[dramatic percussion music]
- HEY, WELCOME TO "NASA LAUNCHPAD."
I'M YOUR HOST, VINCE WHITFIELD.
YOU REMEMBER US TALKING ABOUT CRYOGENICS
WITH AEROSPACE ENGINEER ROB BOYLE
HERE ON "LAUNCHPAD," RIGHT?
ON THAT EPISODE, WE FOCUSED ON THE USE OF CRYOGENICS
IN TRANSPORT SYSTEMS.
BUT ROB WANTED US TO LET YOU KNOW
THAT HIS PRIMARY AREA OF FOCUS
HAS BEEN IN A DIFFERENT AREA OF CRYOGENICS.
- MOST OF THE WORK I'VE DONE HERE AT GODDARD
HAS BEEN THE USE OF CRYOGENICS FOR EARTH SCIENCE
AND SPACE SCIENCE APPLICATIONS.
DETECTORS THAT WE USE FOR LOOKING AT THE WORLD,
PARTICULARLY IN THE INFRARED WAVELENGTHS,
NEED TO BE OPERATED COLD,
LIQUID NITROGEN TEMPERATURE AND BELOW.
AT THOSE TEMPERATURES, THEY HAVE HIGHER SENSITIVITY,
LOWER NOISE, AND THEY DON'T SUFFER FROM THE GLOW
THAT YOU WOULD HAVE FROM THE THERMAL BACKGROUND.
YOU CAN SORT OF IMAGINE SOMETHING THAT'S BEEN STUCK
IN A FIRE GLOWING RED-HOT.
WELL, IT TURNS OUT THAT EVERYTHING IS GLOWING.
YOUR EYES AREN'T SENSITIVE TO THE LONGER WAVELENGTHS
THAT YOU GET FROM ROOM TEMPERATURE OBJECTS
OR EVEN OBJECTS THAT ARE BELOW ROOM TEMPERATURE.
BUT THEY'RE STILL GLOWING,
AND THEY GET IN THE WAY OF THE SCIENCE.
- SO WHEN WE'RE TALKING ABOUT CRYOGENICS,
WE'RE TALKING ABOUT REALLY COLD TEMPERATURES.
BUT HOW COLD ARE WE REALLY TALKING?
I MEAN, I GET CHILLS WHEN IT'S 13 DEGREES CELSIUS OUTSIDE.
THAT'S 55 DEGREES FAHRENHEIT.
HERE'S ROB AGAIN TO HELP PUT IT INTO PERSPECTIVE.
- IN TRYING TO EXPLAIN TO MY KIDS
WHAT IT IS THAT I'M DOING AT WORK,
I TALK ABOUT THE TEMPERATURES THAT WE'RE OPERATING AT
AND THAT IT'S NOT ONLY COLD, BUT IT'S REALLY, REALLY COLD,
THAT THE HARDWARE THAT WE RUN WOULD NOT ONLY BE COLDER
THAN THE NORTH POLE.
IT WOULD FREEZE THE AIR AT THE NORTH POLE.
THE GASES THAT WE HAVE AT ROOM TEMPERATURE,
IF YOU START TO COOL THEM DOWN,
THE MOLECULES IN THOSE GASES MOVE MORE AND MORE SLOWLY
UNTIL AT A TEMPERATURE THAT WE REFER TO AS ABSOLUTE ZERO.
THE ATOMS IN THE GAS STOP MOVING.
AS THE GAS GETS COLDER AND COLDER, IT CONDENSES.
AND WHAT WE SEE AT TEMPERATURES THAT ARE 70 OR 80 KELVIN
IS OXYGEN BECOMING A LIQUID AT 77 KELVIN,
LIQUID NITROGEN STARTING TO FORM.
AND AT TEMPERATURES DOWN AROUND 25 KELVIN,
WE HAVE LIQUID HYDROGEN.
THE VERY LOWEST TEMPERATURE LIQUID, LIQUID HELIUM,
WASN'T ACTUALLY PRODUCED UNTIL 1905, THEREABOUTS,
AND WAS A MAJOR TRIUMPH OF SCIENCE
TO BE ABLE TO GET SOMETHING THAT LOW IN TEMPERATURE.
THE ABSOLUTE TEMPERATURE SCALE IS SOMETHING THAT HELPS US
UNDERSTAND WHAT'S GOING ON WITH THE PHYSICAL PROCESSES
THAT WE'RE WORKING ON
AND HAS PROVIDED A VERY GOOD MODEL
FOR HOW THE MOTION OF THE INDIVIDUAL ATOMS
AFFECTS THE GLOBAL PROPERTIES OF THE MATERIALS.
- BRR.
GIVES ME CHILLS JUST THINKING ABOUT IT.
ROB WAS TALKING ABOUT THE KELVIN SCALE.
NOW, THAT MIGHT SOUND INTIMIDATING TO YOU,
BUT ALL YOU REALLY NEED TO KNOW
IS THAT IT'S JUST ANOTHER UNIT FOR MEASURING TEMPERATURE,
JUST LIKE CELSIUS OR FAHRENHEIT.
THE KELVIN SCALE IS BASED
ON THE KINETIC ENERGY OF AN OBJECT.
