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Thanks. Please do not introduce a change the diameter of the ball or aerodynamic characteristics. Keep the same as a standard baseball, 'tuning' only its weight. I did not specify thinking would be common sense related to the original post. Whatever a solid lead baseball weight be (if not ~5Kg.) The equation tells me a 2 gram paper ball will be faster. But we know it will not reach farther. Am right or wrong?

Say a baseball weighs 150 grams. A pitcher can throw it about 80 metres away. If it was made 50 g lighter, would the pitcher reach farther ? If it was made 50 g heavier, would the pitcher reach farther ? For sure if the baseball was a 2 g paper ball, the pitcher would reach perhaps only 8 metres away. For sure if the baseball was a 5 Kg solid lead ball, the pitcher would reach perhaps only 8 metres away. How could a baseball weight be 'tuned' to reach farther, getting the most kinetic energy from a pitcher arm ? ... Or is it already weight-tuned as designed ?

To anyone reading this post, do you use facebook? ----> No, but I opened an anonymous account there as I was forced somewhere in order to find data. I'm considering deleting or permanently deactivating my facebook account however is it a smart thing to do in your opinion? ----> Do whatever pleases you. Do you use facebook a lot? ----> No social nets at all. What are some good alternatives to facebook? ----> E-mail. Do you think there is anything wrong with facebook? Do you like facebook? ----> Perhaps was a good thing until got commercialized and intrusive into many sites. How do you use facebook to make all your friends like you? ----> No need for Facebook with true friends.

Heavier, denser materials subject to thousands of years of pounding, grinding and swept by surf... Are they supposed to sink under the lighther silicate sands on a plain beach ? What minerals are typically supposed to lie under the beach sands, down to bedrock or down to whatever stops them from sinking further ?

Read somewhere many years ago, that any three of : Temperature, spark, fuel, oxygen Are needed to make fire. Is that imprecise/incorrect ?

To print and hang... Notice to all employees: We've just been notified by Security that there have been six suspected terrorists working out of your office. Five of the six have been apprehended. Bin Sleeping, Bin Loafing, Bin Goofing, Bin Lunching and Bin Drinking have been taken into custody. Security advised us that they could find no one fitting the description of the sixth cell member, Bin Working, at your office. Security is confident that anyone who looks like he's Bin Working will be very easy to spot. You are obviously not a suspect at this time.

Thanks. Sick of being bombarded with the 'anti-processed' foods, when the pushers do not even define nor know what 'processed' may imply. Taste in food as a metric would change the whole picture; food is nutrition for the body and too few care for the nourishment. A well condimented and fancily presented turd will sell with no problem these days if the price is pumped high enough on a snobbish ambiance place. A granny mixing flour and water; putting on some pieces of cheese and sauce, vegetables and meats to the oven is the same 'process' the pizza places do. But buying from a vendor constitutes a no-no for nutritionists. No sense or yes ? As a guest in a little town in Italy, having a home-made pizza a gramma made... Is it that much different from buying it at PizzaHut ? As useful food, not as flavor pleasure for one or the other. What about nutritional value of both ? What about 'unhealthyness' of both ?

What is the intended meaning for 'processed foods' from the point of view of a food manufacturing factory and from the point of view of dietists/nutritionists, and perception from the general public ? Is boiling/frying something processing ? Is washing/chopping something processing ? Is condimenting processing ? Is refrigerating/freezing something processing ? Is packing/transporting something processing ? What are not 'processed' foods ? An unwashed apple picked from a tree ? Raw chicken meat, with feathers and all ? Sea salt picked from a dry brine pond ? Creek/well water ?

Hi. When a turning wheel comes to rest, there is an apparent tiny backing of the motion. Is it apparent or real ? As in a turntable, a ceiling fan, or any horizontal turning mass when comes to a stop, gives the impression of reversing.

Which is more harmful ? To be told by chemical/biological analysis, not by flavor. Remember that right now, (faucet closed) that filter contains (half a litre?) of a soup of your undesirable contaminants. Your next glass of water is now resting in that soup waiting for you to open the faucet. Maaany years ago, a friend had his home drinking water sterilizer boiler that needed repair, as the float arm broke. I welded, all OK. He told me bought such because his kids were permanently suffering from stomach problems. And the boiler was not helping. I told him to get rid of the contraption and give them straight tap water so they could develop defenses. Illnesses ended in a short time. Perhaps that was the right thing to suggest.

Just wanted to mention, to a person that filters drinking water; that it is a double edge sword. Filtering obviously has the intent to remove whatever 'unclean' contaminants from water, piling up those in the filter. Keep in mind that all those unwanted unclean contaminants are in the filter; and that you are forcing the water source trough that same now unclean path. Determining when is the filter contaminated -5 minutes or 5 months- is tricky. If the filter holds a condensed soup of microorganisms, passing the water source trough them may not fullfill the intentions.

Hi all. Trying to make/modify a magnetic compass. I should be able to attach a ~4mm mirror to the pointer or disc. The orientation of the mirror should be rotatable, by moving a dial or mechanism that will not impair or interfere with the heading. In other words, a mirror on top of the disc center, facing -say 135 degrees and reposition it to -say 170 degrees. Seems a dry compass, disc type instead of pointer or wet type would be preferred. How would you handle the repositioning mechanism ? ======================================================================================== By the way, how did compass got its name mixed up in English with the other compass, being both navigation aids ?

