 |
Podcast TranscriptThe Naked Scientists: Science Radio & Science Podcasts |
| 8th Jun 2002 | < Previous Show | Next Show > | |||||||||
|
||||||||||
Do you Dunk ?
Some people hate it, others can't drink tea or coffee without doing it - I personally love dunking biscuits in my coffee or tea. If you're like me then this new invention is for you. Dominic Skinner from Surrey has come up with a design for a mug that incorporates a biscuit-stacking shelf in the base ! The shelf can take up to 3 biscuits and the mug comes in right and left handed versions - why ? because if you held it in the wrong hand then all the biscuits would fall out every time your took a sip !
8th Jun 2002
Bra to Detect Breast Cancer
UK scientists at De Montfort University in Leicester have developed a bra that can detect breast cancer in minutes, and at a much earlier stage. It could mean fewer women will have to undergo breast X-rays or biopsies to find out whether a growth is malignant or benign. The bra uses a technique called electrical impedance tomography which involves passing a painless electrical current through the breast. Electrodes in the bra material pick up the electrical signals and feed them to a computer which builds up an image of the breast, highlighting any abnormal growths. Wei Wang, who heads the De Montfort group, said "it is capable of detecting smaller growths than the current methods [of mammography] and doesn't use harmful radiation". The new bra is going to be tested by a Chinese company. If the results are good, you could find one in your doctors surgery within 3-5 years.
Magnetic resonance spectroscopy (MRS) for the non-invasive detection of breast cancer
8th Jun 2002
|
Why do we have leap years ? Anne, Cottenham |
|
the reason is that a year - the time it takes the earth to complete its journey around the sun - doesn't actually have a full number of days in it - in other words there is a small amount of extra time left over at the end of the year. So we add an extra day every 4 years to keep things synchronised. But, this still leaves a small error which calendar-makers correct for by skipping a leap-day 3 times every 400 years ! To work out which ones to leave out if the first 2 digits of the year are not divisible by 4 then they are skipped - so in the last 400 years, 1700, 1800, 1900 were NOT leap years (because 4 doesn't go into 17, 18 or 19), but 2000 was. |
June 2002 |
|
|
Can you really break a glass with your voice and if so, how ? Paul, Bourn |
|
Yes, but with difficulty. The science behind it is that all objects have frequencies at which they naturally vibrate - you know that annoying rattle in your car that tends to be worst at certain speeds ? These frequencies are called resonant frequencies. When a singer makes a note sound waves travel through the air as a pressure wave which we hear because it makes our ear-drum vibrate in sympathy. In the same way a wine glass will vibrate. If you can hit the resonant frequency of the wine glass, by singing just the right note, and make the note loud enough, eventually the glass will try to vibrate more that the material is able to and it will shatter. |
June 2002 |
|
|
Why does your hand look funny if you wave it quickly in front of the television or a computer screen ? Alex, Jesus Lane, Cambridge |
|
This is due to an effect called strobing. Although the computer screen looks like it is displaying a continuous picture, the image is actually being replaced with a fresh one between 65 and 100 times a second, so the screen behaves a bit like a large camera flash, taking 100 pictures per second. Since our eyes can only see things that are flashing at less than about 25 times per second, we see a continuous image on the screen. So what happens to your hand ? When you wave the screen is essentially taking a series of rapid snapshots of your hands, giving the bizarre impression that your fingers are jumping across the screen, and that you can see through them. |
June 2002 |
|
The contents of this site are © The Naked Scientists® 2000-2008. The Naked Scientists® and Naked Science® are registered trademarks.