8 ms·
If you do not work on an important problem, it's unlikely you'll do important work. It's perfectly obvious. Great scientists have thought through, in a careful
by GuiA 7y ago
If you do not work on an important problem, it's unlikely you'll do important work. It's perfectly obvious. Great scientists have thought through, in a careful way, a number of important problems in their field, and they keep an eye on wondering how to attack them. Let me warn you, `important problem' must be phrased carefully. The three outstanding problems in physics, in a certain sense, were never worked on while I was at Bell Labs. By important I mean guaranteed a Nobel Prize and any sum of money you want to mention. We didn't work on (1) time travel, (2) teleportation, and (3) antigravity. They are not important problems because we do not have an attack. It's not the consequence that makes a problem important, it is that you have a reasonable attack. That is what makes a problem important. When I say that most scientists don't work on important problems, I mean it in that sense. The average scientist, so far as I can make out, spends almost all his time working on problems which he believes will not be important and he also doesn't believe that they will lead to important problems.
Richard Hamming, You and Your Research
http://www.cs.virginia.edu/~robins/YouAndYourResearch.html http://www.cs.virginia.edu/~robins/YouAndYourResearch.html
- kiba 7y agoTime travel back into the past is understood to be impossible.
- myrandomcomment 7y agoThe math say time travel is possible, but the energy required would consume the universe, depending on what paper your read. There is no reason math wise the arrow of time only goes in one direction.
- ekianjo 7y agoErm, there is something fundental discovered in thermodynamics that we call entropy. Energy only flows in one direction and time as well.
- myrandomcomment 7y agoSo you know, I in general try not to pull comments out of thin air. https://www.sciencealert.com/thermodynamics-arrow-of-time-reversed-under-quantum-conditions https://www.sciencealert.com/thermodynamics-arrow-of-time-re... https://www.pbs.org/wgbh/nova/article/scientists-reverse-arrow-of-time-in-quantum-experiment/ https://www.pbs.org/wgbh/nova/article/scientists-reverse-arr... Etc.. The MATH allows it.
- chmod775 7y agoCertain kinds of it. Time travel to the past in a parallel universe at least doesn't cause any logical problems ('paradoxes') to arise. https://en.wikipedia.org/wiki/Time_travel#Interacting_many-worlds_interpretation https://en.wikipedia.org/wiki/Time_travel#Interacting_many-w...
- ekianjo 7y agoAnd where would the information about parallel universes be contained?
- ozzmotik 7y agoi would figure in that parallel universe lol, or if you want to be more general, in some overarching metaversal container leading out to the omniverse at greeter degrees. but that's just me ¯\_(ツ)_/¯
- ekianjo 7y agoSo the universe would be composed of infinite energy?
- mr_mitm 7y agoYou mean everettian worlds? In the wave function.
- Khelavaster 7y agoFar, far away in our infinite space. Further than we can see, because if we look more than 14B light years away we're blinded by the Big Bang of our own creation. Max Tegmark calculated out that parallel universes are probablistically present around 10^21 an 10^23 light years out from us, if matter's about as dense and as randomly distributed as in our universe.
- archgoon 7y agoWhich he alludes to with the phrase "They are not important problems because we do not have an attack." That said, closed time like curves are not excluded as possible by General Relativity.
- zitterbewegung 7y agoYes, a more in depth analysis of this can be found at https://en.wikipedia.org/wiki/No-communication_theorem https://en.wikipedia.org/wiki/No-communication_theorem
- DoctorOetker 7y agothis should properly be called a conjecture, as I have never encountered a formal proof of this "theorem"
- garmaine 7y agoPhysicist here (by degree, not profession). What you state is not true: by currently accepted physical theories, time travel to the past IS very much possible. It's known as a "closed, time-like curve" in the literature. Now, most mechanisms explored for doing so wouldn't allow travel back further than the initial creation of the time travel device, so you could say that time travel to our past is not possible since the construction of such a thing is necessarily in the future. But as a matter of physics, general relativity allows it. Now that said, most physicists are convinced that time travel cannot be possible, because if it were then paradoxical situations could be constructed--e.g. going back in time and killing yourself (the earlier you) before you entered the machine, or killing your grandfather before your father was born, etc. There are as many theorized rules preventing or limiting time travel as there are physicists that have looked at it, but critically they are all ADDITIONAL rules, postulated not to explain observable phenomenon but purely to think up a way time travel paradoxes might be avoided. Physics, as currently understood from available experimental evidence, 100% allows time travel to the past, paradoxes included.
- trhway 7y ago> then paradoxical situations could be constructed--e.g. going back in time and killing yourself (the earlier you) before you entered the machine, or killing your grandfather before your father was born Can't the paradox be resolved by considering it as a fork/branching of a new reality/timeline where the grandfather is killed, kind of similar to many world interpretation in QM. I'd speculate that using model of lazy fork it may be possible to get some ballpark estimates on energy requirements/etc. below the typical "all the energy in the Universe". Such forks/perturbations possibly also dissipate, like a small wave in the pond, and the forked reality gets naturally merged into the mainline ( i think this is how QM's many world while possibly true is still compatible with "realistic" situation of limited number, may be even just 1, Universe mainlines)
- pdonis 7y ago> by currently accepted physical theories, time travel to the past IS very much possible Only if you make use of exotic matter, which nobody has ever observed and which there are good reasons to think cannot exist.
- smacktoward 7y agoLots of things were understood to be impossible until they weren’t.
- Khaine 7y agoPBS Space Time just did an episode on this. Turns out, based purely on the maths it is possible, however highly improbable for us to do it. https://www.youtube.com/watch?v=pGnMiGrYmPE https://www.youtube.com/watch?v=pGnMiGrYmPE