Life Definition and 1000 Threads

Hi all, I've browsed this form for a while and have gotten some help but now need to ask some personal advice. I'm currently a junior in chemical engineering at a top-20 engineering school. I don't know what I want to do with my life. My original plan was to go to grad school, get a PhD...

The Paradox of Life A bit beyond perception's reach I sometimes believe I see that Life is two locked boxes each containing the other's key.

http://www.nasa.gov/mission_pages/msl/news/msl20130312.html

I have an external HDD with a lot of information stored in it, my question is what exactly the life span of an external HDD? Thnaks in advance.

Hi. I have this tendency to go into these existential crises, and my current one revolves around deciding what to devote myself to. I'm currently a high school senior, and I'll probably be going to Duke U next year for college. I'm strong in most subjects (super in humanities and social...

I am fairly new to nuclear chemistry and I was just curious as how to find the half life of a helium nucleus. Would it be the same as finding the half life of 1 neutron x2 and 1 proton x2? Or is this the completely wrong way to do this. Also would the half life be the same as a helium atom or...

My friends who don't believe life elsewhere exists often use the argument of "Well if life exists then why haven't they found us yet?" The only thing I can think of to explain it to them is it would be the same as a man in a fishing boat lost at sea somewhere in the pacific ocean, only the...

I have two questions: I have often heard physicists such as Victor J. Stenger argue that life could evolve and thrive in universes with physical constants vastly different than our own. I am curious to know what kind of universes these physicists propose. Can physical constants counterbalance...

How would you calculate the half life of an isotope without being given any other information? Would you need to use the Gamow factor?

First of all hi to the forum, I've read topics here for years but this is my first post. I thought I would post this up for the sharp minds here as this is really baffling me. I have moved into a new house with an older style fridge and a couple weeks in I pulled out an ice cube tray and it...

I studied mechanical engineering in college, so electrical engineering isn't my strongest suit. Basically I have a 12V car battery that I need to discharge to 70%, how can I do this? I know that I can monitor the state of charge by determining the open circuit voltage after ~24 hours of...

no moon=no tides...no tides=no life... Is that entirely correct?? I was recently discussing origins of early life on our planet, the other person stated that he had read (from Prof Brian Cox I think) that: no moon=no tides...no tides=no life. Although our moon is the main influence on our...

Can dark matter form planets and dark matter life?

Homework Statement Your task is to determine: a.the length and bore of cannon that is required to accommodate an 80 kg Clown with an over-arm measurement of 48 inches b.the amount of fuel that is required to launch the Clown at the same angle as you did with your model...

I was curious, why is it that dogs will live somewhere in the 10-20 year range, but humans make it to 80, and animals vary so much?

Homework Statement Definite integral: \int \frac{\ln(x+1)}{x^2+1} dx from x=0 to x=1 (sorry I don't know how to do integral boundaries with tex) The Attempt at a Solution I just am clueless on how to do this, I'm almost 100% sure you are not supposed to find the anti-derivative...

I am wondering in this day and age, how feasible is it to go without things like facebook? Are there major hindrances to going without a social networking account? The same could be said about this forum. There are people here that use this forum with similar purposes as facebook: they are the...

Lately I've thought a lot about life and death, about how we are observers of a universe, how we experience our surroundings and what happens to our consciousness when we die. You try and imagine absolute nothingness and fail to comprehend how you as an entity can even cease to exist. It makes...

How is it possible a patient looses consciousness and at the same time remain alive? in anesthesia, coma or unconsciousness due to injury/accident. Because I believe it is the consciousness that give life to a living being. Isn't it become an inert body without consciousness. Or in...

Hi, I'm new to the forum and came here because I could use some help. At the moment I am really confused because I know that A = DecayConstant * N, where A is activity and N is the number of atoms before decay. Isn't the Activity is how many atoms decay after 1 second with a specific value of...

Homework Statement I have two questions that I just don't even know where to start The activation energy for the reaction CH3CO CH3 + CO is 71 kJ/mol. How many times greater is the rate constant for this reaction at 170°C than at 150°C? A) 0.40 B) 1.1 C) 2.5 D) 4.0 E) 5.0 and A...

I graduated college with an EE degree (and lots of chemistry) back in 2008. I went into a PhD program for a year and was somewhat successful in my research and good enough in my classes. However, I had a nervous breakdown that forced me to leave. I looked for a job to no avail and went back...

I am a structural engineering grad student in IOWA. I have used 16 months out of my 36 months of Montgomery GI Bill benefits. It has taken 2 years but I am beginning to fall out of love with structural engineering. It seems like anyone can look in the AISC manual and find the formula and...

Hello, I have seen graphs of Battery's DoD (depth of discharge) vs Life Cycles. But at the same time, "life cycle" is defined as the no. of COMPLETE charge-discharge cycles that a battery can perform before its nominal capacity falls below 80% of its initial rated capacity. Here's the...

Hi everyone, I work as a mechanical engineer in Ws Atkins in the analysis and asessment of offshore structures. We are producing a MatchCad spreadsheet at the moment to do what we call a stiffened joint check. I am posting here to try and get some advice on how to approach and/or solve my...

