1. S

    GR deals with what is Real.

    Somewhere around 1 x 10-18g in a vacuum is a new constant. The diffraction gets too small to identify fringes. It's a natural size for the object to be physical and to never be in superposition. Uncollapsed(stateless | unphysical | virtual) Quantum Waves + State(Matter Field or wave collapse...
  2. K

    Ideal gas vs. real gas calulations

    Dear Physicists, I would ask about the confirmation of my concept, because at work I don't have any thermodynamic specialist to consult it with. I am not a physicist and probably this problem will be trivial for you, but I will appreciate any comments. My project is to recover greenhouse...
  3. M

    Is Simultaneity "Real"?

    In my paper, "Accelerated Observers in Special Relativity", PHYSICS ESSAYS, December 1999, p629 I gave a proof that (in regards to the well-known twin "paradox"), the current age of the home twin (she), according to the traveler (he), as given by the CADO reference frame (which is completely...
  4. P

    Is Dark Matter Real?

    Way too many times physics amateurs have posted claiming dark matter isn't real and we should listen to them etc. I've ignored those threads because they weren't credible. However there's an article on this subject in Scientific American this month entitled Is Dark Matter Real by two...
  5. H

    Questions on confusing lever mechanics in the real world (not mathematical)

    This is based on a confusing question my brother asked out of curiosity. I know how levers work, i.e., I know they trade distance for power and vice versa. What we want to know is why that actually works in the real world, because thinking about it, it doesn't seem to click. My brother has a...
  6. P

    Real World Free-Fall Simulator Help Please

    Here’s the scenario: I have a 1.2kg dart that is dropped from a height of 50m and penetrates into the ground to a depth of 0.09m. I can calculate (with wind resistance), the velocity, the kinetic energy at impact, the momentum at impact. Using the 0.09m penetration depth, I can also...
  7. K

    How real is the fitzgerald contraction of SR

    Here is a simple question presented without a lot of maths but just a diagram I made in Inkscape paint software (attached). It shows a couple of box cars going through a tunnel which ar attached together (not shown). However when the wheels are placed over two sensors simultaneously (shown as...
  8. H

    Real World airflow problem: countering inflow of cigarette smoke

    Dear Ladies and Gentlemen! Lead-In: I would like to ask about my real world problem. I live in an apartment house, first floor. My neighbor has his west side balcony 1.5 meters from mine. The balcony is cca 3 meters wide and 1.4 meters deep. My door is on the right part of the longer side...
  9. C

    Instants: real or abstractions?

    They say that instants are only convenient mathematical abstractions. That no real fact occurs only "in an instant". But when I throw a pebble vertically upwards, it has a highest point in its trajectory. The pebble is not in that position for a milisecond, because a milisecond is a time...
  10. K

    Real World Thermodynamics Question

    So forgive me if this isn't the typical question fielded here, but I have a practical application question concerning thermodynamics. Say you have 9 electronic devices that have a maximum, constant heat output of 110°F in an enclosed space that's roughly 11'x4' canister with no airflow. Each...
  11. F

    Special Relativity effects; real or imaginary?

    Clock A is at rest in space. Clock B is traveling at a uniform velocity 0.5C relative to A and is heading directly towards A. As B passes A the clocks are synchronised. A notes the distance B has travelled after one year is 0.5 light years. Question: From B's perspective... 1. how...
  12. E

    I need help to get started. I know how to do it for an IDEAL GAS but not REAL GAS

    Hi all, I understand ideal gas process path well but not for real gases. Can someone help by pointing me in the right direction? I have attached a file jpeg file with the question. Thank you so much for your time and help guys.
  13. K

    Is the Fitzgerald-Lorentz contraction "real"?

    Is the Fitzgerald-Lorentz contraction "real"? My question was motivated in part by this thread: @AndrewS's illustration of a spring is good enough for my purposes. If one observer, in relative motion to the spring, sees the spring as...
  14. K

    is QM momentum wavefunction for real?

    I was watching the Quantum Mechanics lectures on MIT open courseware. I notice they define momentum wave function as the sum (integral) of the amplitude of all wave functions multiplied by 1/sqrt(2*pi) * exp(ikx) so that the entire equation comes to be: Psi(x) = Integral(1/sqrt(2*pi) *...
  15. Z

    Real Life Thermo/Fluids problem: Moisture transfer between two streams?

    This isn't a university question, but a real life one, and I was hoping to get some help with this problem. There are 2 streams from 2 pipes merging into one: Air @ 60C with 0% RH Wet DSG (10% Water Content) Info: When the two streams merge into one, the volumetric flow rate is...
  16. R

    Real life water tank question

    Hope someone can help with this ... and as it's a REAL question, I need the right answer! I am planning to fit a water level gauge to a (narrowboat) fresh water tank. There are products available that measure the water pressure at the bottom of the tank, and so all you need to do is calibrate...
  17. MBW

    Are singularities Real?

    A recent post by topsquark indicated that electrons (and similar particles) are volume-less singularities. While I recognise that many mathematical systems will include singularities, my "gut feeling" is that they had no place in the "real" world. Indeed I always thought that when physicists...
  18. S

    What is a REAL IMAGE?

    Q: What is a REAL IMAGE? A: A real image is one that can be formed on a screen. This is a question and an answer to that question given from my physics text book. My question is: is the distance from the screen to the light source known as the focal length? Any input would be greatly...
  19. I

    Real World Physics Question

    Hi. I hope this is the proper forum for a non-student. I am trying to figure something out from work. You have a pickup truck with the tailgate down. No one knows the maximum amount of weight that the tailgate can hold. Someone says to get a single large piece of plywood, such as 4' X 8'...
  20. W

    Real gas

    In my latest lesson on physics, I found it quite difficult to understand the van der waal's equation. With (P + a/V^2)(V-b)=RT I have difficulty in understanding a/V^2 and -b added to the ideal gas law. Could anyone explain a bit detail for me?(Wink)