• How Far Can We Go? Limits of Humanity - In a Nutshell
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[QUOTE=SpartanXC9;50311180]Nah once we achieve faster then light travel we probably could[/QUOTE] I was really just asking how fast the nearest local group was receding, it depends on the distance, and can be determined using Hubble's law. I just couldn't be bothered to check myself, and I wouldn't assume they'd make such a big mistake in the video.
[QUOTE=Hauptmann;50308011]That was pretty depressing tbh[/QUOTE] The more of these videos I see, the more I'm convinced that physics is a cosmic horror of the real world. Which raises the question of how physicists manage to stay excited about their job rather than devolve into gibbering madmen.
[QUOTE=SpartanXC9;50311180]Nah once we achieve faster then light travel we probably could[/QUOTE] Do you have like a google alert that tells you every time someone posts something about the speed of light on Facepunch so you can tell everyone that there's nothing special about the speed of light and scientists are all liars? [editline]13th May 2016[/editline] [QUOTE=NixNax123;50310744]one more question. so the closest galaxy outside our local group is ~2000 kpc. so that means it's moving away from us at about 150 km/s. nowhere near relativistic speeds; so couldn't we catch up to it? i could be calculating this wrong, but for us to [I]not[/I] be able to reach something wouldn't it need to be about 4,200 megaparsecs away from us (traveling ≥ c)? which is much further than the Maffei group is from us, so couldn't we go there?[/QUOTE] I'm not honestly sure how they determined the whole Local Group thing. Maybe it was under the assumption of a billion years in the future or something, or by time time we could reach the edge it would be expanding away from us faster than light, or prohibitively fast. [editline]13th May 2016[/editline] [QUOTE=Feroaffer;50310769]Are we anywhere near close to understanding and creating FTL travel? if that is even possible of course.[/QUOTE] Based on our current understanding of physics, it's impossible. So either it is impossible, or no, we're nowhere near close to understanding it.
[QUOTE=JohnnyMo1;50312615]Do you have like a google alert that tells you every time someone posts something about the speed of light on Facepunch so you can tell everyone that there's nothing special about the speed of light and scientists are all liars? [/QUOTE] We use to thing the wind was as fast as we could go, now we're traveling faster then sound. I'm sure one day we could eventually go faster then light!
[QUOTE=SpartanXC9;50312685]We use to thing the wind was as fast as we could go, now we're traveling faster then sound. I'm sure one day we could eventually go faster then light![/QUOTE] Read up on the theory of special relativity. It explains why traveling faster than light is impossible. To accelerate a massive object to the speed of light would require putting an infinite amount of energy into it, as well as myriad other issues, e.g. faster-than-light travel creates big issues with causality (faster-than-light is in some sense equivalent to backwards-in-time). Relativity is extremely well-verified. It has stood up to every test anyone has ever thrown at it. It explains quite well why we find particles going all sorts of speeds, but never faster than light. It explains why we discovered the [url=https://en.wikipedia.org/wiki/Oh-My-God_particle]"Oh-My-God" particle[/url] traveling incredibly close to the speed of light... but not faster. If the speed of light was not any sort of special limit, why do we find massive particles traveling at speed so close to it, yet never above it? And look at the 2011 OPERA neutrino anomaly. Neutrinos (which we expect travel very quickly, almost the speed of light) were detected to be traveling faster-than-light! Everyone expected some sort of experimental error, and ta-da! There was a loose cable. The experiment was re-analyzed with the new error source accounted for, and the neutrino speed went back to around its previously expected value. There's several good reasons to expect that the speed of sound is not an ultimate limit even if you've never invented planes that can surpass it. The tip of a bullwhip can travel faster than sound, and those have been around since nearly the time of Jesus.
