The Earh's orbit is basically fixed in space, but it does rotate slowly. This is called the precession of the perihelion. This is not to be confused with the precession of the Earth's axis, which takes about 26,000 years to complete a cycle. The precession of the perihelion, which is what you...
Rather than a law, there are patterns of nuclear stability. Referring to this chart from Wikipedia, you can see that stable isotopes fall along the valley of stability. This is a line with equal numbers of protons and neutrons for low atomic numbers, but bends towards larger numbers of...
How can that be? The sun and Alpha Centauri are only 4 light years apart. It's like saying that Los Angeles is 3000 miles from New York, but 6000 miles from Brooklyn.
I think the OP's question is what would a star map look like from Alpha Centauri. Most of the distant stars would look about the same, but the positions of the nearby ones would change. In what constellation would the sun fall? I've never seen such a map, but it would be very interesting. We...
I think there are more important papers on this topic. I found this paper by Bhatt, et.al.
https://arxiv.org/abs/2108.05787
where they calculate the fermionic mass rations from the eigenvalues of the matrices of the Jordan Exceptional Algebra to be very interesting.
The six diffraction spikes are more caused by the three supports that support the secondary mirror. As said above, the Hubble has four secondary supports, so you get four diffraction spikes. The three Webb supports lead to six diffraction spikes, because you get one opposite to the support as...
Since the Tusi Couple is a hypocycloid, and the actual orbits are ellipses, how could this be said to be a discovery of the planetary laws before Kepler? Also, what about Kepler's second and third laws, which are probably more important than the first?
All the wavelengths in this picture are in the infrared and far outside our visible range. If you plotted this picture using "real" colors, it would be black.
Turns out there is in fact a substantial fee, so I told them I'm not interested. Why should I pay them to help populate their website?
Thanks for the responses here. It never would have occurred to me to ask if there was a fee.
No fee was mentioned. Here is the main part of the message I received. I am inclined to do it, but I thought I would check here first:
"I would like to speak with you about your studies and our interest to feature your work in our video publication, SciPod.
If you are not already familiar...
Hi all. I've been approached by SciPod to contribute a short video on my work. Has anyone here done this? Are they reputable? Are they worth the effort?
Here's a link: https://www.scipod.global/
It's easy to convert distance modulus to distance. See this Wikipedia page for example. But do you also have redshift for these objects? How can you plot a Hubble curve without redshift data?
Did you check whether your CL100 BJT is still functional? Your circuit will reverse bias the emitter-base junction of that BJT when the output of the second op-amp goes negative. Reverse biasing the emitter-base junction of a BJT usually destroys it.
No! Its redshift is "actually" negative. It's redshift of -0.001 means it is moving toward us at 0.001*c ~=300 km/sec. The Hubble constant is about 70 km/sec/Mpc. At Andromeda's distance of 0.75 Mpc, the cosmological redshift is about 50 km/sec, which is much smaller than the 300 km/sec that...
I like this quote from Feynman,
"Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that? ' because you will get 'down the drain', into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.”
I may be wrong, but I don't think ChatGPT has real-time access to the internet. It was trained off internet content, but it can't search the internet to respond to your prompts.
As @pasmith said, reading from the diagram, the semimajor axis is about 0.1". This is the θ in your second formula. It is not a declination, it is the angular size of the orbit.
You need to accept that Avogadro's law is true to a pretty high degree of accuracy, and has been tested for over a hundred years. So if it is very strange to you, it can't be that the law is wrong. It must be that you are not understanding what it says. The law doesn't say anything about...
If you haven't used Python, it's probably best to query Simbad directly from the web interface. Below is a screen shot of the query. It's the same basic syntax and returned the same list of 2162 objects.
I just query Simbad using Python. The code snippet below should give you what you want. It returned 2162 items. It's going to be up to you to determine which ones are actually physical members of the Beehive cluster and which ones are chance associations.
import numpy as np
from...
I would start with Stellarium, which is a free download (https://stellarium.org/). You just click on the stars you are interested in, and you will get everything you listed except the spectrum, although you will get the spectral type. I'm attaching a screenshot.
Thanks for this explanation. If this model is correct, does that mean that there are two types of black holes? (1) "normal" black holes formed from the collapse of ordinary matter, and (2)these more exotic black-hole-like objects that are filled with dark energy?
If you actually do the experiment, you will find that your initial assumption of, "with negligible air resistance" is a bad assumption. Unless you are moving very slowly, air resistance is the primary drag on a bicycle.
I don't know why you would call it a"shabby little secret". It was all very clearly publicized. Those numbers were never hidden. You just rely too much on popularizations of the results rather than reading the true stories.
You are given three things:
(1) v = ay + by^2 where a and b are constants
(2) at 1.5 mm from the surface the velocity is 75 m/s
(3) at 3.0 mm from the surface the velocity is 105 m/s.
From these, you should be able to set up two equations with two unknowns and solve them for a and b. Have you...
Yes, in general it's very difficult. You need to simultaneously solve for the metric and the motions of the bodies in a way which is self consistent. People worked for decades and were unable to get the codes to converge. Then in the early 2000's they evolved new techniques which allowed the...
This is a very interesting problem. For the Kepler orbit (Newtonian, no GR), it is possible to re-write the equations of motion to read: $$\frac{d^2u}{d\phi^2} + u = \frac{GM}{h^2}$$ where u = 1/r where r is the radius, and h is the specific angular momentum, which is a constant of the motion...
I agree. I hear "this class". This reminds me of when I was learning French. I had one of the Harry Potter books on audio book, and I had the text copy as well. I would listen to the audio and say to myself, "They are just not saying all of those words!" Then I listened to it over and over...