I had an odd experience few years ago while staying in a new hotel in Liverpool during an unexpected snowfall. The hotel was a new boutique style of establishment in greatly altered premises dating back to the 19 century commercial heyday of the city. In the early morning I had a tortuous journey thru heavy snow from Manchester by a slow train that was eventually halted for a significant time after an announcement by the driver that the signal cabling along the next stretch of track had been stolen overnight, another market pointer to the steadily growing value of copper, I noted. Eventually by means of coordinated mobile phone calls, the train moved slowly past all the signals set by default at red and trundled safely into the station.
My hotel room was cold and the temperature outside the snow covered skylight windows comfortably below zero. The heating was under floor and so rather slow to respond, and it was difficult to determine whether it was answering to changing the thermostat. Despite assurances from the staff that the temperature would soon rise, it seemed to get colder and eventually a fan heater was brought to help out. Someone at reception suggested that because the heating was new it was important not to turn it up too high.
Much later in the afternoon the building engineer called by, much concerned by the old wives tale about not turning the heating up too much because it was newly installed and like me confused by the fact that the heating was working just fine in the corridors outside, so much so that I left my door open. Fortunately the master panel for all the room heating was just opposite my door and so we looked together at what it revealed before the engineer investigated the temperature in the room next door where the guest had left for the day. It was very warm next door.
Suddenly the engineer realized what was cause of our problem. The heating in the room next door had been wired to the thermostat in my room and my heating to next door’s thermostat. The result was a beautiful example of what engineers would call a Thermal Instability. When my neighbors felt too warm they turned their thermostat down. As a result my room got colder, so I turned the temperature up on my thermostat which made them feel warmer still so they turned their thermostat down even further making me colder still, so I turned my head up even more, fortunately they gave up and went out.
This type of instability feeds upon the isolated self interest of two players. Some more serous environmental problems can arise because of the same sort of problem. If you run lots of fans and air conditioning to keep cool, you will increase the carbon dioxide levels in your atmosphere, which will retain more of the sun’s heat around the earth, which will increase your demand for cooling. But this problem can not be solved by a simple piece of rewiring.
Is cosmology on a slippery slope towards science fiction ? New satellite observations of the cosmic microwave background radiation, the echo of the so called Big Bang, have backed post physicists favorite theory of how this Universe developed. This may not be a good news.
The favoured model contains many apparent coincidences that allow the Universe to support complexity and life. If we were to consider the multiverse of all possible universes, then this is special in many ways. Currently modern quantum physics even provides many ways in which these possible universes that make up the multiverse of all possibilities can surface.
Once you take seriously the suggestion that all possible universes can exist then you also have to deal with another strange consequence. In this infinite array of universes there will exist technical civilizations, far more advanced than ourselves, they may have the capability to simulate universes. Instead of merely simulating their weather or the formation of galaxies, they would be able also to go further and study more the formation of stars and planetary systems. Then having added the rules of biochemistry to their astronomical simulations, they would be able to watch our evolution of life and consciousness within their computer simulations. Just as we watch the life cycles of fruit flies, they would be able to follow the evolution of our life, watch the civilizations grow and how to communicate with each other, even they can watch them argue about whether there existed a great scientist in the sky who can created their universe and who could intervene at will in defiance of the laws of nature they habitually observed.
Within these universes, self conscious entities can emerge and communicate with one another. Once that capability is achieved the fake universes will proliferate and will soon greatly outnumber the real ones. The simulators determine the laws that govern these artificial worlds, they can engineer and fine tuning that help the evolution of the forms of life they like, then we can end up with a scenario where the statistically we are more likely to be in a simulated reality than a real one because there are far more simulated realities than real ones.
One of the physicist has recently suggested that this high probability of our living in a simulated reality is a reduction ad absurdum for the whole idea of a multiverse of all possibilities. But rather than face with this scenario, question, is there any way to find out the truth ? There maybe if we look closely enough and spend more time.
For a start, the simulators will have been tempted to avoid the complexity of using a consistent set of laws of nature in their worlds when they can simply patch in realistic effects. When the Hollywood company makes a film that features the reflection of light from the surface of a lake, it does not use the laws of quantum electrodynamics and optics to compute the light scattering. That would require a stupendous amount of computing power and detail. Instead of that the simulation of the light scattering is replaced by plausible rules of thumb that are much briefer than the real thing but give a realistic looking result as long as no one looks too closely.
There would be an economic and practical imperative for simulated realities to stay that way if they were purely for entertainment, but such limitations to the complexity of the simulations programming would presumably cause occasional tell tale problems and perhaps they would even be visible from within.
