lens vs. image sensors in digital photgraphy

Discussion in 'Photography' started by aniramca, Dec 9, 2006.

  1. The only speculation is by those denying warming is real. The
    evidence is overwhelming that the earth is warming, and from
    multiple lines of evidence. The controversy is really what fraction
    of that warming is caused by people and what proportion of each
    cause is contributing to the total effect.
    You apparently don't understand the scientific process. It is certainly
    true that a bad paper can be published, or papers with mistakes,
    but it is also interesting to see the rapid response corrections
    and counter papers published. Scientists make their careers on
    being correct, and seem to delight in ripping someone else's
    work apart, in order to become king of the nerd hill for a while.
    It is a system that works well. Much like the back and forth
    discussions in these newsgroups, science discussions are played
    out in the scientific literature in the form of letters to the
    editor, gray literature (e.g. institution publications), peer-reviewed
    journals, and more recently web sites. Until web sites, this
    interaction took months to years in the paper publication
    process.
    There will never be conclusive proof in some people eyes.
    The question is what constitutes enough evidence to convince
    you or me, or someone else?
    This is a great example of the scientific process. Some scientists
    came out and said the earth would suffer global cooling.
    But others stepped in and analyzed more data and refined the
    models and found those scientists were wrong. That happened
    decades ago. Since then more data, more research, more refined
    models, and the answer keeps coming up the same:
    global warming is happening and we are getting refined data
    and answers to determine the causes of that warming.
    Initially, some scientists said it was all due to people.
    Others stepped in and should that was not the best answer and
    showed the sun is varying and contributing to the warming.
    (Did you know Mars' polar caps are also shrinking?).
    So the scientific process is working very well indeed.
    Decades of research are overwhelmingly point to warming.
    Evidence is becoming clearer that a portion of that warming
    is due to people. What the exact fraction is is what
    is currently being discussed the scientific literature.
    Excellent! Correct.
    This is an interesting read and raises interesting issues. But I note
    you are focusing on CO2 and as outlined in the above link, there
    are numerous sources causing the warming. Then also notice, no one
    is talking about whether warming exists or not, but the relative
    contributions of each source.

    It is also of interest to note in the above web exchange that
    there is little discussion of water vapor, the gas causing the
    most warming. It is ignored because it "is not a well mixed
    gas." Another reason is that it is so variable and there
    are no good measurements of it in the historical record. That
    makes it difficult to include in the models. Hmmm....
    Certainly if there was no sun, we would all freeze, and certainly
    the sun is the major cause of warming. The changing sun is now
    pretty well established, and is being precisely measured and
    included in models.
    "The Day After Tomorrow" was really bad in my opinion.
    The freezing thing was totally absurd.
    1) education.
    2) I do make fundamental measurements on material properties.
    A fundamental parameter in the heat balance equation is the
    albedo (reflected) of the earth's surface. For any spot
    on the earth, that albedo changes as a function of incident light.
    Climate models need to include this.
    You are over reacting. We need to change by developing better
    technologies that are less polluting. We (people in many
    nations) are doing that, but is the rate fast enough?
    For example, Europe is way ahead in developing wind farms.
    There are many technologies and are "cleaner" and cost nominally
    more. Where I live (Colorado) we voted to mandate (at increase
    taxes) a higher percentage of renewable energy, including wind
    and solar. I have solar cells now, even one on my car
    (a custom thing), and will continue to invest in that direction.
    Yes, sea level rise is increasing, yet another factor in the growing
    list of indicators of warming. The rise was about 0.15 mm/year
    for ~3000 years, then 1 to 3 mm/year since about 1900,
    and higher (3-4mm) today. (long term historical data from
    tide gages and geologic records, latest from satellites)

    Here are data from precise satellite measurements:

    http://sealevel.colorado.edu

    from 1995 to today sea level has risen about 40 mm.
    When the oil runs out, will the naysayers adapt or die out?
    Others will have converted to solar/other long before that. ;-)

    On the positive side for the photographic thread, if the solar
    flux is increasing, we'll all be able to use shorter exposure
    times. On the negative side, the higher temperatures will
    mean more thermal noise in our digital camera images.

    Roger
     
    Roger N. Clark (change username to rnclark), Dec 23, 2006
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  2. aniramca

    smb Guest

    I don't deny that the data show a warming trend. My objection is the
    politicization and overreaction before knowing exactly what is
    happening and why. Again, the earth has warmed and cooled
    considerably over the eons. There's nothing new under the sun. We
    can measure things better these days, but that's no need to go off
    half-cocked.


    Exactly. Much of what used to be considered scientific fact is
    sometimes just the product of oversized egos.


    The bigger issue is how we react to inconclusive and sometimes
    contradictory data. IMO, even if the data conclusively prove that
    the earth is in a prolonged warming cycle, I don't think there's a
    thing we can do about it short of preparing for warmer weather.


    The problem is when people like Al Gore take what is merely being
    discussed, present it to the public as fact, then push for regulations
    that will seriously harm the economic well-being of the population.

    Do I get a green Earth Day sticker for my forehead? ;-)



    Exactly. I think when all the dust settles we'll find that the Sun
    is by far the greatest contributor.
    Amen to that.

    But all the education and measurement in the world isn't going to
    change a process with planetary inertia behind it. It may make more
    people aware of it, that's all.


    That's not overreacting at all if indeed global warming is disasterous
    and it is caused by human activity. If we are really responsible for
    what is happening, merely reducing things won't do anything to reverse
    it.

    The little things you do are symbolic, that's all. Try telling the
    developing countries that they have to forego fossil fuels because
    scientists in the developed countries have decided it's bad for the
    planet. That ain't going to happen.
    And I just saw on the news that the first inhabited island was
    officially lost to rising sea levels. So this is happening. Now,
    will wind farms and hybrid cars do anything to bring that island back?
    Those who live on the coasts would do better for themselves to invest
    in some inland property rather than solar cells on their roofs.

    The conversion to alternate forms of energy will be driven by
    economics, not by people feeling they are saving the planet. When
    the oil truly starts to run out, the free enterprise system will do a
    very nice job of bringing those sources of energy to market.

    It's interesting that there are those who believe that oil is actually
    a renewable resource produced deep under the surface, and as evidence
    they point to oil fields that they thought had been running out
    mysteriously refilling. Hmmmm.....


    Yes, always look on the bright side! Me, I'm looking forward to not
    having to retire to Florida if Florida will be brought to me...


    Steve
     
    smb, Dec 24, 2006
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