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Physiology & Medicine / Why doesn't the medical profession make better use of the internet?

« on: 04/04/2013 20:01:19 »

There are quite a few "self diagnosis" sites (for want of a better description) and I think these are all very popular and quite useful. I have a feeling that GP's are not always of that opinion, however, as it can lead to surgeries getting populated by the "worried well" and, worse, people becoming sceptical about their GP's all knowing, God-like status - now, thankfully, largely gone.

This is not what I am referring to in the question however. It is just that the popularity of such sites means that people are willing to spend time discussing their ailments and learning about diagnoses and treatments. This is a huge and underused resource of knowledge that is not being utilised. Clinical investigations and trials are very expensive and often do not yield statistically adequate conclusions. It seems to me that there are a lot of medical issues, large and small, that could be aided by a few websites just asking people to contribute.

There are sites that already try to describe symptoms which may point to a particular ailment. But no use is made of whether or not the results were accurate. Indeed there is no way to report it. Statistics on the accuracy of prediction would seem to me to be valuable data and a good way to hone how to weight particular symptoms in pointing to specific ailments. The efficacy of drugs is another way to gain a much better statistical weight than some trials. Of course these do not replace trials, especially double blind trials, but the potential numbers can become very useful, especially in looking at possible side effects for example. Diagnosis can often, at least at first, be done by having a patient describe a pain; not just where the pain is but also whether it hurts when touched, when breathing or what sort of pain it is. The language for pain description is far from universal (I actually think descriptions of taste for wine tasting is better developed) and this could be made much better honed by questions and answers on the internet.

I won't go on but the gist of this is that this could be done at low cost and, with existing software used widely in market research, could be very well statistically analysed and results collated.

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Physiology & Medicine / Is there any potential for long term eye damage from LED lighting?

« on: 21/03/2013 20:41:16 »

I was not sure whether to ask this in the physics section or here because it crosses both field to some extent. Incandescent lights (the old filament bulbs) give out light over a wide spectrum which we perceive as white because the detectors in the eye see an even amplitude in each of their RG and B detection ranges. Fluorescent lights do not but, to an even greater extent neither do LEDs. Although some LED lamps also rely on a fluorescent coating, generally these lights broadcast in 3 very narrow spectral regions. Is there any reason to be concerned that the very sharply defined spectral lines would affect our eyes - at least some of the receptors - by having a high intensity in these small spectral regions? Whilst natural light is also "spiky" because it comprises emssion spectra there is a lot of spectral lines involved. This is not so with LEDs.

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Just Chat! / Why have some topics disappeared?

« on: 03/03/2013 13:49:31 »

Someone asked a series of 4 questions (they looked like exam questions) which I answered but with a comment that, if they were exam questions or homework, they would be better working out the answers themselves. When I look back now (a couple of hours later) the questions and answers have disappeared.

Have these been expunged somehow, is it a fault or can the questioner simply withdraw the question (and, along with it, any answers)?

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Physics, Astronomy & Cosmology / Which satellite was this?

« on: 20/08/2012 13:42:10 »

Whilst having a few drinks in my neighbours garden (with my neighbours, I should add) we observed a very bright, large (and slightly diffuse) red light moving fast and silently across the sky. As it was an hour or so after sunset I assumed it was a Low Earth Orbit satellite reflecting the sun. As it was so bright, I thought it may be the ISS however it was moving from East to West and the ISS does not go this way.

It was on 17th August 2012 and more or less overhead over Orpington, Kent, UK. There seems to be a few websights that will predict satellite positions or even give you the current position of lots of LEO satellites but I could not find any that will do this retrospectively, i.e. where I can put a location and time (in the past) and ask what satellites were overhead. Has anyone got any ideas?

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Physics, Astronomy & Cosmology / Have they found the Higgs boson?

« on: 04/07/2012 09:12:18 »

So it seems. News of great gravity I think :-)

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Physics, Astronomy & Cosmology / Is the Pioneer anomaly solved now?

« on: 20/04/2012 10:16:31 »

I see the latest, and painstaking, research by Turyshev, Toth and Ellis, Kinsella, Lee and Lok seems to show that both Pioneer crafts anomolous deceleration is due to thermal radiation from the instruments and from the nuclear power source. This must be disappointing to those looking for the somewhat more exotic explanations.

