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Externet

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Posts posted by Externet

  1. Laziness, yes, mental laziness is the factor. 

    And whoever says that English is evolving :  NO, languages do not evolve.  Languages are degenerated and contaminated by lazy ignorants.  Spell check ?  Wait until A.I. takes over.

  2. Isn't speed of light / frequency = wavelenght ?  and speed of light / wavelenght = frequency ?

    Instead of frequency / speed of light ???

    17 minutes ago, Genady said:

    p = hv/c  =  h times frequency / speed of light

     

  3. Thanks.

    1 hour ago, MigL said:

    Photons do not have mass, but they do have momentum ... ... p = hv 

    OK.  We are then not talking momentum p = mv = mass times velocity.    It is then momentum p = hv  =  h times frequency  =    p = h/lambda   

    What is h ?   What is the formula E energy = hv ?

    Or, it is not momentum; it is impetus, or impact, or some other wording  ?  Is it wrong terminology ?  Calling two things the same name ?

  4. Greetings. 

    Those solar sails proposed for space probes collect the impact of photons to provide propulsion.  I think.   The photons stop moving when reach/hit the 'solar sail' or always bounce and keep going at the speed of light ?  Is the collision to those sail surfaces the one that creates a force as reaction from their action ?   How different is from a boat sail and wind ?

    The photons from the sun reaching earth provide some push ?  How many photons hit the earth per unit of time; is there a tiny shift of the orbit due to reaction to photons ? -Explain as simplistic as possible, please-

    Solar sail - Wikipedia
  5. 57 minutes ago, geordief said:

    Could they have attached one or two "echo locator" devices on the side of the Titanic before they paid it any visits ?

    It would send reports to the surface every few hours.

     

    Would it be able to scan the area on a continuous  basis  and be useful in this sort of a need.

     

    At that range would it have  a directional ability?

    Unsure if you mean echo locator as a ping beacon, or a 'repeater' attached to the Titanic that picks up nearby? submarine noises/com and relays in higher power to surface/distant receiver.

    If a locating/searching receiver is at surface -say 5Km- from a beacon in the lost submersible,  to triangulate in 3D the arriving timing shifts of a signal to find its source, I have to assume it would take synchronized time receivers hundreds of metres or Kms apart to measure and compute direction for the 1500m/s acoustical propagation signal.  And that is if they are not moving by currents/tumbling by the seafloor.  Sea is not water at rest.

    If by magic they had an extra week or even a month of air supply, they would still be doomed, no food, no heating, no drinking water, probably no light in board. 🥵

  6. The "contact" communication with a submarine can be conducted in ultrasonics, ultra low radio frequencies, optical methods.  Radio waves are severely attenuated in seawater. ☹️

    Tridimensional directional sensing/finding at long ranges is not simply achieved, worsened by noise floor levels and interference masking signals.   Side-scan sonar is very limited in range to conduct a search.

  7. Hello.

    Germinated indoors in January, now my oxheart tomato plants are fruiting reaching 1.30m.   Read about trimming, topping, thinning, pruning...

    Question.  Can an adult fruiting tomato plant be topped down like at 60 - 80 cm height keeping its roots intact and moved indoors during the winter season, kept from too much growth by pruning; to have a mature and well grown plant ready to resume production in next spring, with no need to wait 4 months from seed to become just a young plant, perhaps even fruiting indoors meanwhile ?

    The point is to keep alive a plant that otherwise would freeze-die in order to gain/save future time.

  8. Regards. 

    Some of you may have that stomach acid reflux, take the calcium bicarbonate tablets, or the pink stuff, or fancier reliefs.   Next time, please, have a gulp of wine and come back with observations.  I have tried some liquor (anise) too and worked.  Bourbon, meeeh.   Would like to see your reports.  Thanks. 🤔

  9. Greetings. 

    Is there a method with science instead of the tales of experts, to analyze if a mushroom will put me in a casket or not ?

    My backyard has since a couple of days, shiny gold color 15cm. mushrooms on sunlight, silver color when overcast.  How to preserve them alive or ensure their propagation ?  The smell is just like fresh champignons.  Went to take pictures a moment ago, a visitor intruded.  Color today shows as more whitish.  Would a close-up image of some part help identifying ?

    image.png

    Adding pictures...

    image.thumb.png.ecfe5b9f2a5eacbc10c28e0c54e3c461.png

    image.thumb.png.27ed15fb3b565ac0a60aa0c0e68f0b51.png

    image.png.e6b95d907e5847248076a109e66dbed2.png

  10. Hello.

    Baptism is considered a Christian sacrament, but was practiced by John since before Jesus became Christ.    How does it work ?   When did baptism originate; on what religion ?

    What belief did baptism supposed to do to a person ?

  11. Hi. 

    Recycling of solar panels will be addressed soon, if not already a thing to consider.  What happens to the cell that loses some efficiency in a couple of decades ?   How much is the efficiency loss ?  ~20% ?    What could it be in 100 years ?   In my young years studying electronics, read  "a transistor is theoretically eternal"  The silicon in them is not exposed to sun rays but encapsulated in epoxy.  Is that what makes a conservation difference ?

    What is the 'aging agent' ?  Solar radiation ?  temperature cycles ?  moisture ?  particles ?

    There is mainly two types, the monocrystalline and the polycrystalline cells.  Always read about their efficiencies but never saw longevity differences published.  Is this a physics more than a chemistry thing ?  ---> Please move as deserved.

    There is a smell that large solar plants sell their aged panels at a good 'discount' and profit from it instead of paying for recycling...  financial strategies...

  12. Go to your balcony, roof, backyard now and check how fast is the wind.  By installing one you could find a very expensive wind generator doing nothing.  Same daily, like 90% + of time ☹️  And not very pretty.

    If you own a hilltop in the farmlands or a cliff, then I 🤐

    7 hours ago, Genady said:

    I have already decided for myself against this project. Today I've read this, additional drop pushing in the same direction: Solar panels - an eco-disaster waiting to happen? - BBC News

    It also adds to what

     

    Hello.  Am fully against the linked article point of view.  Nobody buys an automobile, matress, shoes, a house, clothing, computer because is easier to recycle.  There is maaaany important things in spending/investing than focusing on our garbage.

    Besides, somehow, recyclers will make a profit.  Glass will be mixed in asphalt, aluminium will be reused as beer cans or something, conductors will conduct again, silicon will find a niche.

    The platonic ideal of avoiding waste is very noble, but reality is waaaay different in this case.  I could bet the article author has never had a solar panel.

     

    This is the balance to look for in the future, not the recoverable waste balance.image.jpeg.8bb09da1d5d063ea7591738cdfe41f77.jpeg

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