Science words

Some words used across various scientific disciplines. Click on a word to see the definition.

A

abundant

Hydrogen is the most abundant element in the universe, and the third most abundant on Earth (after oxygen and silicon).

accumulate

Fossils contain isotopes of elements that accumulated in the organisms when they were alive.

accuracy

In classical physics, the accuracy of measurements has always been limited by the measuring instruments used, and no instrument is perfect.

active

Even greater specificity is provided by specialized transmembrane proteins which act as active and passive transporters for a huge diversity of molecules.

adaptive

In rare cases, such long-distance dispersal can lead to adaptive radiation, the rapid evolution of an ancestral species into new species that fill many ecological niches.

adjacent

But midway between two adjacent nodes, the string vibrates with the largest amplitude.

advanced

How advanced were Alhazen’s inventions and theories?

aggregation

Hydrophobic interactions between sickle-cell hemoglobin proteins lead to their aggregation into a fiber.

alignment

When the wire carries a strong current, the alignments of the iron filings show that the magnetic field induced by the current forms concentric circles around the wire.

alpha

Some of the alpha particles were deflected from their original direction through very large angles.

amplify

Assistive listening devices serve to amplify a specific small range of frequencies for people who have only partial hearing loss in that range.

application

One useful application of superconductivity is superconducting magnets.

approximate

Because a linkage map is based strictly on recombination frequencies, it gives only an approximate picture of a chromosome.

array

The Very Large Array, located near Socorro, New Mexico, consists of 27 radio antennas, each 25 meters in diameter.

availability

Under some conditions, prokaryotes can increase the availability of nutrients that plants require for growth, such as nitrogen, phosphorus, and potassium.

axis

When a bat is held at its end, its length is greatest with respect to the rotation axis, so its moment of inertia is greatest.

B

beta

Alpha particles can usually be stopped by a piece of paper, beta particles can penetrate a few millimeters of aluminum, and gamma rays can penetrate several centimeters of lead.

by-product

An additional advantage of fusion reactors is that few radioactive by-products are formed.

C

calculation

Filled with confidence that his calculations could be useful in determining chemical structures, Karplus published a paper that included what has become known as the Karplus equation.

calibrate

During calibration at the crash-test site, engineers calibrate the sensors in the heads of crash-test dummies by removing the heads and dropping them from a known height.

capability

Sweat alone has been used to power a radio for two days, demonstrating the capability of a new skin patch.

catalyst

But to understand what a chemical catalyst or a biological enzyme actually does, think of it as a helper particle.

characteristic

In music, the mixture of harmonics that produces the characteristic sound of an instrument is referred to as the spectrum of the sound.

circuit

Once a capacitor is charged, the battery or other source of potential difference that charged it can be removed from the circuit.

climate

The structure and biochemical functions of the leaves of C4 plants are an evolutionary adaptation to hot, dry climates.

compatibility

When two sex cells fuse, the outcome may depend not just on the compatibility of the genes stowed in their nuclei, but on the behaviour of another group of organelles in cells, known as mitochondria.

complement

DNA strands are an attractive option as components of nanoscale structures because of the way they lock or “zip” together when the sequence of bases in a pair of strands complement each other.

component

A diagram of the basic components of a spectrometer is shown in Figure 18.

condense

The fuel itself was obtained by distilling oil – heating it up to a specific temperature and waiting for the kerosene fraction to boil and condense.

configuration

This charge configuration is called an electric dipole.

conserve

The mammalian kidney’s ability to conserve water is a key terrestrial adaptation.

continuous

Thus, the coil and the shaft are kept in continuous rotational motion.

conventional

People who choose alternative medicine over conventional treatment for their cancer are more likely to die from the disease.

convert

Generators use induction to convert mechanical energy into electrical energy.

coordinate

The measuring stick can serve as the y-axis of our coordinate system.

curve

The graph of decreasing temperature versus time of a hot object is called its cooling curve.

cycle

Most animals exhibit cycles in reproductive activity, often related to changing seasons.

