This is something that fascinates mainly about Romania and Ukraine, but surely is not unseen elsewhere, at least in old photographs. An insane number of wires hanging overhead, along and across every street of every village or minor town, supplying every house, every barn, every chicken coop and every dog house individually. At least in larger towns and cities they tend to bury the wires, but the chaos in the sky created this way can sometimes turn into quite a spectacle. What is the greatest mess you've seen in this regard?

The recent story of the nurse having sex with a COVID patient made me wonder: If two people in full PPE had intercourse - removing just enough PPE for the act - would that act be a vector for transferring COVID? Everything I’ve read about focuses on transmission vis the eyes, nose, or throat.

(This is just a hypothetical because I’m curious, I’m not planning on trying it 😅)

I'm taking a CCNA course, and my professor explains that all kinds of wireless networks travel through the air. I'm a telecom engineer and know that electromagnetic waves don't need a physical medium to propagate (example: Space communications). And he is also a professor at my university, he teaches a course called "wireless networks".

I'm kinda shocked! or I'm being really stupid and shouldn't be a telecom engineer. but a person like that shouldn't be the course professor for a CCNA certification.

The setup is very basic: A tank with a drainage pipe that runs at a decline for a while and then releases its contents into the blades of a turbine.

The turbine can be made to suit the type of fluid, but the tank and pipe dimensions must be the same for any fluid.

What I want from the fluid:

1. Safe to touch. No extreme hazards like crazy flammability, explosiveness, etc.

2. Inexpensive

3. Lower evaporation rate than water at 40-115° F. The fluid will be exposed to the air.

4. Equal or better power generation than water

What do you guys recommend?

Hi all,

Currently struggling to understand how different line codes (such as unipolar, Manchester, NRZ etc.) relate to the transmission medium used for the data. I know the Manchester encoding is used mainly in IEEE 802.3 Ethernet, but I don't know why. I have the same problem for other line codes. I can't seem to find a good source anywhere, I would appreciate it if someone could point me in the right direction.

Thanks in advance.

Not a sound engineer in the slightest, only know a little about the doppler effect, and am trying to find a mechanism between two mediums that produces the loudest sound and to harness said mechanism

In preparation for a shopping centre redevelopment the local power company buried about 200 meters of an overhead power line. At either end of the buried section there is a power pole that looks like something that was destined to be the leg of an offshore drilling platform. They spent several weeks digging the foundation and putting in a concrete platform. In contrast, the other power poles in the series are just the normal looking wooden type that you would find running through a residential street. https://imgur.com/a/b7H12 https://imgur.com/2XeTw8b

I would like a ~50kV powerline that isn't wooden.

As title said, we're looking for Wireless Video transitters/reciever suggestions, we just got a new projector which hangs in the ceiling, the screen/wall and tables are probably 10-15m from the Projector and we're looking to ditch the cable.

So if we have a wave on a string of varying linear density traveling from a lower density to a higher density section of the string, the speed of the wave's propagation slows down and its wavelength shortens (assuming the frequency remains the same). It sort of makes sense why the frequency doesn't change, since the driver is not changing its frequency.But, if the speed of the wave's propagation slows down due to going through a denser medium, why wouldn't the frequency be affected by the medium? Isn't frequency just the speed of the individual points on the string moving up and down? So shouldn't they also slow down if they are now moving up and down in a denser medium? And then the amplitude changes?

Hi, I'm currently researching the possibility of using an Arduino as part of a first year university project whereby readings from some sensors could be managed by an Arduino and then transmitted over a medium distance at 433MHz to either another Arduino or a laptop. From there it would be uploaded to an online database.

Looking online I've come across lots of shorter range transmitters/receivers (>100ms) but I've had a harder time finding longer ranges (especially at the required 433MHz).

The receiving device could be a laptop or another Arduino - whatever is easiest. Using 3G/GPRS is not at option as the idea of the project is to apply this rural outdoor areas with poor satellite coverage.

As far as boards themselves go the Leonardo seems to fit my needs but any suggestion there would be welcome. Thanks in advance, if there is something extremely obvious I am missing here please say as I am very inexperienced!

