Pleiades

That’s what I was thinking; the room temperature has no effect on the time it takes to fill the airbed. Now, if you filled it up part way, with cold air outside in the winter, then brought it inside and warmed it up, the air would expand filling the bed the rest of the way. Hope I didn’t take all the fun out of the trick question.

Check out the NightStar flashlight:

http://www.nightstar1.com/

http://www.webbikeworld.com/flashlight/shake-flashlight/

 

I had a good look at one of these flashlights in a store; it’s pretty big and not very bright. There are small magnets at each end of the shaking tube; they do the same job as the springs YT mentioned. I can’t recall exactly, but I’m pretty sure it uses a capacitor. It uses a white LED.

What you are looking for is called GRP (Glass Reinforced Plastic), commonly just called “fiberglass” (http://en.wikipedia.org/wiki/Glass-reinforced_plastic).

 

I’ve often wondered why they can’t make space vehicles with GRP since it’s light, strong, can withstand quite a bit of pressure and is air/water tight. The main reason I came up with is that it doesn’t block you from the type of radiation commonly encountered in space. You could get around this limitation with shielding, possible metal or even water, if the hull is designed to have pockets in it for storing water.

It might say 120mA… (times that by 1000 to get Amps).

You mean divide 120mA by 1000 to get amps.

 

Moving on: If the voltage drop of diode is greater than or equal to the supply voltage, do you still need a resistor (assuming you use a battery for the power supply)?

 

Also, let’s say you use a 2.5v LED @ 30mA and the appropriate resistor in series with a 9v power supply, how much power is lost to the resistor? According to http://led.linear1.org/1led.wiz you need a 220ohm resistor that burns 500mW while the LED only burns 75mW. If you are concerned about saving power, you should always try and match the supply voltage and the LED forward voltage.

Another cool, but probably unfeasible idea id like to try is some sort of deep sea probe that would be lowered about 2 miles (3.2km) down, and would have some kind of video recording device, and some lights. Somehow I don’t think I’m going to find off the shelf parts that can withstand 4700psi (32424kPa) at 32F (0C), but it’s a cool idea nonetheless. Apparently alkaline batteries can be modified to withstand 10,000psi, and freezing temperatures, so that’s ok (http://pergatory.mit.edu/rcortesi/portf/highpresbat/highpresbat.htm).

 

Well, there is only one way to find out about the ICs and that’s to do some testing, and it could be several months before I get the opportunity to get out into deep water.

 

The low temperature will be an issue for the deep sea probe, but not for the ROV since the water temp at 200 feet is nothing extreme in my area.

 

If I do use a computer in the ROV, it’s going to need solid state storage, probably a Compact Flash card; I assume EEPROMs will be ok because they don’t have an erase window.

 

While I’d love to make the ROV completely wireless I don’t think its going to work. There are 2 ways that I know of to have wireless communication underwater: acoustic ultrasound modems and ELF/VLF radio. Both of these technologies have extremely small data capacities which are no where near enough for video, one acoustic modem I looked at has great range, but only transmits at 15 kilobits/second, about 1/3rd as slow as a 56k computer modem. VLF radio is even slower. A blind ROV is worthless and I can’t think of a way to do wireless video underwater. This is not unexpected, as all the ROVs I’ve looked at use a tether to link them to the surface.

 

Time to do some testing I guess.

Glad I’ve piqued your curiosity. I may end up not using a computer at all but let’s entertain the idea for a while.

 

The capacitors can be replaced with matching ones of the type you mention, so that’s no biggie. The problem with the ICs did cross my mind, but now you’ve got me worried, how big an air pocket are we talking? Will it allow the resin to deform enough to crush the core? Can the resin be replaced with something more flexible without damaging it?

 

I don’t think there will be a problem with overheating; I’d be using a low power computer (something like this: http://www.mini-itx.com/store/?c=2#p1601) so the heat it generates should be able to conduct through the oil, which conducts heat better than air, but worse than water. If it’s a problem, I can make some sort of metal “heat pipe” that conducts the heat into the ambient water.

 

What do you mean by radio circuitry? If you mean something like Wi-fi or Bluetooth, I’m not planning on using anything like that (wouldn’t get too far through the water). I don’t know much about choke coils, but would they be affected by the oil?

