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3. ## iNow

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## Popular Content

Showing content with the highest reputation since 03/28/04 in Posts

1. 8 points

## Matter creates gravity

OK let's clarify something here. First consider the following definitions. Mass is resistance to inertia change Energy the ability to perform work. Spacetime a geometric model system with 3 spatial dimensions with 1 time dimension. In physics dimension is an independent variable or value that can change without affecting any other mathematical object. So how does mass curve spacetime. Well GR models bodies in free fall that is without any force applied. Time is given units of length and can be called an interval. This is done by setting c which is constant to all observers and adding a unit of time. So the time coordinate is given units of length by ct. $(t,x,y,z)=(ct,x,y,z)=(x^1,x^2x^3x,x^4)$ the last is in four momentum form for convenience as its useful to model a particle trajectory along the x axis. Now what is spacetime curvature. Well space is just volume... (Very important ) it isn't a stretchable bendable fabric... Those are just analogy descriptive. What spacetime truly means by curvature is the worldline paths for light it us the null geodesic. If you shoot two laser beams in flat spacetime those beams stay parallel. If spacetime is curved then the beams converge for positive curvature and spread apart for negative curvature. This is a consequence of how the mass term affects the time it takes for a particle to go from emitter to observer. That whole resistance to inertia. So let's drop two objects toward a planet. You have the usual Centre of mass. As the objects free fall they do not stay parallel. They will converge upon one another as they approach the center of mass. That what is really meant by curvature the free fall paths are curved. Not the volume of space.
2. 8 points

## When did God put the soul in humans during evolution?

So looking at the image below, it appears that Galagidae have recognizable soles, but Cynocephalidae do not : and when we look at a primate phylogeny, we see the split between these two groups is around 65 million years ago: So soles originated about 65 million years ago, give or take. You meant soles as in soles of the feet, right?
3. 8 points

## So are quantum entangled or teleported particles instantly there

So if I change the charge of one plate, somebody can measure an instantaneous change at the other plate. Wouldn't that be a violation of special relativity? @Menan You show that you do not understand entanglement. Let's go one step at a time. First a classical example. I have a bag of balls, they are all red or green. Without looking I pick two balls, and I put them in separate boxes. I keep one, and send the other far away. Then I open my box, and see it is a green ball. What can I conclude about the colour of the ball in the remote box? Right, nothing. And why? Because there was nothing special with my picks. It could have been two reds, two greens, or one red and green. Now I pick, looking of course, one red and one green, and put them in two separate boxes. So what I did here is 'entangle' the balls. Now I shuffle the two boxes, so that I do not know which one is which. If I open one, and see that it is red, I immediately know that the ball in the other box is green. And of course, this is independent on the distance. If I send the second box lightyears away, and only then open my box, I still know immediately what some alien sees when he opens his box. I know it because the observations are correlated. And the correlation already happened at the moment of my picks. That is the moment of entanglement. It is not when the boxes are opened. Now in quantum physics, there are processes where two particles pop out, which have e.g in one aspect always opposite values. Say the direction of spin. So if I measure the spin e.g. in a vertical direction, say it is 'up', then I immediately know that the other one will measure spin 'down', when also measured in the vertical direction. But as with the balls, the 'moment of entanglement' is when these particles popped into existence. But in quantum physics a few things are different: first, it is impossible to say which particle has which spin without measuring (it is as if I created the green and red balls, including their boxes, without knowing which ball is in which box). But as the two particles are entangled, if I measure both, the measurements will always be correlated. And there is nothing special with correlation: if I send one particle far away, and then measure my particle in the vertical direction, and the alien measures his particle in the same direction, I will always know what he measures: the opposite of my measurement. The 'spooky' aspect comes in when we do not know from each other in which direction we measure the spin. It can be vertical, horizontal, 30o, 45o, 55.3977o. What we find is that the correlation is stronger than one would expect if we would assume that the particles already had a definite spin from the beginning. But it still is correlation, not causation. As with the red and green balls, there is no direct causal relationship between my and the alien's observation. The causal relationship goes back to the moment of 'entanglement'. Everything afterwards is just correlation, and therefore cannot be used to transfer information. And because there is no causal relationship between my measurement of the spin of my particle, and the alien's measurement, I cannot use entanglement for sending information. And all this is very well understood by all quantum physicists, and is no secret at all.
4. 7 points

