Cool Definition and 276 Threads

Me and a couple friends are trying to resurrect the old physics club at my university and could use some cool inexpensive experiment ideas to try and boost attendance and have some fun. Any ideas?

Is the only reason air moving over your body caused by a fan or breeze feels cool because of increased evaporation of moisture from your skin? Or does it blow air being warmed by your skin away from your body to be replaced with relatively cooler air? Also, does air movement also produce...

So we humans are burning fuel releasing heat and energy into the atmosphere. (Let's not bring problems about global warming into the topic) And, so there is the major source of energy from the sun's radiation which hits on Earth by adding more energy and heat into the system. I know that some...

It is absolutely miserable here. Me nor the kids will dare venture outside until after 7pm due to the heat and humidity. The AC runs almost non stop unless I shut it down for brief periods during the day. Once the outside temperature is sustained at 90+ F on average (from 11am-6pm), in the...

is it possible that instead of heating the junction ... of thermocouple... we supply the current n the juntion cools down... which when touched felt cold... according to the supply of current...?? if not then is there any method of doing that

Click on the right side of the picture to scroll through. http://www.telegraph.co.uk/earth/earthpicturegalleries/7875310/Scientists-discover-new-marine-species-in-the-hidden-depths-of-the-Atlantic-Ocean.html

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Found these while pokin' around on Youtube and they made me prouder of what I do. http://www.youtube.com/watch?v=zSgiXGELjbc&feature=related http://www.youtube.com/watch?v=XGK84Poeynk&feature=related" There are 6 different videos but these two are the best in my opinion. Enjoy.

Ya know, rare Earth magnets and crap like that. Anybody know of some other cool things to have sitting around the house?

In thermodynamic books I read free expansion does NOT change the temperature of the gas as no work is done against any medium. Therefore initial internal energy equals to final and as internal energy only the function of temperature the temperature does not go down. I keep reading after the Big...

I have to create a demonstration for my physics class which will be delivered to a local elementary school. Has anyone seen anything of particular interest? The major restriction is that this has to be something the kids can interact with in some form. For example, one year a group created a...

I'm just watching a lecture series with Mark Whittaker in and he states (while talking about primordial roughness and sachs-wolfe effect) "the property that atomic matter has dark matter does not, is that it can cool" but he leaves it at that and provides no further clarification,and I am...

Hey guys I got a thought question. When air is moving, it is said that they have a higher kinetic energy than still air. Thus, the temperature of moving air should be higher than still air right? But then sometimes on a hot day why does the wind make us feel cool? I know there's hot wind but...

Go to: http://www.txt2day.com/" Enter the 10 digit phone number, no dashes Return e-mail (optional) You select the destination cell phone's provider Normal tweet text message Answer the anti-spam question (don't forget or the message won't be sent) Press send... That's it... Rhody...

i have to take a photo demonstrating a Kinematics Phenomena. I do one every unit but this unit is really sutmping me. For the optics unit i took a picture of a laser bending through glass, for waves i took a picture of light interfering through a diffraction grating, for electricity i took a...

This is cool. This is a one-bladed fan. And now I know how to upload to YouTube...

I'm still really confused about the speed of light. I'm kinda new at this so bear with me. Does the speed of light depend on the frame of reference it is in? For example let's say you have a ball moving at 10m/s in a car moving at 20m/s. This would mean that from the Earth's frame of reference...

I never had friend in my life ! I need physics friends and cool science friends. Hi, this is me kiran Do you want to know how I look like ? here is my vdo. NASA selected my vdo https://www.youtube.com/watch?v=<object width="560" height="340"><param name="movie"...

http://www.wired.com/wiredscience/2009/12/octopus-tools/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+wired%2Findex+%28Wired%3A+Index+3+%28Top+Stories+2%29%29"

This is Beethoven's 5th, but with a catch - it's depicted using bar graphs. It shows what instruments are playing and generates an animation to go along with the music. The colors correspond to the instruments and the level of the bar to different notes. The user has even given instructions on...

If you are writing a paper perhaps this might be useful to bounce around words. It's a dictionary and a thesaurus that connects words in a visual way: http://www.visuwords.com/

like mixing household chemicals together to get a cool reaction to help my brother for the science fair? please don't say baking soda and vinegar half the school is doing that for a volcano.

I was messing around in class, and I found that there's a small set of rules one can use to draw a directed acylic graph (it looks like a tree, but isn't) such that the number of nodes at a distance d from a "start" node is equal to the (d+1)th Fibonacci number. The graph is pretty neat...

I just sat my first materials science exam today and one question just stuck out in my mind which I was unsure to answer, maybe someone here could give me an insight. "1kg of Aluminium requires twice as much energy to raise its temperature than 1kg of steel. However, aluminium has a larger...

http://www.nameyoyo.com/hehe/100.jpg http://www.nameyoyo.com/hehe/200.jpg http://www.nameyoyo.com/hehe/300.jpg What do you think?

I'm supposed to be sleeping but I can't because its too damn Hot! I've always thought it is easier to keep warm when it is cold out than it is to keep cool when it is hot out. Scientifically speaking which is "easier" in a real world scenario and why?

