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.
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 whichionise 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 limitedamong users of wireless telephones for glioma and acoustic neuroma, and inadequateto 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.
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
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.
I got into a chat on twitter with an astrologer last week. Long story. Anyway, during the following night, one of her aquaintances sent a whole bunch of tweets as a followup to our discussion, so I thought I'd blog my response instead of a tedious twitter back and forth. Feel free to discuss in the comments! Oh, and apologies for the delay in responding, it's been a hectic few days...but then, you already know that :)
First: Check out this video, it's a classic:
Richard Feynman on what science is:
In Black below are the tweets I received overnight, in blue, my responses. I was originally going to post a single piece, but figured it would be interesting to see the original tweets also.
Science is "Flick the switch, light goes on." Faith is "I hope the Power Co. didn't cut me off - ok
I don't have to have "faith" in astrology, because it observably and repeatedly works.... who's observing, and under what conditions? If we're only taking your word for it, then I'm sorry - not good enough.
And I know there's little "scientific" evidence for it. -like.....magic, then, no?
Of course they used to pack wounds with cow dung before anyone heard of "penecillin" ...and not understanding hydrogen fusion never stop the Sun from shining.
Most skeptical arguments seem to boil down to "I haven't seen any proof that fits my worldview." -no, the view is that if there's sound evidence to support the claim, I'll change my mind AND my worldview.
In other words, Sagan's "Extraordinary proof (etc)" statement may be true, but it also mentally sets the bar pf "proof" as high as you want it to be. -it should be high. The more extraordinary the claim, the more extraordinary the proof required. If we accept astrology as valid, it means that the fundamental laws of nature as we understand them today are completely wrong. These laws have been challenged again and again, and any predictions made using them have been verified and replicated the world over.
Consider all the many, many, many studies -
about the effectiveness of antidepressants. Antidepressants are a crap shoot, but since we like
to think of the psyche as being the result of chemistry, we want to use chemistry to change it
Billions in research, and the best antidepressants can do is about 60% effectiveness -not aware of this, but I'm sure it's more complicated than a sweeping general statement like that. At a guess, I'd say efficient marketing by manufacturers, incorrect prescriptions to people that don't actually need antidepressants etc. More of a business ethics problem than a scientific one, IMHO. But then again, I don't have the whole story and I'm sure it's VERY complex.
But when I as an astrologer come up with 8 or 9 out of 10 predictions right, a skeptic starts with "The Forer Effect" or "The Barnum Effect" or the "well, that's not how planets work" argument. - these are well documented phenomena. When you say you're "right" - based on what kind of prediction? Specific like "you'll slip on the stairs at work at 2.30pm on March 23rd, but it'll be only a mild sprain) Or vague like "there'll be big changes in 2011" , ie Barnum-type cold-readings? Who decides you're right, you or the client? Under what conditions?
We've stopped throwing virgins into volcanoes, yet the "superstition" of astrology persists. Now that just couldn't be because maybe astrology works or something. Noooooo. :) -correct :)
Every argument I've heard against astrology can be applied to any branch of psychology. -Confusing pop psychology with clinical psychology and psychotherapy. Work by Skinner, Pavlov, and Milgram are among the best known examples of predictive, peer reviewed studies that stand up to the test of time. Psychotherapy doesn't have a lot of fans in the hard sciences as there are problems regarding falsifiability.
Do I understand the mechanism by which astrology works? Hell no. -does anyone? So why are there no astrological research university departments to discover how it works? Surely uncovering the mechanism of astrology, if there is one, would be a monumental discovery. Einstein, Newton, Feynman, Dirac, Fermi: so long, farewell. Countless Nobel prizes await the discoverers of such a mechanism. I may not understand how every part of a car works, but I can find someone who does. If I want to, I can go all the way up to the engineers that designed it using the cumulative results of centuries of scientific research.
