Carl Sagan - A few links worth perusing

The first five awe-inspiring minutes of Carl Sagan's award-winning Cosmos series.

Carl Sagan reading the now-legendary Pale Blue Dot passage from the book of the same name.

Carl Sagan on the Tonight Show hosted by John Denver, standing in for Johnny Carson; classic Carl Sagan.

The Demon Haunted World: The classic work on critical and skeptical thinking. It's a lifechanger.

Carl Sagan interviewed by Ted Turner circa 1989. This is part 1 of a 5 part series on YouTube, Carl Sagan at his best in describing our common humanity, space, the benefits of scientific literacy and the fragility of our  world. Classic Sagan - time very well spent.

Carl Sagan's Baloney Detection Kit: The classic tool for critical thinking and detecting fallacious and/or fraudulent arguments, and a lot of other resources.

Posted via email from John's posterous

Fix for iTunes Store hanging at "Accessing iTunes Store"

Just found this, hope it helps someone :)

FYI: I'm running iTunes 10.5 on Windows 7 (64 bit), but apparently this works on Mac OS too......it may be due to upgrading o 10.5 last week, but I'm not certain that's what caused it. Anyway, on to the fix!

Symptom:

when you do anything in  iTunes Store, itunes seems to hang showing "Accessing iTunes Store" in the banner.

Fix:

• Open iTunes - go to the top bar, click the 'Store' drop down menu
• Then click 'De-authorise this Computer'
• Enter your password
• Close & relaunch iTunes
• Click 'Store' again then click 'Re-authorise this Computer
• Enter password

et voila, the store should work properly again!

Source:

http://forums.macrumors.com/showthread.php?t=1113558

Posted via email from John's posterous

Paris Airshow 2011 Photos

See the full gallery on Posterous

Posted via email from John's posterous

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

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:

"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:

IARC report: http://www.iarc.fr/en/media-centre/pr/2011/pdfs/pr208_E.pdf

http://en.wikipedia.org/wiki/Microwave

http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health#Cancer

http://en.wikipedia.org/wiki/Photoelectric_effect 

A list of other items in the same "2B Possibly Carcinogenic" category:

http://en.wikipedia.org/wiki/List_of_IARC_Group_2B_carcinogens#Mixtures

PZ Meyers on the IARC report:

http://scienceblogs.com/pharyngula/2011/06/is_your_cell_phone_cooking_you.php

Phil Plait weighs in:

http://blogs.discovermagazine.com/badastronomy/2011/06/01/why-im-still-not-worried-about-my-cell-phone-hurting-my-brain/

http://scienceblog.cancerresearchuk.org/2011/05/31/who-verdict-on-mobile-phones-and-cancer/

Posted via email from John's posterous

Fukushima Vs Chernobyl - A Fair Comparison? Some Resources To Learn More

There's been a lot of fearmongering about the Fukushima incident, comparing it to (or its being "worse" than) the Chernobyl incident. Make no mistake, it is a very serious situation, and warrants careful attention. But with words like catastrophe, radiation & radioactivity being bandied about with reckless abandon, there's a lot of unnecessary anxiety out there. These words have a lot of emotional baggage attached to them, and tend to cause irrational overreaction.Time for some reason. For starters, look at this:

Sources and distribution of average radiation exposure to the world population

(Source: WHO: http://www.who.int/ionizing_radiation/env/en/)

That's a lot of natural radiation! What is radiation though? And how does it relate to radioactivity? Further below are some resources I found useful in trying to get a grip on all this. In a nutshell:

• radiation is and always has been around us;
• the danger is all about the dose received over time;
• comparisons to Chernobyl are not helpful, and even that event, the worst nuclear accident in history, doesn't appear to have had the health impact we have been led to believe it had;

The links below are a good starting point to help you learn about the differences between the Chernobyl and Fukushima incidents; hopefully you'll also find out what the following mean:

• Radiation, the different kinds and their effects on health; 
• Radioactivity, how it's measured and what is meant by "half-life".
• Radiation dose

These concepts aren't beyond anyone of average intelligence. You don't need a physics degree to get an understanding of the basics (I certainly don't have one!) but once you have a grasp of these ideas, the situation seems less frightening. And that can only be a good thing.

Links:

http://iaea.org/newscenter/news/tsunamiupdate01.html - IAEA's daily updates on the Fukushima situation:

http://resources.nei.org/documents/japan/FactSheet_Chernobyl_Fukushima_4-12-11.pdf - Comparison of Chernobyl and Fukushima incidents

http://mitnse.com/2011/04/12/new-provisional-ines-rating-a-chernobyl-primer/ - Overview of the Chernobyl incident.

http://www.who.int/mediacentre/factsheets/fs303/en/index.html - WHO followup of Chernobyl health impact

https://xkcd.com/radiation/ - a very useful diagram charting relative doses from almost none (bananas!) to fatal, short term massive doses.

http://www.mitnse.com - MIT's Nuclear Science Engineering website, chock full of useful information on nuclear physics and technology.

http://mitnse.com/2011/03/16/radiation-introduction-and-radiation-status-for-fukushima -What is radiation? A good introduction.

http://www.who.int/ionizing_radiation/en/ - WHO on ionizing radiation

http://www.who.int/ionizing_radiation/env/en/ - WHO on natural and manmade radiation

Various articles:

http://www.lvrj.com/health/experts-nuclear-fears-overblown-119678799.html?ref=799

 http://topicfire.com/share/Fukushima-Chernobyl-Rating-But-Not-Chernobyl-Bad-17236188.html

http://www.ans.org/pi/resources/myths/

 

Posted via email from John's posterous

A Thought Experiment - The Case For A Cheap, Dumb-Terminal Google Tablet

Gmail. Google Calendar. Google Documents. Google Chrome. In terms of functionality, do these sound familiar? These are the basic requirements for most modern office (home or otherwise) workers: email, calendar, word processor\spreadsheet\slideshow apps, and internet browser. What's missing? An operating system.

Of course in these days of cloud computing, an OS on a local hard disk is somewhat passé. So right now we we have our Google Accounts to keep all of the above in one place. But it's a little cumbersome. You still need a local computer with its own OS. Or do you?

Imagine a dumb terminal, a Google netbook or a future, Google tablet if you will, that connects securely to a virtual Google desktop environment. All you need is a boot process that runs a citrix-type client from a small flash drive. Kick it up, log into your Google account and you're online, in a virtual Google environment. You surf the internet using Chrome and instead of your office suite of applications you have Gmail, Google Documents, Google Calendar. You don't need to backup your device: if it gets stolen, lost or otherwise destroyed, your data is still safe online. On the downside, you need a reliable internet connection, and you don't have much control over the local device, but that hasn't stopped the iPad from selling. Maybe allow for an offline mode in more expensive models?

These could be cheap, $100 laptop-type devices that we've heard about, or they could be flashy status symbol devices like the ipad. I think trying to compete with the iPad would be a foolish move even for Google, so I'll go with the low end, low maintenance device.

Anyway, just a few thoughts on what I think Google might do in the next year to 18 months. Let's see what happens.

Posted via email from John's posterous