Ok, let’s say we build a Dyson sphere at 1 AU, that’s nice because that’s where the earth is. At that distance, if we used all the matter in the solar system (excluding the sun) we’d only be able to make it 28 feet thick. In fact, we wouldn’t even be able to make it 28 feet because I calculated all this using the volume of all the planets, not their densities.

 

There is however enough matter to make a ringworld of reasonable size.

You're not going to find a battery that supplies 40,000 volts.

26,666 AA batteries in series? j/k

 

If you hook up some D cell batteries to the secondary end it will step up the voltage pretty outrageously. You could probably get up to 40,000 volts with just a few Ds. It's amost all voltage, very little amps so it's not lethal or anything.

As far as I know, transformers only work with AC (alternating current), you need additional circuitry to put DC in, or to produce DC with, a transformer.

I’m thinking of building my own ROV (remotely operated vehicle) which is basically a remote control submarine.

 

Ideally I’d like the ROV to be able to withstand going fairly deep, say 200 feet, which means it will need to withstand high pressure (6 atmospheres / 88psi / 608kPa). I was thinking rather than build the ROV out of materials that can withstand such pressures, why not fill it with an uncompressible yet inert liquid, like oil?

 

Well, one reason not to do this is that the electronics inside the ROV might break under the pressure anyway. At the very least I’ll have a video camera in there (lets not worry about the oil changing the optical properties of the camera just yet) along with some motors for propulsion and I may also want to have a small computer in there. So my question is: can anyone think of a component in a computer or other complex electronic device that would not be able to withstand such pressures? I’m a little worried about the capacitors.

 

Thanks in advance.

It’s been a while since I learned all this but let me try and explain. It all has to do with heat flow; heat is always trying to flow from a hot area into a cold one, in order to reverse this flow we need a heat pump, air conditioners and refrigerators are types of heat pumps.

 

Imagine it like water: water wants to flow downhill and as it does this we can extract energy from it (think hydroelectric power plants). If we want to move water uphill, we have to spend energy to pump it back up. (In case you are wondering, it is possible to extract energy from heat as it travels from a hot area to a cold one, using sort of a reverse refrigerator)

 

There are two sides to a phase change cooling system (such as a fridge) a hot, high pressure side, and a cold, low pressure side, the compressor is what produces the pressure difference, the expansion valve keeps the two sides from equalizing.

 

Consider what happens in a refrigeration system. The refrigerant (your working fluid) is forced from the high pressure condenser through a small tube (the expansion valve) as a liquid, when it reaches the condenser; the pressure is much lower (because the compressor is sucking from the evaporator) when the liquid comes out of the tube into the low pressure area it evaporates into a gas becoming cold. You may notice the same thing happens when you let the air out of a tire, or spray a can of air duster upside down. As the cold gas travels though the evaporator it picks up heat from inside the fridge. The compressor then raises the pressure of the gas and pumps it into the high pressure condenser, turning it into a liquid (just like the air duster has a liquid in it). The liquid now holds the heat energy from the inside of the fridge and the heat energy from the compressor. Because it is now hotter the heat wants to flow out of the system into the air near the back of the fridge. Once the liquid has passed though the condenser it is more or less the same temperature as the air behind the fridge. The now cooler liquid then goes back through the expansion valve and the cycle begins again.

 

So, in short, the compressor is necessary because it has to force the refrigerant from one phase (gas/liquid) to another.

 

I hope this helps some; I’m still a little fuzzy on the whole idea myself.

Try just plugging in the laptop's power "brick" without the laptop connected or turned on, see if you still have the problem. If you do, I’d consider replacing the brick.

If you want to turn electromagnetic radiation into electricity, you’d be better off using visible light; just buy some solar panels. I believe there is about 1 kilowatt of solar energy falling on 1 square meter; of course, solar panels are like 12% efficient so you get more like 100 watts.

'']So is lead actually any better at stoping radio waves than any other metal? I really dont see why it could be, but it seems to be a pretty darn common belief.

Lead is better at blocking radiation than other metals because it is denser. Next time you get an X-ray, ask what the jacket they give you is made from, its lead. Also, if you go around the back of a hospital you can usually pick up lead containers they use to ship radioisotopes to hospitals (at least they do at my hospital). The lead is about 2 inches thick, and it shields a tiny amount of material, like smaller than a film canister.

