"Please Violate the Laws of Physics for Me" - When the Customer Cannot Be Right
In my workplace, a common joke is: “Just let me know which laws of physics you want violated, and I'll work you up a budget.” This quote is originally attributed to a NASA engineer.
I asked the chief engineer how often we received requests that actually violate the laws of physics, and he said, “For the consulting projects, about once a week.” In a review of our most recent consulting projects, I found he was right.
Common Requests That Violate the Laws of Physics
A periodic request we receive is a design project asking for an antenna much smaller than what could conceivably handle the frequencies they want to receive. In one case, someone requested an antenna design for an antenna with the gain of a 10-foot dish in an antenna the size of a postage stamp. You can have an antenna the size of a postage stamp, or the gain of a ten-foot antenna – but you cannot have both. There are times when an array of small postage stamp antennas is the solution.
The frequent real-world solution is for the person to get an antenna larger than they’d like to have performance similar to their requirements. Or, due to budget, they get an antenna smaller than they’d like that doesn’t hit the lowest frequencies.
This customer-request dilemma should be contrasted to the situation where the engineering team doesn't know the operating conditions, thus contributing to failure of the product in the field. For example, in one case, already-hot operating temperatures plus the Arabian Desert in the summer added up to temperatures darn near solder-reflow temperatures. FPGA components started to detach from the motherboard, leading to failure.
Human Errors and Ignorance
We get more exotic requests from people who don’t understand physics at all. One man wanted assistance designing a solar energy collector that let light in but didn’t let energy out. The design engineer let him discuss his idea with the intent of finding out why he thought this was possible at all. When he said it was the same energy source aliens used to run their space ships and NASA was keeping it secret, he was politely dismissed.
We’ve received repeated requests for designing energy-harvesting antennas. Yes, you can harness the energy from radio waves, Wi-Fi signals and so forth. However, unless you are sitting right underneath the local FM station’s tower, you can’t collect much energy. The wireless energy collected is partially lost in conversion to electrical energy. Thus energy harvesting is possible via receiving antennas, but it isn’t an economical way to power another receiving device. This is the reason wireless power systems typically require you to put your device on the surface that is charging it; and the benefit of that is eliminating the wires and plugs, not efficiency. Solar arrays located in space that beam down energy to receiving antennas on Earth would be efficient in part because there’s relatively little loss sending energy down from space and because they could be huge in the first place.
One common engineering joke is that hardware engineers assume software can solve everything while software engineers assume hardware can solve everything. When it comes to software-defined radios, many engineers assume that one single, simple antenna can be matched up with the all-purpose software defined radio. In short, if the SDR can process anything, there must be an antenna that can receive anything, too. In reality, you can have one antenna that receives all signals but none of them without heavy interference, or an array of antennas that receive a frequency range well.
There are bizarre requests that turn out to be failures in translation. One German customer seemed to want something that was out of science fiction, when in reality it was someone trying to translate low “free space path loss” from German to English as a technical specification. Free space path loss had been translated by Google into "it's the road you are traveling along, they are not charging you to travel on the road but it is costing you to travel on the road." This story is a result of my time working with Kent Britain, WA5VJB, of Kent Electronics.
The team commonly gets requests to design a very specific type of antenna with tight tolerances and performance specifications, only to be rebuffed when told how much it will cost.
Just because you can dream it up doesn’t mean you can achieve it, especially when the laws of physics are involved. With a good engineer, a real-world compromise in design can be achieved—if you have sufficient budget.