But peasants packing wounds with cow dung weren't microbiologists either ...they just saved lives. Is that "scientific"? Well, they observed results... ...and (surprise!) found they were repeatable. No lab involved, but still "scientific." -not sure about the facts of cowdung, but the process is sound. Hypothesis, experiment, replicate. Science is not a body of knowledge, it's a process. The knowledge changes, and in fact does when new evidence contradicts previous observation. The process is to get past the human factor. Ego, error, sloppiness, and fraud can all slip in. Peer review is designed to catch this. It's not perfect (nothing involving humans is!), but in the long run it works. The fact that I'm typing this on a computer that could've run the entire Apollo Program is testament to that, as is the Apollo Program itself.
Meanwhile, billions of $ pouring into "String Theory," and many careers built on it So where are all the correct predictions made by String Theory"? Anyone...? Anyone...? -String theory is controversial even in the scientific community. It makes plausible claims but at this moment in time, they are untestable experimentally. Because of this, some physicists claim it's more like philosophy than science. I have no opinion; it's completely over my head, although I did enjoy the Elegant Universe! In the meantime, in mainstream science, astronomers have discovered planets outside our solar system (any incidence for astrology, by the way?) we've rendezvous'd with comets (how do they figure into horoscopes?), the Cassini mission has spent years studying the Saturn system, New Horizons will get to Pluto in a few years, and Messenger will get to Mercurian orbit in March of this year. In the 20th century we discovered that we live in a galaxy, one of billions, in a universe far bigger and older than any of our ancient ancestors could possibly have fathomed. We discovered that the anomalies in Mercury's orbit (precession of perihelion) was due to relativistic effects and can be explained by General Relativity. What advances has astrology made in the last century? Where are the predictions made by Astrology?
Astrology should have nothing to fear from science, any more than any other pursuit Sadly, most of the skeptics I hear seem to use the "scientific worldview" as the club
they use to dismiss anything that doesn't suit their preconceptions. In other words, they Make Science their Dogma, and (paradoxically) become as benighted as those they like to feel superior to. No surprise, really: skeptics are humans too. Humans do that.
But if Science is a controlled, logical search for the truth, I like to think it DOES
apply to Astrology. It *should*. It's just that I rarely if ever see it applied.
This "scientific worldview" that you seem to lament created the world we live in today. The computers we work on, the cars we drive, the medicine we take, the clothes we wear, our telephones, food, longevity. It's true that some skeptics get on their high horses about views inconsistent with science. I know, I'm sometimes one of them. But the scientific method has gotten humanity this far. It's improved our lives (at least in first world countries; geopolitics is another matter altogether) immeasurably in the last century. Imagine our great-grandparents hearing of today's world: mother and child will most likely survive childbirth; all of your children will most likely live to adulthood. You'll most likely live to at least your mid-seventies. We can speak with anyone, anywhere in the world instantaneously. We can get anywhere in the world within 2 days. The body of knowledge we call science changes regularly as new discoveries overturn old ones. The "scientific worldview" means that if you present me with evidence for a claim, I'll listen to it and I'll sincerely evaluate it. If it's convincing, then I'll change my mind. Simple as that.
I first saw this on @ProfBrianCox 's "Wonders of the Solar System" and it blew me away. We see sunsets all the time on Earth, but to see one from the surface of another world is simply stunning.
This is Mercury. That little bright light you sometimes see in the sky, low on the horizon in early morning or late evening. It's a real place. And we humans sent a spacecraft, MESSENGER, out there and it sent back this picture among others.
It never ceases to amaze me that we can do this. Simply spectacular.
So, the solar cycle will reach its maximum in 2013.
I'm betting that when 2012 comes and goes without the end of the world, there'll be solar maximum hysteria right on its coattails. It may even start before then, but it's coming. You saw it here first :)
That's not to say there aren't potential problems. Heightened solar activity such as increased flares and CMEs can wreak havoc on satellites and unprotected electrical grids on Earth. Steps can and should be taken to mitigate these risks. Spacecraft such as SOHO, SDO, GOES, STEREO as well as the the venerable ACE are studing the sun and the space weather environment and can give us advanced warning of increased activity. Check out the links below for more information on solar science and space weather.