[QUOTE=maeZtro;50308196]At the speeds science and tech moves forward today I wouldn't be surprised if we could traverse the entire universe in a billion years, our understanding of physics would probably be very different from now.[/QUOTE] Our understanding of physics will only be very different if it turns out that we're currently very wrong. [editline]13th May 2016[/editline] [QUOTE=SpartanXC9;50312685]We use to thing the wind was as fast as we could go, now we're traveling faster then sound. I'm sure one day we could eventually go faster then light![/QUOTE] "We were wrong in the past therefore we must be wrong now"
[QUOTE=Kljunas;50313150]"We were wrong in the past therefore we must be wrong now"[/QUOTE] It's such ridiculous reasoning too, considering everyone thought just like SpartanXC9 did 120 years ago. Relativity was a radical new theory, met with huge resistance, and it was only until repeated tests that people started to accept that this is how reality is. It's not as though someone said "Light is really fast, we probably can't ever go faster." The speed of light as a speed limit was not the default belief. No such limit exists in Newtonian mechanics. Its acceptance was hard-won. Back in 1931 a book of criticisms of relativity was published called (translated from German) [I]One Hundred Authors Against Einstein[/I]. Einstein, that witty bastard, quipped something to the effect of, "If I were wrong, one author would have been enough!"
[QUOTE=SpartanXC9;50312685]We use to thing the wind was as fast as we could go, now we're traveling faster then sound. I'm sure one day we could eventually go faster then light![/QUOTE] You need to take a physics course before making statements about physics. This post is wrong on so many levels.
When we finally achieve FTL I'll be there! and I'll be the one laughing!
[QUOTE=SpartanXC9;50314101]When we finally achieve FTL I'll be there![/QUOTE] Why do I bother typing up reasonably long explanations to you when I know you aren't going to pay any attention or have any sort of argument of your own?
[QUOTE=JohnnyMo1;50314109]Why do I bother typing up reasonably long explanations to you when I know you aren't going to pay any attention or have any sort of argument of your own?[/QUOTE] Nah man I know you're right it's just fun to dream thats all
[QUOTE]If the speed of light was not any sort of special limit, why do we find massive particles traveling at speed so close to it, yet never above it?[/QUOTE] Forgive my ignorance, but I heard some where that space between things is an illusion. I forget where I read it but is this true?
[QUOTE=Dayzofwinter;50314149]Forgive my ignorance, but I heard some where that space between things is an illusion. I forget where I read it but is this true?[/QUOTE] I don't know what that could possibly mean. Space between things as far as modern science is concerned is very real.
[QUOTE=SpartanXC9;50314123]Nah man I know you're right it's just fun to dream thats all[/QUOTE] You may enjoy reading about the Alcubierre drive. It's still got huge problems (it relies on matter that we have no reason to believe exists, and it causes problems with causality) but it's at least a neat general relativity trick to create something like faster-than-light travel. Closer to reality than "turn on your rocket boosters until you're going faster than light."
[QUOTE=JohnnyMo1;50312857]Read up on the theory of special relativity. It explains why traveling faster than light is impossible[/QUOTE] FTL travel may not be completely impossible. I'm sure you've heard of the Alcubierre warp drive which shows you that accelerating an object is not the only way to get from point A to point B. While further research may prove it completely unfeasible - it still shows that there is potential. If you told somebody about the concept of a warp drive 100 years ago they'd think you're insane. I've no doubt 100 years into the future when there's a greater understanding of the world we live in that other concepts will also have circumvented the speed limit (like said drive). With that said there's no reason to not be optimistic, only that it probably won't happen in our lifetimes.
[QUOTE=TrulliLulli;50314236]FTL travel may not be completely impossible. I'm sure you've heard of the Alcubierre warp drive which shows you that accelerating an object is not the only way to get from point A to point B. While further research may prove it completely unfeasible - it still shows that there is potential. If you told somebody about the concept of a warp drive 100 years ago they'd think you're insane. I've no doubt 100 years into the future when there's a greater understanding of the world we live in that other concepts will also have circumvented the speed limit (like said drive). With that said there's no reason to not be optimistic, only that it probably won't happen in our lifetimes.[/QUOTE] See my above post! The Alcubierre drive has problems which are basically fatal. Spacetimes containing Alcubierre drives can contain closed timelike curves, which basically means that without violating the local speed of light limit, we can go back in time. Ergo causality is not safe, which is exactly why we need the speed of light limit to begin with! That's even ignoring its myriad practical issues (which you can read about on its Wikipedia page). The Alcubierre drive is a neat mathematical curiosity, but in terms of practical methods of faster-than-light travel, it's no better than hoping we'll just find a way to turn on our rocket engines long enough that we speed up faster than a light beam.
