Saturday, 25 June 2016

Mike's Bees!

Mike, a work colleague of NSB, has recently undertaken a course in Beekeeping and with a view to having his own hive. Thought that it might be worth sharing Mike's Beekeeping story with you!

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3rd April
"First beekeeping lesson! Great fun."

Todays Beekeeping suits look GOOD!

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10th May
"The beekeeping stuff arrived today! It's like Christmas! Tried on the bee suit, God it's hot. Now, all I need is some bees, maybe I should get a net."
Showtime!

"A beehive typically consists of two distinct parts. A brood box and a Super. The brood box is usually about a foot tall and contains large frames upon which the bees can build honeycomb and raise more bees. When the frames are almost full the beekeeper puts a grid called a "queen excluder" on top of the brood box -this grid is specially sized so that workers can get through but the queen can't - then puts on a Super filled with frames.

Schematic of a beehive 

Mike's brand new hive, smoke gun and tools

The Super is usually half the height of the brood box. The bees then fill the Super frames with honey but because the queen can't get up there there's ONLY honey - makes it easy to extract.

So that's the basics, if you get lots of bees you can add more Supers - more Supers = more honey. If a beehive gets too crowded the workers will create a queen cell , grow a queen, she (or sometimes the old queen) will then leave the nest with about half the bees - which is why you sometimes get swarms."
Incidentally, the hive, like most in the world is based on the Langstroth design from the 19th century. This was the first design that allowed individual combs t obe removed and took advantage of the observation by Huber that bees would keep a "bee space" of 5-8mm between combs. As this is the space between the combs in a Langstroth hive, the bees to not join the combs up. This enables the beekeeper to slide any frame out of the hive for inspection, without harming the bees or the comb, protecting the eggs, larvae and pupae contained within the cells. It also meant that combs containing honey could be gently removed and the honey extracted without destroying the comb. The emptied honey combs could then be returned to the bees intact for refilling. Langstroth's book, The Hive and Honey-bee, published in 1853, described his rediscovery of the bee space and the development of his patent movable comb hive.

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22nd May
"Interesting beekeeping tidbit I picked up from today's lesson.....bees can sting through your protective rubber gloves. Little sod. Still, I took it like a man, no crying or screaming, just a "ow you little git - you die now!" (which of course he was going to anyway, still........)"

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12th June
"I was given a hive chock full of bees by a chap who had to give it up because he became dangerously allergic to bee stings (this can happen). As a result the beehive I got had not been inspected for 8 months - you're supposed to check them weekly when it's warm and dry enough.

Got to the allotment, the hive is very heavy but can't check it for about a week to let the bees settle.

There is a big IF about them settling down, common bee rules state that you move a hive either 3 feet or a minimum of 3 miles otherwise the bees will go back to the original spot. Well we've moved them just under 3 miles so they might not stay - we're keeping our fingers crossed."

The 2nd Hand Hive, complete with bees...

So how do bees make honey? Well, what happens is that the worker bees extract nectar from flowers and store this in their extra stomach (called a "crop") where it is chemically modifed by enzymes. When back in the hive, the honey is passed between bees several times by regurgitation until it is eventually placed in in a honeycomb. But it is still a thin liquid, so bees flap they wings to evaporate much of the water off before sealing the honeycomb cell with wax.

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18th June
"The girls seem to have settled in! Gonna open up the hive tomorrow and see what sort of population I have. The hive could be full of honey or full of disease or parasites, I'll find out tomorrow, fingers crossed."

Video here

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19th June
"Well I did it. Took the top off and unfortunately the top super (layer) didn't have any frames so the bees have made their own combs. Also, there's eggs and larvae in the upper layers so no idea what's going on there. Gonna have to bring in an expert. No sign of disease though."
.....A lot of bees

Bees had got busy in the top section of the hive,
 making their own honeycombs

Video here

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24th June
"So today, with the help of an experienced keeper I took a look at what I had. The hive consisted of TWO Supers and a brood box. The queen excluder was on top of the brood box. So far so good. We saw that the top Super had no frames and so the bees had build their own combs which were all over the place. We decided to look at that last because it was heavy (hopefully with honey).