I have a pretty good understanding that when polarized light is incident on a surface it will change handedness (Right handed polarization, to left handed polarization for example) and remains will remain circular if it is incident at an angle less than the Brewster angle, otherwise it will retain its handedness but become elliptically polarized.

But what happens to the transmitted wave? How does it's handedness change? Can it ever remain circular? What happens at normal incidence?

New cases in the last 24 hours:

• 77 new locally acquired cases:
  • Of these locally acquired cases, 55 are linked to a known case or cluster – 39 are household contacts and 16 are close contacts – and the source of infection for 22 cases remains under investigation.
  • Thirty-two cases were in isolation throughout their infectious period and nine cases were in isolation for part of their infectious period.
  • Thirty-three cases were infectious in the community, and three cases remain under investigation.
• 1 death
  • Sadly, a woman in her 90s from south west Sydney died yesterday at Liverpool Hospital. She was a close contact of a locally acquired case and was tested for COVID-19 on Friday, returning a positive result early yesterday morning. It is understood she was not vaccinated.

All of greater Sydney has been issued an extension to the stay-at-home order until Friday midnight, 16 July.

• The following reasons allow you to leave your home: shopping for food and essential goods, medical care or compassionate needs, outdoor exercise, essential work or education when you cannot work or study from home
• For rules, please see here: https://www.nsw.gov.au/covid-19/rules/greater-sydney

COVID-19 restrictions tightened across Greater Sydney

Given the growing number of infectious cases in the community and unlinked cases of community transmission, COVID-19 restrictions will be tightened across Greater Sydney including the Central Coast, Blue Mountains, Wollongong and Shellharbour.

The following additional restrictions are in place from 5pm Friday the 9th July:

• Outdoor public gatherings limited to two people (excluding members of the same household);
• People must stay in their Local Government Area or within 10kms of home for exercise and outdoor recreation, with no carpooling between non-household members;
• Browsing in shops is prohibited, plus only one person per household, per day may leave the home for shopping;
• Funerals limited to ten people in total.

The four reasons to leave your home remain in place:

• Shopping for food or other essential goods and services (one person only);
• Medical care or compassionate needs (only one visitor can enter

New cases in the last 24 hours:

• 50 new locally acquired cases:
  • 26 of those cases were infectious in the community, 13 cases were in isolation throughout their infectious period. 11 cases were in isolation for part of their infectious period.
  • 37 are linked to a known case or cluster – 14 are household contacts and 23 are close contacts – and the source of infection for 13 cases remains under investigation.
  • Of those currently in ICU, one is in their teens, one is in their 20s, one is in their 30s, one is in their 40s, three are in their 50s, six are in their 60s, two are in their 70s and one is in their 80s.
  • Of the 47 COVID-19 cases admitted to hospital, 79 per cent are unvaccinated.

All of greater Sydney has been issued an extension to the stay-at-home order until Friday midnight, 16 July.

• The following reasons allow you to leave your home: shopping for food and essential goods, medical care or compassionate needs, outdoor exercise, essential work or education when you cannot work or study from home
• For rules, please see here: https://www.nsw.gov.au/covid-19/rules/greater-sydney

COVID-19 restrictions tightened across Greater Sydney

Given the growing number of infectious cases in the community and unlinked cases of community transmission, COVID-19 restrictions will be tightened across Greater Sydney including the Central Coast, Blue Mountains, Wollongong and Shellharbour.

The following additional restrictions are in place from 5pm yesterday:

• Outdoor public gatherings limited to two people (excluding members of the same household);
• People must stay in their Local Government Area or within 10kms of home for exercise and outdoor recreation, with no carpooling between non-household members;
• Browsing in shops is prohibited, plus only one person per household, per day may leave the home for shopping;
• Funerals limited to ten people in total (this will take effect from Sunday, 11 July).

The four reasons to leave your home remain in place:

• Shopping for food or other essential goods and services (one person only);
• Medical care or compassionate needs (only one visitor can enter another residence to fulfil carers’ responsibilities or provide care or assistance, or for compassionate reasons);
• Exercise with no more than 2 (unless members of the same househ