Writing numbers that are very big or very small ...

In science, you will encounter numbers that are very big or extremely small. These can be rather inconvenient to write out in the normal notation. Powers of ten is a useful shorthand method of writing very large or very small numbers. For example,

One thousand (1000) is 10³ ; reads 'ten to the power 3' and is 1 followed by 3 zeros
One divided by 1000 is 0.001 or 10^-3 ; reads 'ten to the power minus 3'

And that is it - the positive power on ten tells us how many zeros are after 1.
negative powers of ten tell us the position of the 1 after the decimal point.

Distance of the Sun from the Earth is 150 million km or 150,000,000 km or 15 x 10⁷ km.
Diameter of an atom is 0.0000000002 m or 2 x 10^-10 m.

Multiplication and division of powers of ten numbers is very easy...

When you multiply two numbers powers add

When you divide two numebrs powers substract.

Example: Multiply 2 million by 4 million

Longhand: 2,000,000 x 4,000,000 = 8,000,000,000,000

Powers of ten: 2 x 10⁶ x 4 x 10⁶ = 8 x 10¹²

Nuclear Talks...

The following programme is tentative. The talks will be suitable for practically everybody to attend (particularly for those who have felt that science is not for them/ I have never read science/ it is too difficult...). The talks will be presented in a visually attractive manner with no mathematics. The atmosphere is very friendly and relaxed (it is not like school!)

Please encourage your friends and neighbours to come too. The talks are free to attend.

Talk 1: Introduction to the nucleus; we shall address questions about the size, shape, what is the nucleus made of, what holds the nucleus together etc. Rutherford's discovery of the nucleus revolutionised our understanding of the structure of matter.
Talk 2: Radioactivity and its many applications like radio-isotope dating for finding ages of fossils and other objects of historic interest, nuclear medicine etc. will be discussed. Radioactivity is due to the decay of a nucleus into another by emission of energy in the form of alpha, beta and gamma radiation. We shall look at the fascinating history of the discovery of radioactive elements, the reasons why nuclei decay and the nature of the radiation that is emitted.
Talk 3: Nuclear binding energies, Nuclear fission and fusion; explain how energy is released in the fission of uranium and in fusion of hydrogen. We shall look at the particularly interesting history of the discovery of nuclear fission and the development of atomic bomb.
Talks 4 and 5: We look at global energy scene - present and future consumption trends and their impact on our climate. UK energy supply and consumption has special challenges and possibilities. We analyse aspects of nuclear power production in detail with a critical look at those of serious public concerns. Future nuclear reactor designs.

Science for All Talks in East Kilbride....

Fourth in the series of talks aimed to increase public awareness of science will discuss the atomic nucleus and the controversial issue of nuclear power. Study of the nucleus is driven by the desire to learn about the fundamental constituents of matter – essentially, what we are made of? Our understanding of laws that govern the behaviour of matter has benefited enormously from such studies. Paradoxically, the understanding of the nucleus has been responsible for our current view of the origin of the Universe.

On a more practical level, medical advances like MRI, PET scanners, radiotherapy have come about from the study of nuclei. The world-wide-web was invented to facilitate communications between nuclear physics laboratories. Radio-isotope dating techniques have allowed us to establish the way the Earth’s climate has changed in the past.

Nuclear fission has been harnessed to generate environmentally clean power, although it has its associated concerns regarding radioactive waste disposal. The Sun maintains its prodigious energy flow through nuclear fusion of hydrogen. The development of nuclear fusion has the possibilities of supplying limitless energy in the future.

Dr Ravi Singhal has studied nuclear physics over the past forty years. In this series of talks, he will introduce the various ideas for the general audience without assuming any previous scientific background. The talks are suitable for all to attend and they are free. Secondary school students are especially encouraged to come to the talks.