D

data

These ramp experiments provided data that matched the predictions Galileo made in his hypothesis.

decay

Both 12C and 13C are stable isotopes, meaning that their nuclei do not have a tendency to lose subatomic particles, a process called decay.

decode

When John receives the message, he uses his private key to decode it

deduce

Because unlike poles attract, we can deduce that the geographic North Pole of Earth corresponds to the magnetic south pole and the geographic South Pole of Earth corresponds to the magnetic north pole.

default

For decades, the default approach has been to assume a “stationary” climate — one in which the odds of extremes have remained unchanged.

degradation

This highlights the link between environmental degradation and health.

deplete

Forestry experts have cautioned that Ghana’s natural forests may run the risk of being depleted in the next 10 to 20 years.

design

The relationship between the incident pressure and the electric signal is microphone sensitivity, an important parameter in microphone design.

detailed

Sites like El Gigante that allow detailed analysis of maize over time, especially stretching back more than 4,000 years, are quite rare.

detect

The system has the capability to detect planet-size bodies on the outer fringes of our solar system.

device

The next step is to adapt this device to test for and identify environmental contaminants.

diagram

In force diagrams, all forces are drawn as if they act at that point, no matter where the force is applied.

differentiate

Thanks to new spatial models that were used to evaluate the movement of the whales, we could differentiate behaviors and gauge the speed of the whales during their reproductive and migratory periods.

diffusion

For small insects, diffusion through the tracheae brings in enough O2 and removes enough CO2 to support cellular respiration.

directional

Volunteers also were given directional coordinates within a predetermined segment of the Appalachian Trail and instructed to set up their camera within 100 meters of that location.

discovery

Women like Henrietta Swan Leavitt, Williamina Fleming, and Annie Jump Cannon made some of the most important discoveries in astronomy in the early 20th century.

discrete

Following initial migration to Australia, Aboriginal groups lived in “discrete geographical regions” until the arrival of Europeans.

disperse

A circular eddy in the bay region may prevent its larvae from moving out into the Kuroshio Current and being dispersed northward up to Taiwan.

disposal

A major impediment to research has been the lack of accessible and reliable information on spills, wastewater disposal and the composition of fracturing fluids.

distribution

The distribution of the intensity of the different wavelengths varies with temperature.

disturbance

Activated carbon can be spread on the surface of a contaminated sediment or soil, without physical disturbance, and left in place to mix into the sediment surface.

diversity

Knowledge of archaeal biological diversity and their role in evolution has rapidly expanded in the past decade.

drawback

While climate change may be beneficial in this way to monarchs, there are also potential drawbacks.

dynamic

Pan-STARRS also has given us an unprecedented view of the dynamic and transient nature of astronomical phenomena.

E

efficiency

Airflow through a wheel or wheel well can have an important impact on the overall aerodynamic performance of a car and therefore an important impact on its efficiency and range.

electronic

Interpreting the positions and intensities of the peaks on the resulting graph can give insights into the electronic structure of the diamond.

embedded

The clues to answer this question lie in our ability to learn from Earth’s deep past—the crucible of our present world—embedded in the fossil record.

encode

Such 3-D reconstructions encode important information for astronomers about how massive stars actually explode.

enhancement

Current restoration plans also include enhancement of oyster density using hatchery seed and the addition of new hard substrate where needed.

entry

Investigators can use bullet entry wounds to determine exactly where a shooter was when a bullet is fired.

environmental

The value of this is that it forces us to think differently about the history of human-environmental interactions in North America.

equation

To calculate this figure, some 30 different mathematical equations are in use based on the known methane outputs of specific livestock types, the type of food they are fed and their numbers.

equilibrium

For an object in equilibrium, the frictional force must point in the direction that results in a net force of zero.

erosion

The detailed analysis of the surface characteristics of this area of Mars provides avenues for other study, such as the formation of the planet’s regolith, or the crushed-up soil created through erosion and meteor impacts.

estimate

To estimate the energy released in a typical fission process, note that the binding energy per nucleon is about 7.6 MeV for heavy nuclei and about 8.5 MeV for nuclei of intermediate mass.

evolution

Such a stage in the evolution of the turtle shell had long been predicted by embryological research on present-day turtles but had never been observed in fossils.

experiment

Thomas Young’s 1803 experiment provided crucial evidence for the wave nature of light.

extract

Extracting DNA from Phragmites leaves, the ecologist determined how many distinct clones were in each patch and how closely related they were.

F

facility

Consumers could potentially download a free smartphone app that would run in the background, monitoring appropriate frequencies and sending the data to a central processing facility.

feasibility

They examined the feasibility of creating a radio transmitter strong enough for it to be detectable across such immense distances.

feature

 The photon theory of light explains features of the photoelectric effect that cannot be understood using classical concepts.

feedback

Satellite ground operators use the feedback from a device called a magnetometer, which senses the direction of Earth’s magnetic field, to decide which torque coil to activate.

finite

Why was Galileo unable to conclude that light had a finite speed?

flow

Solid objects are not considered to be fluids because they cannot flow and therefore have a definite shape.

fluctuate

Over the past million years, atmospheric carbon dioxide has been generally low and fluctuated predictably within a window of 200 to 300 ppm.

focal

For a spherical mirror, the focal length is equal to half the radius of curvature of the mirror.

form

Because white light can be dispersed into its elementary colors, it is reasonable to suppose that elementary colors can be combined to form white light.

format

Scientific journals can now mandate that authors make their metadata available in a searchable and standardized format, just as they have long done for genetic sequence data.

fraction

What fraction of a radioactive sample has decayed after two half-lives have elapsed?

fragment

The fossil bone is a fragment from a long bone of a large mammal—most likely either a mammoth or mastodon, or less likely a giant sloth.

friction

Because of friction and other problems, the actual efficiency of a heat engine will be lower than the calculated efficiency.

fusion

A star forms when a giant clump of gas pulls together under its own gravity, growing denser and hotter until nuclear fusion ignites.

G

generate

The potential difference between the terminals of a battery is fixed, so batteries always generate a direct current.

geometric

The geometric earthworks of southwestern Amazonia have intrigued researchers, the media and the general public.

graph

The graph shows the electric field strength at different distances from the center of the charged conducting sphere of a Van de Graaff generator.

H

horizontal

Let us assume that the mass moves on a frictionless horizontal surface.

hybrid

Although many different species interbreed in the wild, their hybrid offspring often cannot reproduce successfully.

hypothesis

In an experiment to test a hypothesis, you must change one variable at a time to determine what influences the phenomenon you are observing.

I

image

The image produced by a converging lens is real and inverted when the object is outside the focal point and virtual and upright when the object is inside the focal point.

improved

The 27 antennas at the Very Large Array in New Mexico are used together to provide improved resolution for observing distant radio sources.

increased

For example, proportional mortality of the kelp perch (Brachyistius frenatus) rose as its density increased.

input

If friction is disregarded, the input torque will equal the output torque.

integrated

A computer motherboard is a multilayered collection of integrated circuits containing millions of transistors and other circuit elements.

interference

As they pass through one another, the waves interact to form an interference pattern of light and dark bands.

intermediate

The visible light that our eyes can detect occupies an intermediate range of wavelengths.

irregular

The flow of a fluid becomes irregular, or turbulent, above a certain velocity or under conditions that can cause abrupt changes in velocity, such as where there are obstacles or sharp turns in a river.

L

large-scale

Indigenous groups have always hunted peccaries, but with the continued advance of agricultural frontiers, cattle ranches, new roads and large-scale development projects throughout the region, this species is now threatened with extinction.

limiting

Australian researchers have tested the hypothesis that sea urchins are a biotic factor limiting seaweed distribution.

linear

In particular, is there a linear (straight-line) relationship between brain volume and time?

localized

This localized response produces lesions and protects other parts of an infected leaf.

M

maintain

For example, humans maintain a fairly constant body temperature of about 37°C (98.6°F).

manual

It’s fair for researchers to look at complex hand use among primates and ask if it was a precursor to the manual dexterity that gave rise to modern humans.

manufacture

The industrial manufacture of methanol and ethanol is big business, with methanol ranking among the top 30 chemicals produced commercially in the US.

mapping

The point of mapping the human genome is not just to know how genes interact in general, but to be able to apply that mapping to individuals.

material

In a ferro-magnetic material, large domains of magnetic dipoles are aligned in the same direction.

matrix

One identified a complex sugar between cells—in what’s known as the extracellular matrix—that is nearly five times larger in the naked mole rat than in cancer-prone animals.

maximum

The maximum absorbance corresponds to the highest concentration of the coloured product in solution.

measure

To measure the specific heat capacity of a substance, it is necessary to measure mass, temperature change, and energy transferred as heat.

mechanism

The other principal energy transfer mechanism is electromagnetic radiation.

micro

Micro technology deals with the fabrication of structures in the length scale between 0.1 and 1000 μm and can be considered as an important enabler for micro systems such as miniaturized sensors.

migrate

Humpback whales have distinctive tail markings that scientists use to track individuals as they migrate long distances.

minimize

Competition with elimination reactions can be minimized if primary halogenoalkanes are used.

model

Although the physical world is very complex, physicists often use models to explain the most fundamental features of various phenomena.

monitor

Levels of nitrites and nitrates in water must be monitored, and levels are controlled by legislation.

motor

Magnets are also used in meters, motors, and loudspeakers.

N

natural

Although the carbon cycle is a natural means of recycling carbon, man-made CO 2 emissions from the combustion of fossil fuels and as a waste product from the cement industry contribute to global warming.

negative

The average velocity of an object can be positive or negative, depending on the sign of the displacement.

negligible

A neutron and a proton have approximately the same mass and, relative to these, the electron has a negligible mass.

net

The net force is the vector sum of all forces acting on an object.

noticeable

The property is particularly noticeable for beryllium, which is resistant to reaction with water and acids because of the presence of the protective oxide covering.

null

This is particularly striking since this is neither a positive result (evidence of learning) nor a null result (no learning) but a negative one.

numerical

This kind of estimate is called an order-of-magnitude calculation, which means determining the power of 10 that is closest to the actual numerical value of the quantity.

O

observe

The distinction between contact forces and field forces is useful when dealing with forces that we observe at the macroscopic level.

offspring

The trematodes produce offspring that leave the snails and eventually infect migratory sea birds.

output

Because the purpose of a simple machine is to change the direction or magnitude of an input force, a useful way of characterizing a simple machine is to compare how large the output force is relative to the input force.

P

parameter

To analyze what other parameters affect the force the bird experiences, the researchers created a simplified model from a 3-D printed cone on a flexible rubber “neck”.

partition

The researchers looked at the principle of niche partitioning, which states that two species in the same niche, or ecological distribution of resources, cannot co-exist.

passive

This protection is called passive immunity because the antibodies in the recipient (in this case, the fetus) are produced by another individual (the mother).

patent

Percy Spencer developed and patented the first microwave oven after noticing that a magnetron was emitting heat-generating microwaves during an experiment with radar in 1945.

pathway

The broken filament means that there is a gap in the conducting pathway used to make up the circuit.

periodic

Using the periodic table is a quick way of spotting isoelectronic relationships.

pioneering

The new South Pole Telescope is currently completing its pioneering millimeter-wave survey of a huge swath of sky covering 2,500 square degrees.

polarization

The light is brightest when its plane of polarization is parallel to the transmission axis.

positioning

Describe the positioning of lenses in compound microscopes and refracting telescopes.

positive

We should avoid building up a large positive or negative charge on any one atom.

precise

A meterstick that includes millimeters, for example, will give a more precise result than a meterstick whose smallest unit of measure is a centimeter.

prediction

The results could “drastically change predictions of the fate of coral-reef ecosystems globally over the next 100 years of climate change”.

probability

Hence, there is a probability that the electron will actually be found outside the potential well.

probe

Dark matter in this mass range can be probed by direct detection and by the Large Hadron Collider (LHC).

process

Although the Downs process is the major manufacturing process for sodium, the Cl2 produced represents a minor contribution to the global supply.

produce

Heat is produced and this raises the temperature and opposes the external change.

projection

Most of our estimates for future carbon dioxide levels and climate do not fully take into consideration the various feedbacks involving forests, so current projections likely underestimate the magnitude of carbon dioxide flux to the atmosphere.

propagate

Sound travels well underwater, meaning that noise produced by a reef can propagate several kilometres out to sea.

proportional

Experimental observations show that the magnitude of the force of friction is approximately proportional to the magnitude of the normal force that a surface exerts on an object.

Q

quantify

By using GC-MS and GC-MS/MS techniques, it is possible to unambiguously identify and quantify a drug.

quantity

A vector is a physical quantity that has both direction and magnitude.

R

range

Gases, on the other hand, are compressible and can have densities over a wide range of values.

rapidly

It forms deliquescent, white crystals which rapidly absorb water to give an oily liquid.

ratio

For a heat engine, the efficiency is the ratio of work done by the engine to the energy added to the system as heat during one cycle.

refinement

The authors also demonstrate how the presence and various refinements of the head-joint complex may help elucidate the evolutionary relationships among the Stomiidae.

regeneration

The ability of lianas to rapidly invade open areas and young forests may dramatically reduce tropical tree regeneration.

relatively

It is relatively easy to lift someone if you are both standing in a swimming pool.

reproduction

Giving up both freedom and light for safety and a reliable food source, the crab’s ultimate goal is successful reproduction.

resonance

A striking example of structural resonance occurred in 1940, when the Tacoma Narrows bridge, in Washington, was set in motion by the wind.

resulting

When one end of a conductor is more pointed than the other, excess charge tends to accumulate at the sharper end, resulting in a larger charge per unit area.

robust

We wanted to conduct a robust study by looking at both the historical record and field experiments.