## My first thousand

Just did not want to let this pass without a party (Dutch treat...). You are all invited at the lakeside! (Just Click on the picture to see it full size.) Thank you to all from who I learned a lot, and also thank you all who understand less than I do about certain subjects, but force me me to rethink, or make my viewpoint clearer, or force me to read some book or article (again). I noticed that much of what I read is influenced by topics here in these fora. And thanks to those who make this forum possible, moderators, administrators, sponsors, etc. Up for the next 1000!
5. 7 points

## Special Relativity - simple questions?

SR does not claim that such an observer will always see the Earth clock run slow, if by see, you mean what his eyes or instruments directly record. In this usage of see, he will see it run at a rate of T = To ((1-v/c))(1+v/c))1/2 where v is positive if Earth and the Observer are receding from each other and negative if they are approaching each other. A factor contributing to this observation is the the distance and thus the propagation time for signals is constantly changing, getting longer when receding and getting shorter when approaching. This factor works out to be c/(c+v) When you factor this out of the first equation you are left with the time dilation equation. This means that there are two things to consider: what you see happening to the Earth clock, and what is happening to the Earth clock. So while while receding from the Earth, the observer will see the the 1000 Hz signal as being 500 hz and the Earth clock as ticking 1/2 as fast as his own,. Taking into account the effect of the increasing distance, he will determine that the Earth clock is ticking 0.8 as fast as his own. He will meet up with the object when his own clock reads 1.01.2022 (as the distance between Earth will be only 1.2 ly as measured by him and this is how long it takes to traverse this distance at 0.6c.) He will see the Earth clock reading 1.01.2021, but determine that it is 8.07.2021 on the Earth at that moment. Now at first, you might be tempted to think " But wait, if he sees 1.01.2021 on the Earth clock, and the Earth is, according to him, 1.2 ly away, wouldn't that mean that it should be 3.15.2022 on the Earth by his reckoning?" This is not the case. The light he is seeing at that moment left Earth at a time when the distance between them was less than 1.2 ly, so the time it took the light he is seeing took less than 1.2 years to reach him from the Earth. Now he accelerates in order to come start the trip back towards Earth. We will assume a minimal acceleration period. Now this is the part where people tend to get tripped up. After he is done and is now approaching the Earth and not receding, we will assume that he still reads 1.01.2021 on the Earth clock by visual means. However, he will no longer conclude from this that it is 8.07.2021 on the Earth. Instead he will conclude that it is 6.05.23. During the return trip he will see a frequency of 2000 hz from the signal and the Earth clock tick twice as fast as his own. But again, taking into account the decreasing distance effect, he will conclude that the Earth clock is ticking at a rate 0.8 as fast as his own. Thus he will see the Earth clock tick from 1.01.2021 to 1.01.2025, but conclude that it ticked from 6.05.23 to 1.01.2025 during his return leg. (see will see it tick off 4 years, but conclude that it ticked off 1.6 years. Again, it all come back to what happens during that acceleration period. As far as anyone at rest with respect to the Earth is concerned, nothing special beyond the standard SR effects take place. But for the observer actually undergoing the acceleration, things aren't this simple. For him, the rate at which clocks run depend on which direction they are from him relative to the acceleration he is undergoing and the distance from him in that direction. Clocks in the direction of the acceleration run fast, and those in the opposite direction run slow (beyond what he sees. This even effects clocks that share his acceleration. A clock in the nose of the Ship will run fast and one in the tail will run slow. ( in this case, since there is no changing distance between himself and the clocks, what he sees, will be in perfect agreement with what is happening to the clocks. While this may seem to be at odds with common sense, it is how a Relativistic universe works. A problem with your questions is that they only deal with particular points of the whole scenario without taking in the whole picture. It like comparing two men walking and only considering where they end up. Below we have the paths of two men, Red and Blue, over the same interval. If you just look at where they end up, you would conclude that Blue walked a shorter distance because he ends up closer to the starting point than Red does. But when you consider the whole interval, it is clear that Blue walked a further distance. The same thing is true with SR, if you only consider the end results, you are missing what is really going on.
6. 7 points