The ‘Science for All’ is managed by Dr. Singhal in partnership with Scottish Enterprise and Glasgow University. In previous talks, Dr Singhal has discussed the subjects of The Universe, Climate Change and Nano-technology. Further details about the programme may be obtained by contacting ektalks@yahoo.co.uk

The websites http://www.scienceforall.co.uk and http://ektalks.blogspot.com give current updates about the science awareness programme in East Kilbride.

Science For All Talks start in February.....

Atomic Nucleus and Nuclear Energy

Dr Ravi Singhal
http://ektalks.blogspot.com/

http://www.scienceforall.co.uk/

Free Science Talks for Secondary Pupils & Adults

No Science Background Needed

11 am – 12 noon on Saturdays
16, 23 February; 1, 8 & 15 March 2008
James Watt Auditorium, E.K. Technology Park, G75 0QD
(Ample free parking on site)

Talks aimed at increasing public awareness of science, Dr. Singhal will look at the atomic nucleus. Ten thousand times smaller than the atom, the nucleus carries most of the mass. The first three talks will aim to answer some of the questions:

What is the nucleus made of?
How do we study the nucleus?
How is the nucleus held together?
What are nuclear fission and fusion?
How have nuclear applications benefited mankind?

The last two talks will look at the science of nuclear energy production. This is a topic of vigorous current debate in the U.K. and is of great public interest/concern – particularly in relation to limiting carbon emissions, securing energy supplies, nuclear waste management and safety.

The talks are designed for the general audience and no prior background in science is required. Secondary school students are especially encouraged to attend. The presentation promises to be visually attractive, entertaining and thought-provoking. The talks are free to attend.

In Partnership with: Physics Department, Glasgow University
Scottish Enterprise, Lanarkshire

Further Information: ekTalks@yahoo.co.uk

Positive feedback in global warming...

Most studies indicate that global warming is happening quicker than previously thought.

Positive feedback is probably responsible for some of it. An example will explain how this works:
Arctic ice is highly reflective and sends a good fraction of sun's energy back into spcae. If the ice melts then it is replaced by darker looking water which reflects less light and absorbs more of the incident energy causing additional warming. This warming then melts more ice that then results in still greater absorption of solar energy. And so the cycle goes on, feeding on itself. All the evidence is that the amount of arctic ice is shrinking rather rapidly.

Another example of positive feedback may be the oceans that are vast sinks of carbon di-oxide. Water vapour and carbon di-oxide are two main gases in the atmosphere that prevent energy from escaping from the earth. Warmer oceans create more water vapour and also absorb less carbon di-oxide. This then creates more warming etc.

Recent studies have found that oceans are absorbing only half the amount of carbon di-oxide from the atmosphere now compared with the amount they soaked up 12 years ago. This is too rapid a change and a real cause of worry about a run-away situation resulting...

Need to do something positive...!

Nobel Peace Prize for Climate Change Campaigners...

Climate change campaigner Al Gore and the UN's Intergovernmental Panel on Climate Change (IPCC) have been jointly awarded the Nobel Peace Prize for 2007.

The UN's IPCC, comprising 3,000 leading climate scientists, is the world's top authority on global warming.

The Nobel committee said it wanted to help the world focus on the threat it faced from climate change.

I think it is a good decision and timely. We must be very close to the 'tipping point' when sensible measures to avoid a runaway scenario may not work. Hope common sense prevails.

Two extra suitcases and going no where...

Morbidly obese is someone with body mass index (BMI) greater than 40 - acceptable is 20 to 25.
A BMI of 30 makes you obese.
BMI is calculated by dividing your weight in kg by square of the height in metres.
This is like carrying two 20 kg suitcases everywhere you go - travelling or not. What the extra baggage does to the joints is not difficult to guess. The greatly increased risk of a number of cancers, diabetes and heart problems is well documented. And what about BP (and I do not mean British Petroleum!)

This is the worrying trend found by a study of 12000 people over the past ten years. Number of morbidly obese has doubled - probably not too different than the increase in the number of take aways or the increase in the number of TV channels. The waist size is on average 1.5 inches bigger. It is all very worrying...