scale
esiegel | July 18, 2012"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." -Stephen Hawking
The Universe is a vast, seemingly unending marvel of existence. Over the past century, we've learned that the Universe stretches out beyond the billions of stars in our Milky Way, out across billions of light years, containing close to a trillion galaxies all told.
Image credit: NASA, ESA, S. Beckwith (STScI) and the HUDF Team.
And yet, that's just the observable Universe! There are good reasons to believe that the Universe continues on and on beyond the limits of what we can see; the…
rallain | August 25, 2010You know I wander around the intertubes, right? Who doesn't? Anyway, I saw this collection of strange google Earth images. Yeah, it is kind of dumb, but this one made me think:
That article said the image was from TechEBlog, so there is that.
I have no idea what this thing is, but it is clearly tall. How tall? Instead of searching online for info about this structure (that wouldn't be any fun), I figured I could do a quick analysis of the shadow. Here we go. First, I need to make some measurements. It turns out that Tracker Video tool for analysis is also quite excellent to use for…
rallain | June 25, 2010The oil spill is still in the news (sadly). One thing that keeps coming up is the speed that the oil bubbles rise to the surface. This is important in different oil-capture methods. The common statement is that smaller bubbles of oil can take quite a long time to reach the surface and larger bubbles can take about 2 days.
This is one of those cases where things do not scale quite the same. Suppose there is a spherical oil bubble rising at a constant speed. Here is a force diagram for such a bubble:
If this drop is going at a constant speed, then all these forces have to add up to the…
rallain | May 12, 2010ScienceBlogs.com is running "Ask a Science Blogger". The basic idea is that you, the reader, get a chance to ask questions to us, the bloggers. You can either post a comment in the link above or send an email to .
I would like to go ahead and answer one of the questions already posted. nemski asks:
How big does the world appear to an insect?
I like this question because it can be answered at different levels. First, what do you mean by world? If you mean "the Earth", then the answer would be that the Earth essentially appears the same to an insect as it does to us humans (from a size…
rallain | April 16, 2010If you have been on the internet, you surely have seen this website showing the sizes of different starships. Way cool. Here is a small sample - but it doesn't do the site justice. You really need to go browse around.
Of course, I can't let something like this just go. One of the things I always think is interesting is to consider objects of different size. Perhaps the general idea is that you can just scale stuff up or down as you like. But, it doesn't work this way. Let me start with my own spaceship. It is a sphere with a thruster on the back. It just holds one person.
Now, what…
rallain | December 15, 2009Maybe you have noticed how much material there was (for me at least) in last week's MythBusters. One of the myths they looked at was the bus jumping over a gap in the road from the movie Speed. I am not looking at that myth, it has been discussed many times in many places. Rather, I am going to talk about scaling the motion. As typical with the MythBusters, they like to make a scaled down version of the event. It's cheaper that way. In this case, they made a 1/12th scale model of the bus and the road. The question was: how fast should the model go?
The first question to ask is: what do…
bioephemera | May 10, 2009
We all know some cities "feel" smaller than others. But this set of subway maps presented at the same scale makes the differences obvious.
Just for fun, I made this image layering four of maps from major world cities in red, black, gold, and blue. Recognize the cities? Answer after the fold. . .
Sizewise, the winner here is London, shown in red. New York, in black, is a close second. The much less complex gold-green pattern is Washington, DC - note that it only approaches the size of New York and London because of the long spindly commuter line reaching north into Maryland. And that dense…
rallain | September 14, 2008Can you believe it? Have you seen this video?
Are you thinking what I am thinking? WOW. How could these people not follow my rules for cool internet video. Once again, here they are:
1Keep the camera stationary. This way I don't have to keep moving the origin in the movie.
2Don't Zoom. Same reason, this video followed that rule.
3Include a clear and obvious calibration object. A meter stick would work, or even a Kobe Bryant (I can look up his height). Maybe it could be a Ford F-150 that has a known length. Something!
4Include the mass and height of all people involved.
5Use high…
awild | April 30, 2008
Crypticerya bursera Unruh 2008
Baja California
Cory Unruh describes a new species of scale insect in the genus Crypticerya in this week's Zootaxa. The diagram above shows a highly stylized version of the back (at left) and underbelly (at right) of the insect, with peripheral illustrations of the various pores, appendages and hairs. Scale insects have such an unusual morphology that the people who work on them have had to create a unique system for keeping track of their various characters. Most entomologists- myself included- require additional training to make sense of it.
Like all scale…