Consider: with the micro, you have to use a crystal to set the reference frequency. How good is your crystal? Now how good is it at -20 degrees C? At +60 degrees C? The 555, along with a couple of good capacitors and resistors, will hum right along with predictable performance at the temperature extremes, for dirt cheap.
Someone previously said they would have used a PIC 12F629, and I would too. This is an 8-pin device (like the 555) and has an internal oscillator with an accuracy of +-4% over -40C to +125C which is good enough for biochemistry, so to speak. And not much worse than most capacitor based circuits... You can also get new 6-pin devices, but I never used them yet.
I'm not quite sure how the circuit in the original article worked, as it had no capacitors or resistors (perhaps the DHS hacked the site). But a PIC12F629 based solution would not have needed any additional components either
The PIC does have disadvantages - it has a slightly higher power consumption than the low-power 555, and it leads to feature creep - I would have wired in a button and a time delay so that the kite didn't start taking pictures for 10 seconds after it was launched (or 20 seconds if you press the button twice quickly, or not at all (cancel) if you press and hold it for 5 seconds...). But perhaps most of all it costs £50 for a cheap programmer and I think this would put off people who were less interested in the electronics side of things.
In a recent case in the UK, a driver forgot that you need to pull out to overtake cyclists. The cyclist died and the driver was fined a few hundred pounds. She did not lose her license as it was deemed that this would cause her hardship.
Imagine a computerised car was involved in a similar accident. The damages against the company that built it would doubtless be _far_ higher. We seem willing to tolerate human fallibility to a much higher degree than we are willing to tolerate fallibility in machines.
Even if robot drivers get better than human drivers (probably not that hard in many cases - I'm feeling guilty for missing a red light yesterday) I don't think we'll see them on the roads anytime soon.
I live in the North of England, and very little of my riding time is on the flat. I don't know what the gradients are, but 8% doesn't seem a lot to me. There are no great mountains, but there are quite a lot of small but vicious hills. The biggest gradient I've climbed on a recumbent was 20% in Glasgow. It was quite a short hill (otherwise it really would have beaten me) but I got to the top.
I don't think anyone would choose a recumbent to ride up the Alpe d'Huez, but I'm sure the TDF guys could if they wanted to. I'm not really interested in racing (I simply cycle to work and to the shops) but I don't think the recumbents would necessarily lose out overall.
An unfaired racing recumbent can hit 43kph on the flat, using the same amount of power required to cycle at 33kph on a racing bike.
What proportion of the tour is spent going up hills that are so steep that a recumbent becomes 25% slower than a racing bike? I'll bet it's less than 50%
Of course there are other factors: I'm not sure whether a recumbent rider can sustain a smaller or greater power output than a racing-bike rider. But even if the recumbent rider lost, his bum would hurt less at the end of the tour. I have ridden long distances in the past (max 160miles/day) and at the end of the day that's what counts for me!
It's easy enough (albeit difficult) to stimulate neurones with electricity - people have been doing that for centuries. Of late, nanotechnology has made it possible to connect to hundreds or even thousands of neurones at once, either to inject signals or to monitor them at work.
What we don't understand very well, is how the brain encodes data of any kind - whether in the visual system, the auditory system or (though we may have a slightly better handle on this) the motor system.
We can model how an individual photoreceptor works, and we have a vague understanding of what happens at the first synapse, but after the second synapse it's largely a mystery. Visual processing occurrs concurrently with transmission (from eyeball to all the different areas in the brain).
For example, there are cells in the brain that we know react differently to different colours, but is that all they react to? Perhaps they only react to coloured lines, or will only react if another colour is or is not present in the background. And how do they transmit information - is it in the number of spikes they fire, or in the timing between these spikes. Can the information only be decoded if you correlate it with the firing of another cell (or perhaps a few dozen cells) amongst the zillions of neurones that are found in each CC of brain tissue. The answer is that don't know the answers to any of these questions. Textbooks talk glibly about parallel processing paths for motion or for shape perception; of 'colour' areas or 'edge detectors'. In reality it's a lot more fuzzy than that. What we don't know far outweighs what we do know.
