kenny1999

Hi all I am the thread starter,

Let me give a less complicated example.

If I don't put down on a list about what to buy in the supermarket or grocery stores, e.g. vegetables, fruits, drinks, etc. and if it's more than 5 items, I have hard time in the street recalling what to buy by my brain,

The only solution is EITHER go back home, sit down, and think

OR walk around the big grocery stores without any direction, but look around everything and when I see the things I need, then I can recall, Oh yea, that's it.

Is it abnormal?

It is said solid state hard drive is more durable because it doesn't have any moving parts. In other words, why, spinning drive with moving parts is less durable? Assume that they never drop from height or get damaged, does a moving part of any device fail more easily? What is the reason behind?

Do you find that you are not able to think or analyze things clearly when you are outside, (i.e. Not at home), you are only able to focus on the environment and the problems you see with your eyes and make your direct or natural response to it by your sense, not by your brain?

Why am I asking this question? I find that I am not able to think deeply or clearly when I am outside. For example, a salesman in a street stall talked to me and wanted me to join or subscribe to their mobile or cellular data plan. I had hard time understanding what he said, it wasn't language barrier at all, it was because I wasn't able to think clearly at all if it was a real deal or any hidden charges when I am not at home (BUT in fact, it's not rocket science). I had to write down what he said and brought it back home, sitting on the sofa, then I was able to think very clearly.

Another example is, if I don't write down what to do on a paper or put it in my mobile phone before I go out, I will have hard time recalling what to do when I have gone out. However, it only limits to minor things like buying a new towel, buying a pack of cola, picking up mails in the nearby post office. One time, I had to do a number of minor things like what I have mentioned, I didn't put it into a paper, then when I was outside, I wasn't able to recall at all what to do, then I had to go back home, feeling relaxed, and then I could recall, Oh yea, buying a bag of table salt, a pack of dry cells, and a USB cable for charging (ALL minor things.)

It looks like my brain has shut down partly or totally when I am outside, or at least, hard to run it.

Is it abnormal? Or common to most healthy adults? Is it a sign of getting old? In fact, I am 30+ and not physically active.

Over the last few decades we have breakthrough in communications, from the time that we can only call by landline and hear only sound from another side to now that we are carrying a mini computer around (e.g. smartphone) that we can do many things with it.

However, it looks like that there isn't any breakthrough in medicine (If I am not wrong). Yes, there may be better technologies, better methods, better analysis and understanding of a patient and a disease but it looks like the root of problem cannot be solved, for example, if one has diabetes, he cannot be cured totally but has to manage for a life time, if one is found cancer at its advanced stage there is little thing a doctor can do to change or wish for miracles.

Do you agree?

2 hours ago, TheVat said:

Sugar accelerates various degenerative diseases and the aging process, so usually the option with least sugar is the best.  What you want is food with a lower glycemic index - you can google charts that show glycemic index for most foods.  (Figs or bananas for example are better than refined sugar sweets, as they have more fiber to slow absorption in the gut)

And watch out for empty calories with bad side effects, like this....

https://www.cnn.com/videos/media/2022/12/02/cocaine-bear-trailer-moos-cprog-orig-bdk.cnn

If, to put it simply, avoiding sugars, how about salt? Is it another thing that should be avoided in order to achieve better health?

I truly understand that there is no one answer to this question because ingredients for different brands may vary a lot. but I mean, on average, in general, relatively speaking.

My guess is, chips is the best, ice-cream is the worst, choco is better than sweets. Am I correct?

51 minutes ago, studiot said:

 

Most electronic circuits are pretty dust and dirt proof by nature.

The main threat to these circuits is that they attract dust and dirt and that dust and dirt will coat the circuit board, components etc with a layer of dirt that sticks.
This layer then thermally insulates the board and components and may cause some of them to overheat and fail.

Most circuit boards can also be taken out and scrubbed in mild soapy water (or scrubbed in situ).
So long as the assembly is thoroughly dried out before power is again applied everything will be OK.

I have studied some information on web, it's like there is usually a layer of coating applied to the surface of many circuit boards. In that case, how could dust and dirt affect the function of the board? Is it because the coating is an added cost so it doesn't apply to cheap boards?

4 hours ago, exchemist said:

I think you mean disassemble. To dissemble means to lie.

I should think the main risk from ingress of dust will be dirty contacts and hence poor electrical connections at points where subassemblies are joined together. 

 

Yes, typo, it's disassemble. 

Does it practically require significant amount of dust and dirt which is usually due to intention or accident before it is enough to affect the electrical connections?

Someone in an outdoor open area dissembles and repairs an old Television, cars and traffic around, full of dust and dirt and polluted air. Are most circuit boards, electronic components of any kind, manufactured in any generation able to tolerate dust and dirt to some extent by design?

Is it just considered and designed to have some protection so that surrounding pollutants cannot make too much damage or is it not particularly designed but it has to be a lot of dust and dirt ( e.g. which are done by accidents or with intention ) before any damage can occur?

From the scientific viewpoint, is it making a real difference? I think any cheap cloth would do the same job, if no debris is stuck when you wipe your delicate screen with your cloth, if there is any, then a cheap one or expensive one would scratch your baby too.

I'm living in a developed country where I have never experienced starve, I may have experienced overweight more often. I know that, I understand that for a balanced diet, one cannot live with fruit and vegetables. Here I have two major questions about this.

