Life Definition and 1000 Threads

For a planet to be able to support life, it needs to have a source of energy. In our case this energy comes from the sun. But in this paper, the author argues that a rogue planet (a planet that has been ejected from its stellar system and no longer orbits any star and is wandering in...

Within about a month, Perseverance and Tianwen-1 will reach Mars. There is a lot of excitement about these missions, and anticipation of a possible mid-2021 discovery of extraterrestrial life. NASA's chief scientist, Jim Green, thinks we are close, and is worried that people aren't ready for...

Under the topic of simple harmonic motion comes the composition of two SHM's with the same angular frequency, different phase constants, and amplitudes in the same directions and in perpendicular directions. composition of SHM's in same direction: say a particle undergoes two SHM's described by...

If this pans out, it would be nice. I had read FB founder Mark Zuckerberg bought one of these chambers for his wife, but can find nothing about it now, only that Justin Bieber sleeps in one. :rolleyes: https://www.yahoo.com/news/human-ageing-process-biologically-reversed-153921785.html

Life, on first glance, appears to violate the second law of thermodynamics. This is because we see an apparent increase in complexity over time, i.e. a decrease of entropy. The resolution of this apparent violation is supposed to be that the sun provides enough energy and expends enough entropy...

is maturity a requirement to succeed in life? what do you think about immature famous people social media shows? if you find a weakness in this question please let me know!

I encountered a website with statistics for a large number of video games, specifically regarding their availability across various platforms, their sales over time and some other things and methods to visualize them I found this really helpful. Might there be other services like this that...

Hi, some time ago I wondered if it's possible to calculate fatigue life (number of cycles to failure) for complex models analytically, based on static FEA results: https://www.physicsforums.com/threads/fatigue-life-hand-calculations-based-on-static-fea-results.994264/ Unfortunately, it seems...

Hello Everybody! I am new to electrical engineering and only had 1 formal intro class on the subject (albeit I did very well in it) and have found myself in a position where I need to design a circuit for a micro reflex sight I have been designing. So let me first describe how my competitors...

Hi, advanced FEA programs allow their users to perform fatigue analyses. However, there are still many programs where such simulations can't be performed. I've heard that in such case one can use results obtained from regular linear static FEA to calculate fatigue life manually. Theoretically...

Which appeared first on Earth, animals or plants? Also, which appeared on land first?

Lets suppose we could build domed cities on Mars. The surface of the planet has major temperature shifts. Would people inside the domes experience such things too, or no, since if the dome can provide enough radiation protection, it provides enough heat insulation too? With present day anti-rad...

SETI is searching for a signal from space. What is this signal supposed to say? Hi, here we are.? We were broadcasting signals into space for 50 years before we actually knew we were doing it. Those first signals are still going, but they are not traveling in a big sphere. They're going in the...

I have a problem with plumbing in the bathroom at my condo (quite old) that I am living. The plumbing inside the walls of my bathroom make this whistle noise always and it goes away when I flush the toilet. And then it comes back again after sometime. Do you know what could be happening here?

I'm considering making a Natural Selection Simulator (possibly in Java). I've always been fascinated with the idea that so many traits can evolve independently of each other in the same population (even little things like tufted ears and loss of tail, etc.) and I want to see it in action. Like...

I don't know enough biology to ask this question in a well framed manner. I don't know at what point a primitive self-replicating thing is considered a living individual - I expect that is a matter where reasonable people can disagree. I am sure that is not the only ill-defined concept in my...

Long times have been that I've decided changing my job from engineering to theoretical physics. Because I don't want to learn the rules that have been discovered by any scientists and make a situation about getting it real :]. I want to learn how the rules of nature is being discovered and what...

Summary:: A link I posted on my life experience. Here. it is. Al Before I even start let me state I was never a marks oriented student. I did what I needed to get by. This philosophy got me through High School and into my local state collage way back in 1959. I always felt learning was...

Specifically he homes in on the multiverse and the 10^500 number that crops up. Basically he ends up saying that the whole concept of the multiverse virtually renders any TOE into pointless oblivion. So with this in mind I was wondering if I could also use the multiverse as an explanation for...

I've read here the following: "Currently, the Moon is moving away from Earth at a rate of 4 cm (1.5 inches) per year. In 50 billion years, if the Earth and Moon are not engulfed by the Sun, they will become tidelocked into a larger, stable orbit, with each showing only one face to the other"...

Today's APOD (Astronomy Picture of the Day) https://apod.nasa.gov/apod/ap200428.html contained a reference providing answers to the question: How will humanity first discover extraterrestrial life? The reference is https://apod.nasa.gov/apod/ap200429.html. The title of the reference is 100th...

Do all stars in their life cycle (t) emit energy (E) that follow a bell shape curve? If yes, is the curve symmetrical always? How is this related to nuclear and thermal time scale?

Summary:: Specifically, how Earth and life on it would have evolved if our planet was twice as massive but with the same composition of building elements? Could humans or sentient, upright walking creatures appear in the evolutionary scale in a twice as strong gravitational field? How that...

I watched a video lately describing how life could have arisen on Earth near the hydrothermal vents, with the exact way it formed being unknown. This made me wonder could there be a very simple configuration of DNA (or RNA?) that could give rise to life? I'm thinking the earliest life forms may...

There are lots of decent articles about this, examples: https://www.space.com/40435-finding-aliens-humanity-reaction.html https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact - in part, discusses how speculative this subject can be Well, since Jenner first...

https://www.space.com/alien-life-europa-enceladus-second-genesis.html

What would an alien world with oceans of vinegar instead of saltwater be like? Would the atmosphere be air or something else? Since I could easily say the lifeforms living there breath air different than us. The whole reason for this is I want to see bio-propelled rocket lifeforms. Take a tiny...