So, we can already interface to the brain, but it will be a long time before we can transmit or decode detailed information. Maybe it doesn't have to be detailed in order to be useful. For example, we can show people a picture of a scene that they may or may not have seen before, and determine whether their memory flags up a 'match' - or nothing at all. We can make people see arrays of big blobs of light, but not a picture. But it still may be enough to aid partially sighted people.
So work away, but be modest in your aims, and humble. The brain is wonderful, but it is still largely a mystery to us.
They say their system reduces rail wear, because of the way in which it corners. Rail maintainence should be reduced to once every 25 years - incredible!
Why wouldn't regular trains be able to use the same system to reduce rail wear.
I agree it would be a better idea to have a graded licensing system, but as a psychologist I think that using psychometric tests to determine who should be able to drive and who shouldn't is a bad idea.
A good example is that of professional tennis players and other sportsmen. Everyone assumed they would have much better reaction times than the common man, but when they were tested they found their reaction times were only a little better than everyone else's. The difference was that they were able to anticipate their opponent's moves well in advance, and were able to move more fluidly in response.
Most 21 year olds will have pretty good vision and reaction times, but some will make much better drivers than others. The key difference is one of attitude, not raw ability. Introducing more stringent tests emphasizes ability rather than attitude, and may discriminate against people with minor disabilities (e.g. colour-blindness, depth perception) that do not seriously impair their driving.
A point of interest is that the USA has much stricter vision testing than almost any other country, yet its road death rate is amongst the worst in the developed world.
I would like to see a 'graded pass system' where drivers took a slightly less stringent test and were allowed to drive for a while to build up confidence and skills. A few months later they would take another test allowing them to drive faster and carry > 1 passenger.
I ride somewhere with lots of hills, and I've never yet had to push. I'm certainly slower going uphill than I was on an 'upright' but it's not really a big difference - I don't race and I ride a recumbent primarily because it's more fun and more comfortable than my old bike.
Recumbents probably are slower uphill, but the jury's out as to whether they are slower overall. Unfaired recumbents have won several road races where both recumbents and upright bikes were allowed to compete with each other.
Of course, it's silly to compare faired recumbents with unfaired uprights but there are good reasons why it's difficult to compare uprights v. recumbents.
Almost all world-class cyclists ride diamond-frames, because that's where the money and the competitions are. They can't simply compete on a recumbent for a day, because they use different muscles for each type of bike.
Most recumbent records were set by part-timers - for example one recent world speed record was set by a female chef aged around 50.
Would you please read my original post more carefully before reprimanding me for carelessness.
There was no scheduled bus transport to the airport, so there was no way I could have 'taken the right bus'.
The night before my flight, I asked directions at the youth hostel where I was staying. We looked at the map, and found 'airport boulevard' directly next to the airport. Part of the problem was that I had to walk a long way round the perimeter. This wasn't clear from the large-scale map that we had.
In the airport they confirmed that there was no bus stop at the airport; no Greyhound bus stop at the airport; no (cheap) shuttle bus to the airport; no train service to the airport. In other words, someone had built an airport without any public transport provision whatsoever. Unbelievable.
Regarding telephones - the USA uses a different mobile telephone system from most of the rest of the world, so I would have had to buy a new mobile to use there if I was to take up your first suggestion. Perhaps I could have found a telephone box, but the few people I asked told me it was just 'a mile or two' to the airport (I estimate it was 5-8 miles). I should have been aware of this possibility as I know from past experience that people are terrible at converting between driving distances and walking times.
Lots of posters criticise you for being arrogant - this may be the case, but I read your question as "I have some gifts, but this is not reflected in my academic accomplishments to date. I am worried my capabilities will go to waste, and I will feel unfulfilled."
Is this fair?
As some of the other posters have mentioned, you will need more application in order to succeed in any field. However, there are benefits to being an all-rounder and my suggestion would be to find a varied field. This way you won't get too stuck-in-a-rut.
I code in C, assembly and Matlab. I also write code for PIC microcontrollers.
I see very few links between the way I code in assembly, and how I write the higher-level languages. Yet according to this article I should have the makings of a guru. Where am I going wrong?
Presumably everyone understands binary encoding, shift right and left instructions, and the like? Anything much beyond this is liable to be very architecture-specific - which is bad. I look forward to the day when I can choose between a number of architectures and run the same open-source programs on each. I loathe X86, and I dislike apple for other reasons.
