mossoi

How many sides? Depends on how many pyramids you glue to it Seriously though mathematically it can be said that the number of sides of a circle tends to infinite as the length of each side tends to zero. Anything more than that and you are getting into philosophy of maths.

As for the hottest something can get, that depends on pressure and I don't think a practical hottest possible temperature has been recorded. Once a gas reaches sufficiently high temperature it will become a plasma (stripped of its electrons if I think) - plasmas exist at incredibly high temperatures and pressures.

Cold is not added to a body it is created by the absence of heat - the heat must go somewhere so consequently between any two areas at different temperature there is a temperature gradient. This gradient can be very steep, for instance a very cold object placed next to a very hot opject or very shallow if two objects of similar temperature are placed together. For an object to be at 0 Kelvin and remain there the temperature gradient between it and it's surroundings would have to be flat, as would the gradient between the sorroundings surroundings and so on like the layers of an onion. This is not possible.

If they had then it would have only been for a very very short time and probably not 0 degrees exactly. Anything at 0K will gain energy from its environment immediately.

Nothing is 0K - space itself is just above 0K but for anything to be at 0k it would have to be perfectly insulated which is not possible.

Nope waggy isn't a word. Imagine something that wags it's tail a lot. Also take a look at this page http://www.physik.uni-augsburg.de/~ubws/nitrogen.html It has numerous 'fun' things to do with LNO2 lots of which involve pouring it straight on the floor with no adverse effects on said floor.

Indeed - a large, warm, waggy object called Rover.

When I say it's not THAT cold I don't mean relative to other liquid gasses I mean not so cold as to instantly freeze a large, warm object.

If it was sprayed on a dog or cat it would probably burn the localised area but it wouldn't make a dogcicle unless the dog was fully immersed for quite some time. Liquid NO2 isn't THAT cold and time is need for the transfer of energy when freezing any object.

The sole of their shoe might feel cold for a moment. I'm not supporting the idea because I don't think it's sensible for safety and cost etc. I just want to point out that making the pavement cold will not result in holes everywhere.

I've been reading this thread for a couple of days and I think some of you guys have got the wrong idea about making things very cold. When you reduce the temperature of something it becomes more brittle - liquid nitrogen will make things very cold and very brittle but it won't make a slab of concrete as delicate as a sheet of glass. You'd still have to hit the paving slap with something like a sledgehammer to break it because it is still inherently strong - it's just more brittle and less able to absorb an impact. The demonstrations using delicate roses are all well and good but rose petals aren't particularly strong as well as being very thin so easy to snap if made rigid. The liquid NO2 would not need to be sprayed either - it could quite effectively be administered by allowing it to slowly flow out of a nozzle using gravity alone.

Yes, it's very well known and has been for decades. This is why doctors retire behind a lead screen when they x-ray you or leave the room and why you are given a lead apron to wear if you are having a limb x-rayed. Most vets will also ask the oldest person to hold a pet for an x-ray as they have less time to live and can more afford to use up some of their lifelong "radiation quota" - strange, but there you go. It's deemed a justifiable risk to expose people to small amounts of x-ray radiation in order to diagnose injuries and infection. I think the main drive of the article is that x-rays are causing MORE cancer than was previously thought. In the forties/fifties shoe shops in Britain used to have x-ray machines for measuring the size of feet. My parents tell me of how they used to play with it when they were waiting for their parents. This is before the implications of x-ray exposure were fully understood.

I don't see what's wrong with a gay marriage. I'm not so sure about adoption in such cases as it's affecting another party who may or may not be adversely affected by a different home lifestyle. As for anti-sodomy laws - well two consenting adults in the privacy of there own home - why stop them? It's not gonna upset anybody.

Through incremental changes as a result of evolution. The tall giraffe I'm referring to above is not as tall as today's giraffe but is just taller than the average allowing to outlive the shorter giraffes until there is another mutation where giraffes get taller again.