Even if the simulators were scrupulous about simulating the laws of nature, there would be limits to what they can do. Assuming the simulators or at least the early generations of them have a very advanced knowledge of the laws of nature, it is likely they would still have incomplete knowledge them, we know some philosophies of science would argue with you this must always be the case. They may know a lot about the physics and programming needed to simulate a universe but there will be a gaps or worse, errors in their knowledge of the laws of nature. They would of course be subtle and far from obvious to us, otherwise our advanced civilization would not be advanced. These lacunae do not prevent simulations being created and running smoothly for long periods of time but gradually the little flaws will begin to build up.
Eventually their effects would snowball and these realities would cease up to compute. The only escape is if their creators intervene to patch up the problems one by one as they arise. This is a solution that will be very familiar to the owner of any home computer who receives regular updates in order to protect it against new damages or to repair gaps that its original creators had not foreseen. The creators of a simulation could offer this type of temporary protection, updating the working laws of nature to include more things they had learned since the simulation was initiated.
In this kind of situation, logical contradictions will inevitably arise and the laws in the simulations will appear to break down occasionally. The inhabitants of the simulation especially the simulated scientists will occasionally be puzzled by the observations they make. The simulated astronomers might for instance make observations that show that their so called constants of nature are very slowly changing.
It is likely there could even be sudden glitches in the laws that govern these simulated realities. That’s because the simulators would most likely use a technique that has been found effective in all other simulations of complex system like the use of error correcting codes to put things back on track.
For example, take our genetic code, if it were left to it’s own devices we would not last very long. Errors would accumulate and death and mutation would quickly ensue. We are protected from this by the existence of a mechanism for error correction that identifies and corrects mistake in genetic coding. Many of our complex computer systems possess the same type of internal immune system to guard against error accumulation.
If the simulators used error correcting computer codes to guard against the fallibility of their simulations as a whole simulating them on a smaller scale in our genetic code, then every so often a correction would take place to the state or the laws governing the simulation. Mysterious changes would occur that would appear to contravene the very laws of nature that the simulated scientists were in the habit of observing and predicting.
So it seems enticing to conclude that if we live in a simulated reality, we should expect to come across occasional glitches or experimental results that we can not repeat or even very slow drifts in the supposed constants and laws of nature that we can not explain.
You can imagine that there are an advanced civilizations in this world that have perfected the art and science of traveling in time.
It is very important to realize that this kind of traveling into the future is totally uncontroversial. It is been predicted to occur in famous Einstein’s theories of time and motion that so accurately describe the world around us and is routinely observed in physics experiments. Like two identical twins were separated with one staying here on Earth while the other went on a round space trip then the space traveling twin would find himself younger than his stay on Earth brother when he returned to meet him. The returning twin has time traveled into the future of the stay on Earth twin
For now, time traveling into the future is just a matter of practicality, can you build means of transportation that can withstand the stresses and achieve the velocities close to the speed of light necessary to make it a noticeable reality ? Time travel into the past is another matter entirely. This is the realm of we called changing the past paradoxes, even most of them are based upon a misconception.
This is an observational proof that time travelers are not engaged with this systematic economic activity in this world. The key economic fact that we notice is that interest rates are not 0%. If they are positive then backward time travelers could use their knowledge of share prices gleaned from the future to travel into the past and directly invest in the stocks that they know it will increase in value the most. Sure they would make huge profits everywhere across all investment and futures markets. As a result, the interest rate would be driven to zero. Or, if interest rates were negative, so that investments are worth less in the future, all time travelers could sell their investment at its current high price and repurchase it in the future at a lower price so as to travel backwards in time to resell at a high price again. For that reason, the only way for the markets to stop this perpetual money machine is by driving interest rates to 0%. Hence the observations that exist interest rates that are not 0% means this type of share dealing activity is not being carried out by time travelers from the future.
The same type of this argument would apply to any sectors that related to the finance. This example might seem rather fanciful but on reflection might not the same arguments not be leveled against many forms of extrasensory perception or para-psychic forms of knowledge ? The people who could foresee the future would have such an enormous advantage that they would be able to amass stupendous wealth quickly and easily. They could profit big money every week. If reliable intuitions about the future did exist in some human minds, then they would provide the owners with an enormous evolutionary advantage. They would be able to foresee hazards and plan for the future without uncertainty. Anything that endowed its owners with that insurance policy against all eventualities would spread far and wide and its owners would soon come to dominate all population. The fact that psychic ability is apparently so rare is a very strong argument against its existence.
It takes a long while to complete one large jigsaw puzzle, but just an instant to check that the puzzle is solved. It takes a fraction of a second for your computer to multiply 2 large numbers together but it would take you or your computer a long time to find the 2 factors that have been multiplied together to make one big number. It has long been enough to suspect but never proved or disproved (I believe there is a 1 million dollar prize for doing that), there is a real division between what we call Hard and Easy problems that reflects the amount of calculating time that needs to be used to solve them.
