Laser in the sky

Mon 11 Dec 2023, 17:15

What sort of energy consumption and output would be required to produce a beam of that dimension? And why purple or is there no technical restraint on colour apart from preference? Never got a viewing perspective to see any curve in the beam.

Sun 10 Dec 2023, 10:28

The tenant of Cornbury Park is David Howden who set up the Howden Insurance Group -- A-Plan Insurance recently merged with this group and changed its name to Howden Insurance. It was David Howden's 60th birthday party, as Andrew Chapman also indicated.

Not "fancy" -- the story of Howden is here: https://www.howdengroup.com/uk-en/about-us

Sun 10 Dec 2023, 00:28

Who was the private party for??? Must be someone fancy with that beam that could be seen from Deddington!

Sat 9 Dec 2023, 22:47

So it turned out they were trying out the Galvanic Beam ready to bigenerate Doctor Who this eve. 

Sat 9 Dec 2023, 22:12

Harriet, interesting choice of name when commenting on a group of disgruntled forum peeps. Thanks 

Sat 9 Dec 2023, 21:05

My grandchildren and I think that it looks beautiful ❤️

Sat 9 Dec 2023, 19:58

Is the river related to Liz?  Had they asked its permission?

Sat 9 Dec 2023, 19:08

Leicester had a Diwali laser, 7 miles long highlighting the river Soar. I wonder how many people complained about that? It'd have been cleared by all the necessary agencies, environmental and otherwise.

Sat 9 Dec 2023, 18:42

Just to add to that, I’ve estimated that for a laser beam of diameter 5 cm to ionise the air around it would need a laser of  more then 23 mega watts. The lasers used in light shows are of the order of several watts, so several million times too weak. 

Sat 9 Dec 2023, 18:28

They would see a curved beam, just with a different perspective. The atmospheric bending is unrelated to the effects of a plasma, which requires a laser of massively higher intensity than would be used in a laser show. A laser beam of that sort of intensity will actually have sparks and a corona around it. 

Sat 9 Dec 2023, 18:28

They would see a curved beam, just with a different perspective. The atmospheric bending is unrelated to the effects of a plasma, which requires a laser of massively higher intensity than would be used in a laser show. A laser beam of that sort of intensity will actually have sparks and a corona around it. 

Sat 9 Dec 2023, 18:26

Can be seen very well from my in-laws house in Kings sutton

Sat 9 Dec 2023, 18:16

Paul / Frank - what would someone in a plane see, flying over it? An arch as well? Or a straight beam? 

Sat 9 Dec 2023, 18:11

Does anyone have any idea on timings for tonight’s laser light show? Really looking forward to it….

Sat 9 Dec 2023, 18:11

Does anyone have any idea on timings for tonight’s laser light show? Really looking forward to it….

Sat 9 Dec 2023, 18:02

Beware of having a noise abatement order served on Cornbury if you crank up the music too loudly when it's not a public event. We had one served on us at at Cornbury when Geno Washington played there for us!

It was a while ago!

Sat 9 Dec 2023, 15:51

Rest assured, Harriet, if Wilderness (or Blenheim, for that matter) ever stage something on the scale of last night’s bat cave signal, I’ll object to that too. Happy Christmas!

Sat 9 Dec 2023, 14:11

Surely a silent light show is 100 times better than fireworks?  Good luck and happy birthday to the birthday boy hope he has a lovely weekend.  

Sat 9 Dec 2023, 13:28

I don’t think the owls have been invited…..

Sat 9 Dec 2023, 13:16

Interesting observation that nobody complained when wilderness had a laser display, people wanted to be able to see it, but for a private party all the Karens come out. 

Sat 9 Dec 2023, 12:31

Has anyone considered the owls?

Sat 9 Dec 2023, 07:49

John, you can sleep safely knowing that the laws of physics are safe. The bending of the light beam occurs because the refractive index of the atmosphere decreases with height causing the beam to gradually bend. On a hot day the opposite happens and when the ground is very hot the refractive index of the air near the ground decreases and light from the sky is reflected creating a mirage.

Sat 9 Dec 2023, 07:28

What a brilliant thread. Cheered me up no end.

Fri 8 Dec 2023, 23:39

Apparently a certain local insurance magnate turns 60 this month. Presumably he thinks it’s cool too.

Fri 8 Dec 2023, 23:37

The kids on the way back from the carol service at St Mary’s thought it was terrific. (“Santa’s letter delivery” was one theory I heard advanced.) And who can deny that a purple laser in the sky is a really cool thing if you’re 7.

Fri 8 Dec 2023, 22:45

It really upset my pet hamster 

Fri 8 Dec 2023, 22:11

Here you go............now you know why it curves??!!

June 2009 Issue

The Sciences

Two years ago physicists demonstrated that a laser beam traveling through the air can bend slightly if certain components are asymmetrical, forming what is called an Airy beam. Now researchers have shown that pulsed, high-intensity versions can leave curved trails of plasma. Shot out like a stack of pennies, each pulse, one centimeter wide and lasting 35 femtoseconds, passes through a glass plate that turns it into a triangular shape, in which an intense peak falls on one side of several weaker peaks. The brightest part heads in one direction, while the dimmer ones go the opposite way. (The momentum of the entire pulse remains straight, however.)

Being extremely intense, the bright spots ionize the air behind them and leave a curved plasma stream in their wake. The self-bending beam, described in the April 10 Science, does not curve by more than the beam's diameter, but that amount is enough to help physicists probe the structure of laser pulses.

Fri 8 Dec 2023, 20:25

The laser beam was incredibly distracting when driving back to Charlbury after dark. Let’s hope tomorrow’s light show is worth it for the party guests and that it doesn’t cause any accidents. The sheer arrogance of projecting light across a distance of several miles as part of a private party is breathtaking.

Fri 8 Dec 2023, 20:06

There are no planned fireworks 

Fri 8 Dec 2023, 20:03

Please don't let there be fireworks!!

Fri 8 Dec 2023, 19:51

Hi All,

Just a quick message to confirm aliens (or advance parking technology) haven’t landed near Charlbury; and it is testing for a light show at a private party at Cornbury House tomorrow night.

We are hoping for great weather after an initial wet start tomorrow - so keep your eyes peeled for more.

Apologies in advance if noise travels in the wrong direction tomorrow evening… everything has been set up to limit any impact as much as possible.

We (and the the deer) are looking forward to seeing everyone on New Years Day. 

Fri 8 Dec 2023, 17:58

Yes, but the one I've just seen from a footpath starts picometer size at ground level and gets bigger the closer it gets to the clouds.

And, much though we'd all support SUV-devastating lasers (and many of us would vote for a rate precept to authorise buying one if the Government ever got round to giving British people control over their local spending), Star Wars technology works the other round. 

Anyway: Michael Gove would refuse funding.

Fri 8 Dec 2023, 17:31

It's rumoured to be West Oxon's new parking control system based on star wars technology. It can pinpoint yellow line infringements in a nanosecond, accurate to a picometer and then obliterate the offending vehicle with minimal damage to the surrounding area. 

Fri 8 Dec 2023, 16:54 (last edited on Fri 8 Dec 2023, 16:55)

Anyone know why there's an incredibly bright light beam, changing colour, emanating from behind Cornbury House? Aliens?! Celebrating Robert Courts's elevation? There seems to be another from Ditchley too.

Fri 8 Dec 2023, 16:54

There’s a laser beam coming from maybe Witney direction shining in the sky. How does it appear curved? This puzzles me, as an Engineer. Ye canny change the laws of physics!