Markakis Xuckerberapolis the founder of faceForum and the issuance of worthless shards of pottery as shares
Since I seem to be dismissing that paper for trying to use thermodynamics to define the probability of a living system I wanted to quickly add that I am explicitly not dismission it. I'm dismissing the summary that conflating the definition of life with a lower bound on it's thermodynamic probability. Often times thermodynamic bounds are very useful in ruling out how something did not happen and to identify the high probability way something could have happened.
Take for example, the observation that most complex living systems are beautiful as well. Why are they beautiful to us. I think it is because they visually have organization. And the single most obvious facet of organization are symmetries at large scale. For example, atomically speaking your eyes are very far apart. Yet your body has this beautiful bilateral symmetry.
THe obvious question is whether symmetries in living systems occur because living systems select for symmetry because there is an evolutionary advantage to it or because of thermodynamics.
to see this take something simpler. The packing of seeds in a sunflower is optimal in some sense (fibonaci) yet one might believe there's a chance it's just a thermodynamic accident not a careful selection.
In fact drill down a little more and consider the fact that nearly all proteins in your body form homo dimers that are symmetric.
an interesting paper
comes to the stunning conclusion that this symmetry is not from evolutionary selection! it's overwhelmingly improbable that function can arise from random collisions between proteins, and the only likely way two proteins can collide and form a low energy conformation that last long enough to perform a function is for collisions that form a symmetrical arrangement. Almost all other collisions wont last long enough for the dimer to perform a function (such as catalyzing production of a useful metabolite). Since Natural selection cannot operate on anything that doesn't do something to increase fitness this means that assymetric collisions are completely invisible to the organism. Therefore thermodynmics can rightfully claim that nearly all protein symmetry arrises simply from thermodynamic probability not from natural selection having a prefernce for symmetry. This is not to say that symmetry has no selectable characteristics. It's just that at the molecular level, those selectable characteristics are not required to explain the emergence of symmetry as we observe it. The frequency that we observe symmetric versus asymmetric homo dimers of proteins is exactly the frequency we would expect at random due to thermodynamics.
Thus the interesting thing about this new work in thermodynamics is it sets a lower bound on the conditions needed for life to emerge. It does not however define the probability of life emerging.
If we define life as the ability to organize and propopagate information then the highest form of life is a salt crystal or any self propagating organization of atoms with long range order. A diamond has far lower entropy than any living system. Like wise if we define it as system that processes energy to propogate itself then we have Fire as the ultimate for of life.
clearly gasses (disorded are dead) and crystals are dead. SO is life a liquid (in the middle of the two)? Again obviously not.
The best definition of a living system in terms of information tehory concepts I have come across is the one by David Wolpert who coined in the term self-dissimilarity in reaction to the vogue study of self-similarity in self-organizing systems. For example, a pile of sand is self-organizing system that is ever changing but also ever-self simmilar. it's not alive either
so solids, liquids, gasses and self-simmilar self organizing systems are all bankrupt as a informational definition of life. What's self-dissimilarity then?
It's the concept that the organizational principles of a system can suddenly change as one crosses scales.
imagine one zooms out from a microsope from the atomic scale. at first you see the atom and it has some interesting symmetires in the way the electron oribits have some simmilarities. at a higher scale we see the molecule. then the collection of molecules. soon we see the patterning of molecules.
we observe that this is infact cell. then many cells. then it's an organ. then its many organs. then an animal. then a school of fish. then zooming our we see schools of fish separated across the ocean.
the key insight is this. at each scale everything you infer about the information content and predictibitly of adjaceny in the pattern works to predict the patterns propoagation at a slightly larger zoom. Up until it suddenly fails. you reach the edge of the liver or the edge of the cell or the edge of the animal. then the lower scale is useless in predicting how the next scale up is organized.
these abrupt steps in dissimilarity is a halmark of living systems. the degree of information gain at the step is phenomenal. this is different than saying for example that a composite rock is alive. the difference is that the system is processing information and energy across these organizational boundaries. that's pretty much the best definition of life interms of a single defintion that can be plotted on a graph. the x-axis is the zoom, and the y-axis is the predictability of the next larger scale from the lower one. you see steps. that plus the processing of information across steps is a living system. If you accept this you might feel like their are non-traditional defintiions of life as well. for example, if a bacteria is living thing, is it possible that a community of bacteria is also a lvifing thing. Perhaps the earth is too.
What's intriguing here is that systems with this property may imprint themselves on other systems. you might for example be able to spot radio emissions or atmospheric molecular composition that displays the imprint of dissimilar steps in it's self organization.
SO unless this theory considers this, I'm skeptical about it. Salt is self organizing but it's not alive. It is however highly probable. Indeed eutectic separation is highly propable but it's just physics not life.
conservation of evil. It has to go somewhere. Comcast seems to be at the root of every bad deed these days. I think we figured out that google is dumping its evil quota on comcast.
I just bring a car jack, and jack the seat in front of me right off it's rails.