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Technology / Why does my energy saving light bulb flash when not switched on?

« on: 27/03/2012 14:18:43 »

A curious thing. I was lying there counting Neils jumping over a gate when I noticed the light briefly and dimly flash. Better than a Neil flashing I thought. So I noted that the light flashed about every 29 seconds. On a second night the time between flashes was 24 seconds. It seems very consistant on any one occasion though; at least it stayed the same until I went asleep.

What could be the cause of this given that the light was switched off? It is the main light in the room with only one switch (single pole on the "live" wire) on the wall about 15 feet away. The light is connected via a twin cable from the ceiling rose where there is an unconnected earth wire. As a result it is hard to see any current path.

In the UK the neutral line is earthed at a substation (I think) so there can be a few volts of AC on the neutral line. I can only think that this must be enough, combined with the capacitance of the switched-out live wire to provide some tiny amount of power and I guess this could be enhanced a bit by some RF harvesting. However, I still don't know how this could produce the regular very low frequency pulses which I can only think is to do with the electronics in the light bulb. The light bulb is one of the new electronic fluorescent job with some means of making it instantly bright on switch on.

Any ideas?

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Just Chat! / What is this object?

« on: 04/09/2011 15:52:08 »

This object was discovered during building work being undertaken at my neighbour's house. I don't know what it is. It is very heavy and seems to be made of steel. Well engineered and surprising not very rusty. The structure is hollow - maybe some sort of water jacket - and seems to have guides to allow accurate butting to another structure. The steel is at least 5mm thick and no obvious signs of welding - it looks well machined. It may also abutt so as to form a hollow asymmetric tube, but I can't be sure.

Houses here were built around the mid 1920s. We are close enough to London and Biggin Hill Airfield that bombs fell and aircraft were shot down in this area during WWII but it doesn't fit with any bit of a bomb or aeroplane that I know.
 
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Technology / Is Google's patent acquisitioning right?

« on: 18/08/2011 16:06:14 »

Google have put in an offer for Motorola Mobility of $12.5B. The prime reason for this is to buy the 17,000 patents that Motorola have accumulated over the years and so they can defend future threats from Apple or Microsoft. It has been suggested that Microsoft may try to buy Nokia as a result - both companies would like to get some of Apple's business.

Now I don't have any sympathy for Motorola here as they have used the patent system as a means of maintaining their superiority in the US market for years. Of course this is the way the game is played. It is reckoned that to be a major player in the mobile phone business you have to have 20,000+ patents. It does not matter much whether they are valid or truly defendable from an engineering perspective; if you can afford the lawyers, you can win. In fact nobody takes you on as the only winner would be a bunch of law firms.

I know I have had a rant (err a discussion) about this before, but does anyone else think this is not actually what the original intention of patents was really about?

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Plant Sciences, Zoology & Evolution / What is digging holes in my garden?

« on: 09/04/2011 17:03:30 »

This is probably more for "Gardener's question time" but I thought I would try here. Something has decided to start digging small holes in the lawn. The holes are roughly 4 inches (10cm) in diameter and 3 to 4 inches deep. If I fill them in they get dug out again. There seems to be a sort of "track" visible joining up some of the holes; it is hard to describe, but the lawn looks different inside the tracks from the surrounding lawn but is not very pronounced.

The main animals we see are foxes (no. 1 suspect), squirrels (no. 2 suspect) and various garden birds (though apart from possibly Crows or Magpies, I can't see that they would be able to do this. Someone suggested that we may have cockchafers under the turf and the foxes are digging them out.

Any ideas?

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General Science / Why do people drown in quicksand?

« on: 28/03/2011 11:01:22 »

Is drowning in quicksand common or just something that happens in films and TV dramas? It would seem, at first sight, that a suspension of sand in water would have a net density rather higher than just water and would therfore be reasonably bouyant. I can see that the viscosity of the mix would make it hard to swim in although it should be possible with some modified technique. Or is it the case that the suspension of particles in the water does not behave in the same way as a uniform fluid of the same net density? Are you just displacing the water part so that, somehow, the sand particles, that are also displaced, don't count in providing the Archimedean upthrust?

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Just Chat! / What's wrong with University education today?