7. 6 points

## My grand daughter!

My son holding my grand daughter!
8. 6 points

## The Border Wall or Fence

Implicit here is a false suggestion of equivalence. That’s not the case. If a kid walks down the hallway in school and gets punched in the face and has his lunch money stolen, is it his fault for carrying lunch money or walking freely down a public hallway? No, of course not, but if you think “both sides” need to compromise here then that’s precisely what you’re saying... that the kid is equally guilty as the bully. Trump last year said send a bill to my desk and I’ll sign it. Republicans were in control so drafted their version. Democrats agreed to vote for it and provide billions of dollars for this wall last year, and the compromise was that dreamers would get status. Trump backed out. He moved the goalposts. He said I want more. Funding ran out in December and Democrats said, fine... we’ll sign the republican bill yet again... we’ll compromise... but want money allocated to smarter enforcement options. A wall is not smart, and even countless republicans across the nation and some on Fox News itself agree. Trump said no. Eff you, a wall or nothing. Democrats said, Republicans still control all 3 branches of government. Since they’re in control, they need to get their president onboard. They couldn’t. President had a tantrum. Paper tiger in the Oval Office. Said he wants a shutdown. Shutdown began. Democrats took control of the house in January and on Day 1 passed a bill to reopen the government. Senate leader McConnell would not even bring it to the floor. Democrats later said they’d give more money for border protection, just not a wall. They compromised. President still refused. Wall or nothing. Eff the workers. Democrats passed multiple other bills to reopen parts of the government and agreed to negotiate terms on border security. They AGAIN voted for the previously passed republican funding bill from December. McConnel AGAIN wouldn’t bring it to the floor. Today Democrat senators continued to pressure McConnell to bring the bills up for a vote. He refused. He said it was pointless because the president won’t sign. Democratic Senators reminded him that they had the votes to override a presidential veto... that they are a co-equal branch of government and need to act like it. McConnell left. He just walked off the floor. Still no vote. Democrats will again pass a bill tomorrow to reopen the government. The bill will be the one drafted and previously agreed to by republicans. I agree there’s a lack of compromise here, but to say it’s equal across the aisle is absurd. The bully is trying to steal the lunch money. The other side has already offered to share their sandwich with him and are not at fault merely for having lunch money in their pocket.
9. 6 points

## What if Einsteins Definition of Simultaneity is incorrect?

Right, he is saying that the speed of light in both directions is the same with respect to any inertial frame as measured from that frame. So in the following example we have two observers. One standing along the tracks and the other traveling along the tracks in a railway car. Two flashes are emitted from two points along the tracks that are equal distance from the track observer. the light from these flashes arrive at the midpoint observer at the same moment as the railway observer is passing him. Thus both observers detect the light from the flashes at the same time. Like this: For the midpoint observer ( or anyone at rest with respect to the tracks) these flashes were emitted simultaneously, as shown by the expanding circles: However, for the railway car observer, events have to occur differently. He still detects the light from both flashes simultaneously, and they arrive when he is adjacent to the track observer. But unlike the track observer he has not remained halfway between the emission points the entire time. He is not an equal distance from the emission points when either of the flashes was emitted. But he must also measure the speed of light for each of the flashes as being the same relative to himself. But since the distances each of these flashes travel relative to him are not the same, in order for the light of the flashes to reach him simultaneously, they must have left at different times. And the sequence of the events for him occur like this: For the track observer, the flashes are emitted simultaneously, but for the railway observer they are not. This is the relativity of simultaneity: Events that are simultaneous in one inertial frame are not so according to another which in relative motion with respect to the first frame.
10. 6 points

I am pleased to now add CharonY and Strange to the list of gullible fools wonderful people willing to sacrifice their time for the greater good here at SFN. Congratulations!
11. 6 points

12. 6 points

## Stephen Hawking Passed Away 3/14/2018

Stephen Hawking has passed away at the age of 76 on Pi day, 3/14/2018. http://www.bbc.com/news/uk-43396008 https://www.theguardian.com/science/2018/mar/14/stephen-hawking-professor-dies-aged-76?CMP=fb_us
13. 6 points

