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Plant Sciences, Zoology & Evolution / Re: what's the evolutional advantage of our having fingers of different lengths?
« on: 20/04/2015 23:32:22 »
Great explanation. Thanks!
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Plant Sciences, Zoology & Evolution / what's the evolutional advantage of our having fingers of different lengths?
« on: 20/04/2015 04:05:58 »
I'm curious as to the evolutional advantage of human fingers having different lengths. Why is it so? And what would happen if they were all of the same length?
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General Science / Re: Why are bricks rectangular, not triangular?
« on: 06/08/2014 04:33:47 »
Thanks. I guess the answer is more of an economic concern than a physics one.
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General Science / Why are bricks rectangular, not triangular?
« on: 05/08/2014 02:45:29 »
Triangle is the most stable polygon in geometry. I'm wondering why then the building bricks are all rectangular, not triangular?
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Plant Sciences, Zoology & Evolution / Re: Why does a giant squid have huge eyes?
« on: 27/03/2012 03:43:22 »
Interesting new perspectives, Don_1 and CliffordK. With your theories, I wonder if we could extrapolate that to other deep-sea life forms (those living in the same depth as the giant squid) and claim that they too should have developed disproportionately large eyes (w.r.t. their bodies)?
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Plant Sciences, Zoology & Evolution / Re: Why does a giant squid have huge eyes?
« on: 20/03/2012 23:27:55 »
Yeah, I also thought it might be related to taking in as much light as possible. But apparently that doesn't explain why the eyes have to be so much bigger than necessary. Anyways, thanks for the replies.
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Plant Sciences, Zoology & Evolution / Why does a giant squid have huge eyes?
« on: 16/03/2012 04:13:18 »
I was listening on the radio this afternoon, and one interesting story was about the giant squid having the world's largest eyes of any animal (the size of a basketball). There have been lots of debates about why their eyes are so big. Researchers have made calculations for what various eye sizes would allow the giant squid to see in the depth of the ocean where it's total darkness, and they assert that a much smaller eye would have served the squid well in its natural habitat. So far, it remains a open problem.
What are some of th competing theories/conjectures about the giant squid's disproportionately huge eyes? Thanks.
What are some of th competing theories/conjectures about the giant squid's disproportionately huge eyes? Thanks.
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Plant Sciences, Zoology & Evolution / Are there any birds that travel long distance (hundreds of miles) alone?
« on: 27/08/2011 23:07:45 »
Hello,
The birds that seasonally migrate a long distance (hundreds of miles) all seem to be traveling in flocks. Are there any birds that travel such long distace alone? f not, perhaps, it's because group travel has advantages over single travel, e.g., safer than individuals, less tiresome (airstreams from others' wingtips help staying afloat), etc?
Do we know of any birds in the history of evolution that had the ability of travel long distance alone?
Thanks.
The birds that seasonally migrate a long distance (hundreds of miles) all seem to be traveling in flocks. Are there any birds that travel such long distace alone? f not, perhaps, it's because group travel has advantages over single travel, e.g., safer than individuals, less tiresome (airstreams from others' wingtips help staying afloat), etc?
Do we know of any birds in the history of evolution that had the ability of travel long distance alone?
Thanks.
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Technology / Why's my digital camera unable to faithfully capture various dynamics in music?
« on: 26/08/2011 03:00:22 »
Thanks guys for all your informative replies. I looked up the camera's manual, and there's no mention of AGC, nor are there any settings hat let you tweak any video-recording parameters except resolution. I can only guess that the AGC is built in, and they don't want users to temper with it. Anyways, I'll try with Audacity. Thanks again. [
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Technology / Why's my digital camera unable to faithfully capture various dynamics in music?
« on: 25/08/2011 03:58:06 »
I have a Sony Cybershot DSC-T700 digital camera. As an amateur pianist, I often use its video-recording function to record me playing the piano. In a piano piece, you play different dynamics at different passages, sometimes pianissimo, sometimes a little more forte, that sort of things.
I'd like to think I do a fairly good job playing these different dynamics. However, after recording a piece and playing it back, I often find that the recorded audio does not faithfully capture the various dynamics.
It could certainly be that I'm not playing the dynamics well enough, but I'm also wondering whether it could be that the audio recorder in the camera is too rudimentary to do that. Anybody have any ideas?
And, what about a digital camcorder? Would it have a better audio-recording system built in to do a better job of capturing the dynamics?
Thanks.
I'd like to think I do a fairly good job playing these different dynamics. However, after recording a piece and playing it back, I often find that the recorded audio does not faithfully capture the various dynamics.
It could certainly be that I'm not playing the dynamics well enough, but I'm also wondering whether it could be that the audio recorder in the camera is too rudimentary to do that. Anybody have any ideas?
And, what about a digital camcorder? Would it have a better audio-recording system built in to do a better job of capturing the dynamics?
Thanks.
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Technology / Is shopping online safe
« on: 16/06/2011 03:37:43 »
To the OP:
When you do on-line shopping, it's better that the computer you use is connected to a LAN line (i.e., with a network cable) rather than do it wirelessly. Wireless communications carry a greater risk in most circumstances.
When you do on-line shopping, it's better that the computer you use is connected to a LAN line (i.e., with a network cable) rather than do it wirelessly. Wireless communications carry a greater risk in most circumstances.
