Relativity-ly Speaking

Hi Guys,

New post this time. It's late and I'm tired, so I thought I'd give all the relativists among you a conundrum to enjoy.

This is one that's based on the theory of special relativity, and also one that I posted long ago on Philosophy Forums before it went away. You may still be able to find it under my nom-de-net of Psychotick.

This is based on the commonly known twins paradox. Most of you will be familiar with the basics of it. In essence special relativity says that if you have two twins and you stick one on a rocket ship and he flies away at high speed and comes back, because he's been traveling at a significant fraction of the speed of light, he will have experienced less time. So when he comes back to Earth and meets his twin brother, he'll actually be younger than him.

Now about three or four years ago it occurred to me that this scenario is self defeating. (From a philosophical / logical point of view. Those of you who've watched The Good Place - which is brilliant by the way - will have heard the oft repeated complaint that "this is why everybody hates moral philosophers". Here I'm going to expand that to "this is why everybody hates philosophers!")

Okay, so lets get back to the paradox - and try and place it within the frame of special relativity. Now the first tenet of relativity is that there is no absolute inertial frame of reference. A complicated way of saying that you can't look at an inertial problem from the outside. You can only examine it from the perspectives of the - usually two - inertial frames of reference concerned. Call them A and B - or in this case the rocket ship and Earth.

Immediately you do this, you run into a basic problem of definitions - and no I don't mean that semantically. In short if we have no absolute inertial frame of reference, then it becomes impossible to say that a rocket ship leaves Earth. You can only say that if you have an external perspective on the situation such that you can see that the Earth is stationary or alternatively moving at a standard rate with no accelerative force acting on it, while the rocket ship is traveling away from it. Since you don't have this by definition of the theory of special relativity, you can't make this statement.

Instead the statement you have to make is that the earth and the rocket ship are moving apart.

I know, that sounds screwy. But within the confines of special relativity, it's correct. And you can understand it from a practical perspective too. If you're on the rocket ship and you stare out of the port hole at the retreating Earth, who are you to say that you're the one who's leaving the Earth and it's not leaving you? If you're not accelerating, you won't feel any motion. So the only thing that tells you you're leaving the Earth is your understanding that the Earth is huge and you blasted off from it. Likewise if you're on the Earth staring at the rocket ship, the sensation of gravity makes you think that you're standing still and it's leaving you, but that is no part of special relativity.

Alright, now lets hook this new definition into the twins paradox. Now according to the original paradox the rocket ship was leaving Earth. Now we can say instead that the rocket ship and the Earth are leaving each other. If that's the case than our two twins are both in the same situation. Each sees the other leaving him at whatever speed, and according to special relativity that means they're both in the position of claiming that because the other is traveling away from them at a significant fraction of the speed of light, and therefore both will expect the other to have experienced less time. Which means that when they come back together, there should be no real difference in elapsed time. Time slowed down equally for both of them.

So now we find ourselves in a conundrum - I think I'll call it a Psychotickian Conundrum! There are two options. Either the paradox doesn't hold, and we don't expect the twins to come back together having experienced different amounts of time - despite what we are constantly being told has been observed. Or the basic tenet of relativity, that there is no absolute inertial frame of reference, does not hold.

Now of course those who believe in relativity, are going to argue that it's due to mass, gravity and acceleration, none of which I would point out are a part of special relativity.

Okay, so enough of this. I'll leave you to your head scratching, and just finish with this most basic of all understandings. This is why everybody hates philosophers! We love to poke holes in things!

Cheers, Greg (aka Psychotick).

Christchurch

Hi Guys,

So, I'd guess everyone has heard about what happened in Christchurch on Friday. Certainly everyone in New Zealand has. And I'd guess most kiwis are a little like me, shocked and horrified by such a terrible act of violence. All of us will be saying - this is New Zealand - We don't have things like this. Not in Godzone.

But it seems we do. Even if the offender has to come here from another country to murder innocent kiwis who were doing nothing more than praying. (Note that I will only refer to him as the offender. I do not want to use his name and give him a single ounce of fame.)

