Comments on: Make your coffee with a laser

By: danielrigano

danielrigano — Sun, 15 Nov 2009 06:31:29 +0000

I think I can cook my dinner with the laser pointer.

By: penske

penske — Sat, 31 Mar 2007 22:08:34 +0000

While you guys are all wondering about the state of the coffee…

I’m more curious whether or not those guys are still employed there.

By: hangman

hangman — Fri, 30 Mar 2007 20:54:15 +0000

i want a laser

By: Aaron

Aaron — Fri, 30 Mar 2007 19:54:12 +0000

Gotta take into account heat losses to ambient, and also to the cup. Though the laser wasn’t heating the cup, it was heating the liquid, and via conduction heat was transferred to the cup. Also different materials have different heat densities-water holds a LOT of heat. Hence being used in nuclear reactors as coolant, steam plants for heat/electricity/propulsion (like subs and carriers), orange groves to prevent freezing, etc.
The heat/energy required to push water over that limit to boiling (thus a ’saturated system’) is quite a bit. I can’t remember exactly the equations…learned them ages ago in nuke school.
Oh, that’d also explain why the water didn’t ‘explode’ out of the cup when he put the teabag into the water-wasn’t superheated. Under normal conditions, water will NEVER exceed 100 c, unless the water is distilled so that there ar no impurities and the cup/container is absolutely smooth, so that there’s no surface for steam bubbles to effectively form. Only under those conditions…or increase the pressure of the system.
Hope that answers questions.

By: Fionny

Fionny — Fri, 30 Mar 2007 02:15:19 +0000

Coffee with less then a spoon full of granules. Weak…. i thought sciency people would at least have 2 spoonfulls. what was in that jar wouldve done 2 cups max…

By: william42

william42 — Thu, 29 Mar 2007 19:31:00 +0000

ok u thought lasers were only like red ppl – but go to http://www.wickedlasers.com and they actually sell blue and green ones too! – bit expensive though

By: Zeiris

Zeiris — Mon, 26 Mar 2007 11:46:21 +0000

@16: Heating is uneven, so no. Would be interesting to see the same thing done in a test tube though.

By: charles

charles — Mon, 26 Mar 2007 03:53:18 +0000

yeah, i know. i mean, we’re comparing a boring old microwave oven to a frickin’ laser! by my count, though, the time(starting from the time they pushed the button that says, “go” to the time that the water boiled over) was about 25 seconds. nearly half the time that it takes for a decent microwave(not the one that’s been in your mother’s kitchen for the last 20 years) to heat up a cup of water to a good degree for coffe drinking. now consider the time it takes for that boiling water to cool down enough that a human can drink it without seriously damaging his flesh, then we have an obvious winner. not to mention all that energy wasted with the laser has a direct effect at the gas pumps.

that laser “hack” is not nearly as practical as you try to make it seem. in theory, lasers are definitely cool. put to good use, such as eye surgery, the absolute coolest, but any 4th grader could tell you, yes, lasers can make water hot. it’s to be expected. this demonstration was just completely lacking in any WOW factor and a microwave is so much more efficient and practical. if the purpose is to show how to move backwards, though, these guys hit the nail right on the point.

By: theTick197

theTick197 — Mon, 26 Mar 2007 02:52:44 +0000

i want to see them make coffee with freaken sharks that have freaken laser beams attached to their head.

By: smilr

smilr — Mon, 26 Mar 2007 02:03:59 +0000

Re: laser vs microwave heating.

the average kitchen microwave will take upwards of 2 minutes to heat a cup of water like those shown to boiling. This laser did the same in roughly 18 seconds. I say the laser wins that speed competition.

By: Mr Jones

Mr Jones — Mon, 26 Mar 2007 01:13:12 +0000

As we all probably know, the definition of “HACK” is dicey and debatable at best—but using LASERS to heat COFFEE??? Now, in my opinion…anybody who does not agree that cooking coffee with lasers is a cool hack needs to turn in their tools and hang up their soldering iron.

on a 1-10 i give it 7 and a half stars with honorable mention of “high coolness factor” but only 7.5 because i dont like coffee. Still its a bit improbable that the average “hardware hacker” will ever get to test this with his (or her) own laser but, cmon! lasers that do ANYTHING besides LOOK cool (which they do very well) including but not limited to ray-guns, light sabers, laser pointers, laser copiers, and YES even laser-coffee makers. are very, very cool. Making lasers do anything different from what they have done in the past is righteous by Mr Jones’ standards……now post some youtube of it cooking a muffin and an egg and a slice of sausage and post the first ‘Laser-cooked egg-mc-muffin” video and ill give you a 9.5 stars!

By: ...

... — Sun, 25 Mar 2007 23:28:42 +0000

The beam appears blue under the camera because cameras don’t know how to respond to IR light. They try to filter as much as they can out, but what does get through usually ends up in the red or blue detectors in the camera.

Nd:YAG only lases at ir wavelengths, the strongest line is 1064nm (that is what this one operates at, it is shown clearly at the beginning). To get the blue/green/red lines you use one or more nonlinear optics, q-switches, opo’s, etc.

By: MightyTwin

MightyTwin — Sun, 25 Mar 2007 19:08:45 +0000

You all are some downright arses. I agree with eliot, this is a cool demonstration of a laser’s abilities. I mean, who doesn’t want a 2kv laser at home? :)

Cheers,
MightyTwin.

By: op

op — Sun, 25 Mar 2007 18:09:16 +0000

@15, from what i know the cuting abilities of a laser are mainly dependent upon:
- power and type of laser used (NdYAG or CO2, depending on what material you need to cut)
- diameter of the unfocused beam
- beam quality (gaussian beam is ideal, etc.)
- focal length
- depth of focus
I'm a student and some of my lectures have covered the basics of laser cutting. There are many experts out there though, so hopefully they can either confirm or correct this.

By: Neagle

Neagle — Sun, 25 Mar 2007 09:40:46 +0000

I think I’d go with the tea. Nice way to start the morning. Now I can I justify a PO for a 2Kw laser?