Sensei

I am sorry if you feel offended.. That was not mine intention.

Somebody with ADHD can't concentrate on one subject for longer time.

Your threads are such chaotic (f.e. post #10, #14). You can't talk about one subject at a time. Do you have ADHD?

When scientists are making experiment, we are trying to reduce influence of other forces to null, and calculate thing that we're interested in at the moment.

Iwonderaboutthings, do you know how to calculate 9.81 m/s acceleration (or other planet/moon acceleration) purely from experimental observation.. ?

My history is not good - but I think the lumpiness of the photon was discovered whilst the other two forces were found to be (or to be excellently modelled as) lumpy through the development of the respective quantum field theories rather than observationally.

Cloud chamber was showed to public in 1911.

Wilson saw the first time traces leaved by cosmic rays in 1894.

Oil drop experiment, to measure quantization of charged particles, was done in 1909. Published in 1913.

Hi Sensei... can you tell me more... Did you calculate with sun-tracking panels or fixed ones?

Fixed.

I was calculating from perspective somebody with solar panels at hand at any time from nearest shop selling them.

Exact model. 1600x800 mm size, with area =1.28 m^2, giving 190 W (15% efficiency), for 315 usd with tax each. 36.6 V and 5.2 A according to shop specification.

I was simply interested "what quantity of them do I need to cover all mine needs".

14 such solar panels (for $4410) = 18 m^2, and it should give me all what needed, including winter time.

Time (whole year) would tell whether it's correct quantity...

Is this 330kWh/month with or without home heating/cooling?

Without. It's what I am personally spending (the most of it is server running 24h/d)

Did you also compute the storage battery capacity that you might need to live, say, 90% of the time off grid?

Nope.

Sorry I meant 1000 MW. Thanks for spotting it.

I wonder what the ratio of land area required for nuclear and solar plants respectively is for producing equivalent output.

Each m^2 of Earth is receiving average 1360 W, but part of energy is absorbed by atmosphere, which gives max 1050 W per m^2.

Solar panel typical efficiency is 15%, so from 1050 W there is remaining 160 W/m^2.

Then you have to take care of that Sun shines just between 4-20 at summer, or between 8-16 (or so) at winter, and max output is varying depending on hour.

For mine latitude I have calculated that I need 18 m^2 to cover all mine needs 460 J/s (which is 330 kWh per month), regardless of season and hour. During day there must be enough gathered for all night.

So if nuclear power station have 1000 MW it's giving energy to ~2.2 mln houses like mine. And it's equivalent to 39 mln m^2 of solar panels.

Couple months ago I even wrote letter to our government showing that their idea to start up new atomic power station for $7bn (10 MW) is simply silly.

For the same money they could buy at detail price solar panels enough for 2 million apartments and make them independent from power stations.

But instead I suggested them to buy/create whole company producing solar panels, which would decrease costs even more..

Neutrino is fermion in mainstream physics, but almost nobody would call it "matter"..

BTW, on Windows when we use from command line:

dir "\\192.168.0.2\" there is error "name of file, volume, or directory incorrect".

But if we will use f.e. dir "\\192.168.0.2\SharedDocs", it's working as expected.

Basically directory listing functions can't work to list volumes.

Not sure about Unix implementation.

You might search google for "list volumes linux" or so.

Why three / ?

Did you tried:

os.walk("smb://dw_fileserver/")

or

os.walk("smb://dw_fileserver")

?

I was using smb path on mine MacOS X, and I could swear it had smb://192.168.0.2/ ....

But maybe mine memory is failing at middle of night.

Tried using IP address instead of name?

One question: Can energy be used for free instead of a tool to earn money?

IMHO, sure.

But that would require redesigning of our current consumptional & money based world.

Instead of selling everything for money, we should give everything what we do for free.

And everybody else can give us what we need also for free.

Such approach is not a problem in small societies, where everybody know everybody in f.e. small village. These people simply trust each other.

In older times before creation of food mass production and refrigerators, that was the only way to handle pig-slaughtering in villages: one family at a time was killing animal, and sharing parts of it to all neighborhoods (otherwise they would simply waste), knowing that they will return them when they will be pig-slaughtering their animal..

In tv documents about Amish they're often building house with neighborhoods. For free. The only cost is price of wood and nails (that would ruin building business & bank mortgage loans, if everyone would build their own house)

But current societies are made of people that barely know each other. Somebody giving something for free is treated as foul and abused. *)

That would require completely new approach to society.

*) that reminds me one local baker that was famous in tv & newspaper giving breads for free for people..

He was prosecuted by government because of not paying taxes from freely given bread..

According to (these complete idiots) government he should utilize (burn) bread that was not sold, not give it away to homeless.

Then everyone would be happy.

Except people that are making money on this business..

Taxes from electricity bills, and power stations dividends, are also significant amount to governments.

I think that the answer about definition of matter is obfuscated with the properties of matter.

When we say: electron (“me”) is a mass particle we identified it as matter, not as a property.

When we say: photon (ph) is an energy particle we identified it as matter not as a property.

Electron particles and the photon particles for somebody seem to be two different things.

I suppose that they are two kind of structure of the same matter.

Sensey in its post, gave the equation of “annihilation” of matter:

 

me+ + me- = γ + γ (sorry Sensey but I can’t identify “e” with “me”.)

e-

and

e+

are just standard mainstream identifiers to inform everybody that you are talking about electron and positron.

m_e is mass of electron or positron, ~9.11*10^-31 kg

1.23559*10^20 Hz (Compton frequency) * 6.62607*10^-34 J*s (Planck const) / 1.602*10^-19 (e) = 510998.9 eV = 0.5109989 MeV

1.23559*10^20 Hz (Compton frequency) * 6.62607*10^-34 J*s(Planck const) / 299792458^2 (c^2) = ~9.11*10^-31 kg

I think here is not at all any annihilation of matter. Is only a restructure of component of so called “matter” and “antimatter”. When I say “components” I allege hypothetic sub-particles of matter – antimatter.

