Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Astronomers Find a Planet Denser Than Lead

Astronomers find a planet denser than lead

Meet the planet COROT-exo-3b. It orbits a star slightly larger, hotter, and brighter than the Sun. The star is not an unusual one in any way, but the planet is definitely weird: it orbits the star in just over 4 days, which is pretty close in, though not a record breaker in and of itself. What’s bizarre is that it has about the same diameter of Jupiter, but has 21.6 times Jupiter’s mass. That makes it denser than lead.
…
This planet is challenging to models. How did it form? It most likely formed farther out from the star — gravitational influences make it hard for a large planet to form close to a star — and then gradually moved in.
…
It was discovered by COROT, an orbiting European Space Agency mission designed to look for stars that dip in brightness as an orbiting planet passes in front of them. That gives the size of the planet (the amount the light dims is proportional to the size of the planet).

As a planet (the alternative is classifying it as a brown dwarf – a failed star, not a planet), COROT-exo-3b would be the densest known planet.

Holographic Television on the Way

Ok, there really isn’t much new since I posted that holographic TV is getting closer. But won’t it be cool when I can have one in my house? And you might need to plan for it in your new house addition 🙂 Also, with the economic news lately a good distraction might be useful – Holographic television to become reality

The reason for renewed optimism in three-dimensional technology is a breakthrough in rewritable and erasable holographic systems made earlier this year by researchers at the University of Arizona.

Dr Nasser Peyghambarian, chair of photonics and lasers at the university’s Optical Sciences department, told CNN that scientists have broken a barrier by making the first updatable three-dimensional displays with memory.

“This is a prerequisite for any type of moving holographic technology. The way it works presently is not suitable for 3-D images,” he said. The researchers produced displays that can be erased and rewritten in a matter of minutes.
…
According to Peyghambarian, they could be constructed as a screen on the wall (like flat panel displays) that shows 3-D images, with all the image writing lasers behind the wall; or it could be like a horizontal panel on a table with holographic writing apparatus underneath.
…
Peyghambarian is also optimistic that the technology could reach the market within five to ten years. He said progress towards a final product should be made much more quickly now that a rewriting method had been found.

However, it is fair to say not everyone is as positive about this prospect as Peyghambarian. Justin Lawrence, a lecturer in Electronic Engineering at Bangor University in Wales, told CNN that small steps are being made on technology like 3-D holograms, but, he can’t see it being ready for the market in the next ten years.

I would have to say I am with those that think this might take a bit longer to be in place. But I would be glad to be wrong.

Milestones on the Voyage to the Bottom of the Sea

Dive! Dive! Dive!

0 FEET: EPIPELAGIC ZONE
Ample sunlight penetrates down to 650 feet, making photosynthesis possible. With abundant plant life (read: food), this zone is the most densely populated with fish.
…
656 FEET: MESOPELAGIC ZONE
Too deep to support photosynthesis: The fish that survive here are sit-and-wait predators that tend to have large mouths and specialized retinas to increase light reception.
…
1,640 feet: Maximum diving depth of the blue whale.
1,969 feet: The Deep Sound Channel, a layer in which acoustic signals travel far and fast.
1,969 feet: Maximum diving depth of nuclear-powered attack subs.

3281 FEET: BATHYPELAGIC ZONE
The ocean is dark at this level; the only glow is from bioluminescent animals. There are no living plants, and creatures subsist by eating the debris that falls from the levels above, including dead or dying fish and plankton.

3,281 feet: Maximum diving depth of the sperm whale. To navigate in the darkness, these whales emit high pitched sounds and use echoes to determine the location of prey.
3,937 feet: Maximum diving depth of the leatherback sea turtle.
4,000 feet: The domain of the Pacific sleeper shark, the largest toothed shark ever photographed. It can reach lengths of 28 feet.
…
5,187 feet: Maximum diving depth of the elephant seal.
…
13,123 FEET: ABYSSOPELAGIC ZONE
In the pitch-dark of the abyss, there is no light at all, the water temperature is near freezing. Of the few creatures found at these crushing depths, most are blind and have long tentacles – tiny invertebrates such as shrimp, basket stars, and small squids.
…
19,685 FEET: HADOLPELAGIC ZONE
Despite the intense pressure and frigid temperature in the deepwater trenches and canyons, life still exists here, especially near hydrothermal vents on the ocean floor. Invertebrates such as starfish actually thrive.