KELVIN IS BASED AROUND ABSOLUTE ZERO,
WHICH ALSO TRANSLATES TO AROUND NEGATIVE 273 DEGREES CELSIUS
AND ABOUT NEGATIVE 459 DEGREES FAHRENHEIT.
ABSOLUTE ZERO IS THE COLDEST TEMPERATURE
THEORETICALLY POSSIBLE
AND CANNOT BE REACHED BY ARTIFICIAL OR NATURAL MEANS.
THE ONLY REAL DIFFERENCE IS THAT KELVIN UNITS
ARE NOT REFERRED TO AS DEGREES.
THEY'RE JUST KELVIN.
A TEMPERATURE CHANGE OF ONE KELVIN
EQUALS A TEMPERATURE CHANGE OF ONE DEGREE CELSIUS.
SO THE TWO SCALES ARE VERY SIMILAR,
BUT THEY START AT DIFFERENT POINTS.
SO ANYWAY, CRYOGENICS CAN BE USED IN SCIENCE APPLICATIONS.
BUT WHAT ABOUT A SPECIFIC EXAMPLE?
- ONE OF THE THINGS THAT WE HAVE IN TEST IN THE LAB RIGHT NOW
IS A SET OF MICROSHUTTERS
FOR THE JAMES WEBB SPACE TELESCOPE.
THE MICROSHUTTERS ALLOW SCIENTISTS TO MASK OFF
PARTS OF A SCENE--
IN THIS CASE, SAY,
IT MIGHT BE A FIELD OF GALAXIES AT VERY HIGH MAGNIFICATION
AND VERY LONG WAVELENGTH--
AND ALLOWS THEM TO PICK OUT INDIVIDUAL GALAXIES IN A SCENE
AND MEASURE THE SPECTRUM OF LIGHT
THAT'S COMING OFF OF THAT INDIVIDUAL GALAXY.
THE MICROSHUTTERS ARE SOMETHING
THAT WERE DEVELOPED HERE AT GODDARD
TO ALLOW ONE OF THE JAMES WEBB SPACE TELESCOPE INSTRUMENTS
TO PERFORM MULTIOPTIC SPECTROSCOPY.
IT ALLOWS THE SPACECRAFT TO OPERATE MORE EFFECTIVELY
OVER ITS LIFETIME,
DOING MUCH MORE SCIENCE IN THE SAME AMOUNT OF TIME.
- AND AGAIN, I BET YOU'RE PROBABLY ITCHING TO KNOW
HOW CRYOGENICS COULD POSSIBLY AFFECT YOU.
WELL, YOU DON'T HAVE TO LOOK ANY FURTHER THAN A HOSPITAL.
- ONE OF THE MOST COMMON ENCOUNTERS
BETWEEN THE AVERAGE CITIZEN AND CRYOGENICS
IS WHEN THEY HAVE AN INJURY.
IF YOU HAVE A KNEE INJURY, YOU GO IN FOR AN MRI.
AND YOU'RE ACTUALLY SITTING
INSIDE OF A SUPERCONDUCTING MAGNET
WITH A CRYOGENIC REFRIGERATOR.
THAT VERY INTENSE MAGNETIC FIELD
ALLOWS US TO PROBE THE STRUCTURE OF THE BODY
WITH SPECIAL DETECTORS CALLED SQUIDS,
SUPERCONDUCTING QUANTUM INTERFERENCE DEVICES,
THAT ARE VERY, VERY SENSITIVE
TO MINUTE CHANGES IN MAGNETIC FIELD.
SO BY PULSING THE MAGNETIC FIELD IN YOUR BODY,
YOU CAN ACTUALLY THEN LOOK AT THE REACTION
OF THE INDIVIDUAL MOLECULES
AND MAP OUT THE DISTRIBUTION OF SOFT TISSUE
IN YOUR KNEE OR IN YOUR ELBOW.
YOU CAN LOOK AT BRAIN STRUCTURE.
YOU CAN LOOK AT BRAIN ACTIVITY
AND UNDERSTAND A LOT OF WHAT'S GOING ON IN THE HUMAN BODY.
IT'S AN APPLICATION OF CRYOGENICS
THAT ISN'T VERY OBVIOUS.
YOU CAN SORT OF HEAR THE NOISES IN THE BACKGROUND
WHEN YOU'RE SITTING IN THE DOCTOR'S OFFICE
BUT DON'T REALIZE THAT THERE'S SOMETHING THAT'S AT FOUR KELVIN
SITTING RIGHT NEXT TO YOU.
- JUST TO BE CLEAR,
NASA DID NOT INVENT MRI TECHNOLOGY.
BUT IT HAS CONTRIBUTED TO ITS ADVANCES OVER THE YEARS.
THAT'S NASA FOR YOU,
FROM PEERING WAY OUT INTO OTHER GALAXIES
TO HELPING PEER INTO OUR BODIES.
THAT'S ALL THE TIME WE'VE GOT FOR NOW.
THANKS FOR WATCHING.
FOR "NASA LAUNCHPAD," I'M VINCE WHITFIELD,
AND WE'LL CATCH YOU NEXT TIME.