1. If I haven't had ANY fruit or vegetables for a few months but I still take in meats and carbohydrates, could I have deficiency in vitamins of any kind?

2. If I practice fasting and do not eat anything at all for a week, and probably drink only distilled water, could I have deficiency in vitamins or other essential materials for life?

I'm looking for medical or scientific advice rather than legend or unproved information on the web sites. Thanks.

approx. 200ml 13-14% alcohol by volume every day, does it exceed daily alcohol limit recommended?

Results on Google suggest that the effect is not yet known. Is there any new research or report suggesting other possibilities?

Only differed by frequency, wavelength but they are all fundamentally done by light, is that right?

When you put a physical credit card or stored value card near a payment device provided by the merchant, is it using the identical technology as that when you put your mobile phone close to the device and pay with your mobile phone without physical card?

59 minutes ago, Peterkin said:

Sure they can harbour bacteria. Bacteria are literally everywhere. Wash the pots and keep on cooking. The heat will kill most of them anyway.

but you don't usually heat the dishware, e.g. dish, knife, spatula, bowl, etc

I mean, fine scratch that you can probably find under light sources and you don't even feel it with your fingers. Are those fine scratches enough to harbor germs and bacteria?

I'm not talking about large scratches or cracks that I'll simply toss them without question.

I find that when I cook with oil, if the pan isn't hot enough, the oil runs slowly, but when it gets hot enough, the oil runs faster. How to explain this phenomenon?

It's said latent heat of boiling water or steam will cause more damage.

I find that when I cook and the water is boiling, if I put my hand near the steam I wouldn't get as much pain as I accidentally put my hand directly into the boiling water. I would probably hold on a few seconds under the steam but if I put my hand into the boiling water I won't be able to withstand one second.

Why is that?

Does white colored object actually reflect all UV so that it is free of being attacked by UV?

or is it also attacked and dyed by UV but since it's white you can't see the effect?

Another question is we know that white clothes is cooler in the summer than black clothes, is it because most light is reflected by white color?

4 hours ago, swansont said:

You are preventing light from reaching the sensor.

My fingers are never big enough to cover the whole button, but it still works. Why?

On 10/22/2022 at 5:38 PM, Ghideon said:

There may be two parts; emitter and receiver, placed close together. An IR emitter keeps transmitting infrared light and when any object comes near, it is detected by the receiver by monitoring the reflected light from the object. If you are far from the sensor the emitted IR light reflected from you will not be registered by the receiver. By blocking the sensor there is no path for the emitted IR light to reach the receiver; the IR light will not be reflected to the receiver.

Below is a picture, note the emitter and receiver: IR LED and photo diode. 

(Source: links to https://www.instructables.com/Easy-Infrared-Proximity-Sensor/ The page describes the principle in more detail) 

You can google for "ir proximity sensor".

Blocking the sensor? Did you mean when I touch it so there is no air in between, then it will block the sensor and doesn't work?

I was waiting for someone in a park and saw this bird. Its neck is full of black and white dots. What is this bird?

On 10/20/2022 at 9:48 AM, swansont said:

Because you aren’t blocking the sensor.

I mean, I wish to know the principle. What is the sensor doing? Emitting infrared or other radiations? However, I think light or radiation could easily pass through our body!

On 10/10/2022 at 4:36 AM, swansont said:

IR = infrared light, so you can’t see it. As I said, you only get enough return when an object is nearby; the beam expands with distance. If you touch it, you’re blocking the sensor, so it won’t trigger

but why when I put my hand near it, it will work correctly and does not block the sensor?

7 hours ago, TheVat said:

 

OK, thanks, I see now.  Normally, automatic doors use a light beam that is interrupted by a body.  Heat sensors don't work well, because weather causes too much variation in both air temperature and in hand temperature.  So, as @Sensei says, it may use sound, so touching it would mess it up (make it "deaf") and it would not work.

Light beam? Sound wave? Can I have some understanding of how it works? Does the device continuously emit light wave and when someone get close to it, it will interrupt the light wave? 

I have some physics knowledge but not too much.

6 hours ago, swansont said:

It could be an IR source and detector. You only get enough return when an object is nearby. If you touch it, you’re blocking the sensor. 

We have these at work for ADA compliance - the door opens automatically rather than opening by hand or pushing a button. Not security-related, as such.

IR source and detector? Can I have some brief understanding of how it works? Yes, when I touch it, it doesn't work, when I am far from it, it doesn't work. Only when I put my hand close to it (but not touching it), it works. Is it using sound wave or light wave or something otherwise? I don't think there is any emitter around, does it itself emit light wave or sound wave so that when I get close to it, the wave is interrupted? 

P.S. As I said, this is not a door for security, it's in the public area, and our building isn't very modern. I only wish to learn about the working principle behind.

5 minutes ago, TheVat said:

Detect your hand?  Not clear what that means.  Your door sensor reads the pattern of your palm?  Or in some way makes a positive ID of your hand?  This sure doesn't sound low budget, if that's what you are describing.  Quite sophisticated in fact.  Like Fort Detrick Biohazard Lab sophisticated.  

OK, my language problem, Let's make it clear, I mean, it detects ANY part of human body and unlock the door immediately, there is nothing about fingerprint or ID, it's not a security door, anyone who puts their hand (or any part of their body) near the "sensor" then it will unlock the door (but it won't unlock if you touch on it, it only works when your hand puts near it but not too far away, and not touching it). I only want to know the working principle of such device.