Fun with Simulators and Thought Experiments

Computer simulation and modeling are amazing disciplines. They are used all over the place. Examples include predicting weather (weather models & earth simulations), testing engineering designs (simulating the design and operations), simulating physical phenomena (testing physical, chemical, and biological models before running experiments), and simulating networks to test things such as computer networks or even human networks to study the spread of  diseases (e.g. how will a new flu outbreak spread through the world). In short, simulation is awesome.

So here is the thing, I argue that if you build a big enough model, a big enough computer, and a good enough simulator, you can probably simulate the universe in its entirety. I think this is possible because I currently think that there is no fundamental random process in the universe (i.e. if you can account for everything, you can predict anything). Actually, there is still argument amongst physicists of whether properties in quantum mechanics appear random because of unknown hidden variables (i.e. randomness does not exist) or because there exists something that is fundamentally random in the universe. .. but let’s skip this for now.

Anyway, let’s get to the cool part.

Imagine that we can build a *huge* simulator that can account for everything and predict (read: compute) anything.  This simulator would be able to replay everything from the moment of the big bang, to the formation of Earth, to the rise of human beings, to the conversations you have with your friends, to me typing this post now. Surely this is an amazing simulator.

Now imagine that you have access to this simulator. Not only that, but being the curious person you are, you use it to fast-forward and play events in the future. So the simulator will tell you what events will happen in the future. So you look at the simulator and it will tell you what I will eat tomorrow, what will life look like in the future, where will your children, .. everything. It will tell you everything. Again, this is an awesome possum simulator.

Now the mind-bending part.

If you look at that simulator to see you future, will your future moves happen because you want to do them or because the simulator told you to do them? For example, if the simulator told me to eat pizza tomorrow, will I eat pizza tomorrow because I want to, or because the simulator told me to? Remember, I can’t trick that program because it would have already accounted for me trying to trick it. So the minute you look at your future you don’t know whether you would have acted that way because you wanted to or because the program told you to.

For example, assume you have been a good person all your life, but the simulator told you that you will become a thief. Would that happen because you would have “naturally” became a thief, or because the simulator told you so?

Luckily (and unfortunately) it currently doesn’t look like we can ever build such a simulator because it has to also account for itself as part of the universe, so it has to be as big as itself plus the universe in which it resides (you see the problem).

For the computer scientists in the crowd, would such a simulator be able to solve the halting problem?

Za3tar goes to England .. (or what have I been up to this summer)

Gosh! I haven’t blogged in ages. I know, I know, I am terrible. So for the sake of the good ol’ times let me share a long-overdue post about what I did these past few months.

This summer was nothing short of amazing! I got the opportunity of a lifetime to go do summer research at a lab in Cambridge University in England, and it was spectacular.

King's College Chapel as seen from "The Backs"
King’s College Chapel as seen from “The Backs”

It was really amazing being in Cambridge. At the time of my visit the university was already 800 years old! Affiliates of that university have contributed to literally every field of science, and they include among others: Isaac Newton, Charles Darwin, James Maxwell, and Alan Turing. Isaac freaking Newton was there! How cool is that! I never expected to be able to go to pub and have dinner at the same table where the discovery of DNA was first publicly announced. This was unreal.

Besides the university, the town of Cambridge is amazing. It is old, has lots of history, and very bike-friendly. People use bikes to get everywhere, and there are bike parking spaces all over town. As a matter of fact, policemen hassle you if you break traffic rules with your bike! I was really shocked by that, and I can’t say that I really obeyed the rules 🙂 I just learned to avoid the police if I am going backwards on a one-way street 😛

Houses in Cambridge
Houses in Cambridge are more “European” than I’m used to

The town and university had much more religious affiliations than I would have thought. There were churches all over the place, and several places in town were named after iconic Christians, e.g. “Magdalene Bridge” and “Jesus Green”. Other than that, the weather in Cambridge was horrible unfortunately. It was cold for most of the time and almost constantly raining, and I was there in the summer! At the end I was glad to go home just to get some sunlight.

I am usually not an outgoing person. However, given that this was my first time in Europe, I decided to take the opportunity and tour around. If you are young and single you can get around Europe very cheaply. They have a huge number of deals for students in almost every country. For example, you can literally find good accommodation for just €18 a night! So I went on a few weekend trips.

Granted, you can never experience a city in just 48 hours. However, you can still have a great time and get a taste of the local culture. The process itself was really amazing. I would wake up Saturdays at around 4am and bike to the bus station, then go from there to the airport to catch the 6am flight to any European capital. I would then spend the weekend there, and travel back on Monday morning. The awesome thing is that Monday noon I would be back in my lab working. Never in a million years would I thought I’d ever get to do that. I’ll tell you more about my weekend trips later, for now let me share some photos from London.

Westminster Palace from the London Eye
A view of Westminster Palace from the London Eye

London was nice. We happened to go there on the Queen’s coronation anniversary, so there were very nice shows and marches around town. We went to Westminster Abbey where various kings, queens, and other famous people are buried. I got to see Newton’s and Darwin’s burial grounds which is very surreal.

Westminster Abbey
Westminster Abbey

Big Ben from street level
A view of Big Ben from street level

All-in-all, England was very nice. Unfortunately I didn’t see much besides Cambridge and London (I opted to go out to other places instead). It took me some time to get used to their accent and coins (they have so many coins) but at the end I was a professional :-P. Probably the only two things I didn’t like were the weather (it rained constantly, and it was cold even though it was “summer”), and the local food. Everybody told me that English food sucks but I didn’t believe that until I went there. The food was bland and tasteless at best. Luckily, you can get plenty of non-English food all over the place. So over all, England was nice place to visit.

Gunman vs. Terrorist

Human life is sacred. I think we all agree on that. So certainly one is saddened at any one’s death. But still, one can’t help but wonder. Usually the way something is conveyed is at least as important what is being conveyed.

Today an attacker in Tel-Aviv opened fire at a club for gay teen Isralis killing at least two people and wounding many. In the AP video report, the police chief says that he doesn’t know if the attack was carried out by a gunman or a terrorist but the evidence leans more towards it being a gunman. What is the difference you say  ? If the event is the same and the victims are the same and the attacker is the same, how can the event be a terrorist attack or a just an act of a gunman.  You would think that it all has to do with a motive. An gunman has his lone sick mentality that caused him to commit his act, while a terrorist does his act insited by other people and in order to strike fear in the general population.

True. But, not always. In Israel any Arab attacker is a terrorist, and any Jewish attacker is a gunman. Regardless of the motive. Yes, I have proof. Remember a few months back, a 19 year-old Palestinian from Jerusalem proposed to his lover and she rejected him, while he was driving back his car got off the road and veered towards some pedistrians, one of the pedistrians immediately shot the driver dead without attempting to do anything else. The Israeli police said that the boy was carrying a terrorist attack, while his family says that he probably just lost control of the car since that boy had no political interest or affiliation. What was interesting in that piece is that the boy was immediately judged to be a terrorist by the Israelis (and thus his family’s home had to be demolished) without any minute of investigation into his background. Simply the fact that he was Arab!

So yes. The words by which you convey an event are often just as important as the event itself.