Hi, could you please introduce me anythings that's related to optics items function in life? books,magazins,movies anything... even good pictures for understanding...(I mean for example you tell me type this ''''' in google and find those pictures for example) if no books or ect, but you...

Let me begin by saying I'm not a student of any kind of physics, I just have a general curiosity about the forces at work in the universe, so for most of the people reading this, my question will probably seem either stupid or strangely obvious! Anyway, my question is this: My understanding...

What was the most nerve wracking experience of your life?

Note: I did not study psychics and only have a vague-ish conceptual understanding of stuff Seems to me one of these points must be wrong: * One can survive passing into the Schwarzschild radius of a black hole * The Schwarzschild radius of a black hole (or it's surface?) represents a...

For some reason when I think of physicists I sort of imagine them to be extremely serious people, don't consume alcohol, don't party, don't go on sunny holidays ect and I know this is stupid but when I think of a physicists I kinda think of them going to bed at 2am after trying to solve some...

What is the best way of describing isomorphism between two vector spaces? Is there a real life analogy of isomorphism?

As the title says, what are some scientifically valid ways to increase your life expectancy? That is, which practices (ex: diet, exercise, etc.) have been shown to increase the average life expectancy in experimental studies?

Hey all, I am a senior at a University here in california. I have 3 semesters left after this before i graduate. (5 year plan..) I am going to be getting a B.s Degree in "Professional physics: advanced study option". Basically they physics required for those intending on going to Grad school...

Who are you going to call when you're mooning about your purpose in life? Generally level-headed and polite members of Physics Forums! Anyway, I graduated in July, and at the start of September started working as a loader, pretty much (complicated story involving social anxiety and, possibly...

Do you believe in existence of extra-terrestrial beings? why/Why not?

Trying to get the 2nd derivative of this expression: ps/(1-qs) where p,q are constants and s is the variable. The solution is 2pq2(1-qs)3 for the life of me I can't get that solution. every time I do it I get 2q/(1-q)2 maybe I should mention that I'm using a probability...

How long have you ran your car battery running on "lowest key position", just playing the radio. How long do you think a 05 model should have it's battery last for this. Range? :]

The heat equation predicts that heat spreads infinitely far over arbitrarily small time intervals. What happens in real life? How does the heat equation get modified?

Here I am asking for help again... I had an experience today that affirmed my doubts about being in graduate school. This morning I had an exam. With approximately one hour sleep (no I wasn't playing video games or cramming, I have a chronic insomnia problem which I have yet to find a...

How may the error on the half life (using Poisson) be calculated? Barlow states that the error on the log would be 1/√N. Why is that?

I am hoping you all could help me. I have been accused of a felony based on these tire marks. I did not make these marks! I do not even think my truck is capable! I am wondering if there is a way for the law of physics to prove this. I am posting all of the information I have that I thought...

Question: A sample of radioactive substance K and a sample of another radioactive substances L have the same initial activity. the half life of K is TK and the half life of L is TL. After a time T, the activity of K was half the activity of L. Expression in term of T, TK, and TL.

I've noticed an interesting observation about how the lives of all the people in my elementary AIG (academically intellectually gifted). Out of the 11 of us, the only two not to go to college came from very poor homes. (Even from the beginning, only 4 of us were the kids of a...

I am an engineering student. I am an average student. I don't think my methods of analysis and thinking are proper. I did take steps to improve my thinking abilities by becoming a left-handed person, solving sudoku and lateral thinking puzzles. I want to be a scientist in my life. But i...

Dear Physics Forums community, This question has been bothering me for a few days, and I must apologize for the ambiguity of it. I'll try to explain it a little bit. I am not asking when the Sun will expand or the Earth cool down via radiative processes. So what I asked myself was: if you...

Jimson asks over on Yahoo Answers The key idea is that after 100 minutes 1/2 remains after 200 minutes 1/4 remains so the fraction remaining after \(t\) minutes is: \[Q=2^{-t/100}\] So if \(80\%\) remains we need to solve: \[0.8=2^{-t/100}\] which we do by taking logs (the base is...

"There are worse things in life than never being someone's sweetie" Just listening to Morrissey and the above line of his got me thinking... certainly one can imagine worse fates in life than never being loved, but how far would you go? Would you choose to be paralyzed but loved dearly by...

The advocators of Darwin’s theory of evolution discover that it is difficult for normal evolution rate alone to form the species diversity now. What factor(s) accelerated the origin of life and species diversity? Reference viewpoints: Novae, especially supernovae, would generate high energy...

1. In daily life, people are often praised for maintaining some particular point of view for the courage of their convictions. A change of mind is seen as a sign of weakness. How is that different in science Homework Equations Well I was reading something at one time that Einstein...

As you can tell from the question, my science knowledge is lacking. :confused: I can see that mammals, reptiles, etc. must eat other living creatures (mammals, insects, plants, etc.) for energy. But do plants, microbes and other types of life forms all depend on eating other life forms? For...