« on: 16/02/2011 14:06:17 »

This could be a long rant from me so I will try to be succinct. I am keen to hear views on this controversial topic.

Over the past 30 years or so it seems that the quality level of those with degrees has decreased. At one time it was a sufficient recommendation for employment (plus a superficial interview) that someone had a degree and especially so if it was 1st or a 2.1. In some cases it was even not so important what the subject was, except for specific technical positions which required the specific knowledge acquired in taking the course. This is definititely not the case any more except for some specific courses at certain Universities, which you have to know about, or more generally, at Oxford or Cambridge. This is for the UK of course and it would be interesting to hear views from people elsewhere. I apologise for not being specific about some Universities that are good in certain areas (like London Imperial with Physics for example), but the general picture is valid I think. I don't necessarily think that the standards of the courses are worse and, in physics the syllabi seem fairly comprehensive. It seems that there is just more pressure to get more students to pass, so the bar has been lowered hugely.

I think the evidence that would support this is:
1. More people attend university and the standards have necessarily dropped to accommodate this.
2. The finances for the universities are heavily supported by paying students from overseas who, given that they pay a substantial amount, expect to get a degree at the end. It is bad marketing if they don't.
3. Examinations are often carried out over a period of time on specific topics which can be learnt for the exam then forgotten.
4. Some Universities allow failed papers (although not in the Finals as far as I know) to be retaken by students at home and handed in later. Southampton 2nd year Physics for example. This could be acceptable in special circumstances but it seems commonplace.
5. I have found that A-level grades are a better representation of ability than degree (with exceptions previously noted). I have interviewed people whose knowledge in all areas was very poor but who, amazingly, had a good degree.
6. MSc courses are even more variable. There are some Universities who award an MSc for just attending!

Now, this is not to say that it isn't great that more people have the opportunity to go to university. Also, there was not any golden age where people were perfectly selected to attend a university. People attain different abilities at different times in their lives so there were, and are, many people who excel at their jobs or even at academic work, who did not get opportunity to go to university. Also there are people who fail at university who can also blossom later. However, it seems to me that we have degraded the ability of the degree to be any sort of indicator to an employer. It is all down to the interview now, and that is not a good measure given the time pressure and the difficulty in assessment in such a short time.

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Just Chat! / what is this observed phenomenon?

« on: 04/12/2010 10:04:24 »

When flying back from Zurich to London City Airport on swissair LX456 yesterday (3rd December 2010), I observed the following:

Things I am sure of:

It was a little before noon (GMT) after a late take off because of aircraft de-icing, The Avro aircraft has a high wing and I was in a window seat a little forward of the starboard engine. Looking out (which I assume was north) there was a vapour(?) trail heading southwards. The trail was very dark (almost black) which seemed unusual as all the surrounding clouds were white. It was also very dense and did not extend back indefinately. I was trying to work out what it was when the pilot made a small course correction to the south and my view was then obscured by the engine.

Things I am not certain of because I am aware of the fallibility of observation:

The trail was some distance away (several miles) but was getting closer quickly. It was higher than our aicraft by a few thousand feet and I guess we were at around 30,000 feet. The dark vapour seemed to be very turbulent and thick encompassing whatever was causing it.

So what was it? I have never seen any aircraft produce such an effect. I did wonder whether it could have bee a meteorite burning up but there was no fireball that I could see. Any ideas?

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General Science / Why does freeze dried instant coffee not dissolve so well if damp?

« on: 21/09/2010 18:59:49 »

I notice that if you allow moisture to get inside a jar of freeze dried instant coffee it causes the grains to stick together. This may be expected if the substance is hygroscopic, and it probably is. But what seems strange is that after this has occurred it takes longer to dissolve the grains in hot water when you make a cup of coffee. Why would this be so?

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Physics, Astronomy & Cosmology / Are photons the only particle with a tangible wavefunction ?

« on: 10/08/2010 12:36:01 »

I have wondered for a long time why the wavefunction associated with a photon is a tangible and measurable change in an electromagnetic field whereas (all?) other particles have a less tangible probability amplitude associated with them. An example is an electron which exhibits interference and diffraction but for which the wave function appears as just an abstract probability amplitude.

Are there any other particles for which the wavefunction is a sinusoidal change in a field? If not, can any insight be drawn from this?

