Monday, March 16, 2009
The beginning of our universe is shrouded behind a huge paradox. Recent observations seem to indicate our universe is open. Which basically means that it has infinite volume. Yet, and here comes the paradox, it started in a single point: the Big Bang.
Sure enough there are alternative solutions to the equations. It could have a closed universe. It's much easier to convince oneself that a closed universe can start at a single point. Imagine you have lost 1 dimension, so you live on a sphere. (there is no such thing as space outside of this sphere: you have become 2-D yourself.) At the moment of the big bang the sphere come into existance and expands fast. whereever you are on the sphere, if you look around you you see other galaxies move away from you. But, since the volume of this space is finite, it's not hard to imagine that at some point in the past it was zero, which was the time of the Big Bang.
Alas, observations say we are not in a closed universe, but in an open one. Logic seems to demand that if space is infinite now, it must have been infinite when the universe got created (unless you believe there was a time after the Big Bang that it suddenly became infinite). It was filled with matter everywhere, and moreover, this matter was expanding outward. In fact, it doesn't matter who you would ask, everyone would tell the same story: the universe is exanding outwards and galaxies that are far away are expanding faster than the galaxies that are close by.
I find that paradoxical. Yet there is a way out. It is described very well here. The basic idea is this. You can switch to another frame of reference. In this view the universe has finite volume and you can visualize it as an expanding sphere again. However, galaxies are packed into this sphere in a peculiar way. Due to the so called Lorentz contraction, distances become contracted for galaxies flying away at very speeds. Since the galaxies at the outer edge of the expanding sphere fly at lightspeed, radial distances are infinitely contracted there. And so we can pack infinitely many galaxies in an infinitely thin slice of space.. In fact, because there is infinitely mass at that rim, it forms a sort of wall (a singularity) beyond which there is simply nothing. So it is not useful to think of this sphere as expanding inside something else. Spacetime is not defined outside this wall. Btw note that you can not visit this wall to peek over it, because it is receding at the speed of light. Also, there is noone really at this edge because the picture looks the same for everyone!
Ok, we have now packed infinitely many galaxies inside a finite volume. Why is space then infinite? For that we need to realize that not only does space contract at high speeds, it also slows down time. So watches on those distant galaxies are moving at a slower rate relative to your watch. Again, this situation is perfectly symmetric: people on those distant galaxies don't notice their watches going any slower (that's because their brains go slower too, so we reason) and moreover, they observe our watches going slower too. Now, we introduce a new cosmic time. This is the time where every observer in the galaxy sets their watch at 0 at the Big Bang and takes their watch with them when they fly outwards. If we now measure the volume of space defined when all these watches display some constant time space becomes infinite. This is because time is standing still at the rim (according to us) and so the infinite space contraction and the infinite time dilatation cancel.
It's head-spinning, but the conclusion is that space was created infinitely large in one point.
Sunday, March 8, 2009
Just saw "Supersize Me". Didn't know it was that bad. I mean, I didn't know it was that unhealthy. What I did know and what shocked me was that you can find (all too easily) junk food in hospitals. Sometimes it is the only option. In hospitals! Then there is of course the schools. The perfect place to get our kids into unhealthy eating habits that will last them a lifetime. It makes me really angry that food companies have become so powerful that they can prevent changing the status quo through lobbying in Washington. (This whole lobbying thing is deeply disturbing and corrupt.)
Fast-food has become so much part of American culture that many people have forgotten how to cook! They eat out or shove pre-made food into microwaves. Every day. Cooking dinner and enjoying dinner with your family (not in front of the tv watching commercials for McDonalds) is becoming something people did in the old days.
So, congratulation and thanks Morgan Spurlock for exposing this worrying development at the cost of your own health. By the time my children are old enough, I will show them your movie. Hopefully it will prevent them from dumping their veggie sandwich in the trashbin and bying the big Mac equivalent in their school's cafetaria.
Saturday, March 7, 2009
There are currently 4.2 millions surveillance cameras operational in the UK alone (thanks to Pietro Perona for pointing this out to me). That is one camera for every 14 people.... The data on your cellphone, such as your social network, your current location and of course your phone calls, can easily be accessed by phone companies. Your credit-card history, your bank transactions, your email, they all present easily accessible information to intelligence agencies. Add to this the immense growth in computer power and the improvement of artificial intelligence systems and it may not be hard to imagine that very soon it may be "1984".
