Happy Birthday Heinrich Hertz

Happy Birthday Heinrich Hertz

February 22, 1857 – January 1, 1894

A pioneer of radio signals and as a consequence the future of radio, all that is possible for wireless originates from the early discovery made by Heinrich Rudolf Hertz (http://en.wikipedia.org/wiki/Heinrich_Hertz) in proving the existence of radio waves. His pioneering works made reality that which was theorised of James Clerk Maxwell (http://en.wikipedia.org/wiki/James_Clerk_Maxwell) discoveries, commonly referred to as Maxwell's Equations how electric charges and electric currents act as sources for the electric and magnetic fields by defining a series of equations for electromagnetism. In science lessons, apart from being reminded that radio waves are analogue in nature, sometimes lecturers may visually demonstrate the forces of electric and magnetic fields using the hand reference: thumb, index finger and middle finger. The thumb represents a active 'source', the index finger represents 'electric field' and the middle finger represents 'magnetic field' at right angles to the electric field.

Hertz demonstrated the existence of radio waves in experiements using two rods that served as a receiver and also a spark gap as the receiving antennae, so that where radio waves were detected a spark would jump, demonstrating radio signals possessed the properties of electromagnetic waves. Moreover, his work is attributed to identifying that radio waves have (i) a 'time' factor and (ii) that the velocity of radio waves was equal to the velocity of light.  Hertz experiements revealed to him how to separate (thus detach) electric and magentic fields from wires and roam in free space; or as Maxwell is attributed to have put it the 'ethereal wind'. 

Hertz
The unit of frequency of a radio wave is referenced as 'one cycle per second' and is named the 'hertz'.

Digital Signalling Background
http://trewmte.blogspot.com/2009/01/mobile-forensics-and-evidence-degrees.html

US Case: Daubert and Cell Site Analysis Maps

US Case: Daubert and Cell Site Analysis Maps

I having been an advocate, as many of you know, for many years for the use in evidence of network operator generated analogue and digital cellular radio maps (eg best server plots/density maps & single cell prediction plots/density maps). That is because they are a composite compiled from collection of visible and discrete detail relevant to the operator's predication. They illustrate, if you will, a visual demonstration of a radio coverage strategy in an area. A recent US Case dealt with cell site maps as part of the evidence. The case of the US v Benford discussed by Law Professor Susan Brenner, at her webblog, makes interesting reading indeed:

http://cyb3rcrim3.blogspot.com/2010/08/daubert-and-cell-site-data.html

There are examples of cell site maps here at Mobile Telephone Evidence (link below):

http://trewmte.blogspot.com/2009/08/cell-site-analysis-csa-images.html

US Case: Daubert and Cell Site Analysis Maps

US Case: Daubert and Cell Site Analysis Maps

I having been an advocate, as many of you know, for many years for the use in evidence of network operator generated analogue and digital cellular radio maps (eg best server plots/density maps & single cell prediction plots/density maps). That is because they are a composite compiled from collection of visible and discrete detail relevant to the operator's predication. They illustrate, if you will, a visual demonstration of a radio coverage strategy in an area. A recent US Case dealt with cell site maps as part of the evidence. The case of the US v Benford discussed by Law Professor Susan Brenner, at her webblog, makes interesting reading indeed:

http://cyb3rcrim3.blogspot.com/2010/08/daubert-and-cell-site-data.html

There are examples of cell site maps here at Mobile Telephone Evidence (link below):

http://trewmte.blogspot.com/2009/08/cell-site-analysis-csa-images.html

More on Cell Site Analysis: http://cellsiteanalysis.blogspot.com

Cellphone starts Gas Stove

Cellphone starts Gas Stove

The New York Times has just published a great news story 21st August 2009 titled 'Hello, Oven? It’s Phone. Now Let’s Get Cooking!' Apparently, a New Yorker's cellphone keeps switching on the Gas Stove with worrying consequences. Updated the link below.

http://www.nytimes.com/2009/08/23/nyregion/23about.html?_r=1&scp=1&sq=cellphone%20starts%20Gas%20Stove&st=cse#

From a technical point of view, Radio and EMI folks will love this story.

UPDATED COMMENTS:

Naturally reading news articles like these, this one is reported in the respected New York Times, they are still often taken with a certain amount of scepticism and caution. The implication of this could be huge, not for sensations sake, but it opens up the doors to those who already have concerns about radio signal saturation.

There are, to put it conservatively, many many millions of mobile phones used everyday around the World. In the UK with a burgeoning population creaking up to 61-million, mobile phone numbers still out-number the population at minimum 2:1. And to create 1-billion texts a month (that's without voice calls/data calls) in UK networks, clearly lots of mobile phones are switched ON and in use.

The underlying concern with this story is that which device will be found to be the culprit (if at all):

- will it be the handset generating spurious emissions causing interference at a particular n-Hz level to unprotected circuitry

- will it be the electronic circuitry on the Gas Stove having poor EMC (electro-magntic compatibility) protection allowing conducted interference

or

- will it be both

It is not clear what will be the outcome of this matter, it may just fizzle out, but if not then this little story could have an impact on the World than even the "radiating us to death" protestors have hitherto made.

The implications could be wide spread, should the findings unearth the conclusion of random occurences of this type of event, because it opens the door to many other possibilities with possible horrible consequences:

- Scenario 1: My house burnt down because the mobile phone ignited the oven/stove without my knowledge

- Scenario 2: There was no trace of an accelerant, save to say, we found an appliance that had started the fire and we cannot rule out that it wasn't a mobile telephone that caused the appliance to ignite it

- Scenario 3: Two bodies were found in a house with no traces of attack or arson, the authorities are puzzled

So the potential for the unforeseen disaster perhaps shouldn't be ruled out, at this stage, but it would be useful to have the exact findings and conclusions published.

In the meantime I wont be having my mobile telephone left switched ON in MY trouser pocket.

Happy Birthday Hans Christian Ørsted (Oersted)

Happy Birthday Hans Christian Ørsted (Oersted)

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Hans Christian Ørsted, one of the leading scientists of the nineteenth century, played a crucial role in understanding electromagnetism. In 1820 he discovered that a compass needle deflects from magnetic north when an electric current is switched on or off in a nearby wire. This showed that electricity and magnetism were related phenomena, a finding that laid the foundation for the theory of electromagnetism and for the research that later created such technologies as radio, television and fiber optics. The unit of magnetic field strength was named the Oersted in his honour.

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http://chem.ch.huji.ac.il/history/oersted.htm

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James Clerk Maxwell

Would Ørsted's work have influenced James Clerk Maxwell? To research here are a few links that records Maxwell's published works and other historical events:

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www.clerkmaxwellfoundation.org/PUBLISHED_SCIENTIFIC_PAPERS.pdf

http://www.phy.cam.ac.uk/library/libraryfiles/clerkmaxcoll.pdf

http://simple.wikipedia.org/wiki/James_Clerk_Maxwell

http://simple.wikipedia.org/wiki/Electromagnetism

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Relevance: these matters all relate to the fundamental building blocks of radio signals, not forgetting, of course, that although we operate today in a digital radio society the waveform of radio signals are still analogue by nature. It is the adopted modulation schemes that define the important information we know that hides and is transported inside the radio signals - data.