Perhaps we become more rigourous by writing assembly for small systems - with very few resources. But beyond this, I can see no real advantages to learning assembly.
I regard myself as a good programmer, but I see my strengths as being clarity of expression and design.
I've worked on audio for museum exhibits and am currently doing work for an audio tour that will be presented at a prestigious museum in Washington, D.C. There are a few firms involved in this kind of work and the equipment is expensive because it is made in small quantities and is extremely rugged. For the portable audio tour devices, there are industrial-grade, sophisticated charging racks and the individual audio devices have buttons and features so that visitors can see the exhibits in any order and learn more about individual stops (think "hyperlink").
That equipment sounds nice, but it's not very relevant to the OP's needs. He/she is building listening stations. The equipment is fixed in position so the complicated bits - the CD-players, computers of what have you - don't need to be rugged like the handsets in your museum. They can be put in cabinets to protect them from the proles.
Using consumer-grade CD players, MP3 players, and headphones for a museum exhibit is like replacing a pay phone outside of a convenience store with a $10 phone from Walmart.
The electronics inside of the payphone are not likely to be much more rugged than the electronics inside of the walmart phone. A CD-player may eventually wear out (moving parts) but an MP3 player should last virtually forever.
I agree any interfaces (headphones, buttons) would have to be rugged.
I have little experience of running more than one sound-card under Linux, but my first approach would be to see how many soundcards I could fit in a 200mhz box (I've several lying around). If it wasn't for the fact that the audio needs to start & stop (e.g. if it could just be looped) I'd be tempted to drive two mono headphones from each stereo soundcard, each playing an entirely different track.
Do you need to cater for people with hearing aids (e.g. installing loop systems).
Also think about hackability. Will you move on and leave the museum people with a system that they don't understand and can't modify or repair? If I used the PC approach, I would be tempted to burn the software onto a bootable CD-rom. That way, even if the hard-disks crash and the computers die, someone savvy will probably be able to build a replacement machine. Document everything you do, explaining precisely how it works.
Do I believe that going to Mars could be done for 3.5 billion, leaving in four years time? Not yet. What we really need is cheap and reliable space access. When this is achieved, everything space-related will surely become an order of magnitude cheaper.
The only thing that I like about this article is the notion that a voyage to Mars could be made into a reality TV show. Because that's what it should be.
Space exploration is exactly that - exploration, and not science. Every time I turn on the news, I hear of a group that's trying to mountain-bike to the pole, or walk to the pole unsupported, or hot-air balloon to the pole, or walk there backwards. It's so futile it makes me weep.
I believe that exploration is a human need, important to us even when it serves no tangible purpose. Leave the poles to the Scientists. It's time to head for Mars!
In some British rivers, we have 'fish-ladders' that salmon & trout can climb up, so that they can still ascend the rivers to breed. These consist of a series of mini-waterfalls and deep pools. The fish think it's all great fun.
Although this team have spent more than the prize money, it seems incredible that they have designed, built and flight tested a prototype for less than the cost of any off-the-shelf space-launch I have ever heard of.
Is this 'cos they're good, or is it the case that the two tasks (suborbital flight, orbital flight) really don't bear any comparison? Five years from now, will Slashdot be covering the Y prize (orbital flight) or ultimately even the Z-prize (presumably an amateur moonshot)
I have an ethnic surname (Jewish, but that's not the point), and I get lots of spam that purports to be from people the same ethnic group... or who have close variants of my own name.
Anyone else notice this, or am I giving the spammers more deviousness points than they deserve?
By 'password' I was referring to antibodies - as I assume that's what the original poster was referring to. There are basic kill-all mechanisms as the immune system is quite baroque - but these are often less than effective.
It does attack everything it doesn't regognize. Everything that is not "you" (where list of tissues that are "you" are set somewhere during pregnancy), is free game. That's what allergic reactions are all about
Common allergic reactions such as the 'peanut allergy' are antibody-mediated. That's why they may start late in life, and why some people are allergic to peanuts but others are not. If your theory were correct, only people who were peanuts would be able to eat peanuts safely. Yet neither peanut-allergy sufferers or peanut-immune individuals are peanuts. The difference is whether their immune systems recognise peanuts as being harmful or not.