Ali Baba and it's sister consumer site, Ali Express, are aptly named to recall the famous arabian theives. I've bought lots of items on ali express and my experience is that anything above $40 for sale is going to involve you losing your money to a thief. Things like Suunto watches sell there under $100 but guess what, they are either counterfeits or you never get what you order. Same with Seagull brand watches. It's a theives market. Sure Ali baba has dispute resolution mechanism but the theives know how to work this to their advantage. A typical transaction goes like this. You buy something and you get a tracking number. The item never arrives. You check the tracking number and it's a real tracking number and it shows the item arrive but was deliver to some other city. You file a dispute. The thief ("merchant") offers you a $20 discount for your inconvenience and promises to reship it. If you accept this offer then you close the dispute and cannot re-open it. Needless to say the item never arrives. The tracking number is just one the thief recycled from some other past shipment to satisfy the alibaba purchase tracking. If you are clever enough not to accept the $20 offer then what happens is the dispute goes back and forth with the theif saying he's out his product and could you please agree to split the cost. If he's lucky you walk the time for the transaction past the Alibaba protection period. If not you remeber to escalate it. Then theres a month or more of incommunicado with the Ali baba site where they weigh your claims of non-arrival with the theifs attempts to seem conciliatory. Perhaps alibaba refunds your money but you don't know till one day it just happens.
I've been down this road so many times with "almost but not quite too good to be true" that this is the norm not the exceptions. The theives know that you know that somethings are too good to be true. so they price they scam appropriately. For example, often one theif will have a dozen different IDs on alibaba and then will sell the same suunto watch for a spectrum of prices. He's effectively titrating for the chumps wariness level. Exactly how much below MFG retail do your antennas go up verus your own greed to get the best deal. So you fool yourself by picking the seller with the price you are willing to believe. But they are the same guy.
Alibaba closes down the theif sometimes, but a week later they pop up with the exact same scam.
Right. I did a more relevant calculation of that here:
Something I've wondered about is why we don't see more relativistic protons hitting earth or the ISS. Is the relative velocity of everything in the universe extremely low? I don't think so. So where are these missing showers on earth right now?
Let's see if I can work this out correctly;
First assume the spaceships weight negligibly different than the mass of the fuel. The thrust needed to push the weight at a steady 1g will be proportional to the mass of the ship at each interval of time. SO the rate of mass burn is proportional to the mass which means the mass is a decaying exponential.
M = Mo * exp( -g * time / thrust_to_weight )
If you think about this for a moment it becomes clear that any amount of mass would do since as the mass gets lighter it takes less fuel so the ship could go indefinitely at 1g. The problem is the assumption that the ship weighs nothing. so let's fix that.
dM/dt = -g*(M+Ms)/thrust_to_weight.
where Ms = mass of ship and M = mass of fuel.
I'm spacing on how to solve that equation so I'll approximate it by saying that until M = Ms we can mostly ignore the ship mass. therfore for a 6.6 year flight time the fuel required is about:
Mfuel = Ms * exp( g* (6.6 years)/thrust_to_weight )
Mfule = Ms * exp( +303,800,000/thrust_to_weight).
So you need a rather high thrust to weight ratio due to the coefficient in the exponetial.
Let the pillory for my "obvious" math errors begin!
it's a matter of fuel with sufficient thrust to weight ratio (unless you want to start thinking about using the interstellar gases as the propellant--- that get's dicey because they will be approaching your craft at near the speed of light)
traveling with a 1G acceleration:
1/2g t^2 = 1/2*11*3E8
so t = 3.3 years to half way. 6.6 years to go all the way and thus 13.2 years for the round trip.
Thus you could easily go there and come back in your lifetime.
Note that this is also Faster than light can make the round trip. However that is not any violation of relativity. THe people on earth would have aged a lot more than 13.3 years during your trip. But you would only have aged 13.3 years.
Last century, I worked for a magazine sales company that did telephone soliciting. We loved it when people slammed down the phone because it meant no wasted time. The worst was when someone wanted to chat. One time a kid answered the phone and I asked for the dad. She said, "He's out in the garage under the car" and ran off to fetch him. It was a dillemma what to do next. Hang up? wait?. Another time the person on the other end kept repeating only the word yes during my sales pitch and then 5 minutes in switched to "can you please speak chinese". Even when I said "goodbye".
These days, I tell them I'm really glad they called and I need to move to the phone by the computer so I can purchase what they are selling. Then I set the phone down and go about what I was doing.
Nah this is just Sony Electronics wanting to leverage their entertainment holdings to sell TVs and PLayers with proprietaty formats while Sony Entertainment wants to maximize sales. Or maybe I got it backward. Anyhow lots of diversified companies have internal conflicts. The IBM PC which uses all non-IBM parts was not made by the primary Computer division at IBM. Samsung also has internal competition with conflicting objectives,
except a lot of places now won't roll the video if the ad is also blocked.