This is an old one, but never fails to amaze me:
When you see stars in the sky, what you’re actually seeing is the light that has traveled for several million years before it actually reached you. Therefore what you’re seeing is the past image of the star and for all you know, the star may not exist anymore!
Underlined part is not true. The only naked-eye object that’s a million (or two) light-years away is the Andromeda Galaxy, and I can’t swear I’ve ever seen it; if I had, it would have been a faint smudge of light from a trillion stars put together. Stars that we can see as individuals range from single-figure light-years away (Alpha Centauri, Sirius) to a couple of thousand (Deneb, a first-magnitude star, is nearly 3000 light-years away but may be 200,000 times as powerful as the Sun).
Speaking of the Andromeda galaxy, we know that just the center can be seen faintly, but if the sky was clearer, the Andromeda galaxy would appear to be much larger than the moon appears in the sky.
I’ll have to go back and reread the rest of the thread; it seems like it’ll be worth while. However, the water “fact” doesn’t pass the smell test to me. The diffusion coefficient of water has been estimated as two billionths of a square meter per second. That means after 10 years, the molecules you poured in spread across about half a square meter due to their intrinsic random movement. Now granted there’s mixing due to evaporation, waves and currents, but unless you dumped those molecules into some sort of trans-oceanic current (I have no idea if such things exist), you probably won’t find them more than a few tens/hundreds of miles away at most.
Yes, that’s a great science fact for sure. Just a shame that you need a serious telescope/camera combo to view the Andromeda Galaxy like that - if only binoculars were enough. 
(And of course you would never get those two objects in shot at once.)
The 3 quarks in a proton only account for 1% of its resting mass. The remaining amount comes from the force carrying particles or gluons. Unfortunately, gluons are bosons which have no mass. So how does this work exactly.
I’m not really qualified to give a proper explanation, but it has to do with the fact that quarks are attracted to one another via the color force which is infinitely strong. Further, a proton is a much more dynamic system than you might imagine. The “exchange” of gluons between quarks is manifested in the form of transient virtual particles which arise from the tremendous energy present only to annihilate when meeting the anti-particle version of themselves. In addition, the quantum vacuum contributes a constant flow background fluctuations termed ‘sea quarks’ which are also part of the system.
And even this is probably only a very incomplete picture of what is really going on. The point is that a) even on this tiny scale, our universe is a seething caldron of controlled chaos and b) the more we learn, the more it seems that what we consider ‘reality’ is much closer to an illusion than we would like to admit.
The expense is why the capstone of the Washington Monument was made of aluminum.
Like Xema said, this doesn’t make statistical sense. If you predefine some sequence and then distribute, then you have an astronomically small chance of getting that sequence. But if, as in your statement, you simply deal a hand of cards, then it’s nonsensical to state the probability after the fact because there is a 100% chance that you will get some sequence, and a 100% chance that it was the one that you drew.
Interesting factoid that’s relevant to my (well, my PI’s) lab: If you take the average length of a protein to be 300 amino acids, then there are 20^300 ways to make a protein of average length out of the standard 20 amino acids. The average mass of a single amino acid is on the order of 100 Daltons or ~2 * 10^-22 grams. Therefore, the mass of all possible protein sequences of average length is ~ 4 * 10^368 grams. But the mass of the known universe ((as of 2005) is about 3 * 10^55 g. Therefore, there is not enough material (by a mind boggling amount) to make every possible protein of average length.
And yet we still try to design them anyway 
:dubious: How can that be right? If I take a glass of water and dump a spoonful of salt or sugar in it, that is going to be an evenly mixed solution within, well, I don’t know exactly, but a few hours at most, surely, and that is without any of the agitation that seawater is constantly subject to. (And sorry, I am not going to read someone’s 70 page thesis to figure it out.)
I like your one about the proteins, though.
No, it really isn’t. Linguistics does not concern itself with such things, any more than biology is concerned with such facts as, for instance, that I have a broken fingernail.
I’m actually not sure I handled the math right; I’ve never actually worked the diffusion of water in water before. I might be off by a considerable amount. However, the difference between your situation and mine is concentration. Fick’s law of diffusion states that the flux of your object through a given area is determined by its diffusion coefficient times the difference in concentration of that object on either side of the area (the concentration gradient). In your case, your salt starts in a spoon-sized volume whereas the surrounding space is virtually devoid of salt. Therefore, the concentration gradient is huge and the salt will quickly flow through the medium.
