# gib65

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## Posts posted by gib65

### Photons can't accelerate, can they?

When a photon is emitted from an electron, is it instantly traveling at c? Doesn't this contradict F=ma*? Or, in other words, doesn't an object have to accelerate if it is to go from one speed (such as rest) to another (such as c)?

*I know photons can be considered massless, but then why are they pulled down by gravity?

### Can the universe contract to less the size of your spaceship?

In each case, the faster you go...the faster you are displaced toward an area of the universe that has most of it's mass that is at rest in your new inertial frame (due to the expansion)...so the behinder you get.

What do you mean by this? How is "most of its mass" at rest at any point in the spaceship's travels? And how does this solve the paradox?

### Can the universe contract to less the size of your spaceship?

I'm in a discussion on another forum. The topic is relativity and length contraction. I'm trying to explain to someone that anyone who measures something moving will also measure length contraction. This was meant to correct a common misconception about relativity - that since certain measurable quantities dilate as one's speed increases (time slows down, length contracts, mass increases), those quantities would have to seem to dilate in the opposite direction from the point of view of the one moving. In the case of this discussion, my interlocuter assumed that if someone traveling in a spaceship close to the speed of light undergoes length contraction, then relative to him the entire universe would have to seem to undergo length 'extension'. I tried to correct this by saying that relative to him, the universe also would undergo length contraction because it would be moving relative to him.

Then he stumped me: it should therefore be theoretically possible to arrive at a speed sufficiently close to c such that the entire universe seems to contract to shorter than the length of his spaceship. The front end would essentially have shot passed his destination and the back end would essentially have regressed behind his point of origin. How does one resolve this paradox?

### effects of junk food on energy levels

So I'm getting the impression that the answer is that added junk food on top of a complete diet of one's daily requirements would not decrease one's energy levels (not in the short run anyway).

Please note (just so there's no confusion): I'm not talking about how much energy one takes in but how 'energized' one feels. Compare a day of drinking coffee with a day of abstaining. If all else is equal (i.e. same food intake), the coffee drinking day would count as 'high energy' in my thinking even though on both days the body takes in the same amount of energy.

### effects of junk food on energy levels

As long as he takes it in an appropriate amount. Excess of everything is bad.

Hmm. I would assume though that if he is to get most of his carbs from junk food, he'd have to take some vitamin suppliments, no? I mean there's more than just carbs to consider when trying to boost up one's energy, right? I heard B6 and B12 are very important.

### effects of junk food on energy levels

He wouldn't have the energy level up because junk food provides fat which can't be used for immediate energy. But balanced food provide carbohydrates.

Some junk foods provide fat, but others provide sugar (eg. candy bar). Are you saying so long as he consumes enough carbs (whether from health foods like fruits or junk foods like candy bars), his energy levels will be up?

### effects of junk food on energy levels

It's common knowledge that eating healthy gives you more energy. So here's a question: does eating junk food reduce your energy even if you've taken your daily requirements of health foods? For example, suppose for a full day, someone ate a balanced quantity of fruits, vegetables, whole grains, lean meats, and lean dairy products. He ate the required daily amount for someone of his type. He's getting enough good quality sleep and he's staying away from drugs and alcohol. If on top of all that he had a fair amount of junk food (say a bag of chips, some pop, a donut, and some buttered popcorn at a movie) would he still have his energy levels up at what they would be if he cut out the junk food or would the junk food push down his energy levels (even though he had the full amount of daily required health food)?

### gaining weight by eating healthy

This is kind of a hypothetical question, so don't read anything into this about my actual life style:

I'm just wondering if it makes sense to talk about being overweight yet healthy at the same time. I'm thinking particularly about snacking on health foods - fruits, whole grain breads, low-fat dairy products (milk, yogurt, I don't know about cheese), low-fat meats (particularly fish), etc. If one was always hungry and always wanted to snack, could he/she maintain his/her health by snacking on healthy foods such as these? Let's add a bit of exercise in there since I know exercise is essential for any healthy lifestyle, plus good quality sleep, abstaining from drugs and alcohol, and all the other good stuff... or would you say there can be too much of even the healthy stuff such that it actually deteriorates your health?

