Hot Definition and 572 Threads

If you had 2 identical stars, one was a very hot star, but the other was cooler. Since mass is relative to velocity, shouldn't the hotter star be more massive than the cooler one since the atoms in the hotter star would have more kinetic energy and therefore a higher speed?

Why does hot air rise? What I'm really getting at is why should the speed of kinetic motion of the individual atoms of heated air rise compared to it's slow moving neighbor, is it merely because it bounces around more often and so all air competes for dominance upward such that the fastest...

I have a question for you all, say you have a pressurized cylinder with water in it, it is at 200*F and at a pressure of 300psig. Now you open a drain valve on the bottom to the atomosphere. Will it flash to stream or just come out as hot water or a combo of the two? What equations and...

I am glad to be back. What is a hot topic that is happening to boggle the mind? To All the Forum People: You are all habit forming! I lost where I was - but, who won all the contests I entered? :smile:

CAn you tell me why will the temperature of the surface will be hotter at the top on the blub rathen than on the side? thank you

If scientists understand hot and cold completely then high temperature superconductivity will become a reality and cold fusion is just child play. Until then, we can do all the theorizing we want but to really understand the universe we must understand what is hotness and what is coldness...

I'm eating some chinese food now. About 2 minutes ago it was hot and tasted good, now it's just kind of warm and isn't as appealing. Why is that?

I have heard this argument all my life. Some say put hot water in an ice tray and it will freeze quicker than cool water. I don't follow the logic to that way of thinking. Do you? What is the right answer?

There is this very tasty Vietnamese soup, which is on the top of my favorites list.. I once made it myself by just putting together the ingredients which I noted in the restaurant.. and it tasted pretty amazing I must say I'd really like to know the original recipe though, anyone an idea...

There was no mention of Moon bases and Men on Mars in his SOU address last night, or at least according to the review I listened to (BBC?). Is this good news?

http://www.sfgate.com/cgi-bin/article.cgi?file=/chronicle/archive/2004/01/19/MNG3G4CAMF1.DTL

This is my first post and I’ve got some questions in regards to our universe. From what I’ve been reading it is known that the universe began in a hot big bang, or evolved from a similar condition. Either way the information we have points to some kind of initial condition, and also a beginning...

Another "new" release from NASA. Just click to join and you'll get these every day. So, I won't post these anymore. This subject has been discussed here on PF before, but this release should answer some of the questions asked...

Hypothetical experiment: I have a single 2-inch by 2-inch by 1-inch thick Neodymium magnet affixed on the outer rim of a 1-foot diameter circular hard plastic disk(1/8th-inch). The disk and magnet are held stationary by whatever means. The underside of the plastic disk has a coating, an...

Who can tell me some typical topics in Condensed Matter Physics nowadays?[?]

Hello all, It's time for a little experiment. As part of my constant quest to stimulate discussion and bring more technical content to physicsforums.com, I am going to occassionally provide links to posts from the usenet newsgroup sci.physics.research, which is a moderated internet-based...

http://www.sptimes.com/2003/10/05/Tampabay/Hot_Psychology.shtml

Ok, had a disscussion other night with my sisters. we were watching aladdin, i called aladdin hot. My younger sister agrees, adding that the prince from the little mermaid was hot too. My older sister disagrees with me, but agrees on the prince, also stating that undoubtedly, dimitri from...

i have heard that there exists an anomaly in amount of neutrinos coming from sun. are there any explanations around? how is the presence of Jupiter sized planets near stars have been explained?

It's a question that boggles the mind. If you answer yes, than God could not eat that burrito, meaning he is not all powerfull. If you give a negative response, you are limiting God's power by saying that he can't make that burrito. Either way you end up with counterevidence to God's existence...

why is the core of our Earth so hot? what causes it to be so? and why some other stars and planets like neptune/uranus (i forgot) does no have such a hot core? and what purpose does the molten core of our Earth serve?

Is ethidium bromide volatile in hot agarose solution? Some people add ethidium bromide to melted agarose solution, or reuse agarose containing ethidium bromide by melting it. If EtBr is heat-volatile, then it may pose danger to these persons. I always feel uncomfortable when remelting gels and...