Newtonian mechanics. While it is true that Newtonian mechanics holds up well enough to be used in most cases it is a poorer approximation than relativity.
That's what I said.
b) Special and General Relativity are 'new kids on the block' as compared to Newtonian Mechanics longevity.
And Newtonian mechanics was the 'new kid on the block' to Aristolean Mechanics. I really think you should read the article I posted. Age is not a good measure of truth value.
I'm not talking about accuracy of measurement. I'm talking about accuracy of our understanding how things work.
In science, these are analagous, and for good reason. If you want to understand a system to a high degree of accuracy, you will devise a model and then an experiment to test that model. during the experiment you will predict measurements you will make of the system. If these measurements are close to what you predicted, you had a good model, and it can be said that you understood the system in question.
We may discover some crazy loophole that allows us to do something like instantaneously move from point a to point b. It is true that our current understanding of the universe makes this unlikely but at one time we thought that light didn't travel at all so who knows.
It seems to me like you are starting from a hypothesis rather than from data. Also, just because it is possible does not make it probable. If there is a loophole like you mention we would be able to observe it somewhere in the universe. As we have not observed such a loophole so it is safe to assume it does not exist.
This is my pet-physics-hate. A lot of people cite relativity and it's intergalactic speed limit to suggest we are unlikely to run into any little green men.
I'm not talking about accuracy of measurement. I'm talking about accuracy of our understanding how things work. We may discover some crazy loophole that allows us to do something like instantaneously move from point a to point b. It is true that our current understanding of the universe makes this unlikely but at one time we thought that light didn't travel at all so who knows.
You've contradicted yourself. If such a loophole is unlikely, then it is also unlikely that we will run into aliens any time soon.
You've contradicted yourself. If such a loophole is unlikely, then it is also unlikely that we will run into aliens any time soon.
I don't think I did.
The loophole is unlikely against our current understanding which will likely change in the future possibly introducing a 'loophole'
And Newtonian mechanics was the 'new kid on the block' to Aristolean Mechanics. I really think you should read the article I posted. Age is not a good measure of truth value.
Further evidence that our intergalactic speed limit may be circumvented by new findings.
If there is a loophole like you mention we would be able to observe it somewhere in the universe. As we have not observed such a loophole so it is safe to assume it does not exist.
The universe is vast and our instruments are limited. So it is not safe to assume anything.
The loophole is unlikely against our current understanding which will likely change in the future possibly introducing a 'loophole'
Our understanding of the universe may change, but the universe does not. Everything we have seen of the universe points to there being no such loophole.
Further evidence that our intergalactic speed limit may be circumvented by new findings.
Did you read the article?
The universe is vast and our instruments are limited. So it is not safe to assume anything.
To quote Tim Minchin, is knowledge so fleeting when you decide to leave your house by your front door... or the window on your second floor?
Also, you don't need to press enter after every sentence and blockquote, there is a preview button you can use to see how your post will format.
I don't have to press enter, but I choose to. You can quote whoever you like but it doesn't change the fact that we would be arrogant to assume we are right.
That depends on what you mean by "assume". Should we take anything to be 100% certain? No. However, when presented with the mountains of evidence we have for something like relativity, it is entirely reasonable to neglect the possibility that we are wrong until we are presented with evidence for it.
You seem to have time to browse these forums that is more than enough to read the article.
I don't have to press enter, but I choose to.
Fair enough, but you should know your posts look horrible.
You can quote whoever you like but it doesn't change the fact that we would be arrogant to assume we are right.
Really, I look at the mountain of evidence we have and say "Well, we have very good models, I shall assume they are right for the time being," you look at the same mountain of evidence and say "Our models must be wrong." If that is not the definition of arrogance, I am a potato.
but it doesn't change the fact that we would be arrogant to assume we are right.
We don't assume that we are right. We have a lot of evidence that says, "This is our current model of how the universe works. According to our current model, this premise has this likelihood of being correct."