In my case, there is no concentration gradient because the concentration of water is virtually constant wherever water is present. Therefore, by Fick’s law, there is no flux. However, Fick’s law doesn’t exactly apply to this case because it only deals with indistinguishable objects. It’s true that there is no net water flux between any two parts of a glass; however, we’re assuming that we can “tag” a water molecule which would otherwise be indistinguishable from the rest and watch it go. Therefore, Fick’s law can’t be used to model its behavior. I don’t have the time or inclination to find out/remember how you’re actually supposed to model that, so I just guesstimated with the diffusion coefficient itself.
A drop of food coloring carefully placed in 2 cups of undisturbed water will be uniform in about three minutes, so the stated rate is way to small. But whatever the number, I don’t think there’s much dispute that mere random diffusion isn’t sufficient.
I’d need to see more evidence that the stated effect was real after (say) 10 years, but if it is, the culprit is far more likely to be the water cycle (evaporation, atmospheric mixing, and rain) scattering the molecules around the globe, combined with the fact that the “scooper” will be doing their scooping only in surface waters. Of course, that would mean that a lake or runoff river would be just as likely as the oceans to have your original molecules. Some of the molecules will get into the water table, but filtering there can take millennia, so tap water wouldn’t have them for most of us.
My gut feel is that if we put some harder numbers into it: we’ll accept even 1 atom from an original 1-cup sample after 10 years in any reasonable surface water (not ice caps, spring lakes, etc.) in the world exceeds 90% probability, that this is likely correct.
Heck, give it 50 years, and I’d bet you could say the same for the water in any given human’s body.
ETA: I’ve definitely left “facts” for “speculation here”
If you say so.
Maybe it should go in the old thread of random facts instead of random science facts. If it’s even true…
Cite?
I don’t think he was trying to prove a point about the shape or size of the planet. As far as I understand, he was trying to find a shorter route to Asia.
All that dilution and mixing, and nobody’s made a homeopathic joke yet?
Oh, then my fact must not have been as surprising as I found it :smack:
Same thing. A shorter route that presumed a much smaller Earth: Columbus had an estimate of his own. Some historians have proposed that he used an argument like Strabo’s, but Dr. Fischer found his claim to be based on incorrect units of distance. Columbus used an erroneous estimate by Ptolemy (whom we meet again), who based it on a later definition of the stadium, and in estimating the size of the settled world he confused the Arab mile, used by El Ma’mun, with the Roman mile on which our own mile is based. All the same, his final estimate of the distance to India was close to Strabo’s. http://www-spof.gsfc.nasa.gov/stargaze/Scolumb.htm
Columbus sailed off, with one part courage and two parts madness, to sail around a spherical world. Actually, his trip was based on a terrible miscalculation. He underestimated earth’s diameter, and he overestimated the width of Asia. He thought Japan lay only 2700 miles west of the Canary Islands. A correct calculation would’ve put it 10,000 miles away – far beyond the reach of any 15th-century ship. And yet Columbus had access to a much better estimate of earth’s size – one that was 1700 years old.http://www.uh.edu/engines/epi230.htm
I’m wondering if my facts are surprising or interesting. I know people have been reading them as they’ve pointed out when I’m wrong.
Back To The OP
Some facts I’ve learned on this board
Some species of tortoise do not die of old age. Neither do some species of jellyfish.
It’s safe to connect a fully charged car battery to your tongue with jumper cables.
Door hinge.
Okay, I have read all the postings so far to make sure I’m not repeating an already posted fact.
• Helium was first discovered on the Sun.
• E=mc² tells us that you get a lot of energy when converting a very small amount of mass to energy. The energy of the Hiroshima explosion was produced from the conversion of 1 gram of matter into energy. (1 gram is about the mass of one paper clip).
• You are making a model of the Universe and you decide to represent the Earth as a 5 inch (12.5 cm) diameter ball. On that scale, how far away would you have to place Alpha Centauri?
The Moon.
on the subject of the distance to the moon, for a long time i’d assumed it was rather close by, reinforced by the models of the solar system we were shown in primary school. it’s actually rather far away - to scale, a basketball would have to be about 7 meters away from a tennis ball. how far away would Mars be?