Physics

I wonder how time become a mystery to those who probe it's nature.But regarding my question,is it really a real thing or just a representation or a meter of how much change a matter had undergone because we all know in the physicality of our observable reality,it change except change itself which the second law of thermodynamics applies. Any more explanation of it to lighten more our understanding is very much appreciated.Thank you....

I understand that the "Twin Paradox" problem is not a symmetrical problem. Aside from the TP arguement. Is there any other basis for the claim that the Universe is not symmetrical?

I've been randomly inspired to draw abstract flow charts, but don't have any technical knowledge of terminology nor quantitative knowledge. I do however believe they are meaningful and am interested if anyone here would take a look and provide insight, or even complete dismantlement. Is it possible for me to theorize scientifically this way or am I a fool? Are there large negatively charged particles that sort of keep an imprint of our existence and make it move corresponding to the protons of our reality?

Hello there, This is my first post on the forums, and I'm excited to be a part of this community full of science and mathematics! I do have a question, though. I understand the concepts and differences between linear and non-linear time, but I have a feeling that I might not be using the concept of linear time to interpret time. For example, when I'm doing something (it doesn't matter how big or small), I remember doing it, but I know I've never done it, and I know I've never done it. To back this up, I see myself standing in an exact position seeing someone's sweatshirt at an exact time when it happens. In a sense, I'm in the future and the present at the same tim…

Does the relativity of simultaneity have any bearing on "before" and "after" ? Is it possible ,dependng on one's FOR to judge that the order of events are different to the order of the same events as judged by another? Or is it only the proximity of events that can be so altered?

If i have a closed system and i want to raise its temperature by raising the pressure to make an autoignition process, how do i control pressure and raise it? And please, what are the methods to determine the autoignition temperature of a solid substance? Note: I am just 16 years old and i am doing a scientific research for a competition, so i need help, please. Thanks in advance..

Everything is a wave, different possibilities. Imagine every decision you make as if you are on a wave. Imagine the double slit expirment using a wave pushing the particle. Ger rid of arrow of time and use wave of time.

I am collecting data for a research paper I am working on, which relates to scientists (as well as students and just people interested in science and how they feel about their role in the production of weapons. If you all could fill out this short survey for me, that would be a great help Here's the link: https://docs.google.com/forms/d/e/1FAIpQLScJCsO5WEOvYak163vWdQahvC99hfd36RA0H5Dv3Hw-opsMsQ/viewform

I have read about a technique that uses very high pressure so that temperature gets very high in order not to use any type of power or energy and the selected thing burns....may any one explains me more details about this technique, what is it called, how true is it because i have a doubt about it. Thanks in advance..

Now, I'm wondering. As I've heard, materials with high dense structure, rich with hydrogen or metals with higher atomic number (denser structure) like osmium, could utterly prevent x ray scanners on customs to penetrate through them, as the strongest neutron scanner has 10MV strongest penetration ability so far (penetrating through 40cm of steel). I'm wondering which metals or other than metal materials, not lead, could be 100% protective against those scanners?

Does dark matter surround a galaxy in a sphere shape ? Does this sphere have a constant density ? Or a changing one, like less and less dark matter towards the outer rim of the sphere ?

first of all, hi, how are you? I was watching the Flash series when in a certain episode appears two villans, one with a radius that reaches the absolute zero (-273,15 °C) and another that reaches Planck temperature a(141 X 10³⁰ °C) the series said that one cancel the other, but we all here know that is wrong, but really, what will happend if this two radius touch one another, and what will happend if an ray at absolute zero touch an body? and if an ray with Planck temperature? I´m waiting thanks (sorry for the bad english, I'm brazillian

Hello all of you, I hope you can help me out here. I'm doing some spectral experiments at university, and I recorded the attached spectrum of a halogen lamp with an integrated reflector. But there are two additional local maxima in the spectrum, at around 806 and 910 nm. I just can't figure out what the source of these is. I hope I'm at the right place for such answers here. Thanks in advance, Rico

Dear all, I 'm someone with an open mind interested in urban myths etc. I found a supposed interview by someone called Al Bielek who claims to have travelled through time. He would have done that in a US military experiment, now it's naive to dismiss all extraordinary claims as there will definitely exist secret technology by the military, though this is quite extraordinary to claim. I seriously listened to what he said (though most likely fake it's still a fascinating story he had to tell and betterctyan most science-fiction) He said that he travelled to the 22nd and 28th century. He described floating cities in the 28th century. The relevant part of the …

Hello guys I'm a bit stumped here - why is [math]a_B[/math] tangential to the right along the x-axis as seen on bottom of the attached photo. I understand that velocity is zero at point B but why is acceleration tangential along x-axis instead of normal? If the bar is falling downward at center G then it has a path about B right? So B should have normal acceleration to the right instead of tangential. Maybe someone can explain that better for me. A bit frustrated here and thanks in advance.