Saying that we should consider a premise simply because we might be wrong is ludicrous. Of course we could be wrong - that's a given in science. But science does not care about what is possible - it cares about which events are more likely.
No good scientist says that it is impossible for any aliens to have ever visited us. A good scientist will say that they almost certainly have not, based on our understanding of the universe. They are as confident in that statement as anyone can rationally be in any statement, and there is no compelling reason to believe that any other state is the "correct" one.
you look at the same mountain of evidence and say "Our models must be wrong."
I do not. I say "I hope we are wrong". Because, as many have said in this discussion, I want to believe.
You seem to have time to browse these forums that is more than enough to read the article.
I have enough time to defend myself, which isn't very noble I suppose. I admit I should find time to read your referenced article out of courtesy. It just isn't happening yet. This all stems from the fundamental thing I discovered while I studied physics. I discovered that I only scratched the surface and that we don't know more than we know (I await the tirade of comments about me not learning anything)
BTW - I formatted the above as requested. I can bend in the wind.
Accepting that we can never travel to the stars because our current understanding of physics precludes it in a practical sense is ludicrous in my opinion. That is what I got from the earlier emails and prompted my comment. If that was not the case I apologize.
Accepting that we can never travel to the stars because our current understanding of physics precludes it in a practical sense is ludicrous in my opinion.
No one said we can't travel to the stars. We're just saying that FTL drives are not possible.
Accepting that we can never travel to the stars because our current understanding of physics precludes it in a practical sense is ludicrous in my opinion.
No one said we can't travel to the stars. We're just saying that FTL drives are not possible.
Doesn't stop some legitimate physicists from trying, however. For example, there is the Alcubierre Drive.
The problem with the Alcubierre drive is that it requires orders of magnitude more energy than one could obtain from the total conversion of all matter in the universe into energy, even at 100% efficiency, just to move even a man-sized vehicle a worthwhile distance at a translight speed. So, unless you know of an energy source that provides limitless free energy or a way to produce some awesome exotic matter that can toy with various properties of either the vehicle or the drive, the Alcubierre drive is nothing more than an interesting thought experiment for now. Just like a wormhole gate.
Wait, was that whole debate boiled down to semantics? I hate it when that happens.If that's the case, I'm surprised you can stand participating in any debate on this forum.Me too.
The problem with the Alcubierre drive is that it requires orders of magnitude more energy than one could obtain from the total conversion of all matter in the universe into energy, even at 100% efficiency, just to move even a man-sized vehicle a worthwhile distance at a translight speed. So, unless you know of an energy source that provides limitless free energy or a way to produce some awesome exotic matter that can toy with various properties of either the vehicle or the drive, the Alcubierre drive is nothing more than an interesting thought experiment for now. Just like a wormhole gate.
Yeah, just about every current hypothetical FTL system has serious problems like the Alcubierre drive. That wasn't my point. My point was that physicists are looking for "loopholes" in relativity to try to find some way to go FTL. Granted, I don't think any of them are doing it as their primary research -- it just seems to be something they do as a fun side project during their spare time. Still, the existence of these potential loopholes, despite their insane energy requirements, leads me to think that FTL isn't 100% impossible like some others posited in this thread. Now, it may be 99.999% impossible, but that 0.001% does give me some hope that perhaps some day a working FTL drive may be invented -- especially as our knowledge of physics increases. It's not like we currently know everything about physics, after all. While I agree that the odds are slim that, oh, something like the disproving of supersymmetry (which seems to be a possibility as current particle accelerators are starting to get close to the maximum possible energy where supersymmetry should appear and have yet to find proof of it) will result in an FTL drive, you never know what the Universe will toss at us as we try to probe its secrets.
That depends on the interpretation of that statement. When I say "FTL drive," I mean a motor that accelerates an object to a translight velocity, which is not possible.