We looked at the middle level Super. LOTS of bees, AND grubs and sealed brood cells and honey - obviously the queen had got above the queen excluder, there shouldn't have been young bees in there. No sign of the queen though - you check every time for the health of the hive and to make sure that the queen is OK, she's hard to find in 50,000-odd bees because she's only a bit bigger, so as long as you can find eggs in cells you know the queen is in there somewhere and still working hard. Well we found no eggs, so we took off the queen excluder and checked the brood box. Every frame had either empty cells or cells with nectar, pollen or honey. No queen, this is bad, very bad- she may have left but in that case why were there still so many bees in the hive?

Beekeepers! This is not the Queen you are looking for...

We decided that maybe we'd missed something and we'd check again the following week. So, to the top Super with the natural combs. We took the cover off and it was brimming with bees, there was brood in the cells too. With natural comb we couldn't look for the queen but we did find a capped queen cell (with a pupating queen) AND an uncapped one with a queen larva inside. Maybe the queen is in this level then.

...Neither is this...

So, no honey for me and a real conundrum. The beekeeper and I discussed various options. Eventually we came up with a real risky plan. I have a spare empty hive so, we carefully (VERY carefully) cut the capped queen cell from the natural comb, we then placed it in the older hive carefully UNDER the queen excluder. The plan is that this queen cell will be tended by the existing bees and she'll take over (she'll have to leave the hive to mate and hopefully come back). We then put a new Super on top with new frames in it.

....close, but still no cigar..

The other crammed Super was placed on top of the new hive brood box with no queen excluder (they call it a brood and half), hopefully the bees will use the extra space in the brood box to keep going. If the old queen is in there and a new queen hatches they might not swarm because there's lots of space for them now so they'll probably fight to the death, cruel but that's survival of the fittest for you.

...Bingo !

Eventually I'll have to get the bees out of the natural honeycomb, destroy it and put in proper frames but that's a long way off.

So, no honey for me yet BUT, if my plan works I might end up with TWO hives - of course I could end up with two dead hives if it doesn't work. Fingers crossed."

7th July 2016
Thought it might be nice to fill in a little information about the group that provided beekeeping training to Mike - the Chesterfield and District Bee Keeping Association.

The CDBKA website is very good, and contains a lot of interesting information. For example, did you know that worker bees only live for 4-6 weeks - except for the last brood of the year that live all through the winter maintaining the hive (and keeping it warm by flexing their thoracial wing muscles to create heat)? No? Neither did NSB until reading one of the articles on the CDBKA website.

Lots of fascinating info on the "General Beekeeping" page also, including an article on how Australian researchers have been placing tracking backpacks on bees to study their behaviour!

Bee with a backpack, obviously!

An article on the CDBKA can be found on the "Bee-Craft" website, which bills itself as the "The Informed Voice of British Beekeeping". The article describes how the group worked hard to replace the post-war beekeepers who were retiring at the end of the 20th Century, and managed to increase members by 19% year on year. This growth in interest was then accelerated by media articles sounding alarm at bee population levels - in one 18 month period members increased from 85 to 160!

And the CDBKA has some high profile alumni, for example, Kim Schofield, beekeeper at the Longshaw Estate.

Related links
Nottinghamshire Beekeepers Association
Derbyshire Beekeepers
Article on how African Farmers use beehives as elephant repellant
The National Bee Unit

Related NSB Content
Talk on reproduction in Bedbugs
Talk "From Soil to Supper"
Wildlife in the Garden
Talk on Dungbeetles and Drugs

Image Sources
All by kind permission of Mike, excepting the following:
Bee with Backpack; Queen, Queen, Queen, Queen

Tuesday, 24 May 2016

Talk : Gravitational Waves I: From Newton's law to black holes and space-time ripples

Another guest post from Gav, who attended a BSA talk recently (with linkage from NSB).....

Back in February, a paper was released confirming that gravitational waves had been discovered at LIGO. Dr Thomas Sotiriou from the School of Mathematical Sciences and the School of Physics & Astronomy speaks at the British Science Association's Public Lecture Series on how we got from Newton to space-time ripples.

The signal that LIGO detected was from two black holes colliding a billion light years away. Each of the black holes was 30 times larger than our sun and the collision lasted for less than a second. 30 solar masses is equivalent to around 10,000,000 Earths (about 10 to the power of 32 kilograms) At the collision, the equivalent of 3 solar masses of energy was emitted - this is enough to power a billion Earths for a billion years. Gravitational waves travel at the speed of light so it took a billion years for the wave to reach LIGO.

