The cyclic variation of the number of sunspots was first observed by Heinrich Schwabe between 1826 and 1843 and led Wolf to make systematic observations starting in 1848.

After the resumption of sunspot activity, Heinrich Schwabe in 1844 in Astronomische Nachrichten ( Astronomical News ) reported a periodic change in the number of sunspots.

Sunspot populations quickly rise and more slowly fall on an irregular cycle of 11 years, although significant variations in the number of sunspots attending the 11-year period are known over longer spans of time.

* Wolf number — a quantity that measures the number of sunspots

The Sunspot Number ( SSN ) is the number of sunspots on the Sun's photosphere in visible light on the side of the Sun visible to an Earth observer.

The number and total area of sunspots are related to the brightness of the Sun in the extreme ultraviolet ( EUV ) and X-ray portions of the solar spectrum and to solar activity such as solar flares and coronal mass ejections ( CMEs ).

The irregularity correlated very closely with fluctuations in the number of sunspots, whose cyclic nature had been discovered in 1844 by the German amateur astronomer Heinrich Schwabe.

The solar cycle was discovered in 1843 by Samuel Heinrich Schwabe, who after 17 years of observations noticed a periodic variation in the average number of sunspots seen from year to year on the solar disk.

Astrophysicist Sallie Baliunas notes that these temperature variations correlate with solar variation and asserts that the number of observed sunspots give us a rough measure of how bright the sun is.

He did not find the planet but noticed the regular variation in the number of sunspots and published his findings in a short article entitled " Solar Observations during 1843 ".

* Heinrich Schwabe reports a periodic change in the number of sunspots: they wax and wane in number according to a ten-year cycle.

The Wolf number ( also known as the International sunspot number, relative sunspot number, or Zürich number ) is a quantity that measures the number of sunspots and groups of sunspots present on the surface of the sun.

As an example, in the " Sun in Time " article, the method was used to show that the number of sunspots on the sun, after accounting for the known cycles such as the daily and 11-year cycles, is very likely not random noise, but rather chaotic noise, with a low-dimensional fractal attractor.

In addition to the philosophical questions, the relationship between mind and brain involves a number of scientific questions, including understanding the relationship between mental activity and brain activity, the exact mechanisms by which drugs influence cognition, and the neural correlates of consciousness.

The Wolf number is a measure of individual spots and spot groupings, which correlates to a number of solar observables.

The number of moles a person has correlates with telomere length.

The number of CGG repeats correlates with penetrance and age of onset.

In general the density of these compounds correlates with the number of chlorides.

Amygdala volume correlates positively with both the size ( the number of contacts a person has ) and the complexity ( the number of different groups to which a person belongs ) of social networks.

# When sequence detection predates disease, or sequence copy number correlates with severity of disease or pathology, the sequence-disease association is more likely to be a causal relationship.

The size of the neocortex in a primate ’ s brain correlates directly to the number of individuals it can keep track of socially, be it a troop of chimps or a tribe of humans.

The temperature and rainfall in the months preceding breeding correlates with the number of young fledging each year and their survival rate.

The differences include the direction of the initial phase of the wave ( positive or negative, which correlates to the direction of flow of current through the electrocytes in the electric organ ), the amplitude of the wave, the frequency of the wave, and the number of phases of the wave.

This form of counselling can be effective alone ; combining it with medication is more effective, and the number of sessions of support with medication correlates with effectiveness.

Some researchers theorize mammalian intelligence correlates to the number of nerve cells ( neurons ) in the cortex of the brain.

It was some time between 100 – 400 CE that individual correlates of state societies had developed to a sufficient number and scale that state-level societies can be confidently identified using archaeological data.

* The age of hedges-" Botanist Max Hooper correlates number of species in English hedgerows with centuries in age ".

It has a number of other biological correlates, including brain size.

It has also been shown that while number density of M. globosa and M. restricta do not directly correlate to dandruff presence or severity, removal correlates directly with amelioration of flaking.

A number of different research groups have identified fMRI correlates of intentional deception in laboratory tasks, and despite the skepticism of many experts, the technique has already been commercialized.

A large number of studies have addressed the problem of neural correlates of mental representations in human subjects.

Studies undertaken towards the end of the 20th century are argued to have shown that conscious experience correlates not with the number of neurons firing, but with the synchrony of that firing.

One advantage to fixing this parameter, as opposed to others such as height, width, or length, is that floor area correlates well with other considerations relevant to zoning regulation, such as total parking that would be required for an office building, total number of units that might be available for residential use, total load on municipal services, etc.

The total cost of ownership correlates strongly to the total number of different images, not the total number of computers, so this is a major cost concern.

For Tom Horn, it turned out, had a number of rancher and cowboy witnesses ready and willing to swear with straight faces that he had been in Bates Hole the day of the killing.

Thus, Margenau remarks: `` A large number of unrelated epicycles was needed to explain the observations, but otherwise the ( Ptolemaic ) system served well and with quantitative precision.

Their expressed standards concerning sex roles, desirable age for marriage, characteristics of an ideal mate, number of children desired are congruent with the values and stereotypes of the preceding generation -- minus compulsive rebellion.

The controversy now revolves mainly around the number and geographic origin of the deputies of the Secretary General and, more particularly, around the nature of his relationship with them.

For those communities which have financial difficulties in effecting adjustments, there are a number of alternatives any one of which alone, or in combination with others, would minimize if not even eliminate the problem.

The Peace Corps can either begin in very low gear, with only preparatory work undertaken between now and when Congress finally appropriates special funds for it -- or it can be launched now and in earnest by executive action, with sufficient funds and made available from existing Mutual Security appropriations to permit a number of substantial projects to start this summer.

These expenditures are estimated to be $12.1 billion, an increase of $187 million over 1960, reflecting additional longevity pay of career personnel, more dependents, an increased number of men drawing proficiency pay, and social security tax increases ( effective for the full year in 1961 compared with only 6 months in 1960 ).

On the remainder of the clear channels, the dominant ( class 1 ) -- B stations are protected as described above, and the relatively small number of secondary ( class 2 ) ) stations permitted to operate on these channels at night are required to operate directionally and/or with reduced power so as to protect the class 1, stations.

And, besides, there are a large number of scholars, artists, composers of music, novelists, poets, essayists, choreographers, lawyers, servants of government, and men of affairs -- hundreds, indeed -- who serve the Foundation well with the advice they give us freely and gratis out of their experience.

In addition, production machinery must in many cases be designed to handle with equal efficiency both natural fibers and the increasing number of synthetics, as well as blends.

You may dress it up with any number of accessories or keep it as simple as you choose.

If your state has no provisions for the numbering of pleasure boats, you must apply for a number from the U.S. Coast Guard for any kind of boat with mechanical propulsion rated at more than 10 horsepower before it can be used on Federal waterways.

Actually, the engine displacement formula is the standard formula for computing the volume of a cylinder of any type with an added factor that represents the number of cylinders in the engine.

Reduces losses from stomach, hookworm, and nodular worms by interfering with reproduction of the female worm by reducing the number of eggs laid and essentially rendering all laid eggs sterile.

In your sales force, will a smaller number of higher-priced, high-quality salesmen serve you best, or can you make out better with a larger number of lower-paid salesmen??

Are your expenses in this area commensurate with the number of employees who benefit from your program??

Actually, there are a number of individual-contributor positions in both operating departments and in the company-wide `` services '' operation that are filled by men with successful managerial experience who are currently broadening their capabilities.

If no specific organization plan exists limiting the number of scientists at each salary level, the result is a department top-heavy with high-level, high-salaried personnel ''.

The railroads have responded by adding 20,000 more box cars with doors 12' or wider for forklift unloading ( a 21% increase while the total number of box cars was falling 6% ) and by cutting their freight rates twice on lumber shipped in heavily loaded cars.

However, whether you arrange to have a European or American model, if you rent a car with the proper seating capacity in relation to the number of people in your party, your transportation expense will average very close to $10.00 per day per passenger.

In order to reduce the number of variable parameters, all experiments were made with a constant arc length of 0.5'' '' and a current of 100 Aj.

The approximate equation is Af, where N is the number of Af with electron line-density greater than or equal to Af, and Q is proportional to the mass of the meteorite.

The bottom part of a burrow has a number of side tunnels or `` cells '', each of which is provided with an egg plus a store of beebread.