Engineer Your Life

Engineer Your Life is an outreach initiative committed to sharing with college-bound young women the opportunities available to them in the world of engineering. Unfortunately they chose to use flash content and the website fails to follow simple usability guidelines (basic stuff like human readable urls, links that work without javascript…) but there is decent content. The use of flash and failing to pay attention to usability are highly correlated in my experience. The site profiles 12 engineers including Judy Lee:

Judy’s enthusiasm paid off. A few months later, the IKEA engineer asked her to design a children’s play mat. Judy was thrilled and soon found herself in IKEA headquarters in Sweden, where she worked with a team of engineers and product developers. It was at this moment that she realized her ideal job was one that truly offered a balance between creativity and problem solving.

Designing for IKEA
Judy began her new project by thinking about the way kids play. “I realized that kids today play indoors a lot. Maybe because the world seems a little more dangerous and parents are more protective. So I knew that this mat had to incorporate some kind of physical play element.” Rather than a static mat, Judy designed one resembling a giant lazy Susan that kids could spin around on. “Once I had the concept, the mechanical engineer in me took over. I needed something simple. Simplicity is awesome. My mat is basically two injection-molded pieces of plastic that spin on a set of interior wheels.”

Judy will never forget the experience of seeing her mat in an IKEA store. “It was incredible,” she recalls, “and it was such important validation for me that my ideas matter, they’re good, and they’re marketable.”

Dream Job at IDEO
Today, Judy has found her dream job in Palo Alto, California, at a company called IDEO, one of the country’s most innovative design firms. IDEO hires engineers, designers, psychologists, and businesspeople who work in teams to develop cutting-edge products (they created Apple Computer’s first mouse, for example). Judy designs children’s toys, pet products, and packaging for over-the-counter drugs and food. “I feel pretty lucky to have such a creative and interesting job. I’m surrounded by brilliant people. It doesn’t really seem like work. It’s just plain fun!”

MicroRNAs Emerged Early in Evolution

New Research Shows MicroRNAs Emerged Early in Evolution

“MicroRNAs have been available to regulate and shape gene expression as far back as we can go in animal evolution—they might even predate animals,” says Bartel, a leader in the discovery and functional study of microRNAs. “They might have helped to usher in the era of multi-cellular animal life.”

First discovered in 1993, microRNAs are strands of RNA that are 21-24 nucleotides in length. They dampen gene expression by intercepting messenger RNA before it can turn the cellular crank that translates a gene into a protein. Earlier, Bartel’s research team showed that each microRNA can regulate the expression of hundreds of genes.

The ability of microRNAs to silence gene expression likely evolved from a more ancient defense against viruses, bacteria, and other mobile genetic elements that can mutate host DNA.
…
The scientists determined that the starlet sea anemone has both microRNAs and piRNAs. In addition, the anemone makes proteins resembling those that interact with these small RNAs in humans. Both types of small RNA were also found in the sponge. The third target of their search, Trichoplax, did not contain any microRNAs, though Bartel suspects they may have existed in ancestral forms and later disappeared.

Carbon Nanotechnology in an 17th Century Damascus Sword

Carbon nanotechnology in an 17th century Damascus sword

Wootz, with its especially high carbon content of about 1.5%, should have been useless for sword-making. Nonetheless, the resulting sabres showed a seemingly impossible combination of hardness and malleability.
…
Amazingly, they found that the steel contained carbon nanotubes, each one just slightly larger than half a nanometre. Ten million could fit side by side on the head of a thumbtack.
…
It isn’t clear how ancient blacksmiths produced these nanotubes, but the researchers believe that the key to this process lay with small traces of metals in the wootz including vanadium, chromium, manganese, cobalt and nickel. Alternating hot and cold phases during manufacture caused these impurities to segregate out into planes. From there, they would have acted as catalysts for the formation of the carbon nanotubes, which in turn would have promoted the formation of the cementite nanowires.
…
By gradually refining their blade-making skills, these blacksmiths of centuries past were using nanotechnology at least 400 years before it became the scientific buzzword of the twenty-first century.

Wind Power Provided Over 1% of Global Electricity in 2007

graph of global installed wind power capacity

Data from World Wind Energy Association, for installed Mega Watts of global wind power capacity in 2007. 19,696 MW of capacity were added in 2007, bringing the total to 93,849 MW. Europe accounts for 61% of installed capacity, Germany accounts for 24% and the USA 18%.

The graph shows the top 10 producers (with the exceptions of Denmark and Portugal) and includes Japan (which is 13th).

New Neurons are Needed for New Memories

New neurons are needed for new memories

Around 15 years ago, researchers discovered that the adult rodent brain contains discrete populations of stem cells which continue to divide and produce new cells throughout life. This discovery was an important one, as it overturned a persistent dogma in neuroscience which held that the adult mammalian brain cannot regenerate.
..
This study shows that inhibiting neurogenesis has strikingly different consequences in two distinct regions of the brain. In the olfactory bulb, it leads to significant shrinkage but apparently does not alter smell-related behaviour. In the hippocampus, the effect on structure is not so marked, but it is clear that newly-generated neurons are necessary for the processes of learning and memory. Exactly how the new cells contribute to memory formation is still unknown.

More interesting stuff. Related: How The Brain Rewires Itself – Scientists Witness the Birth of a Brain Cell – New Neurons in Old Brains – No Sleep, No New Brain Cells

Tidal Turbine Farms to Power 40,000 Homes

Scotland Plans World’s First Tidal Turbine Farms

Scottish Power Renewables will apply for planning permission next year to build the two farms in Northern Ireland’s seabed. The turbines will be manufactured in Scotland in an intentional boost to the country’s green-collar job market. The 98-foot structures have been tested to operate in water as deep as 328 feet, and they spin slow enough to allow marine life to avoid the 66-foot blades.
…
New York City installed its first turbine for their tidal power farm earlier this month, but the Scottish plan differs in that the farms will be located in the open sea, not a river or straight.

Project aims to harness sea power

Projects on the firth could be operational by 2020… The Scottish and Irish sites would host up to 60 of the turbines – 20 at each site – generating 60 megawatts of power for up to 40,000 homes.

Foreign Cells Outnumber Human Cells in Our Bodies

This is one of those area I find very interesting: People Have More Bacterial Cells than Human Cells. Colin Nickerson has written an interesting article on the topic: Of microbes and men

Scientists estimate that 90 percent of the cells contained in the human body belong to nonhuman organisms – mostly bacteria, but also a smattering of fungi and other eensy entities. Some 100 trillion microbes nestle in niches from our teeth to our toes.

But what’s setting science on its heels these days is not the boggling numbers of bugs so much as the budding recognition that they are much more than casual hitchhikers capable of causing disease. They may be so essential to well-being that humans couldn’t live without them.

In this emerging view, humans and their microbes – or, as some biologists playfully put it, microbes and their attached humans – have evolved together to form an extraordinarily complex ecosystem.

The understanding of the complex interaction is something I came to through reading on the overuse of antibiotics. And the more I read the more interesting it gets.

“We can’t take nutrition properly without bacteria. We can’t fight bad germs without good germs,” he said. “It may turn out that secretions from bacteria affect not only long-term health, but hour-by-hour moods – could a person’s happiness depend on his or her bugs? It’s possible. Our existences are so incredibly intertwined.”

However, in the opinion of some researchers, this strange union may be headed for trouble because of profligate use of antibiotics and antiseptic lifestyles that deter the transfer of vital strains of bacteria that have swarmed in our systems at least since early humans ventured out of Africa.