# Search results

1. ### I Distortion of Space Time

Ibix wrote: You really can't do that. That is similar to saying that I cannot make a drawing in only two dimensions. The claim is not to pretend the other dimensions do not exist, rather to provide limits to the scope of thought. A narrower scope often leads to better thinking. Ibix wrote...
2. ### I Distortion of Space Time

Presume we look at a two-dimensional view of space time, with no local masses, and we draw a grid of equidistance spaced lines. The intent is to look at space but not time. As we begin, we look in all directions and the grid lines are evenly spaced. Begin adding mass to the center of the grid...
3. ### I Solar panel angle to the Sun

Tom G, Thanks for the reply. You prompted me to really dig into that formula. I have a workbook that calculates the sun’s noontime elevation for the entire year. Phyzguy, Thanks for your reply. I don’t have Python. I presume your code works, but cramming everything into so few lines with no...
4. ### I Solar panel angle to the Sun

I don't know how to work with vectors that are three dimensional, meaning two angles and a length. I am not interested in the length. The length of the vector to the sun is 93 million miles and the length of the vector representing the panel is infinite. I already did the google search and...
5. ### I Solar panel angle to the Sun

Moved into a house with some solar panels facing due south and some facing due west. Our latitude is 33.8 North in California. We are in the Mojave desert with very little cloud cover. The angle of the roof is 22 degrees from horizontal. What is the equation that will accept the azimuth and...
6. ### Explaining equation to stem class

reply to atyy: No, not comfortable with it. That site does not explain well. It asks question then does not answer. On the second page the author posts the equation d = vt = vf t / 2 Except that the first v has a bar over it. Ok, what is that v-bar. I don't see the explanation. I have been...
7. ### Explaining equation to stem class

I kind of follow along, but have a difficult time. I will look at this some more. In the mean time, my best option is to say that people who understand this have figured it out and we are using the fruits of their labor. If you, the children, want to pursue this I will help, but I will also...
8. ### Explaining equation to stem class

Context! I should have included that in the OP. They do know what square root is, and at least fundamentals of exponents. I am unsure about units, but I do explain that very carefully in the first few sessions on bottle rockets. We spent several of our weeks taking apart gas engines and...
9. ### Explaining equation to stem class

I am a volunteer teaching a STEM class once a week to a class of eight elementary students. From this page http://tbpmindset.org/modules/SECME/Rockets/Rockets_Calculations_Manual.pdf I use this equation for water flow out of a water rocket m = nozzle_area * discharge_coeficient * SQRT( 2 *...
10. ### Water rocket and water velocity

I am going rather slow, spending too much time on Quora. But yes, and I will add in a phrase to consider temperature drop and the resultant further pressure drop. I am doing this because I am a volunteer at an elementary school STEM class, one hour a week. We launched a water rocket a few...
11. ### Powering electromagnets with bicycle power

This sounds like trying to help a child learn to ride a bike. Give them a two wheeled scooter to ride for a while. They can step off of it to either side easier than with a bicycle. It will help them learn the concept of steering the scooter/bicycle beneath them to maintain balance. After...
12. ### How do we see the color violet?

Think about what you "see." The eye connects thousands of rods and cones to the brain and the brain translates those many thousands signals into what we "see." We do not directly "see" the objects we look at, we "see" the image that our brain creates. When the brain receives signals from the...
13. ### Water rocket and water velocity

The document referenced in my previous post provided a formula for mass flow per seconds. After working it for a while the result was 6.98 kg per seconds. With a water load of 0.5 kg, the water rocket is out of water at about the 0.07 second mark. That agrees with our rather imprecise...
14. ### Water rocket and water velocity

Well then. I will shift my reference. I will start here: http://tbpmindset.org/modules/SECME/Rockets/Rockets_Calculations_Manual.pdf and search for a few more. If you have a known good reference, please post. My goal is to enter instantaneous formulas into an Excel spread sheet and iterate...
15. ### Water rocket and water velocity