## Trump Effects

This is the rhetoric pushed by billionaires who don't need the government the way most of us do. Isn't it pretty obvious that the billionaires in politics today are only interested in removing restrictions on themselves, and limiting the money spent on the rest of us? These folks have been hammering this message of "bad government" and "sleazy politicians" for decades, while actively being the representatives with the sleaziest behavior, doing everything they can to make the government bad. They don't care if you have access to libraries, museums, parks, swimming pools, or healthcare. They have all those things taken care of due to their massive wealth, and object to taxes that make these things available to the rest of us. They've chosen to ignore our efforts that brought them great wealth, and instead spend money convincing folks that government needs to be dismantled for OUR good. And now they have this blatant racist sexual assaulter-in-chief who is morally and economically corrupt, and happens to have a deluded following all chanting about bringing down the Fed. Working class folks who think this billionaire has their backs while he whittles away at the very thing that has the best chance of making all their lives a lot better. The wolves have tricked the sheep into removing restrictive fences, and the sheep are all praising the freedom.
14. 6 points

## Why doesn't truth matter & middle ground

Puerto Rico agrees. Black athletes agree. The anti-fascist movement agrees.
15. 6 points

## God and science

Why do you limit your options to 'god did it' or 'everything popped out of nothing'? What about it didn't start, i.e. it's always existed? What about 'we don't know'? Also, as i understand it physicists have found that things do simply pop into existence. And yes, i'm frequently astonished by existence. Why does that imply god? I like this question. Many people seem to question that the universe could either just pop into existence or that it has always existed - but are happy to ascribe these exact same properties to something they call 'god'. Either way something has this property - why not discard the middleman and simply ascribe it to the universe. Depends how god is defined. A god that set up the conditions for the big bang but does not intervene at all thereafter would be impossible to detect, at least with our current capabilities. A personal god that answers prayers and parts seas has been pretty well debunked. Such a god would be easy to detect - we would just look for instances where the laws of physics contradict themselves (i.e. the rules change) - seas start to part, lakes turn into wine, whatever other crazy stuff you think a god might do. There is no sign of such a god.
16. 5 points

## Sorry about the downtime -- we're back!

Fake news! It was a perfect renewal! Absolutely perfect. In a world where even my fridge can give me reminders, I still managed to forget. Luckily Capn was able to social engineer his way through my answering service who sent a page out to me stating "CAPN REFSMMAT - RE: WEBSITE". They even listed a hospital he was calling from 😂. I wasn't on call today so when I heard my answering service text me I about lost my mind until I saw who it was.
17. 5 points

## What if you fall through space time?

No. Space-time should not be comprised of anything like dough. It is not substance-like at all. The concept of space-time is just the recognition that the measurements of space and time are frame dependent and not absolute. The analogy is that in Newtonian physics, space and time are treated like North/South vs. East/West. In such a situation everyone, no matter what direction they are facing, all agree on these directions. Everyone, for example, agrees that town A is 40 miles North and 30 miles East of town B. However the Space-time manner of treating this is that each person uses his own sense of Left/Right and Front/Back. Thus one person facing one direction will say that town A is 30 miles to the left of and 40 miles in front of town B, while someone facing in another direction would say that town A is 50 miles directly to the right of town B. It makes no more sense to think of space-time as being "substance-like" than it would to think of Left/Right-Front/Back as being "substance like". Now I also realize that in GR, it is said that Space-time "curves" in the presence of mass. And to many people this implies space-time being a "structure or substance". This is not what this means. "Curvature" of space-time really just means that the geometry rules governing it are non-Euclidean. In other words, the rules of plane, Euclidean geometry just don't hold.
18. 5 points

## The 11 dimensions of string theory

Glad to be back had some RL issues which are done with now
19. 5 points

## Members in the Mod Queue

thethinkertank has been placed in the queue for spamming the forum with an impressive amount of nonsense.
20. 5 points

## Strange self-induced feeling

Join a science forum and post once...
21. 5 points

## Shamima Begum

Brevity and sarcasm. No wonder no-one knows WTF you're talking about half the time.
22. 5 points

