So for this question, I understand the math but just wanted to be clear on a few things. So I had this question on my midterm but instead of tensile and compressive stresses, it was tensile and tensile stress. I initially thought that the delta sigma in the integral was the maximum stress so in...
Hello! I am using a mixture density network (MDN) to make some predictions. My model is very simple with one hidden layer only with 10 nodes (the details of the network shouldn't matter for my question but I can provide more if needed). Also my MDN has only one gaussian component which basically...
When light is viewed from an accelerating frame of reference it appears to bend at a rate of a/c (the acceleration a being at right angles to c). By the Principle of Equivalence the bending of a beam of light in a uniform gravitational field ought to be g/c rad/sec. In principle you could use...
Hi,
I am not sure what the correct forum is for this question.
Question: When do we need to remove seasonality from time series data to do a regression analysis?
Context:
I am planning to conduct a prediction analysis where I want to find out how a device performs. I hope to estimate a...
As we all learned a long time ago, the trajectories of individual air molecules can't be predicted, but the behavior of macroscopic air masses can be predicted--if imperfectly, as with weather forecasts.
Similarly, the behavior of human individuals isn't always predictable. The less well...
What is the most elegant way of predicting drag on an airfoil in inviscid and incompressible flow? Or is this still an open problem?
It seems like the consensus for airfoils in incompressible and inviscid flow is that they cannot produce drag; or at least, we are not able to predict it...
The roulette prediction algorithm is described here: http://pingless.co.il/roulette.pdf
And I have a problem with the formula attached
Where teta θ is position, velocity and acceleration of the ball. g is garvity force. r is the ball radius from center of the roulette. a is stator incline...
From NASA page:
The inner parts of the rings move around Saturn faster than the outer parts, all in accordance with Kepler’s third law for small objects revolving about a massive, larger one. They orbit the planet with periods ranging from 5.8 hours for the inner edge of the C ring, to 14.3...
Hi, i am trying to understand, how to calculate the deceleration of the object?
I have a small toy car in the track, after i release the car, i want to calculate the deceleration of the car, and predict how many loops, it's going to do, after measuring the timing of some revolutions. Is there...
I am trying to determine the efficiency of a light source for treating plants. When using the light source, there is an equal probability of encountering two different plant species.
The light source has a certain electro-optical efficiency ##\eta_{\text{eo}}##. And each plant type has a...
Newton's law of gravitation cannot be compatible with relativity because the gravity from a massive object applies a force to all other masses infinitely fast. General relativity is supposed to correct this flaw by setting a speed limit on how fast the effect of gravity can reach a distant...
Ok so these are two different goals. But mathematically, I don't see how one can explain well without also being able to predict well. After all, regression is about function estimation regardless of which goal. If we can infer well using the coefficients, then we should be able to predict well...
Homework Statement
A random sample of 100 automobile owners in the state of Virginia shows that an automobile is driven on average 23,500 kilometers per year with a standard deviation of 3900 kilometers. Assume the distribution of the measurements to be approximately normal. Construct a 99%...
With Hurricane Harvey hitting the Texas Gulf Coast, I came across this article, while trying to learn about these different computer models.
I found the article in this PDF file an interesting read. I'm sure that there have been some advances in real-time prediction methods, since this article...
Hello,
I'm working on a (private) Software Project and Part of that is finding a Way to Predict Projectile Positions. My thought's are explained from a Code View a little bit, but I tried to clarify everything so everyone could understand what's going on.
(It's my first time in this Forum, I...
I was not sure where to post this question so if anyone has a better home for it please advise.
I am trying calculate how much temperature a given mass is required to be heated to (oven setting) to reach a target temperature on the surface of a metal like copper. I also need to know this...
String theory and M-theory and Kaluza Klein theories predicts additional extra dimensions
at least 2 recent papers proposed tests these predictions of extra dimensions
String theory phenomenology and quantum many body systems
Sergio Gutiérrez, Abel Camacho, Héctor Hernández
(Submitted on 24...
What do Physicists understand the role, purpose, and proper subject of Physics to be ? Is it a science? Does it seek to gain knowledge or understanding? Of what (if not reality)?
I've heard a number of physicists shying away from words such as "reality" and distancing themselves from basic...
Cross-posted on SE.DS Beta.
I'm just doing a simple linear regression with gradient descent in the multivariate case. Feature normalization/scaling is a standard pre-processing step in this situation, so I take my original feature matrix $X$, organized with features in columns and samples in...
I am looking at a solution. The problem is to predict the number of medical doctors in a county. The data set has a few variables such as the observed number of crimes in that county, proverty level etc.
Since the problem is just to predict, then I assume that a data driven method is necessary...
It is said that GR in the weak field limit it produces Newtons familiar law, so why can't GR produce other formulas for "strong field" which I guess it means at short distances.
Homework Statement
Hello all, I created a predictive model from a data set of observed values and am looking for probabilities for accuracy. Data set A (observed) and data set B (predictive model) have a correlation of 84 % using linear regression. Data set A and B are both normally...
Hello all! For an activity I'm organizing, I have about 16 players. Each player have interaction with 6 others - 3 which on his plus side, 3 which on his minus side (he can't have a partner that's on both sides).
