Life Definition and 1000 Threads

1. Problem statement A steel rod supporting a stress of 8000 psi at 1000 ◦ F is not to exceed 5 % creep strain. Knowing that the steady-state creep rate can be expressed by an equation of the form ##\dot{\epsilon}_{s}^{C}=B|\sigma |^{n} exp \left(\frac{-Q}{kT} \right)## ε⋅, strain rate B...

Dear friends! I had read about a comparison of laws of thermodynamics as follows. " If energy extraction is a game. First law: You cannot win the game. Second law: There is no break even. Third law:You can not leave the game". My problem is that I cannot convincingly understand the comparison...

Hi everyone, I'm reading thermodynamics and I can remember what's internal energy, enthalpy, entropy etc but I'm not sure whether I understand it completely or not as I couldn't find any real life reference to these concepts and what's the significance of learning all these things? Why we name...

I am a undergraduate in an interdisciplinary life science/biochem/mol.bio/physical.chem degree thinking about which optionals to take. For this I have to consider what specialization I want to pick in my major. The two I am leaning towards are biophysics and biochem. There is also medical...

I started my undergraduate physics degree in September, and having been enjoying it a lot so far. As I'm sure any student does - I am aiming for a First. I was wondering if any graduates would be able to help me out by answering a few questions for me on their experience: Are there any things...

I have been struggling to balance my study social life for a while now, when i study for instance i often overdo it doing like 5 hours after school this really accelerates my learning but leaves me feeling slightly depressed, stressed and overworked. However the opposite occurs when i try to...

A couple of days ago i stumble across the two slit vid on youtube and entanglement. before this day i thought quantum physics was just some kind time travel mumbo jumbo ... I am sure you get my level of noobieness from this :) ok questions if you would be so kind :) ( don't forget the...

Does anyone actually believe this statement? I had a few well meaning, though severely misguided, people try to tell me this back when I was in high school. How can it be better? No bills? So what? Do people just forget what it was like to actually be in high school (or worse, did they peak in...

When you found out the information of the ultimate fate of the Universe being 'heat-death' and that everything you love, everything you do and say will eventually be erased. That everything we do has meaning here and now but in the grand scale it serves no greater purpose. How does one recognize...

I'm shopping for a battery-powered USB charger. Someone on Amazon says that as current (amperes) increases, battery life decreases exponentially. He says that using a charger with a current of 500mA gets you 30% more total power from the AA batteries than if you used a charger with a current...

I know, the most dramatic and trite question. I am currently a junior physics and math major. Physics is my primary major, and I am considering an honors degree. I have to write a senior thesis, so I have been research-shopping: I dabbled in particle physics (computational data analysis of the...

I remember, a year or two ago, reading about a group which were simulating the early times of Earth's creation and they wanted to see whether life naturally pops out in it. But now I can't find it again or any other news from that group. Does anyone know about such a simulation?

Hi all, I have recently finished a PhD in quantum physics. At the moment I am a postdoc in the same group. I really enjoy what I am currently doing. I am moderately successful in a sense that I will probably be able to find a second and maybe a third postdoc, but most likely not successful...

Homework Statement Basically, the problem asked for the half life of Thorium-232, given the initial mass and the rate of decay. \begin{equation} \frac{dN}{dt} = 4100 \frac{ \alpha }{s} \end{equation} initial mass = 1.0 gHomework Equations \begin{equation} \frac{dN}{dt} = \lambda N...

The question is simple, was life able to recover from the very long and cold "snowball earth" epoque, which means that Earth was not completely sterile during that period, or, when climate became warmer, life simply reborn again - from scratch?

I know this forum doesn't allow speculation but is there any good theories in science that explain how chemistry can become biology? At the start of the big bang, there was no such thing as life and now here I am, material created by the big bang that has come together in such a way that allows...

Our Earth is going to be engulfed by the sun eventually. Urged by a primitive desire to continue life (human or not), I decided to devote my life to the said goal. I realized this is a risky, life-long endeavour with huge chance of achieving little at best. What is the best strategy for me...

Why do Acetic Acid Battery power devices only for short periods of time? Does it have to do with Capacitance?

Background: Physics Major (3.5 physics gpa), college graduate, pursuing PhD, PGRE: 700 52% I have seen a couple of threads on test taking, but I have a slight different direction. I don't have problems with tests in general. I have done well on many many exams ( physics, math, chemistry...

Hello, everyone. To give you some context, let me give you some background about myself. I apologize if this is overly sentimental but I can't help it. As a child, I was fairly bright and very intellectually curious. I got good grades. I was always among the top two in my class. I loved...

Hello Everyone. I'm pretty much a newb on the forum so please go easy :). My name is Mark, I'm from England, I'm in the late stages of my 15th age and I'm Home Educated. Now.. Where to start? I guess Primary School would be sufficient. Well, I started it as every other child does, however over...

Homework Statement a patient who is undergoing cancer theraphy is given 10 mins of irradiation from a radioactive source that has half life = 2 years. If the same source is to be used for same treatment 2 years later , how long should the patient should be irradiated? the ans is 20 mins .. can...

Wiki claims in stars, heavier than 1.3 solar masses (where CNO plays major role) there is an inner convection zone near the core, but no outer convection zone. Hence, such stars should be "calmer" - no solar flares, less radiation... Am I right?

just wanted to ask your opinion about this topic to see what people think.