Hello, this is more of a question then a topic, but i didn't know where to ask so I'm just gonna post it here So today some workers came to my house and started cutting metal bars with a large machine. After they were done, there was a lot of metal powder on the ground, so I grabbed 2 magnets shaped like a ball and started gathering the powder, and then put it in a container. However there was still some powder on my magnets. It stayed there for 3~6 hours. I used water to try and remove it but it didn't work. So I left it to dry for an hour or two, when I came back I managed to remove it. And when I did. To my surprise the magnetic field of the magnets was much larger, t…

Good day all I need a list of boiling points of various elements in a vacuum but keep coming up with nothing on Google. Any help or pointers to reliable sources is apprecaited. Thanks

from scientific american: "An excited atom in a small cavity is precisely such as antenna, albeit a microscopic one. If the cavity is small enough, the atom will be unable to radiate because the wavelength of the oscillating field it would "like" to produce cannot fit within the boundaries. As long as the atom cannot emit a photon, it must remain in the same energy level; the excited state acquires an infinite lifetime." if its unradiated, how does it know it wont fit? - it hasn't touched or seen the walls.. and why does it 'fitting' really matter, why not just radiate and get all messed up, why does it care at all?

Hello everybody! The Pioneer anomaly is or was a possibly anormal small deceleration best observed at Pioneer-10. http://en.wikipedia.org/wiki/Pioneer_10 http://en.wikipedia.org/wiki/Pioneer_anomaly It was reported by Anderson et al (arXiv gr-qc/9808081v2), Turyshev et al (arXiv gr-qc/9903024v2), and in detail in 2002 by Anderson et al: http://arxiv.org/abs/gr-qc/0104064 This latter paper studies and rejects possible explanations: everyone should read its sections VII and VIII before suggesting residual gas, dust, Sunlight and heat recoil, leaks, unknown planets, dark matter and many many more. The 2002 paper explicitly discarded the infrared recoil by Pioneer's cen…

Hello just re-did my old quiz from 2014 and for b) I got [math]F_{B} = 4,500 N, B_{y} = 13,078.9 N, A_{y} = 1,636.1 N[/math]. Did you get these answers as well? Thanks!

I've heard that biophysics is an interesting and rapidly growing field. However it seems that all the information I find on it is vague. Does anyone know more about this? Also, what use can it be? What can we do with it?

I want to know an expression for the Momentum of this car using the variables in the photo (all of which are known). The lateral force for the left and right wheel are the same, but different from the front wheels. The longitudenal force for the left and rear wheels are different. Delta = steering angle. a = distance between front axle and Centre of Gravity, b = distance between rear axle and Centre of Gravity, c = half the width of the car. Flong l = lateral force of the left wheel, Flong r = lateral force of the right wheel. Can anyone help me with this? Thanks in advance!

I'm just trying to learn about electricity/inventions for fun. Are circuits necessary for all machines to run? If not, what are other ways to deliver electricity to machines, and why do certain ones require circuits? What are some examples of ones that require them and ones that don't?

Due to my dishwasher being broken, I found myself doing dishes by hand for a few days. We have some Correlle dishes that stack very tightly together, and I noticed that when they were stacked while submerged in water, it was quite difficult to pry them apart. A couple of times I even stuck a knife between them to pry them apart. Similarly I was making split pea soup tonight and after rinsing off the dried peas which all have one very smooth flat surface, I found that they dropped out of the colander in one stuck-together clump. I assume the combination of water with smooth flat surfaces is the reason they are sticking together, but I don't understand what is occurrin…

CREATION OF ENERGY Experiment Consider a ball of density 1100kgm-3 and mass 1kg. Consider a tank with water of height 10m. Place the ball in the tank so that it sinks to the bottom of the water. While at the bottom of the water the ball is made to displace an additional volume bringing down its density to 900kgm-3 thus it starts rising to the water surface. Its previous volume was (1/1100)m3 and its new volume is (1/900)m3 The volume added is the new volume minus the old volume (1/900) − (1/1100) = 0.000202m3 The energy needed to work against the water pressure and create this new volume is equal to pressure multiplied by volume 𝐸= 𝑃𝑉 &#…