Basically, what I'd love to know is if the number matches and in the end each...
So say I want to predict the next point in the data.(or outside since its prediction)
So first, I would include all the variables inside the dataset into the initial model. Then I would use stepwise AIC to iteratively reduce the model down to the final model with minimum AIC. ( I can do this...
Hello PF
Why are scientists still unable to predict earthquake? Will it be possible to predict earthquake? Are there any promising research going on?
If only we could know when earthquake was going to hit, how many lives could have been saved!
Tom Campbell posted a series of videos in youtube where he proposes a few variation of double slit and DCQE experiments that might support his theories. He claims that would be possible to predict a future atom decay or a beam splitter behavior that way.
I am very interested about experiments...
It will sound a little bit stupid, but Ill ask anyways:
I have two series systems, the second is an UKF (Uscented Kalman Filter). I was told to reduce the first system in order to that the UKF estimate less states. My question is: What exactly do the states represent? I mean, if I have a...
Read about it here: New Scientist
Hear about it here: https://audioboom.com/posts/5202837-red-nova-in-constellation-cygnus-predicted-2022-ken-croswell-newscientist
How is this done in practice? I know that in GR the gravity is believed to curve not only space, but also time, and this prediction has been confirmed somehow in practice. How can we measure that? Because as far as i know, there is no device that actually measures time, but instead measures a...
I have had many people claim that QM has never made a prediction that has been contradicted by experiment.
Yet as i understand it Qm predicts the vacuum energy density is 10^122 erg per cubic cm whereas the measured energy density of 10^-8 erg per cubic cm. So how is that not an example of an...
Whenever I have a stain (paint, glue etc), I attempt removing it after the following scheme (if unsuccessful, I proceed to the next solvent):
Water, soapy water, alcohol, white spirit, acetone.
My question is...
Is it possible to chemically PREDICT which solvent will be succesqsful on which...
A light particle solution to the cosmic lithium problem
Andreas Goudelis, Maxim Pospelov, Josef Pradler
(Submitted on 29 Oct 2015 (v1), last revised 24 May 2016 (this version, v2))
We point out that the cosmological abundance of 7Li can be reduced down to observed values if during its formation...
I have to filter data with Kalman filter. I know process error covariance Q and measurment error covariance R. Problem is with state transition matrix A, control matrix B and observation matrix H.
First of all, data goes through this transfer function:
##W(s) = \frac{4s}{4s+1}##
I can't get it...
Dear Friends!
Q.There was no direct evidence of binary black holes till September 14,2015,when signals coming from about 1.3 billion light years away were captured by LIGO.
Now my question is that how in advance we knew about the specific colliding pair.Did we theoretically predict the graph...
Hello everybody,
Recently, I read this interview with Edward Witten where he claims that supersymmetry is a falsifiable prediction of string theory.
But then again, I remember interviews with proponents of supersymmetry where they were asked whether the inability to find any hints of SUSY in...
Hello forum,
Is there any method of knowing the location of source and probably intensity of vibration from afar without sorting to a doppler effect?
This is in the same as our auditory sense, when people call us at a distance we could easily approximate how far they are and the volume they speak
Hello folks, I need some physics help.
Some background to get us on the same rails :)
I am developing a 2D game in my spare time. Player controls an object (aka spaceship) in open space (no gravitation influence) by selecting a point in space. A constant force which is always pointed at the...
I'm trying to understand how the SU(5) prediction for the proton decay lifetime of \tau_{p} \sim10^{31} yr has been arrived at. I keep seeing it stated that \tau_{p} \sim \frac{4\pi}{g_{5}^{2}} \frac{M_{X}^{4}}{M_{p}^{5}} where g_{5} is the SU(5) coupling and M_{X,p} are the X boson and proton...
How did Newton predict his third law? If we take the system as the whole universe Newton's third law leads that the net force of the system is zero.Did Newton have an insight about this?
Hi all,
I'm attempting to write something on proton decay (specifically in the p \rightarrow K^{+} \nu channel) and need to understand some theory that predicts it. I'm under the impression that the MSSM is the most straightforward theory. However, I look through introductory texts/documents...
The supernova happened long ago of course, but as far as I know it is the first time the visibility for us is predicted in advance: the host galaxy is at a redshift of 1.49, and due to gravitational lensing we see multiple images with a significant time delay between them. I don't understand the...
I have read many explanations of Bell’s proof that mention in passing something like “According to QM, the correlation between measurements of spin at different angles should be given by the cosine of the angle between them.” Sometimes they talk about 1-cos(x)/2. Sometimes they talk about...
Hi, I've read on the cern website that the standard model does not predict that matter inherently has mass, if this is the case how does the model predict particle masses and also why doesn't it predict that matter inherently has mass? Thanks.
Hello Everyone,
I really can't understand stats and it's driving me crazy.
I have data for births linked with different years, the graphic looks like this
But I need to make a prediction on the births in year 2010. How do I go about that?!
One of my friends majoring in physics with me was telling me that the CMB radiation was not "predicted," by the big bang cosmology, but was in fact a "post-diction," and that the range of values for temp. obtained by Penzias were in fact way off, 5K to 50K and that other "cosmologies," can more...