Life Definition and 965 Threads

So I have a power supply, 9-12 V output and I have a component that takes 9-12 V. When I plug the power supply into the wall and measure the potential across it's leads, I get 16V. I put a resistor across the leads and measure the diff across the resistor. Again, 16V. I look at several...

Is there a relationship between the inverse fine-structure constant (alpha) and the life span of elementary particles?

Yeah is there any correlation between being single for the rest of your life and very successful in Math/physics?

Do You Use The "F" Word In Real Life? A recent post by Evo warning about bad language in an article: I think an English teacher I had pinpointed the biggest problem with the "F" word: those who use it tend to extend it into a multipurpose word that fills all conversational needs. It becomes...

Hello PF. I will give you my thoughts about the chance of there being life in the universe and I would like you too write what you think and maybe come with arguments against me. I am not very pro in any way at all so I may be incorrect in some things and if I am I would be happy if you can...

I just bought lunch at Quizno's. On top of a cabinet, between the cash register and the fountaion drink machine, in essentially the most prominent place in the establishment is this little framed 3" square metal plaque. It's like a little boiler plate off a machine - the lettering is stamped...

How do life and all processes linked to life go along with the second law of thermodynamics? If living creatures decrease their entropy because they are open systems and in a state of non-equilibrium with the environment, in general does the total entropy increase? (for example, if we have two...

Okay, If Uranium's half life is 4.5 billion years, why does it become waste at a reactor before it decays 4.5 billion years later... Forgive me if my question is badly worded or really stupid; I am a high-school student who has just finished the topic of "Nuclear Energy" in my physics class...

Whats the work life of an experimental physicist like? Hours? Pay? Activities and duties? etc. etc.

Homework Statement I'm not in school and although I took plenty of physics back in high school, I've forgotten most of what I need for this. I'm not asking for anyone to do the work for me, but it's been so long I don't even know which formula I should use to solve the problem. I can do the...

Here at National Taiwan University, there is a beautiful lake called the Drunken Moon Lake which is basically right next to my office at Astro-Math Building. I have been observing a family of Common Moorhen for months. The first time I noticed them was probably back in March, when the pair had...

Homework Statement I have some data for "Activity(Bq * 10^4)" and "time". I have already found the half life and everything but I can't seem to see any sources of error in the data Homework Equations I need sources of error. The Attempt at a Solution I said, the half life matches the...

Hey guys! Long time since my last(first¿?) post. A lot has happened over the past few months; I think I need a little catharsis. I just finished my first semester as a physics major and today arrived home (I don’t study in my hometown). Here in Colombia there is a national exam that every...

Does anyone know how many cycles (extend / retract) that a hydraulic cylinder should be able to do before needing repair? The specifics for the cylinder are that there is minimal (almost none) low frequency and low amplitude pulsing of pressure. The cylinder will cycle once every 5 minutes...

Homework Statement half life of carbon 14 is 5730 years. living matter produces 15.3 disintegrations per min per gram of carbon it contains. A 1g sample of a plant from an excavation shows 7 disintegrations per min from carbon-14. how long did the plant die? Homework Equations k = 1/ t...

Hi, Adiabatic, iosbaric and isochoric processes are good approximations for a lot of thermodynamic phenomena in every day life. But the conditions for a process to be isothermal are so artificial that i have grave difficulties to fudge a story. Are there any examples of thermal...

Did you dreamed of future (like place you want to live, work you want to do, partner you want to live with) 10,20,30,40,50, ... years ago and how close you got your near you dreams? I would need to work on finding if I ever dreamed something that I have now. So far, my life have been quite...

I am currently taking calculus, and will be done with differential equations by the time I graduate high school, maybe by junior year. I was wondering what comes after differential equations, because up to differential equations there was a series of maths that you were supposed to take...

So I was thinking about numbers like pi. If you were to measure the area or circumference of a sphere in real life, you would get a never ending decimal. How can this exist in real life? How can an actual physical object have a circumference that is an irrational number?

My life hasn't exactly gone as planned... I graduated in 2008 with a double major in electrical engineering and physics and had always wanted to go to graduate school in electrical engineering and get a PhD so I could one day become a professor. Well, I got accepted to a good grad school and...

I have think I might have a feeble grasp on the idea that simultaneity of events at different points of space depends on the reference frame. However I was having a conversation with my friend and we were trying to figure out if there would be a reference frame where our whole life happened...

Can you convert Half Life into Becquerels? How?

what makes half life(T) of radiation independent of the quantity of radioactive substance? why is it constant whatever the amount of the radioactive substance is?

I've understood the basic idea of why a gyroscope behaves as it does-- which is easily demonstrated by spinning a bicycle wheel about an axis and the exterting a turning couple to rotate the entire wheel about an axis perp. to the axis of spinning...I got the explanation from...

Kinda like "Being John Malkovitch" but not quite. My scenario deals with historical figures that are dead. What if it were possible to relive someone elses life, watch it on a tv perhaps, AND hear their thoughts as they thought them... We have einstein's brain somewhere, right? If it were...

Know more about http://www.great-quotes.com/quotes/category/Life" ...