Northern leg of the LIGO interferometer

Isaac Newton revolutionised physics - his laws of motion and his theory of gravity described how objects move in space. He also recognised that motion is a relative concept. So, while objects do not start spontaneously start moving, inertia also applies to things moving at a constant speed. Newton realised that acceleration was linked with force and forces tell bodies how to move in space. The key point though was the fact that his laws could be tested quantitatively.

James Maxwell came up with theories about light and magnetic fields. He believed that light was a wave while Newton had been convinced that it was a particle. Diffraction patterns verified Maxwell's theory but this behaviour meant that light contradicted Newton's laws of motion - it can propagate in a vacuum and it doesn't obey Galilean relativity.

Albert Einstein set out to solve these issues. He came up with a new relativity principle - The only way for two moving observers to measure the speed of light in the same way is if they are measuring time and space differently. It agreed with Newton's laws of motion for objects at low speeds and it agreed with Maxwell for objects close to the speed of light. He realised that different observers who move with respect to each other don't even agree on space and time - they can experience things at different times or in different places. Space and time are not fundamental entities so Einstein came up with space-time.

However, he wasn't happy with his special theory of relativity because it didn't agree with Newton's theory of gravity (which Newton had created to work with his laws of motion) So, Einstein chose the most drastic way to deal with this - he tossed gravitational forces away completely. Where Newton's forces steer bodies, Einstein realised that you don't need forces to steer. If mass could curve space and another body existed in that space then it would be forced to follow that curve. Curvature = matter distribution.

Dr Thomas Sotiriou

This was Einstein's general theory of relativity. Formulated in 1915, it was verified in 1916. It improved observations of planetary orbits. For example, it predicts the precession of Mercury which Newton did not. Newton also thought that light would not be effected by gravity but Einstein predicted that it would follow the curvature of space-time. This was verified during a solar eclipse when Arthur Eddington saw changes in the known locations of stars.

As bodies move, the curvature that they create in space-time also moves - this creates waves - any body moving in space-time will produce gravitational waves. It takes energy to produce these waves - this energy is lost to the system so objects move closer together. This effect is tiny but it does mean that planets in the solar system are moving closer together - no orbit is really stable. Gravitational waves in the solar system are too small to detect so we need to look at something else. The way to get a lot of gravity is to pack a lot of mass into a very small space.

Which leads us nicely onto the life cycle of stars. Through nuclear fusion, stars create heavier elements out of hydrogen. Up to the formation of iron, this always creates energy. As the energy increases the star wants to expand but gravity keeps it in check. However, once iron tries to fuse with iron, the reaction loses energy and then the star starts to collapse. If it becomes small enough, its density will prevent any further collapse and you're left with a white dwarf. Stars with more mass keep compacting until the density reaches such a level that electrons and neutrons combine. At this point one of two things happen: either it stops collapsing and you have a neutron star or it keeps collapsing and becomes a black hole.

Now we know that not even light can escape a black hole but what does that actually mean. Well, with a big enough sling you could throw stones at the moon ie there is a speed that you can fire something at to make it leave Earth. This is the escape velocity. With a black hole, not even something travelling at the speed of light, the speed limit of the universe, can escape. John Michell first proposed the idea of "dark stars" back in 1784. He even gave a way to detect them - since you can't see them, you must look for their effects.

While the LIGO announcement is huge news, a Nobel prize was awarded in 1993 for the discovery of a new type of pulsar. A pulsar is a neutron start with a very powerful magnetic field and it emits radiation down its magnetic axis. If you are in the right location, you can detect this radiation. If there is another star orbiting around the pulsar, the gravity of this second star will affect the emission of the pulsar's radiation. This gives an indirect way of detecting gravitational waves. Of course, the LIGO discovery trumps this as it is a direct observation.

What does the discovery of gravitational waves mean for the future? Well, it's like a new pair of eyes for us to look through at the universe. Rather than using electromagnetic telescopes, we can now use gravitation waves to experience the universe in a completely different way.

The next talk in the Public Lecture Series is by Dr Helvi Witek on June 16th at 6pm at the University of Nottingham and the topic is Gravitational Waves pt II - How are they detected? For more information, check out the website: http://www.nottingham.ac.uk/physics/outreach/science-public-lectures.aspx

Image sources
Dr Sotiriou via Gav
LIGO