If we relied upon people having social forethought, we'd end up with a bunch of inherently arrogant kids.

We would? Why would they be arrogant?

I'm not sure why we need to concern ourselves with the nobility element if we are discussing selection. Is it because that while violence is (in this instance) selectively favoured, it is not necessarily socially desirable?

Essentially, yes. Just because nature selects for this trait does not mean we should allow it, because fighting to settle our disputes is not a noble thing to do, and ‘noble’ is certainly something an intelligent species should aspire to be.

 

 

That's not quite how it works though. You're missing out whole swathes of genetics like recessivity and so forth, and also ignoring the "genetically bad" effects of medicine, such as the increased resistance of pathogens to antibiotics, and the reduced expression of defences that were previously strongly favoured by the selective pressure of not having medial intervention.

My point was that modern medicine may be encouraging the selection of undesirable traits, or at the very least, not encouraging selection against those traits. It was an example of a human practice which interferes with natural selection, employed to strengthen my case for the implementation of other selective practices, in whatever form.

 

 

The problem is that a few hundred diplomats in meetings with other diplomats don't directly impact the population of the country they are acting in.

Most of the time diplomats don’t do a whole bunch that “directly impact the population of the country they are acting in”, but if they have helped prevent a war, they’ve probably helped prevent the selection for violent traits.

 

 

 

Well I guess the point I’m trying to get across here (I think there’s one buried in there somewhere) is that natural selection has a less significant positive effect on humans (in some cases, even a negative one) than it does on other species, granted, it does still effect us. And since it is less effective, we must begin to select for positive traits via other methods while discouraging the artificial selection of negative traits; they may be indirect methods such as education and they may already be in place, all I’m saying is we should keep them in place, and intensify them. While this is all fine and will certainly help the species progress, people also need to have a little “Social Forethought” (as outlined in the last paragraph of post #75) before they have kids.

Hopefully, at some point in the future, the individual will be able to make such reproductive choices. Until such a time I can guarantee the species will stagnate; we will see less genetic extremities and more mediocrity; in essence, the human species will be nothing but average.

Alright, perhaps I was being a little harsh here; the species might not stagnate, it will merely progress very slowly. If people had a little “Social Forethought” before having kids, i.e. reproductive choices for the benefit of the species as a whole, then we might greatly accelerate the progression of the species, both genetically, and morally. Which I’m sure you’ll agree, is a good thing.

 

 

So, to all you prospective parents out there, think about how it will affect the species before you have a child; have a little “Social Forethought”.

What vampires really are

The mentions the inability of a vampire to cross running water.

 

“Running water, which vampires cannot cross. This varies by tradition with some stories having vampires simply turning into a bat and flying over when faced with this obstacle.”

You could argue that sharks have been stagnant for millions of years, but they are still as effective now as they were when they first began to diversify.

I was responding to this, if you don’t think sharks have stagnated, we don’t need to argue the point.

 

 

There are several pressures that affect evolutionary change: pathogenic influences (as with the sharks), social effects (which can include changing dietary trends, changing family unit models and so on), abiotic effects such as natural disasters and our own influence on the environment, competition from other species (often gets overlooked with humans), and of course the big one - intraspecific competition, which will never go away.

Agreed, but how can you be sure these pressures will result in selection that benefits the human species? Modern medicine gives us a vast array of disease and pathogen fighting weapons, these disease fighting abilities are not dependant on genetics; the most genetically challenged individual may be able to get medical help that allows him/her to live long enough to reproduce, thus defeating natural selection. One could argue that the poorer classes do not have access to modern medicine, but as you pointed out, genetics and class do not necessarily correlate, so there is no guarantee that genetically inferior individuals will be denied access to medicine through poverty.

 

I assume “intraspecific competition” is competition between members of the species. As I have already said, this type of selection is not always effective for the human species. For example, two groups of humans are fighting over some land, the more violent group wins and kills the other, they settle on the land and reproduce, increasing the over all number of individuals with genetic predispositions for violence. Humanity has been doing this for a long time but it’s hardly a noble way of life for intelligent life forms now is it? If we worked to discourage war and advocated intelligent negotiations (which we are to some degree), we would be decreasing the number of individuals with genetic predispositions for violence thorough a self imposed selection. This would not be a natural selection; it would be one of intelligent life, and it would benefit the species.