If a Higgs Boson is found, would its associated wavefunction be tangible gravity waves?

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Physics, Astronomy & Cosmology / Was the puzzle of the connection between QSOs and galaxy clusters ever resolved?

« on: 18/04/2010 20:27:16 »

Back in the 1970s QSOs (Quasi Stellar Objects or Quasars) were thought to be quite close (to explain their brightness) but having anomolous redshifts far in excess of what would be expected. They were also associated with galaxy clusters that were relatively close and having normal quite low redshifts. The association with the clusters was largely statistical but there was also some visual evidence of filaments between the bodies in many cases. It is now generally accepted that QSOs are very energetic emitters, probably due to the accretion disc of a super large black hole at the centre of a huge galaxy, at very great distances indeed. The association with relatively close galaxy clusters has been put down to inadvertently weighted sampling and gravitational lensing by the cluster of a quasar behind. However, I have never seen any explanations regarding the apparent linking filaments - clearly not possible over the distances involved. Also I have never seen a thorough statistical review to see if this stacks up.

While I appreciate the evidence supporting QSOs being very distant, can anyone point to reasonably convincing evidence to refute the connection between the galaxy clusters and QSOs, particularly the apparent filaments and the statistical association?

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Just Chat! / How about this for a clever design?

« on: 18/03/2010 13:49:57 »

A friend sent me this reference. I like clever design but it often falls way short of the hype. This seems an exception.

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Plant Sciences, Zoology & Evolution / How do you deter birds from roosting on your house?

« on: 07/02/2010 22:06:54 »

Now I should start by saying I like birds, but recently I feel our house is being targetted for special treatment, by pigeons in particular. After 25 years of having no problems, pigeons have decided to roost under the eaves on two rather uncomfortable perches but which shelter them from rain. I would not mind except that they crap so much all down the oak weather boarding. Chasing them away is only a very temporary fix as they come back soon after. I tried bird spikes but they only worked for a few weeks then they came back. It turns out I needed specific pigeon spikes. Then they found a way into the loft. I evicted them last week and blocked up the entrances - the stupid things stayed in a very inaccessible place so I had to crawl into the dormer roofspace, pick them up, and bring them out individually. They still think the house is their's though and are haunting the place, finding other roosting places and, of course, crapping. They are very persistent. I can't cover the whole house in spikes, gel or model owls, and, other than shooting them, I can't se how to get them to go elsewhere. Any suggestions?

Amazingly another problem arose a couple of weeks ago. There was a strange noise from the loft/roof area that sounded like an African Lion (listen to African Lion 2 from this site...
http://www.seaworld.org/animal-info/sound-library/index.htm
I reasoned that it was unlikely, living in the UK, that I would have a lion in my loft. I'm not daft - I know lions don't live Kent. Well, I found the source. I have a sealed up disused chimney with just a vent in the kitchen to keep it dry. There is a metal cowl on top and I found that a starling was vibrating his wing against the metal (the way chicks vibrate their wings when asking to be fed). The sound resonated down the chimney to give the rather loud sound we heard. The bird does this just after dawn every day and again at various times during the day. Why? I can only thing he/she likes the sound. Again chasing away does no good as they don't seem to get the message. This has amusement value and so not so annoying (yet), but how does one stop such things once the bird has learnt it likes doing it?

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Physiology & Medicine / How is cancer spread via the lymphatic system?

« on: 31/01/2010 11:33:19 »

I have known a number of people who have been apparently successfully operated on to cure a cancer who have then subsequently died as a result of secondary cancers. Most recently, a person (heavy smoker) had a tumour removed from the tongue and also had the lymph nodes removed but died from cancer in both lungs less than a year later.

Does this imply these cancers result from a common agent that can somehow move from one cell to another and via the lymphatic system? Or is it that cancerous cells themselves are the carriers and it is "rogue cells" in the lymphatic system that move the disease about?

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General Science / Why does scraping one side of a ribbon make it curl that way?

« on: 27/12/2009 13:32:41 »

I noticed that coiled coloured foil or ribbon Xmas decorations are made by drawing the ribbon over one's thumbnail. They then will coil inwards and remain coiled. Does anyone know the mechanism here? Is it just bending over an edge repeatedly to stretch the outside or is it a more subtle structural change to the material?