|How Science Changed Our World
Top Ten Scientific Breakthroughs of the Past 50 Years
Professor Robert Winston presents his top ten scientific breakthroughs
of the past 50 years. Tracing these momentous and wide-ranging
discoveries, he meets a real-life bionic woman, one of the first couples
to test the male contraceptive pill, and even some of his early IVF
He explores the origins of the universe, probes the inner
workings of the human mind and sees the most powerful laser in the
world. To finish, Professor Winston reveals the breakthrough he thinks
is most significant.
Combined Oral Contraceptive Pill
The combined oral contraceptive pill (COCP), often referred to as the birth-control pill or colloquially as "the Pill", is a birth control method that includes a combination of an estrogen (oestrogen) and a progestin (progestogen). When taken by mouth every day, these pills inhibit female fertility.
They were first approved for contraceptive use in the United States in 1960, and are a very popular form of birth control. They are currently used by more than 100 million women worldwide and by almost 12 million women in the United States.
Usage varies widely by country, age, education, and marital status: one third of women aged 16–49 in Great Britain currently use either the combined pill or a progestogen-only "minipill", compared to only 1% of women in Japan.
An integrated circuit or monolithic integrated circuit (also referred to as IC, chip, or microchip) is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material.
Additional materials are deposited and patterned to form interconnections between semiconductor devices. Integrated circuits are used in virtually all electronic equipment today and have revolutionized the world of electronics.
Computers, cell phones, and other digital appliances are now inextricable parts of the structure of modern societies, made possible by the low cost of production of integrated circuits.
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI), is a medical imaging technique used in radiology to visualize detailed internal structures. MRI makes use of the property of nuclear magnetic resonance (NMR) to image nuclei of atoms inside the body.
An MRI machine uses a powerful magnetic field to align the magnetization of some atoms in the body, and radio frequency fields to systematically alter the alignment of this magnetization.
This causes the nuclei to produce a rotating magnetic field detectable by the scanner—and this information is recorded to construct an image of the scanned area of the body. Strong magnetic field gradients cause nuclei at different locations to rotate at different speeds.
3-D spatial information can be obtained by providing gradients in each direction.MRI provides good contrast between the different soft tissues of the body, which makes it especially useful in imaging the brain, muscles, the heart, and cancers compared with other medical imaging techniques such as computed tomography (CT) or X-rays. Unlike CT scans or traditional X-rays, MRI uses no ionizing radiation.
A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons.
The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation. The emitted laser light is notable for its high degree of spatial and temporal coherence, unattainable using other technologies.
Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam." Laser beams can be focused to very tiny spots, achieving a very high irradiance. Or they can be launched into a beam of very low divergence in order to concentrate their power at a large distance.
Temporal (or longitudinal) coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large distance (the coherence length) along the beam.
A beam produced by a thermal or other incoherent light source has an instantaneous amplitude and phase which vary randomly with respect to time and position, and thus a very short coherence length.
Most so-called "single wavelength" lasers actually produce radiation in several modes having slightly different frequencies (wavelengths), often not in a single polarization. And although temporal coherence implies monochromaticity, there are even lasers that emit a broad spectrum of light, or emit different wavelengths of light simultaneously.
There are some lasers which are not single spatial mode and consequently their light beams diverge more than required by the diffraction limit. However all such devices are classified as "lasers" based on their method of producing that light: stimulated emission. Lasers are employed in applications where light of the required spatial or temporal coherence could not be produced using simpler technologies.
Biomechanics is the application of mechanical principles to biological systems, such as humans, animals, plants, organs, and cells.
World Wide Web
Perhaps one of the best definitions was provided by Herbert Hatze in 1974: "Biomechanics is the study of the structure and function of biological systems by means of the methods of mechanics".
The word biomechanics developed during the early 1970s, describing the application of engineering mechanics to biological and medical systems. Biomechanics is closely related to engineering, because it often uses traditional engineering sciences to analyse biological systems.
Some simple applications of Newtonian mechanics and/or materials sciences can supply correct approximations to the mechanics of many biological systems.
Applied mechanics, most notably mechanical engineering disciplines such as continuum mechanics, mechanism analysis, structural analysis, kinematics and dynamics play prominent roles in the study of biomechanics.