[QUOTE=rndgenerator;50314155]I don't know what that could possibly mean. Space between things as far as modern science is concerned is very real.[/QUOTE] Ok the space right now, between us, is an illusion. Once that illusion is "popped", travel is instant. I have no idea where I got the idea. Maybe too much sci fi horror reading or something of the like. I know it is a dumb question (and I admit my ignorance) I just wanna know there some truth to it or maybe I need to stop reading so much marvel comics?
I agree we need optimists who are willing to push our understanding of physics to the brink to develop new technologies to help us out, but I think of myself to some degree as a scientist, and good science needs to be conservative, not optimistic. People who didn't believe in relativity back in the day seem deluded to us now, but relativity was a very radical idea at the time. It was perfectly reasonable for them to be extremely skeptical and push back until the evidence was incontrovertible as it is today. Well, except for the guys who denounced it as "Jewish Physics." They weren't being reasonable. [editline]13th May 2016[/editline] [QUOTE=Dayzofwinter;50314318]Ok the space right now, between us, is an illusion. Once that illusion is "popped", travel is instant. I have no idea where I got the idea. Maybe too much sci fi horror reading or something of the like. I know it is a dumb question (and I admit my ignorance) I just wanna know there some truth to it or maybe I need to stop reading so much marvel comics?[/QUOTE] Measured distances vary based on who observes them. Someone moving with the right velocity relative to me would measure what I call 1 meter to be only half a meter. Is that what you're referring to?
[QUOTE]Measured distances vary based on who observes them. Someone moving with the right velocity relative to me would measure what I call 1 meter to be only half a meter. Is that what you're referring to?[/QUOTE] I do not even have a pre school idea of physics dude. It was an idea I heard some where and was wondering if it had merit. I mean the fastest way to one place to another is no distance, correct? If the distance could be removed, that would be a solution. So I was wondering if it was possible in any shape or form.
If we could directly manipulate the mass of particles ala Mass Effect, couldn't that provide a workaround to the speed of light? Although I'm sure dropping the mass of an object to 0 would have some interesting effects.
[QUOTE=JohnnyMo1;50314276]See my above post! The Alcubierre drive has problems which are basically fatal. Spacetimes containing Alcubierre drives can contain closed timelike curves, which basically means that without violating the local speed of light limit, we can go back in time. Ergo causality is not safe, which is exactly why we need the speed of light limit to begin with! That's even ignoring its myriad practical issues (which you can read about on its Wikipedia page). The Alcubierre drive is a neat mathematical curiosity, but in terms of practical methods of faster-than-light travel, it's no better than hoping we'll just find a way to turn on our rocket engines long enough that we speed up faster than a light beam.[/QUOTE] I agree about the drive, it's more of a research project than a feasible method. To rephrase my poorly worded point; this kind of out of the box thinking may prove fruitful. Nobody thought you could potentially move faster than light until someone thought about bending spacetime. Who knows what other concepts might be out there. I think/hope at some point we'll have to differentiate between actually moving faster than light and travelling "faster" than light. -edit- fuck sake me and my slow posting
[QUOTE=IrishBandit;50314457]If we could directly manipulate the mass of particles ala Mass Effect, couldn't that provide a workaround to the speed of light? Although I'm sure dropping the mass of an object to 0 would have some interesting effects.[/QUOTE] Probably depends how that would work. It's good to remember, though, that mass and energy are interchangeable, so there are some issues which could arise. A massless box full of photons, for instance, has inertia, and hence gains a mass!
[QUOTE=JohnnyMo1;50314322]I agree we need optimists who are willing to push our understanding of physics to the brink to develop new technologies to help us out, but I think of myself to some degree as a scientist, and good science needs to be conservative, not optimistic. People who didn't believe in relativity back in the day seem deluded to us now, but relativity was a very radical idea at the time. It was perfectly reasonable for them to be extremely skeptical and push back until the evidence was incontrovertible as it is today. Well, except for the guys who denounced it as "Jewish Physics." They weren't being reasonable. [editline]13th May 2016[/editline] Measured distances vary based on who observes them. Someone moving with the right velocity relative to me would measure what I call 1 meter to be only half a meter. Is that what you're referring to?[/QUOTE] Wouldn't it also release a hypothetical shockwave of energy upon reentry from it's bubble? Meaning actually getting to where you want to go likely means destroying the area or doing serious damage to it?
