Life Definition and 1000 Threads

Hello everyone, I'm about to finish my undergrad physics degree, and I'm going to apply to a US grad school for a physics PhD. I'm not from the US. Once I get my PhD, the logical next step would be to look for a postdoc position in the US, as I want to dedicate myself to physics and possibly...

Hey PF, I am a third year undergraduate who has been working in a HEP experimental group for two years. So I have had a good deal of experience with the research process, and I know basically what the grad students and postdocs spend their time on in my group. I am still completely...

When I was in high school my grades were poor, no more than a B. In recent years during my senior year I suddenly had a huge interest in physics and math. I began to study day after day and eventually I made it to Multivariable Calculus during my final years in high school (I applied for...

can anyone tell me about various stages of life of a star? when does a neutron star, supernova, pulsar form?

I wonder how and where does resonance is applied in our real life. Any example?

I heard on a recent podcast that most astronomers and physicists of the early 20 th century, if they thought about it at all, believed that the universe always existed, i. e. it had no beginning. Even Einstein accepted the Steady State Theory, along with many others. How did these astonomers...

Does anyone remember the Nasa image of the 'segmented worm' found on Mars? I had recently seen a documentary on PBS about fractals in which it was stated that all biology is based on fractals and that if one could establish a fractal pattern in something, then it was certainly biological. I...

Do you have a will, and a living will that specifies what types of medical interventions you will allow once your body fails you? My wife and I have been pretty dedicated to establishing and modifying both, as needed. Even with both, once you have lost mental faculties (like my mother-in-law...

I'm doing well in undergrad, taking it easy w/ a below average courseload. But i'll actually graduate early due to AP credits. I'll get at least an MS (in statistics maybe?), but my plan sounds unconventional after that. I'm a prty quite person and love my peace of mind more than anything...

I'm a collage student, I rented an apartment flat with my 2 friends. We bought all house things by each of us paying 1/3 of their price. An now we are to break apart, I decided to make a drawing (like lottery) to decide who take which house hold. Assume that, A, B, C: Names of three...

What's the probability of a universe capable of life? In other words, what's the probability that the laws of the universe allow for life? And if the probability is low, does that imply there are infinite universes? Or there is a "god"?

I was watching a video on the JIMO mission to Jupiter's moons: Ganymede, Europa and Callisto. What is the approximate chance of life for these moons? And what about Titan, and Enceladus (misspelled?), can they be ruled out? What is the likelihood for water on these moons? If there is...

If we pick a target star 1000 light years away, from the point of view of an observer on Earth we will need at least 1000 years to send a ship there even with the ship traveling near the speed of light. But, from the point of view of someone on that ship that travels with near the speed of...

The Backyard Chickens The Backyard Chickens gives you information about raising chickens in the city. We try to provide information to help you have a successful and enjoyable time raising your chickens.

I was curious what some factors may contribute to free falling objects not falling at the same rate as would be expected in a vacuum. I remember from physics classes that two objects should fall at the same speed regardless of their weight. I know that surface area and air resistance plays a...

Are there plans to treat the BP oil spill with oil-eating bacteria? http://news.sciencemag.org/scienceinsider/2010/04/can-microbes-save-the-gulf-beach.html

BBC News It's going to be a pretty interesting field to get into now.

http://www.ted.com/talks/viktor_frankl_youth_in_search_of_meaning.html

With the confirmation of water on at least two other major bodies in our solar system so far (Mars, Moon), has this expanded the range of the "habitable zone" when searching for locations of possible life in the solar system?

I think I've screwed up my future. I am in my third year, double major in physics and math (math major more to supplement my understanding of physics), and this semester was just horrid. I made the mistake of moving off campus, working two jobs, and in the time I had to study, could not focus...

-------------------------------------------------------------------------------- The origin of life and humans is unknown.That is to say that humans do not know how they came into being and why humans come to this world. We only know that life and humanity is the product of natural...

Another "Late in Life Physics" thread I should really say "Really really late-in-life" I'm 56. About 20 years ago, I flushed myself out of grad school (physics) largely over just being fed-up. Lately I've been reading again because of the huge number of very good books immediately...

Does a jet engine have a life span?

If you love something, let it go...if it comes back, it's yours, if it doesn't, it never was! What if the day she/he comes back...you are long gone? What if some day you learn that she/he is long gone?

i am taking upgrading, and one of the main reasons i failed physics 30 to start with was due to half life. the book can't explain it good enough to me and either could my teacher. so i have a few questions that i would appreciate a starting point for. How much time elapses before 90% of the...

Homework Statement What mass of Na2 SO4 has an activity of 10.0 mCi? Sulfur-38 has an atomic mass of 38.0 and a half life of 2.87h Homework Equations Half life= 0.693/ k Rate= kN The Attempt at a Solution I'm not sure where to begin the sulfur-38 part is throwing me off All I...

