Asimov

Garyleo: Seeing these lights every time you look up is indication for a prompt dilated eye exam. If as you describe it, it is not normal. Also described as seeing stars, night or day doesnt matter. If you have had this for a long time it may not be a tear as your retina would likely have detached by now and it is to late to treat after a few days.A blow to the head jiggles the retina and one "sees stars". Most tears need to be repaired to preclude possible retinal detachment. Floaters themselves usually are a breakdown of the gel and are more common with age and require no treatment. They can be remnants of the hylaloid ebryological artery discarded after the lens is formed in the eye.A sudden onset of floaters can mean a tear or bleeding Treatable if done quickly.I have had floaters all my life but they have not changed. Dont try to catch them, they will put you away. It may be only traction which is a tugging your retina by the gel in the eye.Mechanical stimulations make the receptors register as seeing stars. This may not need treatment but needs to be seen. Traction, tears and retinal detachments are most common in high myopes as their eyes tend to be longer and stretch the contents.. When I see these symptoms I do a dilated exam and take pictures of the retina and do a visual field exam. This maps blind areas. Usually the tests are negative.Most important when positive however..

MonDie: There may be many configuerations that might be better for us now. But evolution does what is best for our ancestor that adopted the body plan at that time. There was no regard for what might be best for us now. Still we are evolving. Those tails we lost would have made tailoring awkward and been hazardous on a bike.

Studiot: Flight school teaches the essentials you really need to know. Most young men in WW-2 survived flight school in very hard to fly high powered fighters.Ask a pilot about vectors and he may wonder what that has to do with anything. Buy rounds. Flying by the seat of the pants is the favored expression.This can be misleading in bad visibility though. You need know little about light to turn on a flashlight.

Studiot: Thanks, a more detailed perspective. Sorta explains Coanda and Bernoulli. IMO what was bad about the old classical theory in school books was the implication all lift was due to Bournelli My scratch built models with thin zero airfoil wings flew pretty well. Familiar with Cole's Law? Thinly sliced cabbage!

Something from nothing. Unlikely. We live in a cause-effect universe where something never comes from nothing. Ever. To suppose the universe itself came from nothing is possible but illogical. How would we know anyway? Not knowing what or if something came before is no roof of anything. I think I said that right..

Strange and fiveworlds: Thiomersol is called Thimerosol in the U.S. and is not considered toxic in vaccinations. IMO this is because vaccinations are only every so often and the mercury never reaches a toxic level. Used long enough a toxic reaction is almost certain when the murcury reaches a certain level in the body and it is severe when used in the eyes.I was starting practice in the early 70's when soft CL first came out.. First they were boiled to disinfect in special units, later the so called cold solutions came out with thimerosol and it was disastrous for optometrists.Almost everyone eventually had a delayed hypersensitivity to the thimerosol. Pain redness and contact lense intolerance blur and edema were pronounced.. I myself was a victim.And no, I i didnt make house calls in a buckboard wagon. Thimerosol is no longer used for this purpose but intolerance or allergies to preservatives in solutions can occur and we use H2O2,, peroxide for disinfecting.A platinum disk overnight knocks of an "O" leaving pure saline, no preservatives.

The textbook description of how airfoils lift is somewhat flawed. From grade school to pilot schools we are told the Airfoil- shape or path-length explanation of airfoil lift. That is the top of the wing being curved more so air must go farther and faster to meet at the back of the wing resulting in the wing being sucked up a la Bernoulli.Largely incorrect. There is no suction and the parcels of air divided by the leading edge dont meet as such.I assume that a little lift comes from this effect though it isnt the major factor.. The Newtonian or Attack angle explanation is a better description.Air is deflected downward and Newton's 3rd law comes into play.The airfoil is tilted and greates lift by deflection.With elevators the pilot assumes the angle of attack needed to get the desired lift. Stunt planes have symmetrical airfoils that provide all the lift by deflection. I made model airplanes with wings that were flat on both sides and they flew as well as my friend's stunt planes with airfoils.You can fly upside down with airfoils curved more on the top. I've done that on purpose and accidentally.The math is said to work for both explanations and it is a matter of interpretation.Actually the classical explanation seems O.K. for cambered airfoils with no angle of attack. IMO, however the curved top surface serves more to smooth the air flow over the top by delaying separation of the boundery layer.No reference,, my thoughts. Some supersonic fighters have relatively flat airfoils. Klein-Fogleman airfoils get tremendous lift by means of a parasitic bounderary layer as I recall.There is also the 3-D Vortex shedding explanation and a coupla others. IMO most paper planes get their lift by deflection and the Klein Fogleman effect. http://.amasci.com/wing/airfoil.html

Sorcerer:The development answer follows.The embryo has a midline tube from mouth to anus that becomes our gut. Many organs bud out from this tube.If the bud stays single there is one organ. If it divides there are two of the same organs. OK, why does THIS happen? Most animals and all invertebrates have bilateral symmetry. Would you believe this evolved about 600 million years ago. Why? Because it worked. At some point some ancestor did best with the arrangement and number of organs we still have.Two of every organ might now be better or worse as either plan has advantages and disadvantages but evolution is selfish and short sighted and does what works best at that time. Two brains, no thanks. one is confusing enough. Given enough time we could adopt any number of body plans. Lots of time.The Octopus has 2 extra hearts.Some dinosaurs got so big they needed an ancillary "brain" to control the length of its body.We are getting taller unbelievably fast, will we some day need an ancillary brain. Will we sit on it? Will they argue?

