Sunday, June 26, 2011

Paris Airshow 2011 Photos

Afterburners, Giant Airliners And......Sunburn: A Day At The Paris Airshow

It's been six years since I last went to the Paris Airshow, so when France24 announced on Twitter that they were giving tickets in exchange for tweets, I was in like flynn. And so it was on a sunny Friday morning I find myself on the RER B heading out to Le Bourget. Not too crowded, but still there was a 45 minute wait for the free shuttle to the airport.....I remembered it as not being too far a walk and arrived at the entrance in about 20 minutes. After checking in on Foursquare (of course) I pull out my camera and away we go. First stop: Ariane 5,  dominating the Le Bourget skyline. I took a couple of snaps of the engines for old times sake (I have tons from previous visits, but why not?). Then off to see the Americans. A little light this year - no Navy or Army aircraft, but the Air force F15E, F16, C130, C5, C17 and Marine Corps AH1Z and UH1Y still made for nice viewing. I had an interesting talk with a Marine Corps mechanic who told me that the AH1Z is brand new; declared combat-ready only in September 2010 and hasn't yet been on the ground. Interestingly, both the AH1Z and UH1Y share 84% of the same components making maintenance a lot easier. The mechanic also said (in true jarhead style) that the Army's AH-64 Apaches have a big problem with launching Sidewinders but, ahem, the Marine Corps AH1Z has no such issues.....Semper Fi :)

I dropped in to the ESA exhibit before the flight demos and saw a presentation on the joint ESA-NASA Cassini-Huygens mission (incidentally, it's still ongoing, click here for more info). The speaker paraphrased Carl Sagan's Pale Blue Dot when talking about this photo of Earth through the rings of Saturn ; The video on the Huygens probe landing on Titan was wonderful.

And after spending what seemed like an hour trying to get a sandwich at the Paul stand (more like 15 minutes, but still) it's flight time!!

I can't hep but let slip a big goofy grin when I hear screaming jet engines and see full afterburners flaming......yep: military high performance jets. In the air today was the Dassult Rafale, the Eurofighter Typhoon and the Lockheed Martin F16. Even after seeing lots of this, I'm still blown away when I see 30-40 tonnes of metal flitting around the sky like a bat.....awesome.

The French Air Force display team, La Patrouille de France, put on a beautiful display, as alway. 

There was an interesting demo by a Russian Altair amphibious aircraft configured as a firefighter - pretty cool to see it dumping twelve tonnes of water in two seconds!

And then there's the A380 - the biggest commercial airliner in service today. I saw its first public display flight here 6 years ago and it's still a wonder to watch in the air....just goes to show that airliners can put up with a LOT more than their daily grind. It's simply amazing to see it float around like a bubble in the small airspace available above Le Bourget for displays, a testament to both the engineering skills required to build it and the skills of the display pilots.

All in all: I took a truckload of photos (some of which can be viewed here), got a dose of howling jet engines and a little sunburned - a great day :)


Posted via email from John's posterous

Friday, June 3, 2011

Why I'm Not Concerned About Cell Phone Radiation

The International Agency for Research on Cancer (IARC), a part of the World Health Organisation (WHO), recently published a report warning that there might be an elevated risk of certain types of brain tumour in heavy cell phone users. I was surprised to say the least, given that I've previously referenced the WHO as an authority when the swine flu vaccine scaremongering was at its peak a couple of years back. Personally, I'm pretty confident that my cell phone isn't going to kill me unless I walk under a bus while tweeting. Let me explain, using a little biology, physics and common sense.
Cancers happen when an otherwise healthy cell is reprogrammed by a genetic mutation to behave as a cancerous cell. This mutation can occur either by chemical interaction or by EM radiation. The effecting agent is described as a mutagenic agent. EM radiation does this by dislodging electrons in a chromosome which ionise the molecule, allowing it to accept other atoms or molecules which in turn induce a mutation in the chromosome, sometimes leading to cancer. In this case, the effecting agent is described as a carcinogenic agent. (Note: These mutation mechanisms have been around since life first arose on Earth and are fundamental to evolution; they are NOT a result of our technology running amok.)
The IARC claim is that there is a link between cellphone radiation and two types of brain cancer. For this to happen, cellphone radiation would need to be able to ionise the DNA molecule in order to introduce a mutation. This requires a certain amount of energy that cellphone radiation simply doesn't carry. It is non-ionising radiation. To understand more about this, let's take a look at what we mean when we talk about electromagnetic radiation. Below is the electromagnetic spectrum, the range of electromagnetic radiation from longwave radio through visible light all the way up to gamma rays, increasing in energy from right to left. As the frequency of the light increases, the energy it carries also increases.  

How do we know this? (Bear with me here, we'll get to cellphones shortly!) Albert Einstein won a Nobel Prize for discovering the Photoelectric Effect which, essentially, says that light above a certain frequency falling on a metal induces a current. This happens because the energy in the light's photons is sufficient to cause electrons in the metal to move. He showed that red light won't induce a current, but blue light will. Max Planck later found a relationship between the frequency of light and the energy of its photons. As we can see above, red light has a frequency of 700nm (7*10^ -7m), blue light 400nm (4*10^ -7m). It's clear from Planck's discovery that blue light is more energetic than red.  
Now, back to cellphones. Where does this radiation figure on the spectrum? Look at where red light is on the spectrum. Go below it, you find Infra-red, then below it again you find the microwave region,  a range of wavelengths from as long as one meter to as short as one millimeter, or equivalently, with frequencies between 300 MHz (0.3 GHz) and 300 GHz. Cellphones typically operate in the low end of the microwave region, overlapping with the high end of UHF radio frequencies, usually below 2Ghz. Obviously, this is well below the level of ionising radiation, which is beyond the UV region of the spectrum, in x-ray and gamma-ray territory. It can't be carcinogenic.
So why all the hoopla from the WHO? The IARC report states the following results:

The evidence was reviewed critically, and overall evaluated as being limited  among users of wireless telephones for glioma and acoustic neuroma, and inadequate  to draw conclusions for other types of cancers. The evidence from the occupational and environmental exposures mentioned above was similarly judged inadequate. The Working Group did not quantitate the risk; however, one study of past cell phone use (up to the year 2004), showed a 40% increased risk for gliomas in the highest category of heavy users (reported average: 30 minutes per day over a 10‐year period).

'Limited evidence of carcinogenicity': A positive association has been observed between exposure to the agent and cancer for which a causal interpretation is considered by the Working Group to be credible, but chance, bias or confounding could not be ruled out with reasonable confidence. 

'Inadequate evidence of carcinogenicity': The available studies are of insufficient quality, consistency or statistical power to permit a conclusion regarding the presence or absence of a causal association between exposure and cancer, or no data on cancer in humans are available. "

What does this mean then? A correlation has been observed, but as skeptics are fond of saying, correlation does not equal causation. It would appear the IARC are playing the "let's keep an eye on this just in case" card. As far as I'm concerned there's nothing new here. Might there be an issue? Maybe. But it's unlikely. Cellphones have been in mass consumption for over 15 years now and there doesn't appear to be any increase in brain tumours, according to studies done in several countries. I'll be here waiting for the evidence, and if it comes I'll be the first to change my mind. 

Some links:
A list of other items in the same "2B Possibly Carcinogenic" category:
PZ Meyers on the IARC report:
Phil Plait weighs in: