Tag Archives: science facts

Static Stretching Decreases Muscle Strength

Researchers now believe that some of the more entrenched elements of many athletes’ warm-up regimens are not only a waste of time but actually bad for you. The old presumption that holding a stretch for 20 to 30 seconds – known as static stretching – primes muscles for a workout is dead wrong. It actually weakens them.
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A well-designed warm-up starts by increasing body heat and blood flow.
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To raise the body’s temperature, a warm-up must begin with aerobic activity, usually light jogging. Most coaches and athletes have known this for years.
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Athletes who need to move rapidly in different directions, like soccer, tennis or basketball players, should do dynamic stretches that involve many parts of the body. “Spider-Man” is a particularly good drill: drop onto all fours and crawl the width of the court, as if you were climbing a wall.

Why is it Colder at Higher Elevations?

John Hunter at Hurricane Ridge in Olympic National Park

I know it is colder at higher elevations (there is snow on the top of mountains when no snow is left on the bottom). When I was hiking this summer in Colorado and it started snowing I thought about why it was colder in higher elevations. My guess was that it was mainly due to lower air pressure and being higher up in the atmosphere where air was cooler than is was closer to sea level.

So I did some research online and the main explanations seem to be that at higher elevations the air pressure is lower (molecules and atoms under less pressure move more slowly which means the temperature is less).

Hot air does rise, but the amount of hot air is minor compared to the existing cold air in the atmosphere. So when hot air rises from the ground it is cooled down before getting far off the earth’s surface. And as it rises the pressure decreases, which cools it down.

Mountain Environments report, United Nations Environment Programme:

Air temperature on average decreases by about 6.5Â° C for every 1,000 m increase in altitude; in mid latitudes this is equivalent to moving poleward about 800 km. The dry dust-free air at altitude retains little heat energy, leading to marked extremes of temperature between day and night.

Photo of John Hunter at Hurricane Ridge in Olympic National Park.

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.
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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.
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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.
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5,187 feet: Maximum diving depth of the elephant seal.
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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.
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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.

Do Dolphins Sleep?

Do dolphins sleep?, MIT:

Dolphins do sleep, but not quite in the same way that people do. They sleep with one half of the brain at a time and with one eye closed. Dolphins rest this way on and off throughout the day, switching which side of the brain they shut down. During these periods, everything inside the dolphin slows down, and the mammal moves very little.

8 Percent of the Human Genome is Old Virus Genes

In Our Genes, Old Fossils Take On New Roles

It turns out that about 8 percent of the human genome is made up of viruses that once attacked our ancestors. The viruses lost. What remains are the molecular equivalents of mounted trophies, insects preserved in genomic amber, DNA fossils.

The thousands of human endogenous retroviruses, or HERVs, sketch a history of rough times during the 550 million years of vertebrate evolution. The best-preserved one, HERV-K113, probably arrived less than 200,000 years ago, long after human beings and chimpanzees diverged from a common ancestor.

But these retroviruses are more than just curiosities. They are some of the most important enemies we ever had. They helped mold the immune system that is one of the evolutionary marvels of life on Earth.

I must say there is tons of amazing stuff I learn about but I still find retroviruses amazing.

A Journey Into the Human Eye

Zoom into a human eye

The webcast goes into the human eye while describing the microscopic details of the human eye. See more such videos: The Eyes of a Fly – Zoom Into a Fish – Zoom Into a Butterfly

Life After the Chernobyl Nuclear Accident

Silent Spring by Lauren Monaghan, Cosmos

Ever since, a 30 km ‘exclusion zone’ has existed around the contaminated site, accessible to those with special clearance only. It’s quite easy, then, to conjure an apocalyptic vision of the area; to imagine an eerily deserted wasteland, utterly devoid of life.

But the truth is quite the opposite. The exclusion zone is teeming with wildlife of all shapes and sizes, flourishing unhindered by human interference and seemingly unfazed by the ever-present radiation. Most remarkable, however, is not the life buzzing around the site, but what’s blooming inside the perilous depths of the reactor.

Sitting at the centre of the exclusion zone, the damaged reactor unit is encased in a steel and cement sarcophagus. It’s a deathly tomb that plays host to about 200 tonnes of melted radioactive fuel, and is swarming with radioactive dust.

But it’s also the abode of some very hardy fungi which researchers believe aren’t just tolerating the severe radiation, but actually harnessing its energy to thrive.

“Our findings suggest that [the fungi] can capture the energy from radiation and transform it into other forms of energy that can be used for growth,” said microbiologist Arturo Casadevall from the Albert Einstein College of Medicine at Yeshiva University in New York, USA.
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Taken together, the researchers think their results do indeed hint that fungi can live off ionising radiation, harnessing its energy through melanin to somehow generate a new form of biologically usable growing power.

If they’re right, then this is powerful stuff, said fungal biologist Dee Carter from the University of Sydney. The results will challenge fundamental assumptions we have about the very nature of fungi, she said.

It also raises the possibility that fungi might be using melanin to secretly harvest visible and ultraviolet light for growth, adds Casadevall. If confirmed, this will further complicate our understanding of these sneaky organisms and their role in ecosystems.

Pretty amazing stuff. It really is great all that nature gives us to study and learn about using science.

Bees, Hornets and Wasps

Photo of a bee by Justin Hunter

Bee vs. Hornet vs. Wasp

A bee can generally only sting you once, while hornets and wasps can sting multiple times.
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Bees are fuzzy pollen collectors that almost always die shortly after stinging people (because the stinger becomes embedded in the skin, which prevents multiple stings). Bees don’t die each time they sting, though; the primary purpose of the stinger is to sting other bees, which doesn’t result in the loss of the stinger.

Wasps are members of the family Vespidae, which includes yellow jackets and hornets. Wasps generally have two pairs of wings and are definitely not fuzzy. Only the females have stingers, but they can sting people repeatedly.

Hornets are a small subset of wasps not native to North America (the yellow jacket is not truly a hornet). Somewhat fatter around the middle than your average wasp, the European hornet is now widespread on the East Coast of the U.S. Like other wasps, hornets can sting over and over again and can be extremely aggressive.

Photo by Justin Hunter

Cosmology Questions Answered

A great list of Cosmology Questions Answered, including: Why do we think that the expansion of the Universe is accelerating? What is quintessence? What is the Universe expanding into?

Everything that we measure is within the Universe, and we see no edge or boundary or center of expansion. Thus the Universe is not expanding into anything that we can see, and this is not a profitable thing to think about. Just as Dali’s Corpus Hypercubicus is just a 2-D picture of a 3-D object that represents the surface of a 4-D cube, remember that the balloon analogy is just a 2-D picture of a 3-D situation that is supposed to help you think about a curved 3-D space, but it does not mean that there is really a 4-D space that the Universe is expanding into.

Backyard Wildlife: Birds

photo of a bird

The last few days a bird like this one has been chasing a crow in my yard (unfortunately I have not been able to get an action picture of that). If you know what type of bird this is please add a comment.

When I see robins pecking away in the grass sometimes I see them get worms but my guess is they often are eating other stuff. I also see starlings feeding on my lawn. I found some online links that I quote below on what robins and starlings eat.

From the Yardener:

Next to beneficial insects, songbirds consume the most pest insects in your yard. Robins, blackbirds, flickers and starlings will eat a lot of webworms if they are in your lawn. Many seed-eating birds prey on caterpillars while raising their young. Encourage birds to settle in or near your yard and prey on fleas by offering them food, water, and shelter.

Cornell University: American Robin

The American Robin eats both fruit and invertebrates. Earthworms are important during the breeding season, but fruit is the main diet during winter. Robins eat different types of food depending on the time of day; they eat earthworms early in the day and more fruit later in the day.

History And Biology Of European Starlings In North America
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