So have you ever felt a moment where you felt like, I wished there was something like that invented/prototyped. Or have an idea that you wished to be enacted or built. Simple or Crazy, post them. I would extremely appreciate it. (I actually need it for design engineering). I got a few ideas, but...

I was recently doing some thinking about the relation between fossil fuels and organisms. First of all, how do scientists know for sure that fossil fuels are derived from prehistoric life? Do they assume this because fossil fuels are made of organic compounds and therefore must have come from...

What is the oldest part of our galaxy that theoretically could have held life some millions - billions of years before earth? I'm asking purely out science fictionic curiosity. This may sound like an even dumber question, but is there any region on the "map" of the galaxy that contains these...

Life based on carbon needs very especial conditions to thrive, life on Earth is a clear example of that. Lots of time and research have been dedicated trying to find carbon based life elsewhere on the Universe, but that search may be too narrow because that search assumes that life can only be...

My friend in mathematics department told me that one Hungarian mathematician Paul Halmos had said 'The only way to learn mathematics is to do mathematics'. Are amatuer physics enthusiast also do physics in their daily life. I want to learn from them. But what 's meant by "doing Physics"? Can...

Dark Side: I am a 28 year old advertising professional. I am extremely upset with the course my profession has taken. I feel unwanted in my office. I hate what I am doing for a living. On the other hand, I am extremely bad with numbers and math in particular. Bright Side: I love...

Homework Statement The Shroud of Turin, which shows the negative image of the body of a man who appears to have been crucified, is believed by many to be the burial shroud of Jesus of Nazareth. See the figure below. In 1988 the Vatican granted permission to have the shroud carbon-dated. Three...

Gammaray bursts (GRB) may affect the prevalence of life in various different regions of the galaxy. http://arxiv.org/abs/1409.2506 On the role of GRBs on life extinction in the Universe Tsvi Piran, Raul Jimenez (Submitted on 8 Sep 2014) As a copious source of gamma-rays, a nearby Galactic...

I honestly think that this should be one of our main goals as a human race. Why should we do this? Because, we can gain so much by finding another intelligent race. Here is what we can gain: - Just look at all of the bodies of knowledge we have; philosophy, math, physics, science...

How can life be compatible with the second law of thermodynamics? Here is how. Life is a self-organized system. A self-organized system is a system in which organization arises SPONTANEOUSLY, which means that the probability of the appearance of organization is large. But this means that...

Here is a simple analogy that helps to understand the basic idea of the Bohmian interpretation of quantum mechanics. Assume that you have recipes for two different meals. These recipes are written on papers. Hence, these recipes are real. However, when you make the meal, you use only one of...

Draw this description out on a piece of paper if you would like. I cannot figure this out, it has been years since I have done math at this level. I am standing at point A and have a distance of 87.8333 feet to Point B, my azimuth bearing is 123 degrees. I want to move over 20 feet and...

Please if we charge battery with high voltage like the battery charge voltage 4.2v and we supply 5v, is that will reduce the battery life. Thank you

Hi. I'm at a very critical point in my life / education. In 3 months I have to apply to the university I will attend next summer. I'm torn between studying physics or biology - I have had biology for 6 months, physics only for 1 week in my whole life. But I've been interested in astronomy since...

At least according to this article, https://nz.news.yahoo.com/a/-/world/24765825/extra-terrestrial-life-discovered-in-outer-space/ An interesting find, to say the least!

Homework Statement Radioactive nuclei are produced in an irradiated sample at the rate of 10 s-1. If the number in the sample builds up to a maximum of 1000, calculate the mean life and the half-life of the radioactive nuclei Can anyone advise on this one not sure how mean life is found...

This might sound crazy, but I want to study pronging human life span. I am thinking of majoring molecular nanotechnology so that I can use this major to construct an artificial enzyme(medical nanorobot) that lengthens telomere (I know this is not the only issue of aging and death). I am not...

Hey everyone, I have a math problem that I need answered to solve an issue in the real world. So, I am the treasurer of the Honors Student Council, an organization that looks after the Honors Program. We also have 10 Honors Societies. We have been buying food for our giant meetings every...

Tonight I've had a deceptively simple question that I've found maddeningly difficult to get an answer to. What I'm looking for is a list of springs with information on how much they can be compressed and how much energy they store. E.g.: Steel spring from company A has dimensions X, Y, Z and...

Do white dwarf planets ever die and eventually there will be no remains of the sun? What will happen to the gas giants with no sun to orbit?

I will be graduating in the Fall with a degree in physics, but I am afraid. Before now, I had a plan to go to graduate school. However, I've been reading around these forums that people with PhD's in physics are broke, cannot find jobs, and the field of physics seemingly oversaturated so much so...

Please select in the poll what you could use most in your life. If you want, you can tell us why :-p

http://www.cnn.com/interactive/2014/07/world/south-china-sea-dispute/index.html

Hey guys, I need help with a few more questions for this problem set I've been working on. I'm doubting some of my answers and I'd appreciate some help. Question: For the first one, I took v(t) as 0 since that is when it would be stopping or changing directions. Then I solved for t to get...

Hello. I would like to have some suggestion about how to make university life "more productive". I will make this clearer: 1. in the university I will attend (and pretty much in every university in my country) there are only 30-40 students of maths and 40-50 of physics; 2. it has been verified...

Homework Statement http://imgur.com/OInF6O2 The blue table shows the mortality and offspring production rates per year per age class by individuals of an unnamed species. The orange tables shows the starting population at time t, I have to find the number of individuals at T+1 (next year)...