Here is an infrared directional parabolic antenna; widely available at department and hardware stores : ----> http://images.palcdn.com/hlr-system/WebPhotos/84/843/8432/8432593.jpg?_v=5a94e708-b43a-47fc-b9d2-56110847a5a6

Well, even better. Another reason to the list.

Eight years later, after a loong wait for your dozens of opinions in ten pages; releasing mine : ----> Spiders <---- With minuscule brains, -They wait for desired (and correct) wind direction and strenght to glide tethered to the 'planned' target in order to anchor a web. -Admirable uniformity to create the web. -Spacing between turns follows an incremental proportion. Weaker points near center are reinforced closely. Some engineering there. -Follow an efficient spiral path for construction. -Choose sturdier over weak anchoring. -Position themselves to sense and determine direction of prey caught on the web. -Discern debris from prey vibrations. -Hide protected from bad weather. -Decide when to cleanup their webs from debris. -Clean the debris by untangling it and dropping to the correct downwind side. -Know a vertical web is better than in a horizontal plane. -Select higher 'traffic' locations, as near artificial lamps. -Select rain sheltered locations when available. -Know how to untangle the web with no damage to it. -Properly reconstruct damaged sections. -They double threads at weak sections. -Evaluate attacking or not by sizing the prey and danger. -Know where in the prey to direct the killing bite. -The behavior when killing another (even bigger) spider is full of amazing strategy. A great show of technique to watch. -Since very young, fully capable of survival and to do their 'engineering work'. -Preserve captured insects, wrapped for later 'bad days' -Show patience over hunger. -They wait for a calm moment to strike a captive. -Perform evasive actions. -They show precaution by every few steps anchoring a 'lifeline' in the event of falling/losing grip. -Build their nests nearby considering positioning, sometimes bending leaves as housing. -Guard their nests and young. -I believe they have some sort of signalling/communication. -And more I do not remember to type right now. But, do not perform team work. What I have not observed is if the have a 'tool' to cut/dispose a string, or if they ever do such action. In general, cannot comprehend how much of it is from instinct, learned skills, or "intelligence"; but it surely is an amazing animal. Its filament production organ is not related to 'intelligence' , but what a great material !

Pouring some ClNa on ice is a practice to melt ice. As is done on pavements. Pouring some ClNa on ice is a practice to lower the ice temperature and prevents melting of ice. As done on keeping fish mixed with ice for its transportation or storage. Well, it is one, the other or... both. Promotes melting; prevents melting ? Explain please ?

Found an older post, may be of interest for the original poster. ----> http://www.scienceforums.net/topic/29638-how-to-make-a-self-inflating-balloon/

If the blood donor is a patient that somehow survived ebola; would it transfer effective 'experienced' antibodies to a healthy recipient, sort of a vaccine ?

I know nearly nothing important about the subject. Fever is a body defensive mechanism to kill germs AFAIK. Heard something around 43C = 110F being fatal. ¿? Read Saharan nomads live in it, daily. Heard the brain is damaged first. Which are the next organs in danger by overtemperature ? IF other organs can cope with -say 50C = 122F for at least some hours, like my attic in July. If the brain was somehow kept cool by potent external neck-carothids and head cooling apparatus, say at ~35C = 95F and the rest of body in a 50C = 122F chamber... Could that kill ebola virus ? Or, reverse. Cooling the body artificially to a survivable near-limit ?

Me being ignorant in the subject, I wonder if the infected body fluids from ebola patients anywhere including US hospitals that get into the sewage can survive there, taking in account the great difficulty to kill the ebola virus. Patients have to defecate and urinate too. Does it end in public sewer ?

Thanks again, studiot. Solving with metres, the voltage that the strait of Gibraltar tidal current could produce on MHD with the earth magnetic field, is 24 millivolts. A surprisingly low figure. Solving with centimetres, is 240 Volts. Magnetic field N <---> S; current E <---> W

Found. It is supposed to be 12 minutes time.

Hi. In the formula E = V B L for the "Conclusions" paragraph at near bottom of page ----> http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/8630/report/F B being 0.00004 Tesla, V being 2 metres/second, L being 300 metres; Should the V,L units be in centimetres or metres for E to be Volts ? [ Did not copy and paste the pertinent portion here because figure 4 shows 'Copyright' ]

Thanks. Yes, horizontal currents in bodies of water created by changes in vertical levels from tides. The massive insertion of turbines to extract energy from tidal currents cause slowing of currents and some corresponding warming of churning waters. Natural obstacles as straits of Gibraltar, and north of Labrador, Denmark, Malacca and countless others have been doing it for millions of years just as if those massive bottlenecks were turbines extracting (electric) energy. ----> Has that energy dissipation been altering the earth-moon rotation and orbits since day one ? I can see the planet with no shortage of energy in the future. Brutal engineering and costs needed to implement such extraction from tidal currents. Am sure some said Suez and Panamá canals were impossible to build also. ================================= Edited. added: Found "Tidal friction causes Earth days to lengthen 1.6 milliseconds/century. " =================================

Passing a conductive fluid as seawater trough a permanent magnet pipe; will it create electrical current ? How to 'collect' that current ?