## GoFundMe To Help Daedalus

Hello everyone! It has been a while since I was active in the forum. Sure, I post a song here and there, but I just can't participate like I used to. I'm still having problems with my left hip even though I had a hip replacement back in April, 2017. Since then, I lost my job and medical insurance because I simply can't sit and write code for hours on end due to the extreme pain in my left hip. I lost my job as a software engineer in the middle of being treated by my doctor and they want a \$500 deposit to continue treating me. Unfortunately, I don't have any income, I'm unable to work, and I've blown through my savings on living expenses and doctor bills. Most likely, I will need a revision done on my hip replacement to fix whatever is wrong so that I can go back to work and be a productive member of society. So, I'm reaching out to the community and asking for your help! The following link is to my GoFundMe campaign. I've attached photos of how my surgeries went so you will understand how much pain I'm actually experiencing. It's ok if you can't donate. You can help me out tremendously just by sharing this link! Every little bit helps!!! https://www.gofundme.com/clevelandraymond Thank you all so much! I truly appreciate anything you can do. Not only does your efforts mean the world to me, but also to my family as well.
23. 5 points

## How to disprove these creationist claims?

It's pretty easy, and it's been done to death. Most of their arguments are strawmen, in that they make a false or misunderstood claim to attack, instead of a more difficult, legitimate claim. For instance, that the creation of proteins is astronomically improbable, therefore it couldn't have happened. Since they mistakenly think the universe is only a few thousand years old, they can't accept that evolution had millions of years to miss before it finally hit. Many of the arguments are nitpicking Darwin, as if the theory began and ended with him. They ignore what every scientist knows, that theories are dynamic, changing as new evidence shapes them into better and more accurate predictions. And they keep repeating arguments that have been refuted, which is seriously dishonest from an intellectual perspective. I still hear "If we descended from monkeys, why do we still have monkeys?" being spread to ignorant audiences. They study evolution only enough to cherry-pick the parts many don't understand, and then ask questions they don't want answers to. If they really studied evolution sincerely, with an open mind, they would come to the obvious conclusion that there's no other way it could work. Evolution is a fact, and the Theory of Evolution describes how it works, with observational accuracy backed up by more evidence than almost any other theory.
24. 5 points

## The Border Wall or Fence

Kidnapper abducts 50 of your colleagues. Says he will only release them if you let him have sex with your wife. You say, no. Are you now responsible for the 50 colleagues being held hostage? Of course not. The magnitude of stupid required to suggest such a thing is overwhelming. Kidnapper says, fine. Let me have sex with your wife, I’ll also return the many items I stole from your home last year, and will additionally agree not to steal anything else for 2 more years. Agree to this and I’ll release the hostages. Understandably, you again say, no. Are you now responsible for the 50 colleagues being held hostage? Of course not. Are you the one now at fault for “not compromising” with the kidnapper? Of course not. The magnitude of stupid required to suggest such a thing is overwhelming. “What if you just let him put it in the butt?? that’s a compromise” ... that’s where this conversation has devolved into. No. Not just no, but hell no. Yet that’s precisely what’s happening here when posters keep saying Democrats are the ones responsible despite their MANY votes attempting to reopen government and to get workers paid, and despite the obvious obstacle here being Mitch McConnel and the president for refusing to even allow a vote.
25. 5 points

## climate change intensified the amount of rainfall in recent hurricanes

Accusations of deliberate, widespread bias and falsification of results, across every major institution (in several different nations) doing climate science and climate modelling really does require evidence. Evidence of which, if this misconduct was really going on, would leave a much clearer trail than a couple of questionable phrases in one email exchange. There is no such evidence, just accusations or it would have come to light a long time ago. Does anyone really think successive governments across the developed world, many with demonstrated hostility to climate science's reports and studies, could not uncover that extent of deliberate bias and collusion? Or that level of incompetence not be noticed within long running non-secret institutions where high standards - with everything on the record - are essential to everything they do? The claims of bias and incompetence are all accusation and no evidence. We have agencies that can pick out guarded exchanges between anonymous terrorist conspirators but they can't catch out hundreds (thousands?) of published working scientists conspiring within and between legitimate government agencies? They haven't exposed this alleged conspiracy of incompetent science and world subjugation because it doesn't exist. Making casual accusations against ordinary people doing their job (better than some people like) is, itself, a serious kind of wrongdoing (slander), besides being very insulting to people who, so far as evidence goes, have been doing their jobs with all the appropriate care and attention and honesty. All that professional effort to work out how our climate system really works, only to be casually accused of being everything from colluding in incompetence to engaging in a global conspiracy! What upsets me almost more than anything else, is that climate scientists have given us an extraordinary gift in the forewarning and foresight they have given. The window of time to transform the way we do energy has been precious beyond price; that we have been squandering it is not the fault of climate scientists failing to communicate. The persistent counter-messaging by opponents and obstructors is indicative of a far more insidious conspiracy of biased incompetence than even their made up version of conspiratorial climate scientists and green-socialist-globalists. In the face of that kind of politicking, and given the seriousness of the climate problem it is climate scientist who do not resort to advocacy that I find questionable. Mistermack - I think you are too gullible and that you have been gulled. I don't expect you to believe anything from me even if you did give it due consideration. Or from Al Gore or from Greenpeace or whoever; however, I do think you should consider taking the Royal Society and National Academy of Sciences, the NOAA, NSIDC, NASA, CSIRO, Hadley CRU and so on, seriously.
26. 5 points