My heart of course, goes out to the victims and their families. To lose their loved ones in such a brutal and senseless attack must be beyond our understanding. All I can say is that you have my prayers as you do those of all kiwis. 

This is a good country filled with good people, and we apparently let in one rotten apple. We have to make sure we never do that again. And quite frankly we have to get rid of all semi-automatic weapons. That will be my submission when the enquiry is put out for public comment as it surely will be. Let the gun makers cry into their empty bank accounts!

But I want to take a moment here to talk about the revolting ideology commonly called white supremacy. And to express my rejection of it speaking as a white half Aryan man.

Now I'm sure the neo-nasties will try to defend what they believe in. Just as I know that their entire belief structure is a lie. And I'm not just talking about the long since discredited doctrines of racialism and Nordicism. I'm talking about the lies all neo-nasties tell themselves.

It's not just the lie that one race is somehow inherently better than another. It's the lie they cling to in their beds at nights. In their hopes and dreams. That the white race (as if there were such a thing!) is somehow great - and so by extension, are they.

This is patently false. One race is not better than another. And even if one were, these individuals would be the exceptions.

Consider the concept of greatness. The one as espoused by Nietzsche (who only got it half right) and completely misunderstood by the Nazis. Ask yourself, what is a great man - or woman? What defines him or her?

Well one of the things is self awareness. Self knowledge. The very things the neo-nasties clearly don't have. You see a great man or woman looks inside him or herself, especially when things go wrong. He fails a test, doesn't get a job, doesn't earn a high salary or gets hounded by the police. Whatever it is, whatever failure has beset him or her, a great man looks first for the source of failure in him or herself. And when he finds it, he fixes it. He gives up drinking, works harder, stops breaking the law - whatever is needed. In so doing he becomes greater.

But a neo-nasty like the offender and his cohort? They don't do that. They look outside. They blame other people. They didn't get a job? It must be because the system is rigged to favour those brown people. It never occurs to them that the person who did get the job worked harder, studied harder, didn't do drugs or alcohol and didn't get a criminal conviction. And so it goes on. Always, for every failure in their lives, it must be someone elses fault. It could never be theirs!

Another of the things that defines a great man or woman is courage. And courage doesn't mean that they don't know fear. It means that they don't give in to it.

But the neo-nasty gives into fear without hesitation. Just listen to the snippets of the manifesto that the latest offender published. Why did he do what he did? Because there was an "invasion" of people who were different to him. He was terrified that he would be left alone and unemployed, inadequate in a world where people better than him succeeded. That's not courage. That's cowardice.

And then there's weapons - a form of power. The great man or woman doesn't need weapons. He doesn't need to use force to exert his or her will on the world. S/he knows s/he is right and carries with him / her an inviolable authority. Why would he need to use force? He doesn't. The great man knows his thoughts and beliefs are right and that others will see that and accept it.

The neo-nasty on the other hand, craves weapons. S/he craves anything that will make him or her stronger. And the reason for that? Because he or she knows deep down inside, that he or she is weak, even if they can't admit it.

This is the nature of the white supremacist. And of the offender who killed all those innocent, unarmed men and women and children in Christchurch. As well as so many others.

And the reason I wanted to say this? Because while this atrocity was carried out by one man, he was aided and egged on by so many others. All those who supported him. All those who took his feeds and distributed them.

I don't know if it's possible to track you down and expose you to the world. Since you so bravely decided to name yourselves as anonymous! But I do know that if you hold the same views as the offender, then you are the same as him. And if you encouraged him to do this, then you are as guilty as he is.

Don't come to New Zealand. You're not welcome here.

Greg.

Time Travel and Free Will.

Hi Guys,

Just finished off Pawn (finally) and put it out on to the kindle thingie, and so since I had a little time on my hands (no pun intended), thought I'd return to my time travel theme.

This one is not a paradox so much as a simple logical incompatibility between two ideas. Time travel and true free will.

