2022-11-03

Postcrossing (2)

Great news: The first two postcrossing postcards arrived today, one from Germany and one from Canada. 

 


The German card was franked with the German 2022 "Postcrossing" stamp (Michel 3722) of  €0.95, a new addition to my collection.

 


The Canadian card was an anniversary card for World Postcard Day 2022!

In the past five weeks I sent 8 postcards, 6 have already been received by their recipients and two are still traveling. 

 

2022-10-29

US Rail Tank Car videos

 1. Rail Tank Car 101

 


Δυο νέα βιβλία!

Στην σημερινή μου επίσκεψη στην έκθεση IPMS Hellas 2022 είχα την ευκαιρία να προμηθευτώ δυο ιστορικά βιβλία εκδόσεως 2021

 


"Υπόγειες Ναυτικές Οχυρώσεις στην Αττική (1936-1944)" του Κωνσταντίνου Κυρίμη, έκδοση Ελληνικού Ινστιτούτου Ναυτικής Ιστορίας, 2021 (χαρτόδετο, 216 σελίδες). Μια URBEX εξερεύνηση και καταγραφή των ναυτικών οχυρώσεων στην Αίγινα, Φλέβες, Ναύσταθμο Σαλαμίνος, Σ.Ν.Δ. και Υπουργείο Ναυτικών. Περιλαμβάνονται βασικές πληροφορίες για τα έργα και αναλυτική αποτύπωση των υπογείων εγκαταστάσεων.


"Οι Διαβιβάσεις στο Έπος του '40", του φίλου Χρήστου Νοταρίδη, SV0FY, Ταξιάρχου (ΔΒ) ε.α., εκδόσεις Ινφογνώμων, 2021 (χαρτόδετο, 391 σελίδες). Πολύ αναλυτική και αξιόλογη προσπάθεια για την ιστορία των Διαβιβάσεων του Ελληνικού Στρατού σαν τμήμα του όπλου του Μηχανικού, η οποία σπανίως, και μόνο αποσπασματικά, καταγράφεται στις ελληνικές ιστορικές πηγές.


2022-10-15

Greece: World Postcard Day stamps

 

 


On October 6, 2022, Hellenic Post (ELTA) issued a set of four stamps for the World Postcard Day, October 1st, 2022 in both regular and self-adhesive forms.  Although related, the stamps don't bear the Postocrossing logo. Each stamp bears no face value but is rated for "PostCards Worldwide" and its current price is €1.00 at the post offices. The stamps will be on sale until October 5, 2024.

 


2022-10-08

Postcrossing

 


Last week I decided to have a go with Postcrossing. It is an interesting project of exchaging postcards with some Internet support.

Of course I am an old timer in radio QSL cards, but this project is much different. The cost is not trivial, as sending a single card from Greece currently costs about €1.30 - €2: €1 for ELTA postage and €0.30 to €1 for the card itself.

As I am a rookie, I make mistakes related to the rules and the etiquette of the project, but I am learning fast. 

Wikipedia article: https://en.wikipedia.org/wiki/Postcrossing

 

 

According to Wikipedia, we are part the peak of postcrossing excanges, but activity is still quite strong.

 

 



2022-08-15

Heaven & Hell Thermodynamics

The temperature of Heaven can be rather accurately computed.  
Our authority is Isaiah 30:26, "Moreover, the light of the Moon 
shall be as the light of the Sun and the light of the Sun shall 
be sevenfold, as the light of seven days."  Thus Heaven receives 
from the Moon as much radiation as we do from the Sun, and in 
addition 7*7 (49) times as much as the Earth does from the Sun, 
or 50 times in all.  The light we receive from the Moon is one 
1/10,000 of the light we receive from the Sun, so we can ignore 
that... The radiation falling on Heaven will heat it to the 
point where the heat lost by radiation is just equal to the heat
received by radiation, i.e., Heaven loses 50 times as much heat
as the Earth by radiation.  Using the Stefan-Boltzmann law for
radiation, (H/E)^4 = 50, where E is the absolute temperature
of the earth (-300K), gives H as 798K (525°C).

The exact temperature of Hell cannot be computed... [However]
Revelations 21:8 says "But the fearful, and unbelieving... 
shall have their part in the lake which burneth with fire and 
brimstone."  A lake of molten brimstone means that its 
temperature must be at or below the boiling point [of 
Sulphur], 444.6°C.

We have, then, that Heaven, at 525°C is hotter than Hell at 
445°C.

                -- From "Applied Optics" vol. 11, A14, 1972

2022-08-14

Helios Airways Flight 522

 


On Sunday August 14, 2005, Helios Airways flight 522 (5B-DBY, Boeing 737-300) with incapacitated crew crashed at Attica under very unusual circumstances.   The last 10 minutes of UHF radio communications between a pair of HAF F-16 which intercepted the flight and the HAF Control Center have been available online. 


2022-02-02

Fake news about Oxygen!

 

Generating oxygen by heating the potassium chlorate mixed with a small portion of manganese oxide.
Oxygen is a very toxic gas and an extreme fire hazard.  It is fatal in
concentrations of as little as 0.000001 p.p.m.  Humans exposed to the
oxygen concentrations die within a few minutes.  Symptoms resemble very
much those of cyanide poisoning (blue face, etc.).  In higher
concentrations, e.g. 20%, the toxic effect is somewhat delayed and it
takes about 2.5 billion inhalations before death takes place.  The reason
for the delay is the difference in the mechanism of the toxic effect of
oxygen in 20% concentration.  It apparently contributes to a complex
process called aging, of which very little is known, except that it is
always fatal.

However, the main disadvantage of the 20% oxygen concentration is in the
fact it is habit forming.  The first inhalation (occurring at birth) is
sufficient to make oxygen addiction permanent.  After that, any
considerable decrease in the daily oxygen doses results in death with
symptoms resembling those of cyanide poisoning.

Oxygen is an extreme fire hazard.  All of the fires that were reported in
the continental U.S. for the period of the past 25 years were found to be
due to the presence of this gas in the atmosphere surrounding the buildings
in question.

Oxygen is especially dangerous because it is odorless, colorless and
tasteless, so that its presence can not be readily detected until it is
too late.
 

                                                    -- Chemical & Engineering News February 6, 1956