Amaton: Sneezes obviously are intended to clear our upper respiratory tract or inturupt weddings and funerals but are violent, largely uncontrolled and dangerous to our eyes. The head moves violently and an eye can be put out. Natural selection provides a strong protective reflex. You cant sneeze with your eyes open! Try it next time you need to sneez Only a very few can train themselves to over ride this reflex. In optometry school I found an easy way to voluntarily constrict or dilate my pupils at will. Won some bets but Dr, Janks at 70+ years old quickly figured it out. Kept my secret.

Zenfred: The desire to reproduce our genes is not necessary for reproduction. Ask any high school student. Successful species select behaviour that passes on the most genes.Those individuals less prone to sex pass on less genes..Lower organisms that reproduce sexually have no concept of sex. Apes know little or nothing about the connection that coupling has with reproduction but couple for pleasure enthusiastically and protect their young.Prebiotic molecules evolved without any desires at all. Those molecules or arrangements of same that tended to persist and eventually utilized heat to re-arrange surrounding molecules in their image persisted over those that couldnt. Our desire to have children is as if we wanted to pass on genes whether we think of that or not. Ask a potential partner if they wish to join your gene pool and you likely have already failed. Try this at the bowling ally. Buy rounds. Parents often have many children for security in old age or to get more welfare money. Does financial success promote reproduction? Maybe. Wow, a whole world of Donald Trumps? Be still my heart! If one says the driving force to pass genes along is what affects our behavior then they would be refering I would think to a species' collective tendency to persist and compete.Desire wouldnt literally be the correct word. A rock tends to persist, so do Baobab trees. Neither has any desires. Think of DNA as the real life, a kind of super organism. Evolution's most successful of all experiments.Our bodies and minds are only tools developed by them to create more of them,yet they are themselves mindless. Still they have us well trained.

Migl: Thanks for your imput.I dont know whom you were addressing. You are correct about viewing particles as manisfestations of their fields but I dont see the relevance to my original post, the Ferris thought experiment that seems to be overlooked! This thread has drifted as so often they do but everyone learns as we go. I will summarize my thoughts. My references to Einsteins4+papers was to document E=M which states without need for footnotes that E is M. Units dont matter. Sorry if some dont get this most fundamental of relativitiy's tenets. In summary, my opinions. E=M literaly means E=M. Believe otherwise as you wish. Math wont disprove this basic fact. Hard to visualize though. Energy is the ability to do work. To do something. Change things. Many manistfestations. Fundamentally we know its manisfestations. How it makes thing behave No one knows what it is. Everything corporeal in this universe is some form of it. If anyone knows fundamentally what it is, please invite me to your Nobel ceremony. Energy is conserved----- Never changed to, converted to or sorta made into anything other than another form of energy. Ever. Nada. There is energy, and mass must be energy. Unequivocally! Same, not sorta like. Mass is not made of energy. It IS energy. End of story. Conservation of energy, many many sources. Sacred tenet as it were. Matter is many fields manisfesting as well, matter. OK, so? Energy goes a long way Irest my case and members hav clarified and sollidified my interpretations. Thank you and see you in other threads.. T o make me feel better I was told I am sorta right but physicists dont think of it this way. I now consider that a compliment..Feel better already.

Swansont: Actually at least 4 papers. Why bother to look? This is known by just about everyone that studies relativity.Yes, mass is energy. What I have been saying ! No you cant change energy to anything other than energy, another form of energy, like mass which IS energy.Mass and energy are one and the same thing.Call it different forms if you like. Conservation of energy denies changeing or converting or transfering energy to anything but another form of energy, like mass! Duh, double duh. Some have disagreed with this possibly accidently!. Read all the posts. My original tread was intended to help others visualize this sameness of energy and mass not to have to debate it.. We could dwell on basics we basically agree on by splitting hairs indefinately! Beats drinking beer at the beech. MacSwell said I am loosely correct but wrong in a more vigorous sense used by most physicists. If so I can maybe learn from him. His instruction is I hope pending. As to MASS= frozen energy, that is a popular expression by physicists. Literal? Metaphor? Analogy? Nice to met you all. http://www.classle.net/book/mass-energy-equivalence Re: Einstein's 4+ papers Most know about these so I wouldnt bother.