Already, companies such as Google, Yahoo and Microsoft are designing web-applications which are based on tracking large numbers of cellphones. When many tracks intersect in both space and time an "event" happens (for example a baseball game). People present at these events upload text and photos into websites such as "Twitter", creating some sort of self-organizing online news experience. One can imagine a new Googlemaps application where events are shown on a map. You may then click on the event and see the rich multi-media content for that event as it develops.
We are increasingly covering every patch of (interesting) space-time with our multi-media. We may ask the question if this trend is desirable or perhaps even dangerous. Imagine a government having that much information at her fingertips. It may be awefully tempting to use it to blackmail political oponents etc. But, may be we will be forced into this direction, whether we want it or not.
I remember the 9/11 attacks were a shock to me because for the first time in my life I realized there are actually people out there who will go to any lengths to further their religious or/and political goals, even if it means killing millions of people. It is a matter of time before terrorist will get their hands on very small atomic bombs. I do not believe we will be able to prevent these devices from going off in one of our big cities. Perhaps even more dangerous is biological warfare. It's a matter of time before these technologies become so advanced and widespread that they may fall into the wrong hands.
In my opinion, we will see one of these extreme catastrophies in the somewhat near future (plus or minus 100 years that is). At that point, people will be willing to trade all their privacy for security. People will be tagged at birth with a chip and followed 24 hours a day, 7 days a week. A patchwork of cameras and smart software will detect individuals which are not tagged. They will be instantly arrested. The population of this future country will act as one organism that breaths through the internet. It will monitor its constituents and its environment. But who will monitor its government?
This scenario sounds like a nightmare now. But it may be a price people are willing to take in the future. If no explicit measures are taken to keep this information out of the hands of governments or other organisations, the sketched sceneario may simply be a byproduct of the technology that is rapidly becoming available. Of course these measures will presumably be taken in the short run, but my prediction is that in the long run it may prove to be the only weapon against an increasingly sophisticated terrorist kind of warfare.
Even though today this type monitoring and control seems to be taken directly from Orwell's science fiction story "1984", the world in 100 years may be so utterly different that people living then may find it "desirable". We may become "Borg" after all. Resistance is futile.
Sunday, March 1, 2009
After seeing Sicko I was kind of shocked I must admit. I am sure it draws a highly exaggerated picture, but it started to make me think. Here in Orange County health-care seems to be excellent. Perhaps too good to be true. My wife has been offered an MRI scan for her knee after having been told the diagnosis with a confidence bordering certainty. After inquiring why an MRI was necessary in this case the answer was, well, "it's not necessary". So she refused and with no consequences to the remainder of the (successful) treatment.
Myself, I was also recently offered a (insert complicated name here) scan. After asking why I needed it, the response from this frank MD was: "because it is required if symptom X is present". Seems reasonable one could think. However, in my case the symptom was explained away by a very innocent issue. After confronting my (really very good) doctor with this fact, he said: "if we don't recommend it we can get sued". He offered in addition that "in our society we have chosen to over-treat one sub-population (read: the rich) at the expense of not treating another sub-population (read: the poor). I refused this treatment as well (not necessarily out of noble considerations: the scan is definitely uncomfortable and time consuming).
There is also another issue at stake. Hospitals are required to treat anyone who comes into the ER and many of those are not insured. This costs money, lots of money (ever seen an ER bill?) To make up for it, doctors send patients with insurance who don't need scans to have expensive scans anyway. This is their way of making money.
All of this on top of the message of Sicko, namely that it is a really bad idea to place health-care in the hands of companies who think about making profit rather than about making healthy.
So I say to president Obama this. There is a huge opportunity to save an enormous amount of money on health-care by making sure doctors don't over-treat patients (those with insurances that is). I am happy paying the enormous amounts of money I am paying to healthcare right now, but please use this money not to send me from one unnecessary scan to another. Use it to give every citizen in the US the RIGHT of health-care. Let's not be afraid to be socialistic about this (btw socialist is NOT communist). We are after all already quite socialistic about the right of protection through sponsoring the federal government to maintain an army.
In the long run, the increasing costs of new medical technology and drugs will force us to make very difficult decisions on who to treat and who not. A good start would be to assess whether the scan or treatment can detect and prevent a disease that has a probability of killing or disabling that is significantly higher than other risk factors for an average patient. We can be conservative about this and still save big time. In my case, the scan was meant to detect a form of cancer that I was so unlikely to have that my chances of dying in a car accident are many times higher.