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Plant Sciences, Zoology & Evolution / Could polar bears and penguins switch places?
« on: 17/10/2010 00:28:02 »
Thanks for the excellent explanation.
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Plant Sciences, Zoology & Evolution / Could polar bears and penguins switch places?
« on: 16/10/2010 04:23:10 »
I'm wondering if polar bears and penguins could switch their places and still live and populate. Why or why not?
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Technology / Could we develop an underwater GPS?
« on: 10/06/2010 19:58:40 »
Although I'm not sure: with all the water removed from the oceans, how altitude would be determined by the GPS. Currently, is altitude measured with respect to the sea level?
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Technology / Could we develop an underwater GPS?
« on: 10/06/2010 19:52:22 »
Yes, you’re right. I stand corrected. I should have separated GPS-based applications from GPS itself.
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Technology / Could we develop an underwater GPS?
« on: 10/06/2010 17:54:37 »
"If you took away all the water from the oceans the GPS system would work fine on what is now the sea bed."
Mmm… If you’re talking about pinpointing the location of someone standing somewhere at the bottom of the ocean (with all the water removed), the current GPS system could do that. However, for navigational purposes (from Point A to Point B), I think you’d still need to have a map of the whole terrain (as is done on land) for that, which requires mapping of the terrain.
Since underwater GPS navigation’s never been done before, there’d be a number of new factors to take into consideration if we ever wanted to do that (signal propagation, environmental, ecological, etc.). Sonic waves may or may not be the best way, and some modulation/encoding would certainly have to be applied in order to protect/sustain signal propagation in the water.
Mmm… If you’re talking about pinpointing the location of someone standing somewhere at the bottom of the ocean (with all the water removed), the current GPS system could do that. However, for navigational purposes (from Point A to Point B), I think you’d still need to have a map of the whole terrain (as is done on land) for that, which requires mapping of the terrain.
Since underwater GPS navigation’s never been done before, there’d be a number of new factors to take into consideration if we ever wanted to do that (signal propagation, environmental, ecological, etc.). Sonic waves may or may not be the best way, and some modulation/encoding would certainly have to be applied in order to protect/sustain signal propagation in the water.
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Technology / Could we develop an underwater GPS?
« on: 10/06/2010 03:08:23 »
Providing underwater satellite-guided navigation will assume that the GPS system (the constellation of satellites) maps oceanic terrain as it does the land mass on earth. I'm not sure if that's been done. If this were true, then theoretically, one approach I could think of is to deploy a large number of buoys out in the ocean that translate the electric signals to sonic signals and emit them underwater.
Obviously there will be environmental and ecological concerns with this approach. Also, you'll want to ask what the application is that can use such a service. For scuba divers, you probably don't go far underwater to need a GPS system to navigate for you. Most submarines these days have their dedicated satellite uplinks (and the submarines themselves are equipped with powerful antennas) to guide their navigation.
Also, let's face it, there're far more people living on land than underwater. So it probably doesn't make commercial sense to bring the GPS service 50 feet below sea level, even if it's technologically possible.
Obviously there will be environmental and ecological concerns with this approach. Also, you'll want to ask what the application is that can use such a service. For scuba divers, you probably don't go far underwater to need a GPS system to navigate for you. Most submarines these days have their dedicated satellite uplinks (and the submarines themselves are equipped with powerful antennas) to guide their navigation.
Also, let's face it, there're far more people living on land than underwater. So it probably doesn't make commercial sense to bring the GPS service 50 feet below sea level, even if it's technologically possible.
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Technology / What's the diffrence between "off" and "hibernate"?
« on: 10/06/2010 02:24:52 »
NASA's done a real great job with the Mars rovers. They're still functional, more than 10 times the designed life span.
My roommate at grad school (Cornell University) was a student of Steve Squyres, the PI of the Rover project. He lent me a book written by his advisor on the entire history of the project with his first-hand experience (since he was the one who first proposed it to NASA in something like 1990). Pretty fascinating to read.
My roommate at grad school (Cornell University) was a student of Steve Squyres, the PI of the Rover project. He lent me a book written by his advisor on the entire history of the project with his first-hand experience (since he was the one who first proposed it to NASA in something like 1990). Pretty fascinating to read.
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Physiology & Medicine / How do human eyes and ears receive visual/audio signals?
« on: 13/10/2009 20:48:04 »
Thanks. Yes, I've been doing some search on google and have gotten some ideas.
Here's a more focused question. In the inner ear, does the research community have any kind of system model from the input (i.e., the vibrations from the stapes) to the output (i.e., electrical signals induced by the microscopic hair cells in the cochlea)?
Thanks.
Here's a more focused question. In the inner ear, does the research community have any kind of system model from the input (i.e., the vibrations from the stapes) to the output (i.e., electrical signals induced by the microscopic hair cells in the cochlea)?
Thanks.
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Physiology & Medicine / How do human eyes and ears receive visual/audio signals?
« on: 11/10/2009 00:21:12 »
Hi,
I'm hoping someone on this forum can give me some tutorial (both online and off) on how human eyes and ears receive visual and audio signals from the outside world. I'm very new on this, and so would like to read something elementary to begin with. Thanks.
I'm hoping someone on this forum can give me some tutorial (both online and off) on how human eyes and ears receive visual and audio signals from the outside world. I'm very new on this, and so would like to read something elementary to begin with. Thanks.