Not to mention rejection of transferred organs, they are attacked only because they are foreign.
OK - this is partly to do with MHC complexes. But this is only one weapon in the immune system's armoury.
Sometimes it will even be fooled to attack your own parts (diabetes, etc).
Again, the problem in this case is that the immune system recognises them as 'foreign' - not that it has forgotten that they're part of you.
Seriously, though. I am not a virologist or anything, but I'd think if there were some bacteria or viruses down there, they haven't mutated at all since they were entombed. Why? No environmental pressures of any kind.
If there were no environmental pressures, they may still have changed slightly due to a process called 'genetic drift'. In small populations, if being red is no better than being blue, either red or blue organisms may come to predominate. Biologically, there's a subtle difference between mutation and evolution. For example, some DNA mutations may not cause a gene to express a different protein - they have zero effect, but are mutations nontheless. When estimating DNA mutation rates, scientists use such 'silent substitutions' as they are do not affect the blueprint of the organism whatsoever, and are therefore not subject to evolutionary pressures.
No sun (radiation) antibiotics (other than toxins their rivals might produce) and very little environmental change in terms of climate (oxygen, nitrogen, etc). It's just cold, dark wet and very saline. They're probably quite well adapted to that environment.
You're right in that there may well be little cause for mutations to arise - other than perhaps transcription errors when DNA is being replicated which are inevitable - especially in bacteria. Mutation rates do vary with environmental factors such as temperature and the presence (or absence) of mutagens.
Over the course of 2500 years that we're talking about, microevolution is probably pretty much all that has taken place.
The bit that I can't get my head around is how we go from chemical soup to the first cell. I tend to think that this will eventually be explained through natural processes, but its a far grayer area than evolution.
Did you ever hear of hen's teeth? Hens have a gene for teeth, left over from their dinosaur ancestors. When it's reactivated, they grow small teeth. Why would G_d leave left-over bits of dinosaur in hens, if (s)he didn't want us to believe in evolution?
Are you arguing that G_d may not exist, but that we should continue to believe in G_d because it's 'natural' for us to do so?
BTW - You can show that evolution happens in a test tube. I guess it takes a leap of faith to extrapolate from this to dinosaurs and the like, but for once we _were_ talking about bugs in a natural test-tube
Take a single test tube. Seed it with a single progenitor bacterium, and allow it to multiply until there are a few dozen identical bacteria in this colony. Take each bacterium and in turn use it to seed a clean test tube. You might place non-lethal amounts of antibiotics in some test tubes, or place different test tubes at different temperatures. Leave them until each of these daughter colonies has multiplied a few gazzilion times over.
These bugs will no longer be clones of each other - each colony will be composed of subtly different organisms; some strains may prefer different environmental conditions or have resistance to particular antibiotics.
I did a similar experiment once - and we did get these results. Would you have an alternative explanation for these results that is simpler than evolution, preferably one that I can test?
Mutation isn't synonymous with evolution. Random DNA mutations happen at different rates in different species. AFAIK they happen at a roughly constant rate within species - but this rate may change if the species' DNA repair mechanisms evolve, or if it moves to a new environment that is higher in free-radicals or any of a number of scenarios.
I would imagine that DNA mutations would happen at very slow rates in bacteria living in such cold conditions - but the species that were able to colonise such an environment may be particularly interesting ones.
Slashdot Mirror
Someone previously said they would have used a PIC 12F629, and I would too. This is an 8-pin device (like the 555) and has an internal oscillator with an accuracy of +-4% over -40C to +125C which is good enough for biochemistry, so to speak. And not much worse than most capacitor based circuits... You can also get new 6-pin devices, but I never used them yet.
I'm not quite sure how the circuit in the original article worked, as it had no capacitors or resistors (perhaps the DHS hacked the site). But a PIC12F629 based solution would not have needed any additional components either
The PIC does have disadvantages - it has a slightly higher power consumption than the low-power 555, and it leads to feature creep - I would have wired in a button and a time delay so that the kite didn't start taking pictures for 10 seconds after it was launched (or 20 seconds if you press the button twice quickly, or not at all (cancel) if you press and hold it for 5 seconds...). But perhaps most of all it costs £50 for a cheap programmer and I think this would put off people who were less interested in the electronics side of things.