Just the very things: First:http://bluecanarynightlight.com/" Then:http://www.fotosearch.com/photos-images/lighthouse.html" Some people know what I'm talking about.

Hello, I would like to ask someone to help me figure out on what the life-span of the color filters depends. I have information that some of the monochromatic filters of an instrument will "break" after around 5 years when working with the instrument 3-4 hours a day. The filters are illuminated...

There is an obvious connecting with the size of a living creature and how long it lives. I know that this is not always true but for the most part it is. I was wondering what this field of research this is called. Is there an average life span to mass ratio?

Hello all, this is my first of likely many posts here at the newly discovered Physics Forums. I'll do my best to help others out, and hopefully will receive the same in return. I've gotten through about 3/4 of a large problem that I'm working through in my book (no solution manual FTL). Here's...

All the very heavy atoms found in the Earth were created long ago by nuclear fusion reactions in a supernova, an exploding star. The debris spewed out by the supernova later coalesced to form the sun and the planets of our solar system. Nuclear physics suggests that the uranium isotopes 235U...

As far as I know, there isn't any definition of "life" that holds up to a physics standard. Sure enough, we can talk about (bio) chemistry and the specific arrangements of certain molecules, but what I'm missing is a simple, physical definition of life. I know that Erwin Schroedinger once...

It took me a little while to wrap my head around circularly polarized light, or more specifically how this can be done "passively". Wikipedia didn't do much help until I found the article at Polarizer, if any of you were wondering how the new 3D movie technology works. My first question is...

I am a junior in high school in AP Physics. Although not in the curriculum, I have been reading about theoretical quantum mechanics, string theory, et cetera for the past few months and I am extremely intrigued. If I do end up furthering my "physics career," where might it take me? There...

why planethunters and astrobiologists are concentrating on finding life on Earth like planet with an orbit around host star rather than on jupiterlike planets moon i was browsing through the essentials of complex life to evolve on a planet. i am sure you all pretty much know that. plate...

If there existed one universe that could support intelligent life on its own, it is likely to lead to a myriad of simulated universes. True or false?

Where does a nuclear engineer work? At a nuclear plant? Out of an office? There have not been any new nuclear plants built in the US in many, many years. So is there any new designing/innovation going on or is it just maintaining day-to-day operations (checking dials, running diagnostics and...

How does shot peening help improve fatigue life, or rather, how does the compressive surface stress imposed help improve fatigue life? How does materials having high elastic moduli and large grain size prevent creep?

I know a lot of people say water or carbon and some people even say fusion or gravity. I think these are just the building blocks we happen to find in our universe but I think life could exist without any of those things as long as the laws of physics of any particular universe allow for...

Sorry if this isn't the best forum for this question; putting it here due to a gut feeling cos my brain wouldn't tell me where to put it. I'm thinking of an idea for an art project. I'd like to somehow depict what a boring, every-day scene might look like if our eyes could see more of the EM...

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I am having trouble finding the method to figure out if a shaft has finite or infinite life if it is subjected to a fluctuating load. I know how to solve for n(factor of safety) in these types of problems. Is there a value that if n is above it has infinite life.

Guys, our thesis defense is near already. It will be this thursday. I just want to know some more real life applications of Circular Motion involving liquids. The experiment we performed was we placed water inside a bucket then we spin it around. (Vertically) Some water spilled but most of the...

If anyone needs motivation to keep an active life, or work shoulder to shoulder with his/her children to prevent them from ending as adolescent fat slobs, here is something to think about: story of a 11 year double amputee excelling at wrestling...

Once again my professor asked us to ask 6 people the following question and see how they answer it so if you could respond and give an answer, I would really appreciate it. And if possible can you also tell me a little bit about your mathematics background? We are supposed to write up what...

Hi, I am half way of a Ph.D. in theoretical particle physics in an European university. I have started to worry about my future after learning how really difficult it is to get a position, how much do postdocs earn and how difficult it is for some to find a good job outside academy. The truth...

The Greatest Pain in Life The greatest pain in lifeis not to die, but to be ignored To lose the person you love somuch to another who doesn't care at all The greatest pain in life, is not to die, but to be forgotten When you show someone your innermost thoughts and he laughs in...

Rare Earth or rampant life? I remember watching Carl Sagan's Cosmos and seeing the equation for life in the universe for the first time. It really made me wonder if indeed we might find some form of life at one of our nearby extra solar systems. But I remember even then wondering if the...

Question given. Predict how the average life span of a nerve cell located in the brain differs from the average life span of a red blood cell. Provide a basis based on cellular features. I know that the average life span of a nerve cell is the life span of the organism which it lives in. The...

Hi All Following this Physorg article... http://www.physorg.com/news184915200.html" ...here's the webpage of the Professor's Directed Panspermia Society... "[URL Society for Life in Space (SOLIS)[/URL] ...in which he describes a program for propagating microbes throughout the Galaxy, as a...