Other Sciences

hey i am writing up my prac report i have a question about error caluclation. if i take the average of serveral measurements (instead of drawing a graph), and these measurements are [math] 147 \pm 3 [/math] [math] 146 \pm 3 [/math] [math] 143 \pm 3 [/math] [math] 145 \pm 3 [/math] [math] 146 \pm 2 [/math] i get ther average to be 145 (to 3 sig. figs.) , now how do i calucalte the error? do i use a 95% confiddence interval or somethign else? I have on method i think might work, but it gives a very big error compared to the ones for the orginal measurements: this is the method: [math] ( \delta avg)^{2} = ( \delta m_1)^{2} + ( \delta m_2)^{2…

This is something you probably have noticed, but if you have an incoming call while your mobile phone is close to some speakers, you will hear some jitter in the speakers, which can get relatively violent depending on their quality and magnetic shielding. You can conclude that the presence of strong electromagnetic fluctuations in the radio frequency range will induce electrical fields in the electrical-magnetic system. The question is (knowing that light and radiowaves are both electromagnetic waves simply of different frequencies), why is it that if you shine visible light, infared, or UV light onto the speakers, you will definitely get no response, even if the ligh…

im a newbie(a student) in science n tech... but sometimes i get strange doubts...i hope ull understand my doubt :cry: my doubt is.. the color what a person sees, is it the same as another person sees it? what i mean to ask is..for eg: i see a color.. say white.. and my eye sees it in a format say X, and if another person sees white ,will it look like X itself or something else.. people identitify a color by name..but not by a format. from our childhood we call a particular format by a name..but is it same in everyone's view? i dont know how for u can understad my doubt...and also i have no (very very less) knowledge abt science...i hope u people help me..…

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first off, hi. im new here today my question is will time travel one day be possible and will we see it in this lifetime or wont we be around to experience it? all i think we need is the best nasa scientists in the world a few more other scientists, the best mechanics in the world and the best mathmaticall genuis' in the world

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some things i thought of randomly at 1 in the morning.. im no scientist, but this seemed to make sense.. i will just put up a bunch of random thoughts and let you smart people duke it out. In fact, If you think you are good at what you do, try to follow me (open mindedly). warning: i have no background in science or math that is of any note or recognition, so this might get confusing, try to follow me, and take what you will and run with it. im just trying to spark something here. every dimension is composed of the dimension preceding it, and this is how i organize it: space into time into thought into object into space. ( time is placed in space, a thought …

http://www.eurekalert.org/pub_releases/2005-08/mcsc-ooc082905.php Contains the non-steroidal anti-inflammatory 'oleocanthal' that acts by inhibiting cyclooxygenase enzymes.

A friend of mine showed me this, anybody think it would be a good buy for my company. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=5803728326 [/url] anybody think it would be a good buy? feel free to post any other cool gadgets you think would benefit the science community

Many household appliances get power from the mains via a transformer. My question is that when a transformer is plugged in and the application turned off is there still current flowing through the primary? Yes: then there'd be an induced current in the secondary, where does that current go if the app is off? And it'd be a big waste of electricity. No: then the switch needs to go all the way from the appliance to the primary of the transformer (which for some appliances there doesn't seem to be a wire doing this).

As far as I'm aware, there's nothing in physics at the moment that would even remotely suggest the possibility of creating the sort of forcefields that act as solid barriers except to certain wavelengths of light (like the visible range), and can be "projected" at will (unlike glass and plastics, for example). But that said, am I wrong? Is there anything whatsoever in the physics of today that could be used to create something like a forcefield? I've read some articles on using plasma shielding, but that seems to be mainly to shield against radiation, and although one article made allusions to stopping solid projectiles with an extremely dense version, I'm somewhat…

I've used a 'break barrel single action air rifle' type gun once before but never really thought about how they work. Now I am! Here is a link to what I mean: http://www.bbguns.co.uk/843_1_1054906.html Basically you break the barrel, put it back and the pressurised air is loaded. This is an air rifle (not spring) so what I want to know is how the break/unbreak action causes the gun to fill with pressurised air??? Also what is the opposite of breaking the rifle/barrel??? (unbreak the rifle?)