### grape fruit and tomato juice: energy drinks?

I would think so, but I would think it's true of all fruits and vegetables. I was wondering if there's anything particular to do with grape fruit and tomato juice.

### looking for non-caffein energy boost

What definition of the word "natural" are we working with here?

The OP says "If I wanted to give up caffeine and get my energy boost from more natural sources"

Caffeine is formed by a number of plants and we use a fair few of them. It's pretty natural in my book.

On the other hand neither vinopocetrine nor sulbutiamine occur in nature. They are both semisynthetics.

Yeah, maybe 'natural' was a bad choice of words. What I'm looking for can be summed up as follows:

I don't think I want to jump from caffeine to prescription pills. I'm looking for something to which I won't develop a tolerance.

So fruits, vegetables, vitamin pills, etc. I'm also looking for something that won't harm me in the long run if I take it on a daily basis.

### looking for non-caffein energy boost

Caffeine actually is a natural energy boost, since it is found in many beans. There are many other natural energy boosts which are even more effective, such as erythropoietin and prednisone, but you can't get these without a prescription. It used to be possible to buy noradrenalin for injection over-the-counter at German pharmacies, but after the European integration that may no longer be the case. Some claim that ginseng or gotu kola are natural energy boosters, but the effect seems small.

Some vitamins and supplements you might try are vinopocetrine, gingko biloba, or solbutiamine, which essentially energize people by improving cerebral circulation.

I don't think I want to jump from caffeine to prescription pills. I'm looking for something to which I won't develop a tolerance.

Do you know of any products that contain the vitamins and supplements you mentioned (vinopocetrine, gingko biloba, etc.)?

### looking for non-caffein energy boost

If I wanted to give up caffeine and get my energy boost from more natural sources (fruits, vegetables, vitamins, etc.), what would you suggest? I understand it would be extremely difficult to get the same kind of boost from natural non-caffinated substances, but I don't need the same kind of boost (quality and quantity), just something so that I'm not dragging my ass around all day. Any suggestions?

### grape fruit and tomato juice: energy drinks?

A lady told me that she substitutes grape fruit and tomato juice for coffee. She says its a real energy booster. She drinks a full glass of grape fruit juice in the morning and then at noon she has two glasses of tomato juice with her lunch.

Now I doubt this can have the same stimulating and energy boosting effects as caffeine but I'm wondering if there's anything to the claim that grape fruit juice and tomato juice can boost one's energy to even a small degree.

### Does Cold-FX work?

Does it?

Also: if its primary function is to boost the immune system, does it work on pretty much any virus (ex. stomach virus)? Does it work on non-viral illness that the immune system can do something about?

### what's happening to me?

Is it possible you and your family are allergic to something in your house or in the environment? (It'd be funny if you were all allergic to the Christmas tree...) Allergies would produce the cold symptoms and the conjunctivitis. Combine this with a bout of flu at the start of the month and it'd be consistent with your symptoms.

You might try some over-the-counter allergy medicines and see if that does anything. Otherwise, I'd suggest seeing a doctor...

We've had the tree for a while now and I've never reacted to it on Previous Christmases. The medication I got for the pink eye was sold out in 2 out of 3 pharmacies; that coupled with the fact that in the doctor's waiting room was a kid also with pink eye tells me that its something going around.

I'm pretty sure it's an extremely versatile virus or several viruses going around at once (in the latter case, it could also have started with an extremely versatile virus that tends to mutate frequently and therefore ends up being several viruses going around simultaneously). I just wanted to know more about viruses to see if this line of thinking is plausible.