Hello, My material science teacher posed an interesting question today. During the making of an alloy, would it be better to quench it or let it cool slowly? At first I thought the answer was obvious: quench it quickly so in the case the two elements have different melting temperatures...

If you use high voltage to rip electrons away from gas molecules thus forming ions will this have a cooling effect on the gas? Removing electrons from an atom must bring it to a lower energy state, will that lower energy state manifest itself as a lowering in temperature? Could you use this...

Hi, Suppose an infinitely long round bar made of steel of 25 mm diameter, which is traveling at a speed of 10 m/sec. The bar is at a temperature of 950 degrees Celsius. I need to find out how much water (liters per minute or liters per second) do I need to put in contact with the bar in order...

I found this cool little page on winglets, but I haven't had time to read it yet: http://www.b737.org.uk/winglets.htm

ok the proof is kinda complicated and i honestly don't want to wright it out lol but try it out because it works. So my equation states that an inscribed circle in a square has the surface area of the square x pi/4. So say you have a square with side lengths of 5 so the SA of that square is 25...

Homework Statement 1. How much energy does it take to heat 95.3 grams of water from -10 degrees celcius to 35 degrees celcius? 2. How much energy does it take to cool water from 125 degrees celcius to 75 degrees celcius? Homework Equations specific heat of water in solid is 2.06...

Wouldn't it be cool if websites had a virtual reality simulation option? You could put on your headset and (say you chose PF) could like "walk" into a door that said PF lounge. You could find virtua-people there and discuss stuff like this as if you were really talking to someone. You could sit...

deviantART is a cool site for artists and such to show off and sell their work, some on you photogs here might like it. Here's my gallery. http://goetzinger.deviantart.com/gallery/

This reminded me of the "cat herding" commercial. Wonder how she manages the fleas? I can barely afford flea treatment for one cat!

First I have to set this up. Take the words feather and theater, and the th in each one. In old English they didn't use the 'th' they had a different letter for that sound. Actually they had two different letters one for the 'th' in feather and one for the 'th' in theater. Sometimes when...

Star Wars + Legos = Yes I am a big Dork...whatever. I still think this is COOL. Sweeeeet. That's freakin awesome. http://www.flickr.com/photos/23575410@N05/ That kid must have spend a few grand on that. Legos are $$$ expensive.

In the universe, without a heat source does it take energy to cool? For example if there was no sun or gravity or other heat sources, does it take energy to cool? And cool to what temp? 0 Kelvin? Thanks just curious :) Simon

Homework Statement In a well-insulated calorimeter, 1.0 kg of water at 20o C is mixed with 1.0 g of ice at 0o C. What is the net change in entropy Delta Ssys of the system from the time of mixing until the moment the ice completely melts? The heat of fusion of ice is Lf=3.34x105 J/kg. Note...

I recently learned about absorption refrigerators, which only use a heat source to do the cooling, and that got me thinking about applications for the Camaro. First, just for the cabin A/C (not what I care about). Secondly, as a way to cool the intake air (what I do care about). I want to be...

Here is a nice demonstration of resonance and vibrational modes.

http://www.xrite.com/custom_page.aspx?PageID=77 I thought I got perfect. I am aghast to find I did poorly. I'm gonig to blame it on test conditions. I'll try it again under proper lighting and viewing conditions.

I was sitting with my girlfriend yesterday and we were looking at videos of comets and meteorites because I wanted to show her the schumacher levy 9 impacts, that she had never heard of! :bugeye: :cry: Then we kind of did some link following which went a little like this: Comets, meteorites...

Has anyone ever designed and built a K'Nex custom roller coaster? I am completely addicted to doing that! I absolutely love engineering and this is a way to practice without use of any tools or money. I'd recommend you guys try it. Oh and by the way I'm a new member. My name is Nick. ~Nick

Hello again. I come with another physics concept I am struggling with. At first I thought I understood this but the more I think about it the more confused I get. Help! This post is with regard to the insulated 'Keep it Cool' boxes you can buy for taking on picnics or carrying cans of...

Homework Statement find the dimensions of a rectangle with perimeter 100m whose area is as large as possible Homework Equations area = XY 100 = 2x + 2y y= 100/4x x(100/4x) (400x - 400x)/16x^2 1/16x^2 = 0 The Attempt at a Solution well... am lost

Homework Statement Ice at 0.0°C is mixed with 8 × 102 mL of water at 28°C. How much ice must melt to lower the water temperature to 0.0°C? Homework Equations Q = mc(delta)T The Attempt at a Solution c = 4.184 J/g K (delta)T = -28C V = 800 mL I'm not sure what to do since...

A meteor that came down in the NW this morning was caught on camera. A pilot reported seeing it hit the ground.

Experiments have been done in which one volume of water that is warmer than an identical volume of water freezes faster than the cooler volume.Since ice is an ordered structure compared to liquid water does this mean that the walls of the vessel containing the warmer water are able to interact...

Suppose in summer, two consecutive days, the first was hot at 30 centigrade, the second at 20 centigrade. Both was cloudless in the afternoon. There haven't been any rain prior to the days nor after for about a week. What caused the second day so much cooler then the first even though they...