Science newsScience news

Lots of it is about “gene therapy”Lots of it is about “gene therapy” Early (bad) problems:Early (bad) problems:

Results not reproducibleResults not reproducible And some deathsAnd some deaths

Recent successesRecent successes ““Curing” blindness of some kinds and to a degreeCuring” blindness of some kinds and to a degree ““Arresting” a fatal syndromeArresting” a fatal syndrome

Is there new life (one year more of funding) for Is there new life (one year more of funding) for the Tevatron?the Tevatron?

LHC is up and running (Nov. 7)!LHC is up and running (Nov. 7)!

Kuhn on “normal science”Kuhn on “normal science” You were asked to look for Kuhn’s arguments for the You were asked to look for Kuhn’s arguments for the

claims outlined in the 2claims outlined in the 2ndnd part of last lecture part of last lecture What is his argument for the claim that science follows What is his argument for the claim that science follows

the kind of trajectory he outlines (e.g., prescience to the kind of trajectory he outlines (e.g., prescience to normal science to crisis to revolution to new normal normal science to crisis to revolution to new normal science tradition, etc.)?science tradition, etc.)? This is the pattern one sees in the history of science.This is the pattern one sees in the history of science.

What is his argument for the claim that, in normal What is his argument for the claim that, in normal science, the paradigm that underwrites all research is science, the paradigm that underwrites all research is never questioned for a long period of time, despite never questioned for a long period of time, despite anomalies?anomalies? Study, again, of the history and some contemporary examples Study, again, of the history and some contemporary examples

of scienceof science

Kuhn on “normal science”Kuhn on “normal science”

What is his argument for the claim that normal science involves What is his argument for the claim that normal science involves lots of puzzle solving?lots of puzzle solving? His own experience as a scientist and his study of scientific practiceHis own experience as a scientist and his study of scientific practice

What is his argument for the claim that normal science is more What is his argument for the claim that normal science is more fruitful and more scientific than prescience? fruitful and more scientific than prescience? That because there isn’t debate over fundamentals, detailed research can That because there isn’t debate over fundamentals, detailed research can

precede.precede. What is his account of a paradigm?What is his account of a paradigm?

Consider the Leyden jar – a deviceConsider the Leyden jar – a device Consider the heliocentric model… natural selection… Consider the heliocentric model… natural selection…

hypotheses…hypotheses… All “thin” but otherwise somewhat differentAll “thin” but otherwise somewhat different

Scientific ExplanationScientific Explanation

Hempel: The DN model of scientific explanationHempel: The DN model of scientific explanation Deductive (in the case of deterministic laws)Deductive (in the case of deterministic laws) Nomological (theory involving laws)Nomological (theory involving laws)

E (that to be explained):E (that to be explained): ““Uh, oh. My radiator fluid froze last night.”Uh, oh. My radiator fluid froze last night.”

L (relevant law or laws):L (relevant law or laws): Relatively pure water freezes at 32Relatively pure water freezes at 32° F° F

C (relevant initial conditions)C (relevant initial conditions) The temperature was 30 The temperature was 30 ° F for 8 hours last night° F for 8 hours last night

Scientific ExplanationScientific Explanation

Also works as a model of prediction…Also works as a model of prediction… E (that predicted):E (that predicted):

““Uh, oh. My radiator fluid Uh, oh. My radiator fluid willwill freeze tonight unless I freeze tonight unless I add anti-freeze to it.”add anti-freeze to it.”

L (relevant law or laws):L (relevant law or laws): Relatively pure water freezes at 32Relatively pure water freezes at 32° F° F

C (relevant initial conditions)C (relevant initial conditions) The temperature is predicted to be 30 The temperature is predicted to be 30 ° F for 8 ° F for 8

hours tonighthours tonight

Scientific ExplanationScientific Explanation

Hempel: Explanation is a formal (logical) Hempel: Explanation is a formal (logical) relationship between kinds of statements – some relationship between kinds of statements – some reporting what is observed, others theoretical reporting what is observed, others theoretical (carrying forward the empiricist tradition)(carrying forward the empiricist tradition)

Some sciences (e.g., fields in biology) don’t Some sciences (e.g., fields in biology) don’t include deterministic laws, but only statistical include deterministic laws, but only statistical generalizationsgeneralizations

Here the reasoning is inductive and the Here the reasoning is inductive and the conclusions (explanations and predictions) only conclusions (explanations and predictions) only probableprobable

Scientific ExplanationScientific Explanation Hempel: Explanation is a formal relationshipHempel: Explanation is a formal relationship It involves (typical of empiricists in the mid to late-ish It involves (typical of empiricists in the mid to late-ish

1990s) 1990s) empiricalempirical data/observations/facts and data/observations/facts and logical logical reasoningreasoning (in the case of deterministic laws, the (in the case of deterministic laws, the reasoning is deductively valid).reasoning is deductively valid).

The model:The model:1.1. LL11, L, L22 … L … Lnn

2.2. CC11, C, C22 … C … Cnn

------------------------------------------EE

Scientific ExplanationScientific ExplanationEvolution and medicine: How does HIV replicate in a Evolution and medicine: How does HIV replicate in a

way that challenges all anti-viral?way that challenges all anti-viral? HIV virus: RNA-based retrovirusHIV virus: RNA-based retrovirus Replicates at a fast rateReplicates at a fast rate Low copying fecundityLow copying fecundity So lots of mutationsSo lots of mutations

If all of the various “cocktails” stop working for a If all of the various “cocktails” stop working for a patient with HIV, frequently he or she and their patient with HIV, frequently he or she and their doctor will gamble:doctor will gamble:Take the patient off all medications so that the “wild Take the patient off all medications so that the “wild type” re-emerges and blast it with meds that once type” re-emerges and blast it with meds that once worked.worked.