Except for the cost of maintaining the instruments!
In a recent case in the UK, a driver forgot that you need to pull out to overtake cyclists. The cyclist died and the driver was fined a few hundred pounds. She did not lose her license as it was deemed that this would cause her hardship.
Imagine a computerised car was involved in a similar accident. The damages against the company that built it would doubtless be _far_ higher. We seem willing to tolerate human fallibility to a much higher degree than we are willing to tolerate fallibility in machines.
Even if robot drivers get better than human drivers (probably not that hard in many cases - I'm feeling guilty for missing a red light yesterday) I don't think we'll see them on the roads anytime soon.
What's the news?
I live in the North of England, and very little of my riding time is on the flat. I don't know what the gradients are, but 8% doesn't seem a lot to me. There are no great mountains, but there are quite a lot of small but vicious hills. The biggest gradient I've climbed on a recumbent was 20% in Glasgow. It was quite a short hill (otherwise it really would have beaten me) but I got to the top.
I don't think anyone would choose a recumbent to ride up the Alpe d'Huez, but I'm sure the TDF guys could if they wanted to. I'm not really interested in racing (I simply cycle to work and to the shops) but I don't think the recumbents would necessarily lose out overall.
Check out:
http://www.m5-ligfietsen.com/main.php?sNewPage=Mea suring_power
An unfaired racing recumbent can hit 43kph on the flat, using the same amount of power required to cycle at 33kph on a racing bike.
What proportion of the tour is spent going up hills that are so steep that a recumbent becomes 25% slower than a racing bike? I'll bet it's less than 50%
Of course there are other factors: I'm not sure whether a recumbent rider can sustain a smaller or greater power output than a racing-bike rider. But even if the recumbent rider lost, his bum would hurt less at the end of the tour. I have ridden long distances in the past (max 160miles/day) and at the end of the day that's what counts for me!
What we don't understand very well, is how the brain encodes data of any kind - whether in the visual system, the auditory system or (though we may have a slightly better handle on this) the motor system.
We can model how an individual photoreceptor works, and we have a vague understanding of what happens at the first synapse, but after the second synapse it's largely a mystery. Visual processing occurrs concurrently with transmission (from eyeball to all the different areas in the brain).
For example, there are cells in the brain that we know react differently to different colours, but is that all they react to? Perhaps they only react to coloured lines, or will only react if another colour is or is not present in the background. And how do they transmit information - is it in the number of spikes they fire, or in the timing between these spikes. Can the information only be decoded if you correlate it with the firing of another cell (or perhaps a few dozen cells) amongst the zillions of neurones that are found in each CC of brain tissue. The answer is that don't know the answers to any of these questions. Textbooks talk glibly about parallel processing paths for motion or for shape perception; of 'colour' areas or 'edge detectors'. In reality it's a lot more fuzzy than that. What we don't know far outweighs what we do know.
So, we can already interface to the brain, but it will be a long time before we can transmit or decode detailed information. Maybe it doesn't have to be detailed in order to be useful. For example, we can show people a picture of a scene that they may or may not have seen before, and determine whether their memory flags up a 'match' - or nothing at all. We can make people see arrays of big blobs of light, but not a picture. But it still may be enough to aid partially sighted people.
So work away, but be modest in your aims, and humble. The brain is wonderful, but it is still largely a mystery to us.
They say their system reduces rail wear, because of the way in which it corners. Rail maintainence should be reduced to once every 25 years - incredible!
Why wouldn't regular trains be able to use the same system to reduce rail wear.
AC
A good example is that of professional tennis players and other sportsmen. Everyone assumed they would have much better reaction times than the common man, but when they were tested they found their reaction times were only a little better than everyone else's. The difference was that they were able to anticipate their opponent's moves well in advance, and were able to move more fluidly in response.
Most 21 year olds will have pretty good vision and reaction times, but some will make much better drivers than others. The key difference is one of attitude, not raw ability. Introducing more stringent tests emphasizes ability rather than attitude, and may discriminate against people with minor disabilities (e.g. colour-blindness, depth perception) that do not seriously impair their driving.
A point of interest is that the USA has much stricter vision testing than almost any other country, yet its road death rate is amongst the worst in the developed world.