Usually biological system are more complex than man-built systems. Numerical methods are hence applied in almost every biomechanical study. Research is done in a iterative process of hypothesis and verification, including several steps of modeling, computer simulation and experimental measurements.
The World Wide Web is a system of interlinked hypertext documents accessed via the Internet. With a web browser, one can view web pages that may contain text, images, videos, and other multimedia and navigate between them via hyperlinks.
Big Bang Theory
Using concepts from earlier hypertext systems, British engineer and computer scientist Sir Tim Berners-Lee, now Director of the World Wide Web Consortium(W3C), wrote a proposal in March 1989 for what would eventually become the World Wide Web.
At CERN in Geneva, Switzerland, Berners-Lee and Belgian computer scientist Robert Cailliau proposed in 1990 to use "HyperText ... to link and access information of various kinds as a web of nodes in which the user can browse at will", and publicly introduced the project in December.
"The World-Wide Web was developed to be a pool of human knowledge, and human culture, which would allow collaborators in remote sites to share their ideas and all aspects of a common project."
Human Genome Project
The Big Bang is the name of a scientific theory that explains how the Universe started, and then made the groups of stars (called galaxies) we see today. In the Big Bang theory, the universe begins as very hot, small and dense, with no stars, atoms, form, or structure (called a "singularity").
Then about 14 billion years ago, the space in the universe expanded very very quickly (like a big bang), and later atoms formed, and then the stars and their galaxies. The universe is still expanding today, and getting bigger, but colder.
As a whole, space is growing and the temperature is falling as time passes. Cosmology is the name given to how the universe began and how it has developed. Scientists that study cosmology agree the Big Bang theory matches what they have seen so far.
Fred Hoyle called the theory the "Big Bang" on his radio show. He did not believe the Big Bang was correct. Scientists who did not agree with him thought the name was funny and used it. Since then, Fred Hoyle's reasons for not liking the theory have been shown to be wrong.
Scientists base the Big Bang theory on many different observations. The most important is the redshift of very far away galaxies. Redshift is when the light from an object moving away from the earth looks like it has lost energy. Objects moving towards the earth look like their light has gained energy.
This is because of the Doppler effect. The more redshift there is, the faster the object is moving away. By measuring the redshift we can work out how fast the object is moving. Since everything is moving away from everything else at a carefully measured rate, scientists calculate that everything was in the same place 13.7 billion years ago.
Because most things become colder when they become bigger, the universe must have been very hot when it started. Other observations that support the Big Bang theory are the amounts of chemical elements in the universe. Amounts of hydrogen, helium, and lithium seem to agree with the theory of the Big Bang.
Scientists also have found "cosmic microwave background radiation". This radiation is radio waves that are everywhere in the universe. It is now very weak and cold, but a long time ago it was very strong and very hot. The Big Bang might also have been the beginning of time. If the Big Bang was the beginning of time then there was no universe before the Big Bang.
Other ideas that also have a Big Bang do not have a beginning of time at 13.7 billion years ago. Instead, these theories say that the beginning of the universe as we currently know it began at that time. Before then the universe may have been very different.
The Human Genome Project (HGP) is an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make up DNA, and of identifying and mapping the approximately 20,000–25,000 genes of the human genome from both a physical and functional standpoint.
Stem Cell Research
The project began in 1989 and was initially headed by Ari Patrinos, head of the Office of Biological and Environmental Research in the U.S. Department of Energy's Office of Science. Francis Collins directed the National Institutes of Health National Human Genome Research Institute efforts.
A working draft of the genome was announced in 2000 and a complete one in 2003, with further, more detailed analysis still being published. A parallel project was conducted outside of government by the Celera Corporation, which was formally launched in 1998.
Most of the government-sponsored sequencing was performed in universities and research centers from the United States, the United Kingdom, Japan, France, Germany, China and Pakistan. The mapping of human genes is an important step in the development of medicines and other aspects of health care.
While the objective of the Human Genome Project is to understand the genetic makeup of the human species, the project has also focused on several other nonhuman organisms such as E. coli, the fruit fly, and the laboratory mouse. It remains one of the largest single investigative projects in modern science.
