# All Activity

1. Past hour
2. ## Relativistic length contraction and magnetic force

Twin paradox when Earth is the moving frame We analyze the mathematical mechanism that slows the time of the traveler in the twin paradox and explain what distinguishes the traveler's frame from the Earth's frame Please read the article at Twin paradox when Earth is the moving frame.pdf
3. ## Can gravitational waves be affected by matter?

Ghideon, I think your forgot the third measure, namely that there are 'two Ligo's', and a Virgo. If not all three measure the same effect at nearly the same time, it is something local.
4. Today
5. ## Can gravitational waves be affected by matter?

As LIGO is able to detect gravitational waves, some energy has to be taken from those waves. As electromagnetic radiation from some of the sources is comparatively extremely easy to detect, the energy absorbed by even the whole earth would be very small, with no detectable effect on the gravitational waves. Some of the comments after https://stuver.blogspot.com/2012/07/journey-of-gravitational-wave-i-gws.html look at different ways energy could be absorbed.
6. ## Dominant-Rezessive, alleles

I am just interested in biology and genes how it works and the possibilities which genes my child would get. According to the punnet Ssquare, if the father has blue eyes (bb) and the mother has brown eyes, but is a carrier of blue (Bb) the child could get blue eyes. But how is it with if the father has bb and the mother have BB (brown eyes, and no blue allele)? ...according to the punnet square the child will have brown eyes, but I have seen children with blue eyes and blond hair despite the fact that the mother is not a carrier....just look at Shakira and her son, this is the same constellation..so the question is it is possible that the baby get blue eyes when it’s BB and bb ? Maybe genetics are a little bit more complicated than the punnet square..because of this I am here to ask in this forum. Thanks a lot
7. ## Suicide Prevention

The experience of pain can encourage solidarity. Pain of course viscerally hurts. So I find it ridiculous any notion that some are "selfishly" dead or that the mentally ill are "arrogantly" in despair. As I've said before I'm not at all criticising society. I'm merely disagreeing with a few comments one sees around the web.
8. ## Predicting Further Values in a Set of Data

We don't have to use polynomials. There's multiple ways my teacher tells me, but because this is a "problem - solving task" we're to think up of something of our own. Thanks for the tips, I'll definitely check out Runge's Phenomena and ARIMA. Cheers! This is "Maths Methods" In Australia which is the 2nd hardest subject for "Mathematics" Currently Year 11 I'm using the polynomial of 6 because that's the highest available polynomial in excel. I've plotted them and they're all very similar to each other. I then got an average of all these data values and got an "Average Year". I'll be using the Equation from that "Average Year" graph as my Model. But is there anything else I can do to "Refine" it and make it even more accurate?
9. ## Can gravitational waves be affected by matter?

I’m not sure. I guess it might be the small (tiny) amount of lensing ?
10. ## Oh no! Not another conjecture!

Yes (as far as we know). Acceleration started relatively recently - about 5 billion years ago I believe. I’m not sure what you mean by “leave a vacuum” or why that would accelerate expansion. There was a vacuum there before and would be again afterwards And wouldn’t creating “more vacuum” (whatever that means) slow expansion? However, the non-zero energy of the vacuum that allows virtual particles to appear and disappear was an obvious candidate for “dark energy” to drive acceleration. The problem is that this energy is about 10120 times too large.
11. ## Can gravitational waves be affected by matter?

From the source https://stuver.blogspot.com/p/informational-posts.html, bold by me: I'm curious, what are these negligible effects? Without knowing what explosions you might have in mind I'll answer regarding earth vibrations in general. As @Strange said, a lot of effort goes into making sure vibrations are not detected. LIGO uses two basic strategies to shield the detectors from Earthly vibrations, referred to as “Passive” and “Active” vibration isolation systems. Source and more info: https://www.ligo.caltech.edu/page/faq
12. ## Suicide Prevention

Though rare, there has actually been suicide by burning. The poet Sylvia Plath died by putting her head into an oven. Self-immolation by Buddhist monks as political protest for instance has been documented. People who've made suicide attempts are sometimes left with disabilities. There have been cases of the terminally ill dying by suicide. To understand cowardice it may be best to first look to the opposite concept; bravery. I've frequently read that bravery is not the absence of fear but overcoming fear. So there is an element of fear in all death irrespective of how people respond to it. Personally I don't understand how WW1 analogies are helpful given the amount of controversy over the actual purpose of that war. Even knowing you are going to die doesn't always lessen the pain. In fact in the death penalty debate the uncertainty of inmates in death row is often cited as increasing the inmates' pain. Elderly death is obviously still very painful even though they've had up to 80 years to prepare for their death. We all have the same pain fibers so technically deliberate injury and accidental injury would both be highly painful. For people who make such an argument about relatives who find the body of a suicide victim your burning example perhaps wasn't good.
13. ## Light