Dokuchaev, "Is there life inside black holes?" I thought this was pretty cool. "Is there life inside black holes?" Vyacheslav I. Dokuchaev http://arxiv.org/abs/1103.6140 Abstract: Inside a rotating or charged black holes there are bound periodic planetary orbits, which not coming out...

Do you have any ideas like something which helps hearing impaired people to communicate with others who don't know sign language, for example a glove, which translates sign language to text which is displayed or even translates it to speech? Any kind of things like that or can be something...

Homework Statement Consider the following reaction NOBr (g) → NO (g) + ½ Br2 (g) The table below gives the time-dependent concentration of NOBr. Using this data, determine, if the reaction is first- or second-order, with respect to NOBr. Give the rate equation and determine the rate...

Hello everybody. I am currently in a French engineering school, one of the best. The hard part was getting into it; now I am pretty assured to graduate and I just have to follow some very basic courses. I could be perfectly happy, except...I'm not really sure I want to be an engineer...

https://addons.mozilla.org/en-US/firefox/addon/leechblock/ BOOM. *Blocks physicsforums.com* *blocks facebook* *blocks my email accounts* *blocks ... various sites* How do I block actual humans though? Do I need to upload this addon onto my friend who won't stop calling me telling me the...

hi everyone,im ben,my father has told me to study engineering,but i want to know more about career life of engineering. 1)what an engineer do 2)the challenge in this field?i have check about it but many engineer say the challenge is relationship wth other ppl?is that engineering? 3)how is the...

Opposite of half life? If a system is experiencing exponential decay (nuclear decay, capacitors, whatever else), it has a constant half life, and decreases by the same proportion in the same time. I was wondering what term people use to describe systems experiencing exponential growth? Do...

Suppose there were an intelligent lifeform that was made out of antimatter. What would happen if it came in contact with life made out of matter? Could it come close to a matter being? What would happen if it touched a matter being?

High School senior confused in life... :( :confused: I was wondering if anyone had any insight as to which career path I should take? I am interested astronautical engineering, because of my love of space and designing spacecraft seems incredibly interesting and fun... It would be a...

Suppose the men in a country have a mean life span of 79 with a standard deviation of 8. And the women in the country have a mean life span of 83 and also a standard deviation of 8. Furthermore, suppose the life spans are normally distributed. What is the mean life span of the entire...

Moon rocks containing uranium 238, decays to lead with a half life of 4.5 billion yrs. The lunar rock sample you're invistigating contains half of the original uranium 238. How old is the rock? How would I go about solving this? What formula should I use?

Saw this on Monday morning: http://www.foxnews.com/scitech/2011/03/05/exclusive-nasa-scientists-claims-evidence-alien-life-meteorite/ My feelings on the validity of the findings are doubtful or inconclusive at best. Biology and extra-terrestrial life really aren't my expertise so I thought I...

Hello How can I calculate the fatigue life of a variable stress between 0 and 90 MPa in cast aluminum? Do I use the mean stress and compare it with the wohler curve? what is the logic of using the mean stress? Why not the maximum stress? Do I have to use the Goodman or Gerber diagram...

http://www.foxnews.com/scitech/2011/03/05/exclusive-nasa-scientists-claims-evidence-alien-life-meteorite/". Snippet:

http://www.foxnews.com/scitech/2011/03/05/exclusive-nasa-scientists-claims-evidence-alien-life-meteorite/ When you consider the intergalactic scale and that there are something like 3x10^24 stars it seems so probable that life would exist--even in more complex forms. I heard that other labs...

RedZone, Second Life IP Address Detection Tool, Runs Afoul of New SL Policy, EU Data In an odd turn of events that is all too common online these days, an ingenious system created for Second Life land holders to reduce incidents of harassment and abuse by malicious griefers has itself turned...

and would like some input. I've defined myself as an astrophysicist for several years now, and it's been my dream to study astrophysics from early childhood. I went to university shortly after high school, but dropped out halfway during my second semester, largely because of depression and...

Hi there, Someone asked me this earlier when we were talking about radioisotope dating. How do physicists determine the half lives of isotopes when said half life stretches into the millions of years? Random question I know :P -Dan

If you look at Earth 3000 years ago versus the Earth today there is now far more structure, ie cities, roads etc. It is less random, it has less entropy, and that is as a result of life. Especially intelligent life. Considering the solar system as a whole, does the decrease in entropy...

Hi, this is probably just going to be a rant , so turn away if you don't care: I'm taking math courses at my university right now, and I've been self studying math for about a year and a bit more now ( in high school, I only took math up to grade 10.. and it was "essentials" math, I was a bad...

What is meant by discharging capacitor half life (the description). I seem to be getting different description, I would just like for someone to confirm it here for me please.

Unusual paper: http://arxiv.org/abs/1102.1108 Some planets get ejected from their systems and wander off into interstellar space. The authors investigate what would be needed for such a planet to remain able to support ocean-floor life for a protracted period on the order of a billion years.

Check this out: http://edition.cnn.com/2011/TECH/innovation/01/19/smart.roads/?hpt=Sbin Tell me if this is anything more than retarded. I don't mean to sound insulting, but this cracked me up, that's how sad it is. There are so many problems with this, I don't even know where to begin. I'm...

So, if I'm a person who loves physics and has no problems with equations, but simply isn't very creative with mathematics and isn't exactly in love with it either, should I not pursue a career in physics?