Over two years ago I purchased two of these three computers through mail order from Wal-Mart as bare bones computers without any software. One was upgraded with a more advanced video card and faster hard drive (I play games and sometimes render video.) I also put in a floppy disk drive and CD-Rom drive that I happened to have laying around. I loaded Windows 2000 onto both computers, using copies of Windows that had come with my previous (and now dead) computers.
I built the third computer out of ‘computer scraps’ – basically parts of my older computer systems that I kept from previous computer upgrades. This computer has an older motherboard running an older version of BIOS, so I used an old 1.6-gigabyte hard drive on it. I also dropped in a (VERY) old 100 MB hard drive that I had, just ‘cause it was fun. Once I got it up and running, I loaded Mandrake Linux onto it.
Last weekend, the power supply fan in one Wal-Mart computer died, causing the power supply to overheat and shut down. The second Wal-Mart computer, the one with the video card, had two fans that had become noisy, a sign of imminent failure. The next day, the 100 MB hard drive in the Linux computer did something to cause a system failure. Upon reboot, the motherboard didn’t even recognize the existence of either hard drive any longer.
I found a computer store that was open on Sunday, and was able to quickly pick up the fans that I needed, at half of the Radio Shack price. Back home, I re-fanned my computers (to coin a term!) and dug out a new hard drive for the Linux computer. Major Problem! All I had was a used 40 GB hard drive – and my Linux computer’s motherboard didn’t recognize it at all! I spent another hour upgrading the motherboard bios so that the hard drive would be recognized.
When I had some spare time, I took apart the old 100 MB hard drive. The problem seemed to be in the arm, not the drive motor, and I wanted the motor for future projects. While I was at it, I pulled out the heavy duty rare-earth magnets that were also in the drive.
These magnets are STRONG! I have no idea how many milliTesla these are rated at, but it was certainly high enough for me to put one on the top of my arm, and one on the bottom, allowing them to attract each other without falling off.
But what does this have to do with science and pseudoscience?
There are practical lessons here for those who believe in pseudoscience and superstition. If I were a believer in superstition, I’d say there was an element of fate in the failure of 3 computer systems at once. But I knew that a simultaneous failure had a decent probability of happening.
Wal-Mart would never spring for high-end power supplies and fans for these computers. These fans had 20,000-hour life spans. I replaced them with fans advertised as having 80,000-hour life spans. (As an additional benefit, the new fans are super quiet!) And as for the failed hard drive – well, to give you a clue on its age, I got it from my mother when I upgraded her 386 computer! I’m amazed it lasted this long!
I had set up and turned on all these computers at the same time, and except for an occasional reboot – they have stayed ON for the last thirty months!
Fault Tolerance is a fairly well known science – given the properties of a piece of electronics, and the environment in which it is placed during operation, it is usually possible to calculate its lifespan fairly accurately. Engineers use this data, and add a ‘safety margin’ to it. The fan that died did so at approximately 22 thousand hours, or 20 thousand + 10 percent. That seems suspiciously like a ‘round number’ and not accidental – in other words, the designing engineer probably built in a 10% margin of failure.
I’d say that the hard drive’s failure is merely coincidence – it was way past it’s designed life span and should have failed years ago. It failed the day after the other two computers failed.
Another lesson here is that the magnets that I pulled out of the dead hard drive really have no affect on the human body. (Well, if I get these strong magnets too close together where they can grab a bit of skin, it would hurt like crazy! Does that count?)
After playing with the magnets a little, I placed them on the palm and back of my left hand and left them there for over an hour as I read a book.
You’ve seen, I’m sure, magnetic jewelry sold in stores and pharmacies (often right at the pharmacy window!)? The makers of these magnet ‘charms’ claim magnets will heal you. In reality they are selling pure snake oil, (link 2) at a huge markup! A magnet really has no effect on bone and tissue because there is not enough ferrous material in a human body to make a difference!
Magnetic resonance imaging uses a powerful magnetic field to align the spin of protons of the hydrogen atoms in your body, then uses radio frequency energy to alter that alignment slightly – against the magnetic field. When the RF energy is turned off, those protons return to their previous alignment, giving off RF energy that is detected and turned into a viewable image.
MRI machines are equipped with extremely strong magnets – strong enough to yank hundreds of pounds of magnetic material into the machine. These magnets are strong enough to cause a detectable change in the atoms of a patient in the machine – yet at the same time, that patient will feel no indication that anything is different, either in the machine or afterwards.