 

((e- / g-) + (e- / g.)) + ((e+/g+) +(e+/g+)) = me- + me+

equal ((e- / g-) + (e+/ g+)) + ((e- / g-) + (e+/ g+)) = γ + γ here (e+- / g +- ) = (e+- / +-(4*pi*G)^0.5)

Gamma photons after annihilation can be absorbed (and then most likely emitted) by charged particles f.e. electrons and protons, and accelerate them, ionize atoms etc. Instead of 2 photons each with 0.510999 MeV we will have multiple, thousands or millions photons with smaller frequencies, smaller energies, that sum of their all energies is our initial 2*0.510999 MeV = 1.022 MeV energy.

When 2 photons have smaller frequency than Compton frequency they won't be able to change to electron and positron in pair production (reverse of annihilation).

y + y -> e- + e+

When 1 photons have smaller frequency than 2 * Compton frequency it won't be able to change to electron and positron in pair production.

y + nucleus -> e- + e+

Four sub-particles, like in above example, is too few I am afraid.

How to differentiate frequencies, energies?

Right. And when you don't have the math tools, you can't claim to be doing physics.

Not quite. You can make experiment without knowing math describing it. Equations will appear later after gathering enough data and deep analyze. First must be experiment or observation.

Math in science is to predict future, and calculate past state.

f.e. you detect apple to be at time t0 at position x0,

later at t1, at position x1,

later at t2, at position x2,

you can calculate velocity v=(x1-x0)/(t1-t0)

then you can calculate acceleration

a=(v1-v0)/(t1-t0)

and knowing equation d=1/2*a*t^2,

you can calculate when apple will hit ground,

at which branch of tree apple grew,

whether it will smash, or land safely etc. etc.

pls am a final year student of computer science in diploma am having a little challenge with my project and d topic is BOOKSHOP MANAGEMENT AND ORDERING SYSTEM and am using VB10 to design it but at some point am having problem coding a button to update my database pls ur help will be really appreciated

You didn't show your source code..

I agree that technology advances with time. But that's not reason to treat clients like that - leaving them alone with not working hardware they paid for.

There is market for spare elements for older models. But there is no willingness.

f.e. produce 1 mln quantity of single model laptop, and 1.1 mln quantity of gfx card matching for them. 10% more than full sets.

These 10% offer to sell to electronic shops, ebay or whatever other route. Client could buy it for reasonable price, and replace it, if it's damaged.

After all warranty is 2 years, 3 years if extended is purchased. So spare elements have to be taken from somewhere to fix them.

Mine laptop died 1 month after warranty end..

Not first such "accident".

But large LED tv I fixed by myself. And there were thousands threads on the Internet about the same issue as I had, with detail description what to do to fix it.

 

For the record, I don't think repair problems with laptops are due to lack of spare hardware, at least not in my experience. What usually makes laptops harder to fix is that it costs more in labor because you have to pull so much out to get to anything. If you bought your laptop for under $500, you may be reluctant to spend more than $100 to fix it, especially if it's a year or two old already.

Try to buy mother board, gfx card, or cpu for any laptop...

I would be delighted to get gfx card for mine broken laptop on free market. I could spend hours to unscrew everything and replace it. It's not a problem.

I have paid for it $2500 in 2007 (the best and the fastest laptop at that day on the world), and can't get gfx card that for normal PC would be $50. I would even pay up to $300 just to have it running.

Laptop manufacturers force you to buy completely new one, if old one is broken.

If you want to magnify text in web browser press ctrl +

It works with Firefox & Chrome, not sure about others.

5) desktops have far much better LCD panels (laptops have to save power, desktops don't). Your eyes will be working longer.

Never ever buy display without seeing how it works in practice.

If eyes hurt after several hours of work, you have to replace it by different model..

If you're considering a laptop for its portability, know that it's not a good idea to move around with a laptop while it's running. Hard drives like stability.

That's correct. I know many people that damaged HDD this way..

Traditional spinning HDDs can be replaced by flash memory that are in HDD box (SSD - Solid-State Drive), same plugs as normal disk.

But they are expensive. 250 GB for $140. 1 TB for $420.

http://www.amazon.com/Samsung-Electronics-2-5-Inch-Internal-MZ-7TE250BW/dp/B00E3W1726/ref=sr_1_1?s=electronics&ie=UTF8&qid=1404062035&sr=1-1&keywords=ssd+hard+drive

1) if laptop is damaged, you cannot fix it usually. Most likely you won't find any electronic shop willing to fix it. They don't have spare hardware.

2) laptop can easily overheat. It has no good circulation of air inside. I had laptop couple years ago that was shutting down in summer time while playing Counter-Strike: Source for a while. And it killed it permanently (gfx card broken, and couldn't get replacement).

3) if you plan to crunch a lot of data by applications, doing calcs, it's not good choice (see above)

4) limited hardware extending. You can just add memory and replace hard disk.

"The work delivered by the gravity is..."

That doesn't care about distance in axis X something traveled, only by axis Y- height (distance from center of Earth).

If c would be 1 km, answer still would be the same.

Distance 3*h is "c" in below Pythagoras triangle.

And height is "a".

3 stairs have total height h.

Not single stair.

If somebody would say "stair has 33.33 cm. Calculate energy needed to rise mass m, 3 stairs up." Then 3*33.33 cm = ~1 m

And result would be m*g*1 m