The ship is locally stationary with an Alcubierre drive, so it's not true FTL, though you would be moving many times faster than light speed with enough energy relative to an outside observer. Wormholes are not motors, but rather spacetime anomalies allowing us to go through rather than along spacetime, and theoretically beat light originating from a light outside the wormhole to the destination along a straight path (without going through the wormhole) while simultaneously not exceeding its speed.
The thing about "FTL" travel is that every theoretically possible case is not truly FTL. It just circumvents other rules of physics to make it *seem* like it is.
Fair enough. My interpretation of "FTL" is "Anything that gets you from point A to point B in less time than it takes light unassisted by this same method." It could be an engine, a wormhole, or any other method that circumvents physics to achieve "FTL."
I agree that we'll never have some big honkin' engine that pumps out enough thrust to go FTL -- whatever method we use to achieve my broader definition of "FTL drive" will need to play games with physics as you mentioned. Even most common sci-fi FTL methods probably fall into this scope -- the Alcubierre drive was originally conceived as a way to explain how Star Trek's warp drive worked using as much real physics as possible, after all.
Comments
a) Special and General Relativity are better approximations to what is going on than Newtonian mechanics. While it is true that Newtonian mechanics holds up well enough to be used in most cases it is a poorer approximation than relativity.
b) Special and General Relativity are 'new kids on the block' as compared to Newtonian Mechanics longevity. I'm not talking about accuracy of measurement. I'm talking about accuracy of our understanding how things work. We may discover some crazy loophole that allows us to do something like instantaneously move from point a to point b. It is true that our current understanding of the universe makes this unlikely but at one time we thought that light didn't travel at all so who knows.
The loophole is unlikely against our current understanding which will likely change in the future possibly introducing a 'loophole' Further evidence that our intergalactic speed limit may be circumvented by new findings. The universe is vast and our instruments are limited. So it is not safe to assume anything.
Also, you don't need to press enter after every sentence and blockquote, there is a preview button you can use to see how your post will format.
I don't have to press enter, but I choose to. You can quote whoever you like but it doesn't change the fact that we would be arrogant to assume we are right.
However, when presented with the mountains of evidence we have for something like relativity, it is entirely reasonable to neglect the possibility that we are wrong until we are presented with evidence for it.
EDIT: Edited for clarity.
Saying that we should consider a premise simply because we might be wrong is ludicrous. Of course we could be wrong - that's a given in science. But science does not care about what is possible - it cares about which events are more likely.
No good scientist says that it is impossible for any aliens to have ever visited us. A good scientist will say that they almost certainly have not, based on our understanding of the universe. They are as confident in that statement as anyone can rationally be in any statement, and there is no compelling reason to believe that any other state is the "correct" one.
This all stems from the fundamental thing I discovered while I studied physics. I discovered that I only scratched the surface and that we don't know more than we know (I await the tirade of comments about me not learning anything)
BTW - I formatted the above as requested. I can bend in the wind.
Accepting that we can never travel to the stars because our current understanding of physics precludes it in a practical sense is ludicrous in my opinion. That is what I got from the earlier emails and prompted my comment. If that was not the case I apologize.
The ship is locally stationary with an Alcubierre drive, so it's not true FTL, though you would be moving many times faster than light speed with enough energy relative to an outside observer. Wormholes are not motors, but rather spacetime anomalies allowing us to go through rather than along spacetime, and theoretically beat light originating from a light outside the wormhole to the destination along a straight path (without going through the wormhole) while simultaneously not exceeding its speed.
The thing about "FTL" travel is that every theoretically possible case is not truly FTL. It just circumvents other rules of physics to make it *seem* like it is.
I agree that we'll never have some big honkin' engine that pumps out enough thrust to go FTL -- whatever method we use to achieve my broader definition of "FTL drive" will need to play games with physics as you mentioned. Even most common sci-fi FTL methods probably fall into this scope -- the Alcubierre drive was originally conceived as a way to explain how Star Trek's warp drive worked using as much real physics as possible, after all.