Again thanks to Laura for this site. If you’ve ever wanted to know what non-food bits are allowed in food (we’re talking insect parts, rodent hairs, mold, etc) then check out the US FDA/CFSAN Defect Action Level Handbook.
Okay it is gross. Kinda scary too. File under: “OMG I can’t believe I eat that“. You’ve been warned.
Quick, name Newton’s laws … eh, don’t bother I have them summarized below. Regardless sometimes the concepts of inertia, equal and opposite reactions, and force can be hard to wrap your head around. Over on ScienceBase I found this little YouTube video on these very principles. Oh and here’s the list:
Newton’s laws underpin so-called classical mechanics, as opposed to quantum mechanics or relativity theory. I’ve summarised them below, but you’ll get a much clearer understanding of bodies in motion if you watch the video.
- Objects stay still or move with constant velocity unless a force pulls on them or gives them a shove
- Pulling or shoving an object changes its velocity (accelerates it) at a rate proportional to the force of the pull or shove
- If you shove or pull an object it will pull or shove back with an equal and opposite force
Personally I’ve been wanting to do something similar but using a pool table for the example. It all works. The cool thing is that as you make your first break in pool you show all three Newtonian laws! The kid doing the video (and an awesome job too!) used the pool table example to illustrate Newton’s 3rd law. But, if you consider hitting the cue ball with a cue you can illustrate the harder you hit, the faster it goes idea (2nd Law, sorta) and the 1st Law, good old inertia, well once the balls are in motion, they would keep moving around the table if they didn’t have friction (the felt) the bumpers (absorbing energy) and gravity to content with.
Whew, good thing we have Newton’s Laws, a game of pool would be prett dangerous with out them!
I can always count on Laura for good links in the morning. Okay, except the gnome one, but she hadn’t looked at it first, so no hard feelings there.
So here is a scary one, well at least for us caffeine addicts. A group tested the effect of "mind-altering" substances on spiders and their web making skills. The results are below:
Eeek! What I found funny was that the mary jane dosed spiders just lost interest after a while. Okay if this is what caffeine does, I’d hate to see nicotine. Oh, wait I know that one. It would kill them.
One of the great science mysteries of the ancient world is the famous Archimedes Death Ray. The gist is Greek soldiers using highly polished shields to focus the Sun’s rays on an enemy ship and cause it to burst into flame. Of course, this is based on the always fun magnifying glass and Sun trick (which has caused untold carnage to insects). Mythbusters tried to make the Death Ray and said it was busted. Well leave it to geeks at MIT to prove them wrong.
Okay it took some time and they probably weren’t 100% successful, but you know, they came close (flames and all!). Here’s their final word:
The short burn period created a hole through the planks.
Our 2.009 conclusion?
Feasibility estimate confirmed!
Sketch models rock!!
Okay kids, put those shields down and stop trying to set the car on fire.
Tags: Archimedes Death Ray
Thanks again to Laura for this really cool link (she fessed up she got a calendar for Xmas with a cool link a day). Ever want to know more about snow and snowflakes than you ever thought possible? This is the place. I haven’t scratched the surface of the site, but I’m sure there will be cool (ha ha) projects and stuff to do.
Speaking of snowflakes, on CSY:NY last night one of the CSIs fix a snowflake to a slide with superglue to look at its structure and then be able to set a time. Okay, I know CSI is often out there on the science, but this I can’t believe. If all my snow wasn’t melting I might try it. Of course I have slides, coverslips, and glue around! Who do you think you’re reading! ;)
Tags: snow, snowflakes
Yes. Of course it does. It has too, it is sound after all. It has been an urban legend for years though that a duck’s quack doesn’t … proof? Lot’s here …http://buzz.smm.org/buzz/blog/does_a_ducks_quack_echo
SPOILER: Yes, a duck’s quack, like any other sound, echoes. But the WAY a duck quacks, with the long "AAAAAACK" sound at the end of the call, tends to mask echoes, making them hard to hear.
Tags: urban legends
One of those big questions that has been hanging around for a long time in Physical Anthro (long before Quest for Fire and Clan of the Cave Bear) is the whole Homo sapiens and Neanderthal question. Originally it was thought that Neanderthals were part of our genetic/evoloutionary line. Then it turned out we were all hanging around at the same time. So … how did Neanderthals (a dead-end on the whole Homo sapiens line) influence our genetic makeup? Was there significant interbreeding and intermixing? Looks like … no. Sure it appears to have happened (this should come as no surprise), but not to an extent that Neanderthal DNA is around today.