## B Kavanough and MeToo

People are starting to argue with reputation points. I see more and more negatives, on both sides, even for valid points which deserve deliberation. It is a very sensitive subject but, I have come to know that everyone involved in this discussion is a sensible person. Discussion leads to understanding, so if you want your viewpoint understood, discuss it. Don't neg rep opposing views, they're just trying to make their viewpoint understood.
27. 5 points

## Is masturbation healthy?

You will find all relevant answers in this excellent resource: http://stopmasturbationnow.org/
28. 5 points

## Hijack from God and science

This is actually one of the few times there's a simple answer. Science describes god(s) as supernatural simply because they defy observation and prediction, two foundational tools of science. All of them. It's not an atheistic definition. Science describes what the natural world appears to be doing, and gods don't appear in the natural world. Pretty simple. By the way, one can be an atheist without rejecting anything. I'm perfectly willing to entertain the existence of a god if one decides to become observable. In that way, I think I'm actually much more open-minded than you.
29. 5 points

## Why doesn't the electron fall into the nucleus?

Because the electron is not a classical particle (“little ball of mass and charge”), but a quantum object. As a first approximation, you can picture an electron as a 3D standing wave around the nucleus - you can only get standing waves of a given wavelength in specific places, which is why orbitals come in discrete levels. Crucially, there is a lowest energy level, which corresponds to the minimum distance an electron can be with respect to the nucleus (let’s assume here there is only one electron) - and that lowest energy level is not zero. Therefore the electron cannot fall all the way to the nucleus, it can only fall into its lowest energy level, which corresponds to an orbital that is still some distance outside the nucleus. This is a direct consequence of the laws of quantum mechanics, and coincidentally one of the questions that motivated the development of quantum mechanics in the first place.
30. 5 points

## Apology

I just wanted to express my heartfelt apology to the members of the forum. I was on suspension for a year for very indecent behavior. I hope I can rejoin your community once again.
31. 5 points

32. 5 points

## Evolution

I'm told that when naked mole rats sit around shooting the breeze, they discuss how they are a clear aberration. Apparently domestic cats hold much the same viewpoint. Not to mention African Greys. It seems its a tendency of any reflective species to view itself as unique and special. You can probably eliminate any single species from the planet and the biosphere will continue pretty much as it was apart from some small, local readjustments. So you can replace the word "humans" in your statement with the name of any species . If you don't feel a Great White is not a super-fish would you like to take one on in unarmed combat. I suggest it won't be long before you are truly unarmed. Moontanman has mentioned examples of intelligence and tool use, etc. There are plenty of examples of animals that are faster than us, or anything else,have better vision than us, or anything else, can endure lower temperatures than us, or anything else. And so on. If we insist on comparisons that focus on our strengths and ignore our weaknesses it is difficult to not to consider us super, but that seems a biased approach. Overgrazing is common. Predators sometimes kill too many of their prey. The Great Barrier Reef is being destroyed by one of its inhabitants. There are, I think, numerous examples of this. We are better at it than most, but I don't think most of us want to boast about that.
33. 5 points

34. 5 points

## Non-locality

It is difficult to explain why you are wrong because you don't understand the subject and so you just reject the explanations (this has been true in all of your threads). And yet you are the one who constantly quotes the words of others but ignores the science. For example: Dalo: I don't believe X Others: Here is a simple explanation why you are wrong ... D: That's a bit vague, can you be more specific? O: <detailed explanation with evidence and a mathematical analysis> D: I don't need all that maths and what about [irrelevant sidetrack] O: What exactly are you asking? D: How dare you! O: I'm just trying to clarify D: I don't believe Y, as I have been saying all along O: So you have changed the subject D: No, you keep introducing P and Q, but I want to talk about Z O: OK. Do you understand <basic schoolboy physics>? D: Why should I have to? If you can't prove me wrong ... O: <collective sigh>
35. 5 points