Ok, so it's Tuesday, I know.....but this is an astronomical miscellania, so doesn't really count as Miscellaneous Monday!
Herschel images of Rosetta nebula stellar nursery:
Spectacular image from the Herschel observatory. I find this absolutely stunning. Stars are being born. That alone is worth a pause. Think about it. Stars. Being. Born. Excuse the anthropomorphism, but these events are where EVERYTHING comes from. I wrote a post about this a while back: http://jmahony.posterous.com/twinkle-twinkle-little-star-9Huge clouds of matter have collapsed gravitationally and the pressure induced is such that nuclear fusion has initiated in the core. We know how this happens, and can describe it mathematically. To see actually in progress is evidence that SCIENCE ACTUALLY WORKS! More info here: http://tinyurl.com/ychg76k Supermassive Black Hole in Centaurus A :
This is an amazing composite image, in various wavelengths (x-ray, visible and submillimetre), of the Centaurus A galaxy, which has a supermassive black hole at its centre. This shows the extent of this black hole's influence. A jet of X-ray radiation (represented as blue) extends -get this- 13000 light years from its source; the material contained in it seems to be travelling at about half the speed of light! It's absolutely mindblowing. That something this powerful can even exist really should put us in our place, but of course it's far away (about 11 million light years) and not a threat so, ho-hum, few are impressed. But I am.
If you're interested in destruction in and from space, you could do a lot worse than picking up a copy of Phil Plait's "Death from the Skies". It came in the annual book-orgy that is my Christmas list and it's really excellent, highly recommended.
Today I saw something wonderful. Yes, the biggest scientific experiment in history kicked off, but that's not what I'm talking about. Not directly anyway.
Nope. Today science became cool. At least for a short while.
A lot of us already know that. But for CERN and LHC to be trending on Twitter, that's outreach. A lot of people out there like science, but for some reason the general consensus is that it's boring. But science can be exciting. All you had to do is watch the reactions of people on Twitter as the beams ramped up, the excitement was palpable. And when it reach 3.5 TeV, and collisions started, it just exploded
Let's face it. Science is popular. There appears to be a significant geek vote worldwide.
I just hope that those with clout will sit up and take notice.
Someone posted this on Facebook recently, and I just had to share it. Carl Sagan is one of my all-time heroes and this is a real joy, as Denver says in the interview. It seems to take place shortly after the Voyager missions launched and a little while after the Viking mission to Mars.They also discuss the "recent" launch of the space shuttle Enterprise so that would put it around early 1978ish, methinks. This is Carl Sagan at his best. Eloquent, authoritative, but never condescending.
Who is there today that even approaches his enthusiasm for communicating science, as well as his ability to convey complex ideas to a non-scientific general audience? I can only think of one person, maybe two, who give me that same thrill. The first is Dr. Caroline Porco. When you hear her speak, she conveys that same delight and awe in exploring the universe as Dr. Sagan did. Check out her TED talks on the Cassini mission to see what I'm talking about. The second, although this is based solely on the trailer to "Wonders Of the Solar System", is Professor Brian Cox of the University of Manchester. My first reaction to the trailer: this is Cosmos 2010! It really got my geeky juices flowing, and I just can't wait to see it! You can follow Dr. Porco and Professor Cox on Twitter: @carolineporco @ProfBrianCox I highly recommend them.
Carl Sagan was a prolific writer, but two of his books in particular stand out. Cosmos, and The Demon Haunted World.
The Demon Haunted World is a classic in critical thinking. It tackles everything woo-related from alien abductions to ghosts to the afterlife, all the while pointing out that while an open mind is a good thing to have, extraordinary claims require extraordinary evidence. It was the first book of its type I had ever read, and it's safe to say it profoundly changed the way I view the world.
Cosmos is simply amazing. And the television series is an absolute jewel. If you haven't seen it yet, what are you waiting for? Even 30 years later, it still holds up. And for rewatch vallue, you just can't beat it.