Point taken. The document is here: http://www.schulphysik.de/strutz/predictors.pdf On the second page, right side, is the equation for flow rate. Is that a valid equation? Do you recommend something different? I am still working the equation and the units are not working out. I will...
16. ### Water rocket and water velocity

Re siddharth: The newton is the SI unit for force. The nozzle area is 3.8 square cm. Converting that to 0.000308 meters2 does not help much. But OK, I’ll do that. Re Orodruin: No, I am not sure at all. That is what the document says. It can be found with a search for “water rocket...
17. ### Water rocket and water velocity

I found a few questions on water rockets but am not able to understand the equations. The guide I am using has this for the exit velocity of the water: V = sqrt( ( 2 * pressure * nozzle_area ) / water_density ) I plug in the values for my water rocket to get V = sqrt( ( 2 * 17.24newtons/cm2...
18. ### Early universe not homogeneous

Part of what kicked off my flurry of posts is watching Morgan Freeman narrate "Through the Wormhole." I have watched several of them and find them sometimes, and mostly, fascinating, but also sometimes rather simplistic. Problem is, I am in between competency levels. I played an important...
19. ### Early universe not homogeneous

Saying it in another way, to verify we are on the same page, the ratio of high to low presently found now will be held the same as we run the universe in reverse back to the beginning. If so then yes. Here is another perspective on this idea. As the universe expands and cools, the...
20. ### Early universe not homogeneous

I continue to say that the small differences present today indicate that when the universe was much smaller the differences were much greater. That would mean that there were huge differences from one part of the universe to another. In turn that means that something must account for the huge...
21. ### Early universe not homogeneous

First, I was misconstruing the CMB thinking of it as a measure of temperature. But still, CMB is measured in degrees Kelvin. And that is a measure of temperature. And wasn't the CMB much hotter as we look back closer to the big bang?
22. ### An upper limit to the size of black holes?

In an earlier post I make the controversial suggestion that the universe was very heterogeneous in the early stages. I have another conjecture that goes along with that one. Please try to read this with a bit of an open mind. Imagine that there is an upper limit to the size of a black...
23. ### Early universe not homogeneous

Marcue wrote: In any case Charles Law is no good. Don't have constant pressure, so can't use that. Or so it seems to me. And Chalnoth wrote: Two problems here. First, Charles' Law is only valid for a gas under constant pressure Wikipedia says here...
24. ### Early universe not homogeneous

Hello Ben, Oh, I am certain there is far more that I imagine, let alone understand. Still, given the differences in the CMBR, imagine a giant pair of hands crushing the universe back down to a relatively small size. Little differences will become huge differences. Before running out and...
25. ### Early universe not homogeneous

First, I am a rank novice in cosmology, very rank. However, I do see something that puzzles me. I put some numbers in an Excel spread sheet and I calculate that the early universe was far from homogeneous. I did a few limited searchs and did not find a discussion. Here is what I have...
26. ### Detecting absolute motion

You missread what I wrote, then did it again. I will stop pursuing this thread and go to my reading. Thanks to everyone for taking the time to reply.
27. ### Detecting absolute motion

I think something is in error there. If I stand at the fence and move the trolley past me and the fence at 1/2 C, then I should see the trolley be length contacted (while it is moving) and the marks being made 0.866 meters apart. If I hop on the trolley while it wizzes past the fence, the...
28. ### Detecting absolute motion

Too much to grasp right now There are too many things that don't make sense to me to discuss them all and take up that kind of bandwidth on a forum such as this. I have the Sam Lilley's book "Discovering Relativity for yourself" and am reading that. The problem is I don't take well to...
29. ### Detecting absolute motion

One little bit at a time if you please. Only if the fence were moving and the trolley not moving. Only if the trolley were moving and the fence is not. Regardless of which is moving, I see no reason why the marks cannot be made at the same time. If one or the other were moving then that...
30. ### Detecting absolute motion

There obviously is something I am missing. Lets try this. Two markers are one meter apart. The make a mark at the same time. Lets not worry about the mechanics or electronics, or anything about how they are made. Lets presume I cause the marks to be made at the same instance. How can...