 

We don’t need a state imposed eugenics program, we don’t need random sterilization, what we need is people who make everyday choices with the good of the species in mind, not selfish people who makes selfish choices for the benefit of only themselves. Stop fostering the inferior and start promoting the superior, and have some compassion in doing so; don’t kill or sterilize someone with a genetic disease, merely suggest to them that their children will have to live with the very same disease, perhaps they should think twice about having kids.

Alright, lets not take this too far; I’ve said some things that I cant really back up, at least, not without “studying vast samples of the population”. So I can’t prove if “class and genetics correlate”. You are right; I’m making gross generalizations here.

 

 

No, the sharks have most certainly not stopped evolving. Staying in a niche is not the same as failing to evolve.

I agree sharks have not failed to evolve, only that they have no need to because their environment hasn’t changed much; they are still at the top of the marine food chain, and they haven’t had to change much to stay there.

 

 

It would, but you have to understand that "we still have some evolving to do" makes no sense whatsoever as a phrase. There's no goal here - evolution is the population reacting to a changing habitat, nothing more.

Perhaps ‘evolve’ is the wrong word, humans aren’t “reacting to a changing habitat”; they are trying to dominate it, modern man makes his own habitat, the city.

 

 

The fact that we are not animals is also irrelevant: selection doesn't discriminate between the two states of being, and neither does drift.

Agreed, selection doesn’t discriminate; my point is that selection is no longer selecting for the traits that will improve the species (see post #55, paragraph 2). The only problem is that no one is qualified to make these decisions, so I suggest that we modify our social behavior to allow selection to make the correct choices, perhaps by educating people about the dangers of unlimited reproduction. For example modern science has enabled otherwise sterile couples to reproduce, who are we to say that these couples should reproduce when selection has said they should not? It is social practices like these that degrade the genetic quality of the species. Why can’t those couples adopt a child? Why do they insist the child be their own? It seems selfish to me.

I wanted to try and avoid this assumption, but it seems to me that today’s upper class is for the most part, genetically superior to the middle and lower classes. Can we agree that, to a certain degree, class and genetics correlate?

 

If so, I can back up my guarantee. Look anywhere in the world, and you will find the same general trend; the upper class produces less offspring than the middle or lower classes. Now, I’ll make a gross generalization here but intelligent people are more likely to think; “I have no plans to bring children into this god forsaken world”, as you said Sayonara. This is obviously not true in all cases, there are always exceptions, but intelligent people are more likely to be of this opinion than less intelligent people (that or they are simply too busy to have a family). The middle (mediocre) class is more likely to have 2-3 children, an average number. The lower classes are more likely to have many more children, for whatever reason; ignorance of contraception, lack of means to procure contraceptive devices, lack of family planning services or in some cases, children are born so that they can ‘work on the farm’. Poor children are often put to work at a young age. In some extreme cases, the parents may have children so that they can sell them into indentured servitude as a way to make a little money.

 

Let me make it clear that there will always be exceptions, but these are trends that I have observed.

 

Sayonara, when I say ‘average’ I mean it in comparison to today’s gene pool. Today’s mediocre (average) and below average people are more likely to reproduce than the above average ones, thus broadening the average class while narrowing the above average class. It may be that this trend has been in existence for 1000’s of years, I don’t know, but I think it should be slowed or halted. The quality of or gene pool should be rising, not falling

 

The shark has ceased to evolve because it fits its ecological niche perfectly; it has no need to be better (although that could change now that humans are killing them). Humans on the other hand, are different, we occupy no niche and we can excel at many different things. Humans are not animals, and we are no where near living with the rest of the life on this planet in any sort of balance or harmony. We still have some evolving to do, for one it would be nice to try and breed excessively violent tendencies out of the genome, in the past it may have helped us survive, but we are now able to use intelligence to settle disputes, not violence. If we became less violent the world would be a better place, would it not?

Pleiades, I find a couple of things wrong with your argument. First of all what your suggesting is a state-controlled Eugenics program. Any state that controls the fate of its people’s progeny has absolute control. Furthermore, you are suggesting that the people be segregated by gene superiority. This would ultimately result in an elite class with absolute control. History has shown that oligarchy’s do not benefit the society as a whole, but rather divide society into classes that lead drastically different lives. Your elite class would posses all of the power and wealth while the unfortunate masses toiled to support them. There would be no class mobilization because your elite class would have absolute power with their control over the genome. Eventually there would not even be any class struggle because the genes that lead to resistance would be bred out of the worker class.