J.C.MacSwell: Thank you for your input but dont worry about my feelings. Truth is what makes me feel good.I prefer to be entirely and rigorously correct Calder., Ferris and Einstein.,were they speaking loosely when they stated energy and mass are equivalent? If it it has been discovered that there are some instances in which energy-mass equivalence is not correct please let me know. I have found this nowhere. My mind is open. I think one may find energy-mass equivalence hard to visualize but intrpreting it with a grain of salt.? I think not. Basically I want to know this more rigorous sense that I am wrong in regarding mass-energy equivalence. I dont deny what you are saying but I need to know. While I have your attention, doesnt conservation of energy apply? Energy cant be created or destroyed we know. If mass is not energy, then energy cant just become mass, it must BE mass. Right? Conservation. Also, if mass is not equvalent to energy, just what is mass? 25kilowatts of only energy adds 1 microgram mass to an object. Where does this microgram of mass come from if not solely from said energy which must be mass.? Thank you for your time and input. "Why stay we on the Earth if not to Grow ?" Robert Browning

Studiout: I have no contempt for you or anyone on this forum This upsets me and is totally unexpected..The comment was intended to apply to you, me and anyone else in general that is following this thread. I have learned while disagreeing with others and hope they learn too.My intent was palliative, not to offend anyone. Time flys like the wind, Fruit flys like the bananas

ABJ: Direct quotes from Einstein's paper, Timothy Ferris and Wikipedia. Loose? Add 25 kilowatt hours of ANY energy to a mass and you add 1 microgram mass. Loose? 25kilowatthours= 1 microgram mass ----- Loose? We must agree to disagree. All of us. Das wirt alles, danke.

Studiot: " Matter is energy." Albert Einstein Special Theory of Relativity " Matter is frozen energy. This was revealed in what must be the worlds most famous equation, e=mc*2: energy equals mass times the velocity of light squared." Timothy Ferris "The Whole Shebang" page 104, We dont have to agree, just keep on learning .

Thank you for your perspective. I see Calder's thought experiment fell mostly on deaf ears. What Einstein REALLY said is that energy and mass are one and the same. E=M. Not just a way of thinking about it or a metaphor or analogy. Hard to visualize. Energy can manifest itself in different ways but is fundamentally the ability to do work or make change .Also it is mass Not some number. That famous equation E=mc*2 on sweat shirts everywhere serves to convert units of mass to units of energy and back regardless of the units used. It works.It appiies to moving objects as well. Adding 25 kilowatt hours of ANY form of energy to a mass increases it's mass by 1 microgram. Any form of energy. Period. { see Wikipedia, Mass energy equivalence } Energy is mass. Visa versa. More astonishing still, relativistic mass is also energy. Right, the mass-energy total depends on the relative motion of the observer! Not some theory of mine Old stuff. I've presented it as well as I can. That famous equation is literal.. I wont try to defend this most basic and important of relativity's tenets any further. Calder said additionally{and literally}: High-speed motion changes the apparent energy of objects. A moving luminous object seems to shed energy of motion. Einstein inferred light must be heavy. Mass and energy are equivalent: E=mc*2 Matter is frozen energy.

I had difficulty visualizing how mass and energy are the very same thing. This is basic relativity according to Einstein and all good physicists. Calder explains it well: At 1/10 C the energy of an approaching star is increased by 10.55% If receding it loses 9.55% of its energy.This is an average gain of .5%. This only depends on the relative speeds of observer and star.Since C doesn't vary,mass and energy are equivalent. Einstein intuited E=M before putting it to math . Paraphrased from "Einstein's World' Nigel Calder Calder stated additionally, "The rest-energy is the energy required to create matter." Matter is made of energy.

Gweedz: Yup, the black seems brighter by contrast. However the white reflects more.Black is the absence of all the visible wavelengths. White is all the visible wavelengths combined.

Captainzen: Leaving out artificial gravity is irrelevant as it is no different than gravity induced by mass or that by an elevator. It is acceleration pure and simple, hard to visualize. In an elevator accelerating up you feel Earth's gravity plus the gravity of the acceleration by the elevator. Gravity has been described as a geometrical property of space-time. A bending of space time. Like a bowling ball on a waterbed. Never seen that though. It is as if mass is accelerating through time. I visualize it that way. It may not be possible to unify with electromagnetism, weak, and strong forces unless they too are a geometrical property of space time. They have not found gravitons. May not. I wait.

Akassem: They can only sorta guess at the total energy. Energy =mass and they dont know the total mass. Nigel Calder says the universe has all the energy it ever has had. Big numbers though. A lot. However if the universe is all that is ,there is no frame of reference to compare it to. Sagan said the universe is defined as everything that ever is, was or ever will be. Hence by definition there is only one universe. The missing mass may be be lost car keys or sunglasses. "However, there is considerable uncertainty about the mass density of all matter (visible and invisible) and energy (through Einstein's E = mc^2 equation). When one studies the movement of matter in and around galaxies, then it appears that up to about 10 times more mass is pulling at the matter (through its gravity) than is accounted for in the visible stars. This is the "missing-mass" problem. If this factor of ten holds throughout the Universe, then the total mass in the Universe would be about 6e52 kg. If the missing mass were mostly in the form of hydrogen atoms (which is not at all clear) then the number of atoms would be about 4e79." Universe, National Solar Observatory