Scientific ExplanationScientific ExplanationEvolution and medicine: How does HIV replicate in Evolution and medicine: How does HIV replicate in

a way that challenges all anti-viral drugs?a way that challenges all anti-viral drugs?What is being assumed?What is being assumed?

Natural selectionNatural selectionHigh mutation rateHigh mutation rateHow to counter the mutations (let the wild type How to counter the mutations (let the wild type become normal)become normal)

van Fraassen’s accountvan Fraassen’s account Answers to a question such as “why sex?” will Answers to a question such as “why sex?” will

greatly vary depending on context (religious vs. greatly vary depending on context (religious vs. scientific, and within different scientific epochs)scientific, and within different scientific epochs)

Plato, Aristotle, and Aquinas: why are there females at Plato, Aristotle, and Aquinas: why are there females at all? Why didn’t (obviously superior to females) males all? Why didn’t (obviously superior to females) males just “clone” or reproduce among themselves?just “clone” or reproduce among themselves?

In other cultures, sex is regarded as natural and In other cultures, sex is regarded as natural and divinely blesseddivinely blessed

In some contemporary settings, sex may be necessary In some contemporary settings, sex may be necessary and need to be regulated, but it is far less “spiritual” and need to be regulated, but it is far less “spiritual” than celibacy…than celibacy…

van Fraassen’s accountvan Fraassen’s account Explanation is not a formal relationship (defined in Explanation is not a formal relationship (defined in

terms of logical relationships between a law-like terms of logical relationships between a law-like statement and a statement about some phenomenonstatement and a statement about some phenomenon

Many scientists and philosophers now see Many scientists and philosophers now see “understanding’ rather than explanation and “understanding’ rather than explanation and prediction as the primary goal of scienceprediction as the primary goal of science

Explanation in science is a Explanation in science is a pragmatic relationship – pragmatic relationship – context and practice dependentcontext and practice dependent::

““Why” questions are asked, and regarded as Why” questions are asked, and regarded as answered, within specific scientific contextsanswered, within specific scientific contexts

To understand them (and what will count as an To understand them (and what will count as an answer) requires knowledge of the scientific answer) requires knowledge of the scientific context within which they are asked.context within which they are asked.

Scientific ExplanationScientific Explanation Why sex?Why sex?

It is expensive in lots of ways…It is expensive in lots of ways… But it allows for diversity of one’s offspring which But it allows for diversity of one’s offspring which

might protect them in terms of new challenges (new might protect them in terms of new challenges (new pathogens, other environmental changes, etc.)pathogens, other environmental changes, etc.)

The Red Queen hypothesis…The Red Queen hypothesis… Not an explanation of how sex initially evolved Not an explanation of how sex initially evolved

(still an ongoing research question)(still an ongoing research question) Natural selection can’t “look forward” (it’s blind and Natural selection can’t “look forward” (it’s blind and

dumb) dumb)

The Ghost Particle:The Ghost Particle:Searching for NeutrinosSearching for Neutrinos

A particle with no charge and almost no massA particle with no charge and almost no mass Actually there are kinds of them; and if they have no mass that raises a Actually there are kinds of them; and if they have no mass that raises a

problem… so what’s generally said is “experimental results are consistent problem… so what’s generally said is “experimental results are consistent with zero mass…”with zero mass…”

Predicted by The Big Bang TheoryPredicted by The Big Bang Theory The neutrinos left over from the creation of the universe are the most The neutrinos left over from the creation of the universe are the most

abundant particles in the universeabundant particles in the universe First proposed to explain anomalies that challenged the conservation of First proposed to explain anomalies that challenged the conservation of

energy and momentumenergy and momentum Every second, trillions of them pass through our bodies without us Every second, trillions of them pass through our bodies without us

feeling a thing…feeling a thing… So the existence of the particles was predicted by accepted paradigms, So the existence of the particles was predicted by accepted paradigms,

even though they are kind of “spooky” and we are unable to directly even though they are kind of “spooky” and we are unable to directly “experience” them, and it took YEARS before anyone thought they were “experience” them, and it took YEARS before anyone thought they were actually detecting themactually detecting them

A puzzle of normal science…A puzzle of normal science…

The Ghost Particle:The Ghost Particle:Searching for NeutrinosSearching for Neutrinos

My friend, physicist Eric ThraneMy friend, physicist Eric Thrane Completed his PhD in physics at UW 2 years agoCompleted his PhD in physics at UW 2 years ago Is a post doc at University of MinnesotaIs a post doc at University of Minnesota Got Jack and me an insider’s tour of Fermilab and the Tevatron Got Jack and me an insider’s tour of Fermilab and the Tevatron

when he was an intern in physics during summers he attended when he was an intern in physics during summers he attended NorthwestNorthwest

We used to babysit him (GROAN)!We used to babysit him (GROAN)! Here he is in the world’s best neutrino detectorHere he is in the world’s best neutrino detector

Called the Super-Kamiokande Neutrino DetectorCalled the Super-Kamiokande Neutrino Detector Inside Mount Ikenoyama in JapanInside Mount Ikenoyama in Japan An active zinc mine contains 50,000 tons of water that is An active zinc mine contains 50,000 tons of water that is

remarkably pure… thus allowing neutrino detections using remarkably pure… thus allowing neutrino detections using 11,000 hand blown photomultiplier tubes11,000 hand blown photomultiplier tubes

Searching for Neutrinos:Searching for Neutrinos:Eric Thrane in JapanEric Thrane in Japan