S

scope

This phenomenon is important but its discussion is beyond the scope of this book.

selection

Or it could be possible that these other species get some benefit from the fruit, and so there wouldn’t be strong selection for this particular mutation.

separated

The ability of a conductor to store energy in the form of electrically separated charges is measured by the capacitance of the conductor.

sequence

And a modern description usually includes a DNA sequence generated from the animal’s tissue.

signal

A signal was sent to the orbiter to fire the thrusters a final time in order to push the spacecraft into orbit around the planet.

simplify

One way to simplify the concept of motion is to consider only the kinds of motion that take place in one direction.

simulated

A field experiment that simulated a similar range of CO2 exposures, but included future CO2 concentrations up to 500 parts per million (ppm) confirmed the herbarium results.

small-scale

Soon after the dinosaur extinctions 60 million years ago, the ancestors of leaf-cutter ants swapped a hunter-gatherer lifestyle for this bucolic existence on small-scale subsistence farms.

span

With three structures rising like sails over its span, it is the longest of its type in the world at 1.7 miles (2.7 km).

spatial

The high spatial, temporal, and spectral resolution of IRIS was crucial to the discovery.

spectrum

Sounds in the middle of the spectrum of frequencies can be heard more easily (at lower intensities) than those at lower and higher frequencies.

standard

The official standard kilogram mass is a platinum-iridium cylinder kept in a sealed container at the International Bureau of Weights and Measures at Sèvres, France.

static

As the applied force increases, the force of static friction also increases; if the applied force decreases, the force of static friction also decreases.

stationary

Connections to the external circuit are made by stationary graphite strips, called brushes, that make continuous contact with the slip rings.

sustainability

The hope is that we can apply our knowledge of how P. blytheae adapted to environmental changes millions of years ago to predict the sustainability of snow leopard populations in existence today.

synthesis

The normal laboratory synthesis of an oxirane is by the reaction of an alkene with a peracid such as perbenzoic acid.

system

In fact, every function involving the nervous system is initiated by electrical activity.

T

technical

The technical information gathered will help in making informed treatment decisions.

technology

Silver recognized that the technologies used to study giant supernova remnants and other X-ray-emitting celestial objects, could also be used to examine cells chemically.

test

 Kaufman tested the hypothesis that the amount of contrast between the coat color of a mouse and the color of its surroundings would affect the rate of nighttime predation by owls.

tool

The theory of fields was developed as a tool to explain how objects could exert force on each other without touching.

transient

If not for the shafts of transient sunlight provided by leaf trembling, the lower leaves would be too shaded to photosynthesize sufficiently.

transmit

These bones in turn transmit the vibrations to the inner ear, which contains a snail-shaped tube about 2 cm long called the cochlea.

transport

From the vascular cylinder, the xylem sap is transported long distances by bulk flow to the veins that branch throughout each leaf.

typically

For example, speeds are typically expressed in units of meters per second (m/s).

U

uncertainty

This new model of the atom is consistent with Heisenberg’s uncertainty principle, which states that we cannot know the electron’s location with complete certainty.

uniform

A uniform, or evenly spaced, pattern of dispersion may result from direct interactions between individuals in the population.

unit

When scientists do research, they must communicate the results of their experiments with each other and agree on a system of units for their measurements.

usable

Applied fertilizers make up for the loss of usable nitrogen from agricultural ecosystems.

utility

This does not diminish the utility of Mendelian genetics, however, because the basic principles of segregation and independent assortment apply even to more complex patterns of inheritance.

V

variable

To be certain he was observing differences due to weight, he kept all other variables the same.

variation

Variations in those features reflected differences in the animals’ diets.

verify

You can verify some of these values by carefully measuring the slope of the curve.

vertical

Yet calculating the vertical lifting capacity of a small bird or insect is no simple matter.

vessel

Make sure there is plenty of water in the heating vessel, and do not leave the hot plate unattended.

virtual

Astronomers have created the first realistic virtual universe using a computer simulation.

visible

What your eyes recognize as “white” light is actually light that can be separated into six elementary colors of the visible spectrum: red, orange, yellow, green, blue, and violet.

W

waste

The human population may also be limited by the capacity of the environment to absorb its wastes.