Most of the calculations or information gathering task required us to do it by hand, like completing our tax returns, have the feature that the amount of calculating to be done grows in proportion to the number of pieces we have to handle. If we have 3 sources of income we have to do 3 times as much work. Similar on our computer that will take 10 times longer to download a file that is 10 times bigger. 10 books will generally take 10 times to read compare to one. This kind of pattern is characteristic of Easy problems. This may not be easy in the usual sense but when you add few of them together, the amount of work required does not grow very quickly. Computers can easily cope with all these problems.
Unfortunately, we often have another type of problem that is far less easy to control. Each time we add an extra piece to the calculation, we will find that the calculation time required to solve that will be doubles. Very soon the total time required become stupendously large and also even the fastest computers on this earth can be easily defeated. These are what we call by Hard Problems.
Based on that fact, Hard problems are not necessarily horribly complicated or mind bogglingly difficult. They just involve a lot of possibilities. If we multiplying together 2 large prime numbers is a computationally Easy task. You can do it within your head, with 1 pencil as well as paper or a calculator as you wish. But if you give the answer to someone else and ask them to find the 2 prime numbers that were used in the multiplication then they might be facing a lifetime of searching with the world’s fastest computers.
If you want to try one of these Hard problems for your self, one that sounds deceptively easy then find the 2 prime numbers that add up to give 389965026819938.
These operations we name it Trapdoor because it’s like falling thru a trapdoor, it is much easier to go in 1 direction than in the reverse. They make life difficult for us but they also make life difficult for people whose lives we are trying to make difficult for one good reason. All the world’s principal security codes exploit trapdoor operations. When you shop online or withdraw cash from any ATM machine you are using them. Your PIN number is combined with large prime numbers in such a way that any hacker or computer criminal wanting to steal your account details would have to factor a very large number into the 2 big prime numbers that were multiplied together to get at it. This is not impossible in principle but it is impossible in practice in a sensible period of time. A criminal with the world’s fastest computer at his disposal might crack the encryption in few years but by then the codes and account numbers would have been changed by the owner.
For this reason, very large prime numbers are very valuable things and some have been patented when written in a certain form. There is no limit to the number of prime numbers they go on forever but there is a largest one that we have been able to check for primeness by ensuring that it has no factors. There is no magic formula that can generate all prime numbers and it is suspected that no such formula exists. If the formula did and it was found then it would become a major crisis in the world. Any government agency that found it would undoubtedly keep it top secret. Any academic who found it and made it public without warning would bring the world tumbling down. All military, diplomatic and banking codes would become easily breakable by fast computers in one night. The world of online commerce would face a serious threat to it’s continued existence. We would have to move to iris or fingerprint or DNA Based recognition systems that relied on unique features of our biochemistry rather than numbers stored in our memories. But these new indicators would still need to be stored in a secure way.
The factoring of prime numbers is a Hard problem. Even if it is cracked and shown to be an Easy problem by means of a magic formula, you might think that we could just use some other Hard problem to encrypt sensitive information so that it still takes ages to reverse the operation and extract it. It is known that if one of the problems we believe to be Hard could be shown to be Easy by means of some new discovery then that discovery could be used to turn all the other computationally Hard problems into Easy ones. It really would be a magic bullet.
Relativity of motion need not be a problem only for Albert Einstein. Who has not had the experience of sitting in a stationary railway carriage at a station then suddenly getting the sensation of being in motion only to recognize that the train on the parallel track has just moved off in the other direction and your train is not moving at all ?
This is other example : Few years a go I spent 2 weeks visiting an Online University of New South Wales in Sydney during the time that Rugby World Cup was dominating the news media and all public interest. Watching several of these games on TV, I noticed an interesting problem of relativity that was un-noticed by the celebrities in the studio. What is a forward pass relative to ? The written rules are clear, a forward pass occurs when the ball is thrown towards the opposing goal line. But when the players are moving the situation becomes more subtle for an observer to judge due to relativity of motion.
Imagine that 2 attacking players are running in parallel straight lines 5 meters apart at a speed of 8 meters per second towards their opponent’s line. One player, the receiver is a meter behind the other, the passer who has the ball. The passer throws the ball at 10 meters per second towards the receiver. The speed of the ball relative to the ground is actually √(102 + 82 ) = 12.8 meters per second and it takes a time of 0.4 second to travel the 5 meters between the players.
During this interval the receiver has run a further distance of 8 x 0.4 = 3.2 meters. When the pass was thrown he was 1 meter behind the passer but when he catches the ball he is 2.2 meters in front of him from the point of view of a touch judge standing level with the original pass. He believes there has been a forward pass and waves his flag. But the referee is running alongside the play, does not see the ball go forwards and so waves play on.