Summary: Hydrogen peroxide, H2O2, decomposes as per following reaction scheme: H2O2(l) → H2O(l) + O2(g) The concentration versus time data for the decomposition of hydrogen peroxide is given in Table 1. i) Calculate the reaction rate constant, k, graphically, with the aid of Excel software...

Summary: A supply of negentropy into a system is necessary to create states of higher order and complexity. Since the origin and evolution of life involves the creation of ever more complex molecular arrangements of atoms, life could not start without a sufficient supply of negentropy. So when...

Why do metalised film helium balloons only last about a week? Could I improve this result and make a balloon float for a year? (and don't cheat and say just make it bigger) how do I stop it leaking? Are there any better materials to make it from? (unlimited budget) As I understand aluminium...

Summary: At some point, there has to be a point where the "goo' (as described by "Q") becomes us, what is that transition point? What made not life, life? <moved to general discussion> I have been looking around the internet for an answer to this question. The difference between "life" and "not...

The universe after the big event was a lot of lifeless stuff. However, as things settled down the rules behind the curtain were such that life was allowed to develop, they may have even been such that they encouraged the things to happen that were conducive to the process that has resulted in...

If a person is from New York, and he/she wants to visit Paris, Rome, Munich, Bern, and Madrid in a single trip, what's the shortest route to take? Are there any practical online tools you can use to solve this problem that doesn't require you to have knowledge of programming or mathematics?

Does the individual matter in evolution? I remember watching a documentary about human evolution but I forgot most of it, it said that our ancestor decided to stand up and walk one day to see predators better (something like that) and that is the origin of how we came to walk upright. So one...

Theoretically how many billions of years after the Big Bang when life could theoretically exist in any star system? I am thinking how old they are now. And how big the accelerator they had built to probe the Planck scale. Couldn't very advanced civilization created solar system size...

In This paper we have used Ischemia - Repurfusion in chick embryo to study different markes using Western blot. quoting from Paper Various in vitro and in vivo models are currently available to study I/R mechanism in the brain and other tissues. However, thus far, no in ovo I/R model has been...

Consider the full-circle train (radius R) of a great number (n) of wagons, coupled by clocks that can print a dot on the rail. All clocks are synchronised when the train is at rest (in regard to the rail, being the Stationary Frame SF) and then the train is accelerated to a constant speed v...

I am a little confused on how to calculate the bearing rating and life for a gearbox in a mixer application. The only information that they are providing is the following, using a 1/4HP motor, 0.08 HP expected loading, a max torque of 87.2 in-lbs, 175.8 in-lbs bending max, and 632 psi expected...

I seek recommendations and testimonials for books that enumerate the unique factors of the Earth-Moon system that gave rise to life on our planet, its place in the solar system, and the solar system's place in the Milky Way galaxy. If you have read any books on that topic, I would appreciate...

I believe I use a formula such as $$n\frac{t}{T}$$ but am unsure I've never done one without a given amount of the sampleSo if I was to use this I would get 8/(divided by)2.67 = 2.99625468 rounded to either 3 or 2.997 But i don't think this is write because you need to use 1/2 in this...

Summary: Can an interstellar planet be hot enough to heat it's terrestrial moon without igniting fusion? I am a science fiction writer, however I am studying astrophysics to better captivate audiences with real and believable plots, The idea in question is an interstellar sub brown dwarf gas...

How did they calculate the half life of xenon 124 to be longer than the age of the universe if they only observed one decay? Is there some way to estimate half life?

I am in my forties, with a child and a firm to run (little to do with physics). I have a degree in physics, and a MSc in high energy physics (QFT, a bit of string theory, etc.). I did not continue with an academic career, though. Now I feel I want to have, as a goal for the rest of my life, to...

How small should ##\Delta T## be in a collision to be considered elastic? In elastic collisions ##\Delta T =0##, but as far as I know, just atomic collisions are considered perfectly elastic. Then, which criterias are used to considere a collision between two objects elastic?

Hello! I hope you are all doing well! I've been always intrigued by fluid mechanics and decided to try out a quick experiment with my water faucet. After using some equations I found online [1] [2], I plugged a hose to the faucet and let the water run. I filled a 1 quart bowl and recorded the...

https://phys.org/news/2019-01-planetary-collision-moon-life-earth.html The claim is that was how the excess Carbon, Nitrogen, and Sulfur arrived in the Earths crust, without them being in the core. For instance the Carbon/Nitrogen ratio of 40/1 is twice the 'expected' value.

This Science magazine News article discusses a new scenario for early Earth history that is claimed to explain the Earth's surface metal distribution and that it could effect conditions affecting the origin of life. This was before the end of the heavy late bombardment (timeline diagram in...

Homework Statement You have 0.0625 grams of an unstable element and 0.9375 grams of the stable daughter product. How many half-lives has it undergone？ Homework Equations N=No (1/2)^(t/(t1/2)) In which N represents the final activity for a period of time No is the original activity t...

O.K. we all think of Neptune as a "Gas Giant" but I have recently learned that it's more correctly referred to as an "Ice giant" If it truly has a liquid methane and Hydrogen ocean, is it possible that it may contain some form of life? And considering the size of Neptune, that life could be very...

All those joke bars to walk into. Ever consider the people already inside? Let's hang out at Infinity Bar. Yes, located between the Adiabatic AC Repair shop and Moe's Many Manifolds ("Put an edge to your Universe!"). Slide into Infinity Bar and join the fun: ----------------> linguist: "...