### what's happening to me?

It started sometime before December. I came down with some mild cold symptoms. Then, as soon as I thought I was getting over it, I got the stomach flew for the first week of December. The first night I was puking all night. The next day I was okay (i.e. I could function). Then, on the third day, I started getting stomach cramps and extremely frequent diarhea. The stomach cramps peeked in the middle of the day (they got pretty bad) and then over the next 24 hours or so I slowly started to feel better. For about a week, things started to look better for me until I started coming down with more cold symptoms. They still haven't left. Just yesterday, I started getting mild symptoms of pink eye in one eye. Today, I definitely have it in both eyes, and I'm feeling miserable, like I've just caught the cold virus all over again.

In my familly, my wife suffered from terrible cold symptoms for about 2 or 3 days in the week before December. She got over it fairly quickly and hasn't suffered from anything since. My daughter (2 years old) has had major cold symptoms for about the past month, and was throwing up around the same time I had the stomach flew. About two weeks ago, it looked like she had pink eye in her right eye. Today, she's getting better but still has a runny nose and a cough.

So based on this description, what do you think is happening to me (or any of my family members)? It's obviously more than your typical cold virus. It seems to come back repeatedly with a vengence; as soon as I think I'm over it, it comes back and in different forms. Is it one virus that happens to be prone to frequent mutation? Is it several viruses at once? Is it one virus that so happens to manifest different symptoms at different times?

### are there 'spot detectors' in the brain?

Your second question is assuming some sort of duality between the brain and the eye; both are apart of ourselves and should not really be separated. The reason we see spots is the same reason we see any other color' date=' very simply because it's a different color than the area around it.[/quote']

Yeah, that makes sense, Ringer, but whatever is picked up by the retina does get sent to the brain, does it not? From what I remember learning in school, signals are sent from the retina to area V1 in the occipital lobe, and the first types of neurons they are received by are line detectors, motion detectors, depth detectors, and I think a few others, but spot detectors was not one of them. So where it seems a little puzzling to me is when I consider what happens when the retina does pick up a spot or point. It must send a signal of some kind to area V1, and when V1 receives it, what neurons end up firing? Does the signal bypass V1 and go somewhere else? I mean, some center in the brain must be processing the signal because I'm able to think about the fact that I'm seeing a spot/point.

### are there 'spot detectors' in the brain?

I've heard the term 'spot detector' thrown around in some of the brainscience literature, but I vaguely remember learning in university that there are no spot detector neurons in the brain, only on the retina.

So my first question is: are there or are there not spot detector neurons in the brain?

My second question is: if not, then how are we actually able to see spots or know about them? Doesn't being conscious of something require some kind of brain processing of that information? Doesn't the brain have to have some kind of 'detector' mechanism in place in order for us to perceive whatever's being detected? When I look at the stars I surely feel like I'm seeing spots (or points). Same with pencil marks on paper. What brain area is responsible for my perception of these things if not spot detectors?

I see,

So, in other words, if I'm taking Cold-FX to combat my cold, I shouldn't stop just because I've regained my energy. And I certainly shouldn't go out drinking (I've heard alcohol weakens the immune system).

I see, thanks for the info both.

So what does it mean when I've regained my energy after 2 or 3 days. Does it mean anything, or is it just that one of the symptoms has abated (i.e. it's not a sign that the body is making any progress in fighting the virus)?

How do cold viruses work? Everytime I have a cold, I notice there's 3 phases I go through. For the first day, I have this uncomfortable sensation in my nasal cavaty. Then for the next two or three days, I'm totally out of energy and feel like shit generally. Then for the next week or two, I regain my energy but have to deal with a runny nose and a pesky cough.

At what point has the body "defeated" the virus? Is it when I've regained my energy? Or is it when all the symptoms (runny nose, cough) have dissappeared? Are the symptoms just the body's way of getting rid of dead cells and viruses? Is there a chance, after the two/three days of lethargy, that the virus could regain the upper hand, or is it a certainty that the virus is dead and won't come back again?

### brains that receive electromagnetic signals

If any sort of ESP were possible then evolution would have made it common (if not universal) because it would be useful.

That sort of implies that anything we're going to see in the future (assuming it's useful) has already existed. If it's useful, it's been done <-- as that you're argument?