But all materials do have magnetic properties – even living beings – when subjected to a strong magnetic field. This is called Diamagnatism. When an applied magnetic field is strong enough the subject of that field itself becomes magnetic enough to be affected more directly by the applied magnetic field. This property has been used in science demonstrations to levitate (in a very restricted way) animals like mice and frogs. The magnetic field required to do this is much greater than what a patient in an MRI machine experiences.
An MRI patient has no indication that anything is different, either during the MRI process or afterwards. There is no affect on the patient. The frog in the bore of the machine at the High Field Magnetic Laboratory in the Netherlands seems oblivious to any change brought about by the magnetism.
This lack of effect on the human body is why MRI machines are not used as “super magnetic jewelry”, to cure aches, pains and arthritis in the joints.
There HAVE been scientific studies of how specially constructed magnetic fields may affect the human brain. The research here is in its very beginning stages, but has already had surprising results.
In some cases exposure to narrowly focused intense magnetic fields has helped to alleviate depression temporarily. (Link 1, Link 2).
To me, the most amazing study of this sort, by far, has shown that a magnetic field may induce feelings of the supernatural. In a study by Michael Persinger of Laurentian University in Ontario Canada, magnetic fields were shown to induce feelings of God in many test subjects. From the article:
By 2002, [Persinger] had performed the experiment on over 1,000 volunteers. 80% had some sort of supernatural experience. Many say that their experiences were "so profound they would be life-changing had they not understood the mechanistic underpinnings of what they had experienced." About one in every 15 subjects reports an intensely meaningful experience. One saw a figure of Christ in the strobe light. Others, depending upon their cultural background, reported Elijah, the Virgin Mary, Mohammed, or the Sky Spirit. Some have reported out-of-body experiences, a sensation of floating, and a sensation of "great meaningfulness."So, the ‘god’ feeling that religious people experience can be re-created in a lab, without the need for actual god(s). Perhaps this feeling is merely natural, and doesn't have (or need) a supernatural cause at all?
But wait – didn’t I just say that magnetic therapy is useless? What about these scientists using magnetic coils to affect the brain?
Magnetic therapy is useless because the magnets involved are weak and the magnetic fields are broad and haphazardly placed. The coils that real scientists use create a narrow magnetic field is ‘aimed’ into specific areas of the brain. Exactly what is being affected doesn’t seem to be clearly understood – which is why these experiments are valuable.
The biggest difference between the pseudoscience of magnetic therapy and the true science of magnetic brain stimulation lies in how those involved present themselves. The quacks sell a cure-all that they guarantee will work, with lots of anecdotal evidence to back them up. Quacks depend on confirmation bias and placebo effect for results, if any.
Scientists offer no guarantees, only a probability of treatment. They show scientific experiments, repeated by their peers and carefully documented. Their evidence is subjected to careful analysis.
As Dr. Richard Feynman said:
We've learned from experience that the truth will come out. Other experimenters will repeat your experiment and find out whether you were wrong or right. Nature's phenomena will agree or they'll disagree with your theory. And, although you may gain some temporary fame and excitement, you will not gain a good reputation as a scientist if you haven't tried to be very careful in this kind of work. And it's this type of integrity, this kind of care not to fool yourself, that is missing to a large extent in much of the research in cargo cult science.It takes a special kind of integrity to not fool yourself - especially since you are the easiest person to fool. This integrity is demonstrated by good scientists.
We will let the topic of cults wait for later. No more practical lessons for now. I think I’ll go fiddle around with my magnets again.
2 comments:
Ahhhh- Feynman. For edicts on the application of rationality to almost anything, Feynman da man.
Thanks for a simple, clear, science-based explanation of why this magnetic-therapy "movement" is so much crap. I dislike pseudoscience, and despise (because I want to practice allopathic medicine, and because of the direct amount of damage and death it causes) pseudomedicine. (Unless you're in the mood for a rant, don't get me started on chiroquacktors.)
Congrats on your repieced and resurrected computers- and a very envious "neato" to your extremely strong magnets. I've never actually seen or been able to play with any that strong before, and it sounds really cool.
Your quote from Religious Tolerance comes from the book Blind Faith by Du Toit. The book is self-published and doesn't cite his sources. You need to find Persinger's actual experimental data.
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