## Time Does Not Exist

Ironically, under the title “time does not exist” it says “posted three hours ago”.
36. 5 points

37. 5 points

## Why do we think there is dark matter and dark energy?

First off, dark matter and dark energy are two different things and the reasons for expecting their existence are completely unrelated. The only thing they have in common is that they have "dark" in their names. The initial evidence for dark matter came from observations of how stars move in galaxies. Galaxies are formed from stars that are mutually orbiting each other. If we look at a galaxy, and estimate its mass by the matter we can see, we find that there does not appear to be enough to hold the galaxy together. At the speed the stars are orbiting, they should fly apart. We also know how these stars should orbit if the mass is contained to the shape we see it as having. Not only does the galaxy have more mass than that we can see, but the unseen mass must be distributed a lot differently than the part we do not see. For example, in a typical spiral galaxy, a good deal of the mass must be located above and below the disk-like shape we see. If it was made of normal matter, we should see it, if not in the visible spectrum, it should be visible at some other spectrum. This leads us to believe that whatever is causing that extra mass is not made of normal matter, but a type of matter that does not emit or interact with light or any part of the electromagnetic spectrum. Thus the term "dark matter. There have been attempts to explain the discrepancy through developing different models for how gravity behaves, but to date, none have been consistent with all the observations we have made. Dark energy concerns itself with the expansion of the universe. We have known for a long time that the universe is expanding and that distant galaxies are moving away from us. But until couple of decades ago, we assumed that the mutual gravity between the different parts of the universe was slowing this expansion down over time. What we did not know was whether this was enough to eventual stop the expansion all together. In the 1990's a study was made to try to determine if this was the case or not. Basically it worked because as we look at distant galaxies, we are seeing them as they were when the light left them. Thus as we look further away we are looking further into the past. Thus, to explain it simply, by comparing various galaxies' distances to how fast they appear to be receding from us, you can work out how the expansion of the universe has change over time. The surprise came when it was discovered that the universe's expansion was not slowing down, but was speeding up. Not only was it mutual gravity not enough to stop its expansion, but something was overcoming the gravity and pushing the universe apart. They decided to call this unknown influence "dark energy" (mainly because they had already coined the term "dark matter") . We really know very little about dark energy, and the term really just is a place holder for whatever it turns out to be. (Much in the way the terms "X-rays" was coined before we learned that they were just a certain part of the electromagnetic spectrum.)
38. 5 points

## Banned/Suspended Users

scherado has been banned for multiple instances of rule-breaking in his quest to become the Troll King. We apologize that his interruption in the normal rational discourse was all noise and no signal whatsoever. Roger Dynamic Motion has been banned, NOT for incessant hijacking and almost daily irrationality, but for failing to respond to requests for clarity, EVER. Discussion requires that we express our ideas so others can understand. We wish him good luck with his ideas, whatever they were supposed to be.
39. 5 points

## What are some scientific alternatives to the theory of evolution?

This would be very cool. Unfortunately, here in the USA, I don't see that happening any decade soon since there would be parental concern about the radioactivity as well as (unreasonable) religious concerns. * The discussion reminds me of a point I read once that if Darwin had been wrong, the discovery of DNA and how it works would have destroyed his theory and we would have been seeking an alternate mechanism. Instead the discovery of DNA lead to a refinement of Darwin's theory into the even more robust Evolutionary Theory. It is humbling to think of how Darwin, through observation and deduction, derived the process of natural selection and developed his theory and that we have only needed to refine it a bit in spite of more than a century of amazing discoveries. I used to believe in evolution but I no longer do after studying it – now I understand and accept it. I also now see three groups: those who believe in evolution, those who don't believe in evolution – but neither of those groups understand it – and those who understand and accept evolution. I have never met someone who understands evolution but doesn't accept it – all who claim to be such people show that they don't actually understand evolution and really they just don't believe in evolution.
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