I think that might be an idea because I can't really work out what you're saying there Saya The giraffes with slightly longer necks will be able to reach slightly higher leaves and will do better at times when food is scarce. If the population is hit by a particularly bad drought for example the longer necks will be more likely to survive. The other advantage of having a longer neck is the ability to see further, or over objects that you might be feeding on, even an inch in height may be just enough to avoid getting eaten by a hungry lion more often that the sucker with the short neck.

The only reference I can find to sectible is as in dis-sectible. Can you clarify a little more please?

Here's a coincidence. About 3 minutes after I submitted that last post we had a sudden, brief blizzard here. It's not snowed around here for around 5 years and this was a full blown, can't see your hand in front of your face, flurry. If I wasn't a scientist I'd say that psychic meteorological powers were reading the forum over my shoulder. I guess it was warm enough to snow

No bother - I've heard this a lot myself and have always questioned it. My personal idea has been that the water is unable to gather into large enough clumps to fall - possibly because it is freezing too quickly and staying as a fine powder rather than clumping and then freezing.. It seems that there may be several factors though.

Here's something else that seems to be more thought out: "One phrase that is heard time to time is that, "it is too cold to snow today". In actuality, earth's atmosphere is not too cold to snow but rather it is "too dynamically stable to snow". Dynamic stability may be present due to low-level cold air advection, a lack of upper level divergence, and/or a lack of low level convergence. Also, if dynamic lifting does occur it may not produce precipitation that reaches the surface due to low RH values in the lower troposphere. The ingredients for snow are: (1) a temperature profile that allows snow to reach the surface, (2) saturated air, and (3) enough lifting of that saturated air to allow snow to develop aloft and fall to reach the surface. In a situation when it is said "it is too cold to snow" there is in reality not enough lifting of air that causes snow to reach the surface. The phrase "it is too cold to snow today" probably originated as a misapplication of the relationship between temperature and the maximum amount of water vapor that can be in the air. When temperature decreases, the maximum capacity of water vapor that can be in the air decreases. Therefore, the colder it gets the less water vapor there will be in the air. Even at very cold surface temperatures significant snowfall can occur because: (1) intense lifting can produce significant precipitation even at a very low temperature, (2) the temperature aloft can be much warmer than the temperature at the surface. The relatively warmer air aloft can have a larger moisture content than air in the PBL, (3) Moisture advection can continue to bring a renewed supply of moisture into a region where lifting is occurring, (4) Even at very cold temperatures the air always has a capacity to have some water vapor. " METEOROLOGIST JEFF HABY

Here's a couple of explanations I've found: "If it is too cold, the atmosphere can not hold water. No water, no snow. The most prominent example of this is Antartica, the south pole. The precipitation at the south pole is minimum, to the extent that it is categorized as a desert. The precipitation that falls does not melt readily." Harold Myron "The temperature of the air affects the amount of water vapor it can hold. Colder air holds less water. To have a significant snow, you need significant water vapor in the air. At temperatures well below freezing there is not enough water in the air to get much snow. The exception to this is in places on the lee side of a large body of water. Here the air need not hold much water, but only keep blowing." Larry Krengel

No, but that was the Schrodinger's Kittens idea that I heard - maybe it was misquoted but it's still food for thought in the same way that Schrodinger's Cat is.

Meh....whatever. Just so long as it goes elsewhere. You don't have to send it into space - you can put it in another room. It's just to show that by looking at one part of a system you can determine the state of the other regardless of distance.

I thought that the whole Schrodinger's kittens thing was that you had a box containing two kittens and enough poison to kill only one of them. It doesn't matter who the poison is dipensed as long as one can assume that only one cat can die and that it is equally likely to be either. Then you cut the box in half while keeping its' contents unknown but ensuring that you have one kitten in each half of the the box. Fire one box off into space. Then by opening the box that is on earth you immediately know the state of the kitten in the box that is far, far away.

Very expensive graphics cards are usually expensive because they have video inpute/output capability. The actual display adapter is often no better than a normal video card.

The seas (or any body of water) would freeze from the bottom up. Interesting to think of the effects that this would have on EVERYTHING terrestrial!