Quirks and Quarks looked into this last week and talked about some of the recent work to sequence the Neanderthal genome:
All very well, but of course there is another line of evidence from genetics that shows no signs of the mixing that Trinkaus has found. Over the past several years German and American researchers have been scavenging Neanderthal DNA from samples of bone, in an attempt to reconstruct the entire Neanderthal genome. This is a hugely ambitious project, since it’s only been a few years since we’ve been able to retrieve any DNA from fossils at all, and what we have retrieved has been tiny fragments. Nevertheless, the work has reaped enough DNA that it can be compared to modern human DNA. Those results so far show that there are no distinctly Neanderthal genetic codes in today’s human genome. In other words, according to the genetic work, if humans and Neanderthals ever did interbreed, then not only are the Neanderthals extinct, then so are the Neanderthal-human hybrids.
This, of course, doesn’t prove Neanderthals and humans didn’t mix — only that as far as we can tell the mixture wasn’t particularly successful, as it didn’t persist into modern times. The genetic work isn’t yet complete, though, so there may still be some chance that the Neanderthals have lived on. Certainly spending any game night in a sports bar provides some powerful anecdotal evidence for the case.
Like many things in science, I wouldn’t call this case closed. There very well could be sub-populations in the world with some Neanderthal DNA hanging around, but it will take a lot more work finding ancient samples to work with to figure that out
Part of this answer is rather cool, leaves don’t actually turn red (or yellow or orange) … they are always that colour it’s the green chlorophyll that masks it. As trees stop photosynthesis in the fall, the chlorophyll goes away and reveals the "true colours".
There is a greater science question here though. Things in nature don’t just happen for now purpose or reason. The reason why leaves turn, what was the physiological or adaptive strategy in play here, is something of a mystery. ScienceBase linked to a Wisconsin U. article with one theory. In order to store the nutrients and energy for winter, trees have to protect the process from light, by having leaves that change colours they protect the process.
That’s pretty cool, but I still just like the colours.
Tags: why leaves change colour
This news is actually a month old, but I just saw it on CNN and man did it make my blood boil. So a researcher at the University of Western Ontario (usually just called Western) did a study using data from the SATs (those evil tests foisted on kids who want to go to college in the States) and says his results show that men are smarter than women (coverage LiveScience, Daily Mirror).
What makes me angry about this? Come on I’m a man, shouldn’t I be happy to get this news? It’s the use of a known flawed dataset. Look tests, especially the SATs, test how people take tests. They also have significant cultural bias. Yes, I know the "new SAT" is supposed to be better, but frankly I can’t believe that there isn’t an inherent bias in using the SAT scores as a sample. Who cares if it’s a large sample. Who cares that lots of people take it. IMNSHO, it’s flawed.
Do I think one sex is smarter than the other? Yes and no. Generally, I think it’s a draw. On specific things I think one sex has the edge over the other. Does it really matter though? Not a freakin’ bit, unless you have another agenda to promote … and that’s using Science for the Dark Side for sure.
Tags: intelligence
I love the weather. I’ve already talked about my favourite weather signs, now what about something a tad more scientific. How about a barometer? Making one is really, really easy and I’m going to show your how. The kind I’m going to show you is called a weather glass. You can find them in home and garden catalogs, but come on, let’s just make one instead!
Before I get into the make, let’s talk about what barometers do. Barometer’s measure the minute changes in atmospheric pressure that indicate changes in weather. Minute? Yeah, really, really small. Okay low pressure (usually associated with rain) is about 29 milibars, high pressure (nice weather) is about 30. One freakin’ millibar that’s it! Barometers used to be all done with liquids, because they are prevalent and easy to deal with. How? Simple, it’s all PV=nRT. Universal gas law. With temperature relatively constant, changes in pressure will change the volume. Uh huh. Okay, here’s what’s going on.
The bottle is filled with water almost to the top and closed. At the bottom I’ve cut a small hole and used silicone caulk to seal a narrow plastic tube in. I used a little more caulk to stick the tube to the bottle. Okay, note in the picture that the opening of the tube is well below the top of the water. This is really important. So as the pressure from the air pushes down on the narrow opening it changes the water level. Higher pressure, lower level in the tube, lower pressure, higher in the tube. As you can see the water is at the top of the tube and when I took the picture … it was raining. In fact, the tube is nearly overflowing right now. As the storm clear, high pressure will take over and push the water back down.
Now, as low pressure heralds a coming storm, you watch your weather glass for when it rises more than when it falls. You want to know when it’s going to rain, you can tell when it’s clearing up.
So making it … I described it above, it’s really that simple.
Here’s exactly what I used. Some things I figured out. The bottle needs to be almost full so that the tube will be the sensitive part, not the air above the water. Too much air and the tube level will not change. Also keep the bottle out of the sun. Why? Temperature. If the bottle warms and cools it will be temperature not pressure making the water level rise (the increased temp will increase the volume of the water making it go up).
It will take about 5 mins to make this, about 30 mins to dry enough to fill, and a day to get things acclimated to be able to predict the weather. Except for the cutting the hole part, very kid friendly project. Yes, I would also put food colouring in the water to make it easier to see.
This first one was the prototype. The next one I’m going to make will be for my daughter’s class. They’re studying weather, don’t ya know.