Tbh we're not even going to be getting to nearby solar systems, let alone leave the galaxy, let alone leave the local group without some kind of FTL-like travel. The BEST thing we could ever hope for without FTL-like travel is send a ship to alpha centauri with people on board in cryostasis and somehow hope it doesn't go disastrously wrong in the hundred year travel it will take. If we ever get to the point where we can feasibly leave the milky way and even get to another galaxy nearby I guarantee leaving the local group isn't going to be that much of a stretch. Because the only way that is happening is if we figure out space magic teleportation.
[QUOTE=KorJax;50315009]Tbh we're not even going to be getting to nearby solar systems, let alone leave the galaxy, let alone leave the local group without some kind of FTL-like travel. The BEST thing we could ever hope for without FTL-like travel is send a ship to alpha centauri with people on board in cryostasis and somehow hope it doesn't go disastrously wrong in the hundred year travel it will take. If we ever get to the point where we can feasibly leave the milky way and even get to another galaxy nearby I guarantee leaving the local group isn't going to be that much of a stretch. Because the only way that is happening is if we figure out space magic teleportation.[/QUOTE] Actually, you might not even need cryostasis. Relativity does work for us, in a way. If we could develop some sort of tech such that we could accelerate at a constant 1g for very long periods of time, and if we turn our rocket around and decelerate at the half way point so that we arrive at a low speed, we could get to Alpha Centauri in 3.6 years of shipboard time. In fact, going to Andromeda would only take 28 years of shipboard time! The problem is that this takes absurd amount of fuel. Hopefully we perfect some sort of propulsion system like but necessarily a solar sail which will allow us to not have to keep the fuel onboard and to fuel up as we go.
[QUOTE=JohnnyMo1;50315109]Actually, you might not even need cryostasis. Relativity does work for us, in a way. If we could develop some sort of tech such that we could accelerate at a constant 1g for very long periods of time, and if we turn our rocket around and decelerate at the half way point so that we arrive at a low speed, we could get to Alpha Centauri in 3.6 years of shipboard time. In fact, going to Andromeda would only take 28 years of shipboard time! The problem is that this takes absurd amount of fuel. Hopefully we perfect some sort of propulsion system like but necessarily a solar sail which will allow us to not have to keep the fuel onboard and to fuel up as we go.[/QUOTE] How long, exactly, would that be in earth time?
[QUOTE=KorJax;50315009]Tbh we're not even going to be getting to nearby solar systems, let alone leave the galaxy, let alone leave the local group without some kind of FTL-like travel. The BEST thing we could ever hope for without FTL-like travel is send a ship to alpha centauri with people on board in cryostasis and somehow hope it doesn't go disastrously wrong in the hundred year travel it will take. If we ever get to the point where we can feasibly leave the milky way and even get to another galaxy nearby I guarantee leaving the local group isn't going to be that much of a stretch. Because the only way that is happening is if we figure out space magic teleportation.[/QUOTE] I could maybe see a huge ship that makes the trip over the course of several generations, to colonise another planet when our system becomes inhospitable.
What if instead of trying to chase a galaxy that is heading away from us we could just aim for ones heading in our direction (behind us)? Aren't there any universes traveling in the same path as ours that we could reach in the way way future (assuming we had things like suspended animation tech and blah blah)?
[QUOTE=ZombieWaffle;50315266]How long, exactly, would that be in earth time?[/QUOTE] I'm not sure exactly, but not much longer than the distance times the speed of light, I don't think, since the rocket spends most of its time on the trip near light speed.
[QUOTE=noh_mercy;50315383]What if instead of trying to chase a galaxy that is heading away from us we could just aim for ones heading in our direction (behind us)? Aren't there any universes traveling in the same path as ours that we could reach in the way way future (assuming we had things like suspended animation tech and blah blah)?[/QUOTE] That's not how it works. The galaxies aren't all moving in a direction, space itself is expanding, meaning that all the galaxies are getting further away from each other.
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