First, to set the scene a little, a short definition of true (or libertarian) free will. In essence this view of free will says that our decisions, what we choose to do are completely free, and that if we were somehow to rewind the universe a little bit and face the same choice again, we could legitimately make a different choice. In order to do this, libertarian free will requires that that part of our minds that makes some choices, exists outside of the bounds of the normal universe. (No I'm not talking about a drug induced state!) But in essence, it says that our decisions have to be based on something other then the chemicals in our brains, the atoms and molecules of the universe and all of those other physical things that we know exist. Because if our free will, our decision to choose was based in a part of our brain that was completely predicted by these things, then if we rewound and reran the universe all over again, we could only ever make the same choices. Thus our actions would be completely deterministic.

There is a model of free will that is compatible with a deterministic universe - oddly enough it's called compatibilism. And it says yes, our every decision, choice etc is based completely on physical things like brain chemistry and atoms and fields etc, but we still believe we can make free choices. The fact that if someone could somehow know the position and movement of every atom etc in the universe, they could predict with one hundred percent certainty our every choice, is irrelevant. (I tend to think of this as the illusion of free will. It's free in as much as we think it is.)

Anyway enough said about free will, and sorry for the lecture. Now to time travel and why it completely opposes true free will.

So let's say that a time traveller from the year three thousand goes back in time to three thousand BC, a short six thousand year romp. Sounds good doesn't it? But what our time traveller has done in taking this journey, is fixed every single possible action for the entire six thousand years. Absolutely everything that occurs during that time must be fixed exactly so that by the time the year three thousand AD arrives and we're at the point where he's ready to jump back in time, he must be at that point. Every change he made in the past, must have been made for him to be there.

Sounds confusing I know. But let's look at it in another way. Our time traveller goes back to three thousand BC. At that point we know that everything at three thousand AD must be as it was when he left. So if he makes a change in the past, it must already have been part of the universe that led to him being able to jump back in time.

So now he's back in three thousand BC, and as luck would have it, he stubs his toe on a rock. It hurts and he yells out, and a couple of people see him, and maybe laugh. That's the entirity of the change he makes. Sounds like nothing. But it's not. That tiny change would have profound consequences up the line. So say one of those people who laughs is a girl, and when she goes home that night she tells her hubby of it. He laughs too. Then they make love and start the baby factory rolling. Now because of that laugh, that one minute of story telling, they make love one minute later than they would have if he hadn't stubbed his toe. One minute, seems like nothing doesn't it? But this is the butterfly effect in action. One minute and one sperm out of fifty million swimming merrily away as it hunts down the egg. So what are the chances that the same sperm that fertilised that egg in the time line before the man arrived to stub his toe is the same one that arrived in the next version? One in fifty million more or less. Different sperm - different person being born. And of course that new baby grows up in the past to do different things to what the original person would do, and the changes multiply, until finally when the year three thousand AD arrives, the time traveller doesn't exist. That can't happen.

So the only way around this problem is to have the order of past events between the year three thousand BC and the year three thousand AD absolutely fixed. Not a single iota of variation can occur. This in turn means that every change the time traveller thought he made in the past wasn't a change at all. It always had to happen in order for the time traveller to be there at the right time ready to jump back six thousand years.

So stubbing his toe wasn't a change. It had to happen. The girl laughing wasn't a change. She had to laugh. The baby being concieved a minute later, actually had to be conceived at exactly that time after all. And the wrong sperm fertilising that egg was in fact the right one after all.

And as for the rest of us and the belief that we have true free will. If a time traveller could actually leave from our future and arrive in our past, then we simply can't have such a thing. Because every action we take, every choice we make, has to be the exact one necessary for that time traveller be there in the year three thousand ready to jump back. Even if we have no direct connection tothe time traveller.

Now imagine that someone from the very end of time, say forty billion years or so in the future, goes back to the very beginning. Now the entire span of the universe is fixed.

Anyway I think that covers the basic idea. Time travel does not allow for the possibility of true libertarian free will.

Feel free to ask questions or tell me I'm wrong.

Cheers, Greg.