There is a photograph of Earth taken by Voyager 1 as seen from 4 billion miles away (can't you just hear that explosive Sagan "B"!) that has become iconic. Here is Carl himself reading the passage he wrote describing it, taken from his book "The Pale Blue Dot":
Now tell me science has no soul!
Carl Sagan died in 1996 following a long struggle with myelodysplasia at the relatively young age of 62. Such a loss to humanity, but he left us such a legacy. I wonder what he would have accomplished were he still with us?
One thing is for sure: he would never have bored us.
There was a news story during the week about a cruise ship off the coast of Spain getting damaged by an unusually powerful wave, killing two passengers and injuring another. Great piece from Wired about how these waves can form.
A supernova that lasted an unprecedented 555 days, SN2007bi, appears to have been caused by a star that technically should not exist....today. The monster that led to this supernova ought to have been more than 300 solar masses, but this seems to contradict current theories, backed by observational data. A protostellar cloud would gravitationally collapse to form a star at 150 solar masses or less, and would never get even close to 300 solar masses. Stars this large just can't form.
However, that's in todays universe.
Back in the early days, when the universe was less than a few hundred million years old, the universe consisted only of hydrogen, helium and a little lithium which were forged in the first three furious minutes following the Big Bang. Heavier elements had not yet been formed as the universe cooled too quickly after the Big Bang to continue building elements, and the stars that would eventually synthesise them didn't yet exist. Huge amounts of these light elements had to come together before reaching the critical mass necessary for gravitational collapse that leads to stellar ignition, hence the truly enormous mass of these early stars. These first stars burned quickly (quickly for stars, ie a few million years) and brightly before exhausting their reserves of hydrogen and exploding in supernovae, creating heavier elements and sending them out into the universe, in the process reducing and eventually killing off any possibility of these types of stars from forming in the future. But why did it it burn so long? A hypothetical "pair-instability"-type supernova occurrs in stars this big. Hypothetical because it wasn't believed that stars this big could exist.
So how could stars this big exist today?
This supernova was seen in a dwarf galaxy 1.6 billion light years away, too nearby to be from the early universe. From observations, these dwarf galaxies seem to have significantly less of the heavier-than-lithium elements than they should have for their size. The implication here is that these dwarf galaxies may in fact be leftover "islands" of the early universe! The low mass could explain why they never accumulated to form fully sized galaxies.
This is why I love cosmology. The timescales, the distances and the concepts are so awesome, the processes so ferociously elegant....it's humbling to think that a complex glob of carbon compounds on a rock orbiting a yellow star in an insignificant galaxy can even exist to contemplate such things.
The Solar Dynamics Observatory launched today from Cape Canaveral Air Force Station. It will study the sun's activity in order to predict, amongst other things, solar storms that can potentially knock out terrestrial power grids. Solar flares, Coronal Mass Ejections and sunspots will lose some of their mystery as we learn a lot more about the sun over the next few years from this mission. If you've read any of my earlier posts, you'll recognise this phrase: I love it that we can do this stuff; it's soo freakin' cool!! And with Twitter, you can ask knowledgeable people about this stuff as it happens. The 21st century so rocks!
The Solar Dynamics Observatory launched today from Cape Canaveral Air Force Station. It will study the sun's activity in order to predict, amongst other things, solar storms that can potentially knock out terrestrial power grids. We'll learn a lot about the sun over the next few years from this mission. Solar flares, Coronal Mass Ejections and sunspots will lose some of their mystery! If you've read any of my earlier posts, you'll recognise this phrase: I love it that we can do this stuff, it's soo freakin' cool!! And with Twitter, you can ask knowledgeable people about this stuff as it happens. The 21st century so rocks!
Feast your eyes on beautiful Saturn. There are some heartbreakingly gorgeous images here, but be warned: you might end up staying for a while, so make sure you have adequate time! http://saturn.jpl.nasa.gov/photos/?start=1&category=1
