Conclusion:This essay is written in chronic sequence.At first，it introduces some methods commonly used in the searching for truth.In the following scenario where one scientist stands on the precedent scientists'shoulders.Every outcome is achieved with great efforts，eventhough some scientists made some incorrect conclusions，it is by no means that we can deny their contributions to the progression of scientific ideas，because we should see some scientists finally came to the right conclusion based on the fomer incorrect conclusions or were drawn by these conclusions to test these ideas and further got the right conclusions.
Vocabulary
（1）deflection：
n.
1
a twist or aberration; especially a perverse or abnormal way of judging or acting
2
the amount by which a propagating wave is bent
3
the movement of the pointer or pen of a measuring instrument from its zero position
例句:The pointer has a deflection from its orginal place.
（2）geocentric
adj.
1
having the earth as the center
例句：Long time ago，many people held an geocentric outlook on the universe.
（3）phlogiston
n.
1
a hypothetical substance once believed to be present in all combustible materials and to be released during burning.
例句：People alway have a misunderstanding of phlogiston.
（4）aether
n.
1
personification of the sky or upper air breathed by the Olympians; son of Erebus and night or of Chaos and darkness
2
a medium that was once supposed to fill all space and to support the propagation of electromagnetic waves.
例句：Aether is a commonly known chemical substance.
（5）apparatus
n.
1
equipment designed to serve a specific function
2
(anatomy) a group of body parts that work together to perform a given function
例句：Some work only could be finished with the specific apparatus.
（6）cathode
n.
1
a negatively charged electrode that is the source of electrons entering an electrical device
2
the positively charged terminal of a voltaic cell or storage battery that supplies current
例句：You should know which end is the cathode of the battery.
（7）supernova
n.
1
a star that explodes and becomes extremely luminous in the process
例句：The discovery of supernova is the achievement of astronomical observation.
（8）caliphate
n.
1
the era of Islam's ascendancy from the death of Mohammed until the 13th century; some Moslems still maintain that the Moslem world must always have a calif as head of the community
2
the territorial jurisdiction of a caliph
3
the office of a caliph
例句：Caliphate refers to the territorial jurisdiction of a caliph.
（9）astrolabe
n.
1
an early form of sextant
例句: Astrolabe is a device used to observe planets and stars.
（10）ground-breaking
adj.
1
being or producing something like nothing done or experienced or created before
例句:What he has done is ground-breaking.
（11）genome
n.
1
the ordering of genes in a haploid set of chromosomes of a particular organism; the full DNA sequence of an organism
例句:Genome determines characteristics of
people.
（12）stratum
n.
1
one of several parallel layers of material arranged one on top of another (such as a layer of tissue or cells in an organism or a layer of sedimentary rock)
2
an abstract place usually conceived as having depth
例句:A community consists of different strata.
（13）paleontology
n.
1
the earth science that studies fossil organisms and related remains
例句:We know little about paleontology.
（14）untutored
adj.
1
lacking in schooling
例句:He is illiterate because he was untutored when he was a child.
（15）daunting
adj.
1
discouraging through fear
例句:The failure in the competition is really daunting to him.
（16）leap-frogging
abstract:
1
In infantry tactics, leapfrogging (also called The Buddy System) is a technique for advancing personnel and/or equipment on or past a target area being defended by an opposing force.
例句：The progress he made is obvious and leap-frogging.
（17）bodily
adj.
1
of or relating to or belonging to the body
a bodily organ ; bodily functions
2
affecting or characteristic of the body as opposed to the mind or spirit
3
having or relating to a physical material body
adv.
1
in bodily form
例句：we must experience it bodily.
（18）artillery
n.
1
large but transportable armament
例句：Artillery is always used in wars.
（19）relentless
adj.
1
not to be placated or appeased or moved by entreaty
2
never-ceasing
例句：He did nothing but giving relentless
complaining.
（20）alpha
n.
1
the 1st letter of the Greek alphabet
2
the beginning of a series or sequence
例句：We can see alpha used in the math class sometimes.