I would like to see a 'graded pass system' where drivers took a slightly less stringent test and were allowed to drive for a while to build up confidence and skills. A few months later they would take another test allowing them to drive faster and carry > 1 passenger.
Recumbents probably are slower uphill, but the jury's out as to whether they are slower overall. Unfaired recumbents have won several road races where both recumbents and upright bikes were allowed to compete with each other.
http://www.alexmoulton.co.uk/frames.asp?id=reviews
This page compares the speeds different bikes will travel assuming the same power input.
http://www.m5-ligfietsen.com/main.php?sNewPage=Mea suring_power
Of course, it's silly to compare faired recumbents with unfaired uprights but there are good reasons why it's difficult to compare uprights v. recumbents.
Almost all world-class cyclists ride diamond-frames, because that's where the money and the competitions are. They can't simply compete on a recumbent for a day, because they use different muscles for each type of bike.
Most recumbent records were set by part-timers - for example one recent world speed record was set by a female chef aged around 50.
There was no scheduled bus transport to the airport, so there was no way I could have 'taken the right bus'.
The night before my flight, I asked directions at the youth hostel where I was staying. We looked at the map, and found 'airport boulevard' directly next to the airport. Part of the problem was that I had to walk a long way round the perimeter. This wasn't clear from the large-scale map that we had.
In the airport they confirmed that there was no bus stop at the airport; no Greyhound bus stop at the airport; no (cheap) shuttle bus to the airport; no train service to the airport. In other words, someone had built an airport without any public transport provision whatsoever. Unbelievable.
Regarding telephones - the USA uses a different mobile telephone system from most of the rest of the world, so I would have had to buy a new mobile to use there if I was to take up your first suggestion. Perhaps I could have found a telephone box, but the few people I asked told me it was just 'a mile or two' to the airport (I estimate it was 5-8 miles). I should have been aware of this possibility as I know from past experience that people are terrible at converting between driving distances and walking times.
When advertising, please place 'FS:' in the subject line to avoid causing offence. Thanks,
Is this fair?
As some of the other posters have mentioned, you will need more application in order to succeed in any field. However, there are benefits to being an all-rounder and my suggestion would be to find a varied field. This way you won't get too stuck-in-a-rut.
AC
I see very few links between the way I code in assembly, and how I write the higher-level languages. Yet according to this article I should have the makings of a guru. Where am I going wrong?
Presumably everyone understands binary encoding, shift right and left instructions, and the like? Anything much beyond this is liable to be very architecture-specific - which is bad. I look forward to the day when I can choose between a number of architectures and run the same open-source programs on each. I loathe X86, and I dislike apple for other reasons.
Perhaps we become more rigourous by writing assembly for small systems - with very few resources. But beyond this, I can see no real advantages to learning assembly.
I regard myself as a good programmer, but I see my strengths as being clarity of expression and design.
Skywolf
How will such a big, flying-wing shaped balloon support loads of several tonnes without deforming?
That equipment sounds nice, but it's not very relevant to the OP's needs. He/she is building listening stations. The equipment is fixed in position so the complicated bits - the CD-players, computers of what have you - don't need to be rugged like the handsets in your museum. They can be put in cabinets to protect them from the proles.
Using consumer-grade CD players, MP3 players, and headphones for a museum exhibit is like replacing a pay phone outside of a convenience store with a $10 phone from Walmart.
The electronics inside of the payphone are not likely to be much more rugged than the electronics inside of the walmart phone. A CD-player may eventually wear out (moving parts) but an MP3 player should last virtually forever.
I agree any interfaces (headphones, buttons) would have to be rugged.
I have little experience of running more than one sound-card under Linux, but my first approach would be to see how many soundcards I could fit in a 200mhz box (I've several lying around). If it wasn't for the fact that the audio needs to start & stop (e.g. if it could just be looped) I'd be tempted to drive two mono headphones from each stereo soundcard, each playing an entirely different track.
Do you need to cater for people with hearing aids (e.g. installing loop systems).
Also think about hackability. Will you move on and leave the museum people with a system that they don't understand and can't modify or repair? If I used the PC approach, I would be tempted to burn the software onto a bootable CD-rom. That way, even if the hard-disks crash and the computers die, someone savvy will probably be able to build a replacement machine. Document everything you do, explaining precisely how it works.