Also, I'm not sure it would be useful. Isn't it useful for people to be able to hide their thoughts? Would it be useful for the species overall if a select few could inundate the minds of others with their thoughts? Maybe it would, but I wouldn't be do quick to judge.

Lastly, are we sure that there aren't some species on Earth who do communicate telepathically. Do we know what signs to look for as evidence? Only a century ago, we had no idea dolphin's communicated with sonic pings. Did we know to look for that? Did we bother? Have we bothered to think about what the signs would be of other species communicating telepathically (let alone actually looked for those signs)?

All in all, you're probably right, but I'm always one to ask the question: do we know? How do we know? And it's rare that I can ever settle on a yes/no answer.

### brains that receive electromagnetic signals

This is a very interesting video. The key insight that I find interesting at least is that some neurons respond to light. This is interesting to me because it calls to mind the sorts of theories many have put forward of possible mechanisms for telepathic abilities - namely, theories that propose that telepathic communication occurs by way of signals traveling through the air (like radio waves) and the brain functioning as a 'receiver' of sorts. Now I used to scoff at theories like this, filing them under "pseudo-scientific new-aged hippie jumbo-jumbo", but after watching this video, they suddenly seem a bit more plausible. I still think they have a long way to go, but now at least it seems to me a worthy topic for discussion - and I want to discusss it.

First, it should be pointed out that the speaker in the video has only mentioned light as a stimulus for these neurons and that fruit lies are the chief subjects in their studies. I can easily appreciate how light might penetrate into their brain, a very thin layer of tissue separating it from the outside, but when it comes to other animals (like human), we have a much thicker cranium through which light has no hope of passing. That doesn't mean other forms of electromagnetic radiation can't pass through, and indeed it remains a possibility in my mind that some neurons may respond to frequencies outside the range of visible light.

Another thing to keep in mind is that we don't know how prevelant such neurons are in species other than the fruit flies featured in their studies. I don't recall whether the speaker even confirm the presence of such neurons in the human brain.

The biggest hurdle, I think, towards developing this into a full blown theory on telepathy is that even if there were a substantial number of radiation sensitive neurons in the human brain, what would they be picking up. Unless there were also emitter neurons in other people's brain - neurons sending out signals - then the best we could hope for these radiation sensitive neurons to pick up would be static noise. There would have to be brains sending signals as well, and these signals couldn't just be random patterns of electromagnetic waves, but would have to have some significant lingual/cognitive content - that is, some pattern that could be deciphered and translated back into its original form, that form being meaningful human thought.

However doubtful this sounds, it is still interesting to ponder - and when we consider that five years ago, we would have been saying "there is no evidence for radiation sensitive neurons" maybe the lack of evidence for "emitter" neurons that transmit meaningful signals to be received by other brains is also temporary, and in a few (maybe several) years, some evidence might surface.

### given 2 points, calculate angle

Thanks both,

The dot product works for angles from 0 to 180, but beyond that it starts repeating. For example, if (x',y') = (-1,-1) and (x,y) = (0, 0), then theta = 2.356, but if I set (x',y') = (-1,1) then theta = 2.356 - exactly the same. Obviously, I can deduce the angle on the other side by subtracting this result from 2*pi, but it would be best if I had a formula in which I didn't have to do this - the reason being I'm implementing this into a computer program, and I can't just tell it to "eye ball" the angle to tell whether or not it needs to subtract the result from 2*pi. What I need is a formula that gives results that span the whole range from 0 degrees to 360.

Fuzzwood,

Would your suggestion do this? I'm not sure what you mean by "finding the intersecting point". Do you mean the vertex (which wouldn't necessarily be at the origin)?

### given 2 points, calculate angle

I'm not sure if this is in the right sub-forums. If not, please move it.

If I were given two points (x,y) and (x',y'), how can I determine the angle they form? Let's assume that (x,y) is the vertex of the angle, and the other line the angle is to be measured from is (x+1,y). If the angle is to be defined by the area swept from (x+1,y), pivoting around (x,y) is a counterclockwise direction, and reaching the line connecting (x,y) and (x',y'), how would one calculate the angle?

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