You raise some good points here, and I agree, if such a state run eugenics program was implemented in the next few years, it would be a disaster. Fortunately, that’s not exactly what I’m suggesting.

 

You must agree that, in order for a species to progress in a positive direction, a genetic selection of the reproductive members must be made. In most cases we call this ‘natural selection’; this method is no longer effective for the human species. However, at this point in time, neither the individual nor the state is capable of making such selections in the best interests of the species; we are simply too selfish. Hopefully, at some point in the future, the individual will be able to make such reproductive choices. Until such a time I can guarantee the species will stagnate; we will see less genetic extremities and more mediocrity; in essence, the human species will be nothing but average.

Well only a handful of bees within a hive can mate, the queen and the males. There aren't that many males to choose from, but the queen doesn't restict herself much, genetic diversity and all that. This polygamy is not favourable to the workers descended from the original male though, because the new offspring are not as closely related to them. So they usually resist this polygamy, it's more their selectiveness rather than the queens that keeps the number of male mates down. Still the queen will usually have multiple mates during her life. The female worker bees are physically incapable of mating but they can produce eggs that result in male bees (male bees are produced from an unfertilised egg). The other worker bees don't like this though, they aren't as closely related to it as to males produced by the queen) and will destroy the egg and punish the worker.

Well, I didn’t know all that. So, are bees a bad example or not? they were just the first thing I thought of.

 

It doesn’t really matter though; humans should make their reproductive choices to benefit the species as a whole, not the individual. This happens in other species through natural selection, but since humans have deviated so far from what we call ‘natural’, we must resort to other methods of improving the genetic stock of the species.

I also believe that every human should have the chance to be a parent, in the present they could easily adopt a child, in the future (like 100s of years in the future) perhaps the excess children of the genetically superior parents could be candidates for adoption. In any scenario, reproductive control should take into account not only genetics but also the environment in which the child would be raised. For example, we could put in place laws that require a certain income to be met before reproduction is allowed; if people really want that child, they will get the money from somewhere.

I did specify that this would be far in the future, so things could be a little bit different, but let me try and put it in a present day perspective. Say for example we have a parent with a dominant genetic disease, this makes the parent genetically inferior, as the bad trait will always be passed on to the offspring. The parent decides that they do not want to bring a child into the world with the same disease they themselves have had to live with. So they choose to adopt a child from a ‘genetically superior’ parent, i.e. one without such a genetic disease. This scenario has possible already been played out, it could happen in this age. I never said the parent would have to be forcibly sterilized; it is entirely reasonable that they could make the choice to adopt the children of ‘genetically superior’ parents by their own free will.

 

 

Yes, but that's because of humans. Any animal that regulates their reproduction without human intervention?

Very few animals regulate their reproduction, mostly because they are incapable as individuals of making decisions that benefit the species as a whole, unlike humans. The only animal I can think of that does something like this besides humans is hive animals like bees. The queen is very selective of who she mates with, only the best male bee is selected, the queen makes reproductive ‘choices’ based on the genetic superiority of the available mates. Only a handful of the hives members get to pass on their genes, if that’s not “natural regulated reproduction to increase an elitist class” I don’t know what is.

 

Anyone who has read Starship Troopers will know exactly what I am talking about.

While the brain does emit electromagnetic energy, it is very weak; to measure it, the sensors have to be very close to the skull. Also, to induce thoughts in the brain with any sort of electromagnetic energy requires the probes to be almost touching the actual neurons. I recently read an article about affecting the brain with an electromagnet, and the fields used were very powerful, and had little effect. I do believe that we have yet to uncover the full electromagnetic spectrum, so it could be that the brain is affected by waves of a different, undiscovered type. I certainly don’t think it would enable telekinesis tho.

I agree with the theory, I don’t know if it was responsible for “The death of Mars” tho. I believe that this missing planet got to close to Jupiter, and was sheared apart by the gravity of Jupiter.

Lol, if anything, if they did create us as a race of weapons, they surely abandoned us due to our uncontrollable and random behavior. What good is a weapon that fights with itself?