The only thing that I like about this article is the notion that a voyage to Mars could be made into a reality TV show. Because that's what it should be.
Space exploration is exactly that - exploration, and not science. Every time I turn on the news, I hear of a group that's trying to mountain-bike to the pole, or walk to the pole unsupported, or hot-air balloon to the pole, or walk there backwards. It's so futile it makes me weep.
I believe that exploration is a human need, important to us even when it serves no tangible purpose. Leave the poles to the Scientists. It's time to head for Mars!
In some British rivers, we have 'fish-ladders' that salmon & trout can climb up, so that they can still ascend the rivers to breed. These consist of a series of mini-waterfalls and deep pools. The fish think it's all great fun.
Is this 'cos they're good, or is it the case that the two tasks (suborbital flight, orbital flight) really don't bear any comparison? Five years from now, will Slashdot be covering the Y prize (orbital flight) or ultimately even the Z-prize (presumably an amateur moonshot)
Anyone else notice this, or am I giving the spammers more deviousness points than they deserve?
It does attack everything it doesn't regognize. Everything that is not "you" (where list of tissues that are "you" are set somewhere during pregnancy), is free game. That's what allergic reactions are all about
Common allergic reactions such as the 'peanut allergy' are antibody-mediated. That's why they may start late in life, and why some people are allergic to peanuts but others are not. If your theory were correct, only people who were peanuts would be able to eat peanuts safely. Yet neither peanut-allergy sufferers or peanut-immune individuals are peanuts. The difference is whether their immune systems recognise peanuts as being harmful or not.
Not to mention rejection of transferred organs, they are attacked only because they are foreign.
OK - this is partly to do with MHC complexes. But this is only one weapon in the immune system's armoury.
Sometimes it will even be fooled to attack your own parts (diabetes, etc).
Again, the problem in this case is that the immune system recognises them as 'foreign' - not that it has forgotten that they're part of you.
If there were no environmental pressures, they may still have changed slightly due to a process called 'genetic drift'. In small populations, if being red is no better than being blue, either red or blue organisms may come to predominate. Biologically, there's a subtle difference between mutation and evolution. For example, some DNA mutations may not cause a gene to express a different protein - they have zero effect, but are mutations nontheless. When estimating DNA mutation rates, scientists use such 'silent substitutions' as they are do not affect the blueprint of the organism whatsoever, and are therefore not subject to evolutionary pressures.
No sun (radiation) antibiotics (other than toxins their rivals might produce) and very little environmental change in terms of climate (oxygen, nitrogen, etc). It's just cold, dark wet and very saline. They're probably quite well adapted to that environment.
You're right in that there may well be little cause for mutations to arise - other than perhaps transcription errors when DNA is being replicated which are inevitable - especially in bacteria. Mutation rates do vary with environmental factors such as temperature and the presence (or absence) of mutagens.
The bit that I can't get my head around is how we go from chemical soup to the first cell. I tend to think that this will eventually be explained through natural processes, but its a far grayer area than evolution.
Did you ever hear of hen's teeth? Hens have a gene for teeth, left over from their dinosaur ancestors. When it's reactivated, they grow small teeth. Why would G_d leave left-over bits of dinosaur in hens, if (s)he didn't want us to believe in evolution?
BTW - You can show that evolution happens in a test tube. I guess it takes a leap of faith to extrapolate from this to dinosaurs and the like, but for once we _were_ talking about bugs in a natural test-tube
Take a single test tube. Seed it with a single progenitor bacterium, and allow it to multiply until there are a few dozen identical bacteria in this colony. Take each bacterium and in turn use it to seed a clean test tube. You might place non-lethal amounts of antibiotics in some test tubes, or place different test tubes at different temperatures. Leave them until each of these daughter colonies has multiplied a few gazzilion times over.
These bugs will no longer be clones of each other - each colony will be composed of subtly different organisms; some strains may prefer different environmental conditions or have resistance to particular antibiotics.
I did a similar experiment once - and we did get these results. Would you have an alternative explanation for these results that is simpler than evolution, preferably one that I can test?
I would imagine that DNA mutations would happen at very slow rates in bacteria living in such cold conditions - but the species that were able to colonise such an environment may be particularly interesting ones.