The Human Genome Project originally aimed to map the nucleotides contained in a human haploid reference genome (more than three billion). Several groups have announced efforts to extend this to diploid human genomes including the International HapMap Project, Applied Biosystems, Perlegen, Illumina, J. Craig Venter Institute, Personal Genome Project, and Roche-454.
The "genome" of any given individual (except for identical twins and cloned organisms) is unique; mapping "the human genome" involves sequencing multiple variations of each gene. The project did not study the entire DNA found in human cells; some heterochromatic areas (about 8% of the total genome) remain un-sequenced.
Stem cells are biological cells found in all multicellular organisms, that can divide (through mitosis) and differentiate into diverse specialized cell types and can self-renew to produce more stem cells.
In Vitro Fertilisation
In mammals, there are two broad types of stem cells: embryonic stem cells, which are isolated from the inner cell mass of blastocysts, and adult stem cells, which are found in various tissues.
In adult organisms, stem cells and progenitor cells act as a repair system for the body, replenishing adult tissues. In a developing embryo, stem cells can differentiate into all the specialized cells, but also maintain the normal turnover of regenerative organs, such as blood, skin, or intestinal tissues.
Stem cells can now be artificially grown and transformed into specialized cell types with characteristics consistent with cells of various tissues such as muscles or nerves through cell culture. Highly plastic adult stem cells are routinely used in medical therapies.
Stem cells can be taken from a variety of sources, including umbilical cord blood and bone marrow. Embryonic cell lines and autologous embryonic stem cells generated through therapeutic cloning have also been proposed as promising candidates for future therapies.
Research into stem cells grew out of findings by Ernest A. McCulloch and James E. Till at the University of Toronto in the 1960s. There are three sources of autologous adult stem cells:
1) Bone marrow, which requires extraction by harvesting, that is, drilling into bone (typically the femur or illiac crest),
2) Adipose tissue (lipid cells), which requires extraction by liposuction, and
3) Blood, which requires extraction through pheresis, wherein blood is drawn from the donor, (similar to a blood donation) passed through a machine that extracts the stem cells and returns other portions of the blood to the donor.
Of all stem cell types, autologous harvesting involves the least risk. By definition, autologous cells are obtained from one's own body, just as one may bank his or her own blood for elective surgical procedures.
In vitro fertilisation (IVF) is a process by which egg cells are fertilised by sperm outside the body: in vitro. IVF is a major treatment in infertility when other methods of assisted reproductive technology have failed. The process involves hormonally controlling the ovulatory process, removing ova (eggs) from the woman's ovaries and letting sperm fertilise them in a fluid medium.
The fertilised egg (zygote) is then transferred to the patient's uterus with the intent to establish a successful pregnancy. The first successful birth of a "test tube baby", Louise Brown, occurred in 1978. Robert G. Edwards, the doctor who developed the treatment, was awarded the Nobel Prize in Physiology or Medicine in 2010.
Before that, there was a transient biochemical pregnancy reported by Australian Foxton School researchers in 1953 and an ectopic pregnancy reported by Steptoe and Edwards in 1976. At the same time, Subash Mukhopadyay, a relatively unknown physician from Kolkata, India was performing experiments on his own with primitive instruments and a house hold refrigerator and this resulted in a test tube baby, later named as "Durga" (alias Kanupriya Agarwal) who was born on October 3, 1978.
The term in vitro, from the Latin root meaning in glass, is used, because early biological experiments involving cultivation of tissues outside the living organism from which they came, were carried out in glass containers such as beakers, test tubes, or petri dishes.
Today, the term in vitro is used to refer to any biological procedure that is performed outside the organism it would normally be occurring in, to distinguish it from an in vivo procedure, where the tissue remains inside the living organism within which it is normally found.
A colloquial term for babies conceived as the result of IVF, "test tube babies", refers to the tube-shaped containers of glass or plastic resin, called test tubes, that are commonly used in chemistry labs and biology labs.
However, in vitro fertilisation is usually performed in the shallower containers called Petri dishes. One IVF method, Autologous Endometrial Coculture, is actually performed on organic material, but is still considered in vitro.