this question was recently posed to me: "If i take a coin (or bottle top, paper clip etc.) and press it hard to my cheek/forehead then when i take my hand away the coin sticks to my face for a bit before falling off. why?" i suspect this is a chemistry question (Van Der Vaals forces???) but i really have no idea. Can anyone else give a good explaination for this phenomenon? ps. theres no need to make jokes about washing, it still works after you'v just washed.

why july is the hottest month of the year? thanks guys...

http://deseretnews.com/dn/view/0,1249,510054502,00.html pretty spiffy. LOGAN — A widespread belief among physicists nowadays is that modern science requires squadrons of scientists and wildly expensive equipment. Craig Wallace and Philo T. Farnsworth are putting the lie to all that. Wallace, a baby-faced tennis player fresh out of Spanish Fork High School, had almost the entire physics faculty of Utah State University hovering (and arguing) over an apparatus he had cobbled together from parts salvaged from junk yards and charity drops.

This is an article giving advice on how to win a Nobel prize, but I think it's good advice for being scientists in general. http://www.theaustralian.news.com.au/common/story_page/0,5744,16393063%255E30417,00.html

Have you guyz heard about these Mega-Tsunamis? They form from large landslides and can be much taller and more desructive than a tsunami. A show on discovery said that a part of La Palma island off Africa is gonna break off in like a century or so. It would create a huge wave headed to America. Whats your opinions on this? They showed this on a show on discovery, and they may have exaggerated some things because Wikipedia said different stuff. http://en.wikipedia.org/wiki/Megatsunami and the discovery show was http://dsc.discovery.com/schedule/episode.jsp?episode=0&cpi=23086&gid=0&channel=DSC but the link says little about it.

I remember watching a programme, where they stated that a fly experiences huge dilation of time. For example if you moved your hand slowly towards a fly it would percieve it as motionless. How is this possible ? As humans, events can seem shorter...if we're enjoying ourselves, or longer...waiting for a bus for instance. We certainly don't see events visibly slow down. Is this just down to the speed visual information is being relayed to the fly, like high speed film ? I keep on wondering if this has any implications towards relativity...if events are slower to one life form, how do they fit into the frame work of another...obviously they do, but it's kind of bug…

Does anyone know any experiments using house hold stuff that can froth, a bit more extreme that bi-carb and vinigar?

Hey, I'm sure most of everyone here has heard of the Big Bang theory, and that the universe is expanding, etc. etc. But has anyone heard of the opposed theory, that the universe started out big and is imploding? I heard this for the first time a couple days ago and it took me by surprise. I didn't think any of it made a lot of logical sense at first. Then I kept looking around and found little snippets of info about how the red shift makes it seem like the universe is expanding when all it really indicates is that galaxies are moving away from us. Thus, it could be inferred in this theory that objects closer to the 'center' of the universe are falling into it faster than…

I want to block the sound from my neighbour irritating me all the time. What should I consider the properties of sound? Speed?amplitude? Why installing a solid door is more practical than a standard hollow-core interior door for me? Secondly, should I try to reflect those waves, or absorb them with spongy lining? I can't afford expensive materials as I don't want to tell my parents about this. Buying some polystyrenes would be pleasing.

what is it? i tried wikipedia, but couldn't understand the article.

in econ, we were supposed to "invent" something. i came up with a body-heat powered mp3 player. the generator is a small vaccum containor with water and a turbine type thingy in it. the turbine thingy turns the magnet in the genorator. i suppose there may need to be a transformer and a capacitor added as well. would it work?

Hello. The flow of a fluid in pipes improves by the use of venting pipes, placed at certain points, as those shown over the roofs in dwellings. They really do work aiding flow. They are not something just to get fumes out. My fluids mechanics text books from the university never mentioned a word about them. Maybe I had the wrong books, but the thing is I never understood the principles of their use, their preferred locations, the effect of their lenghts and diameters. Can anyone explain how they work and why ? Thanks, Miguel

this has probably been done before but i can't find it. Could you make a wireless mouse (the type with the balls inside) so that when you move the mouse the movement of the axles inside generates enough power to operate he mouse and mabye enough extra to turn a little light on.