Like circularly polarised light?
14. ## Quick LaTeX Tutorial

$\sqrt{a}$

16. ## Light

Polarising filters may be relevant.
17. ## Light

Like a spring
18. ## what is energy audit for pumps

Hi. Need help with Defining energy audit for pumps . Help please.
19. ## Oh no! Not another conjecture!

If the virtual particles appear and immediately disappear, then nothing is added.
20. ## Variations and consequences of the Laws of Thermodynamics

I don't agree with part or all of this but I suppose I can see its relevance for the following post. I tried to indicate I was only concerned with initial and final conditions in my example of how an isolated system can increase its entropy from one well defined value to another well defined value. The total work done in getting from the low entropy state to the final high entropy state, which is an "equilibrium state" where the entire volume y (or A plus B) is in equilibrium, is zero. While transitioning between states work is done. Also the temperature of the gas is lowered and it acquires kinetic energy. As the volume y comes to equilibrium all this work is transformed to heat. At equilibrium the temperature of the gas in the volume y is the same as it was in x.
21. Yesterday
22. ## Oh no! Not another conjecture!

Thanks for not shutting me down. Yes you are right. I knew where to put it, but I got carried away and hit submit prematurely, because I was confident about the details in it. Regarding evidence, I was hoping the in-house mathematicians could clarify or dismiss it. If not, it seems logic that anything added to a volume adds to it, even if it's a vacuum. Quantum fluctuation is the main culprit behind the big bang singularity after all, so it would only seem logic that fluctuation could also accelerate the cosmos.
23. ## Suicide Prevention

Then why don't more suicides burn themselves? I'm just saying it's a poor argument, that the pain is the same. I disagree with your third paragraph.
24. ## Oh no! Not another conjecture!

! Moderator Note At almost 300 posts in, you should know where “I have a conjecture” should go, and that we need a model and/or evidence - some way to test it. Most of the universe is already a vacuum.
25. ## Oh no! Not another conjecture!

Is the universe still accelerating? Sometimes I read articles that argue against it, so I'm not totally sure anymore! But if it is, I have a conjecture that might explain it. It is based on quantum fluctuation. (1) I might not be the first to think of it, and (2) it might be mathematical impossible, but here goes: Quantum fluctuation is (as far as I know) considered a come-and-go phenomena. Hello, goodbye. 2 - 2 = 0. But what if it leaves a vacuum? A tiny tiny vacuum? If so, there must be gazillions of tiny vacuums made every second. Speeding up the cosmos? (Sorry if this is wrongly placed! Feel free to move it to Speculation if needed.)
26. ## Suicide Prevention

It's not so much about who was in the most pain but that there is pain in all death.
27. ## Suicide Prevention

Probably why I specifically made sure to say: You claimed calling suicide cowardly wasn't right because both the suicide and the accidental death have the same kind of pain. I don't think that's true in most cases. Suicides get to choose how and where, they know it's coming, there are many factors that make it less painful. I just didn't agree with that part of your argument.
28. ## Suicide Prevention

Well I think there's a difference in tone between reassurance and ridicule. I agree that we should by all means try to reason the person out of it and strongly encourage them to live; to remind them that the pain is temporary and it will eventually go away. But if a patient just cannot deal with the immense stress and pain they're under I wouldn't try to physically stop them killing themselves. I'm didn't say suicide prevention itself is being turned into taunting but just some opinions you read about online. People suffering from schizophrenia, for example, may have delusions. Pointing out the errors of their logic is certainly helpful. But I don't think "ridiculing" the person will solve it. It could easily backfire and make the person more guarded and defensive and less likely to seek help. Mental illnesses can be quite different. There are bullying victims who may contemplate suicide; chronic back pain sufferers, depressed individuals and so on. Each may require a different strategy in order to help them and prevent suicide. I'm not sure what you mean by your dying examples. I'm afraid there are many different methods of suicide.