Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Network Covalent Solids02:18

Network Covalent Solids

15.9K
Network covalent solids contain a three-dimensional network of covalently bonded atoms as found in the crystal structures of nonmetals like diamond, graphite, silicon, and some covalent compounds, such as silicon dioxide (sand) and silicon carbide (carborundum, the abrasive on sandpaper). Many minerals have networks of covalent bonds.
To break or to melt a covalent network solid, covalent bonds must be broken. Because covalent bonds are relatively strong, covalent network solids are typically...
15.9K
Escape Velocity01:26

Escape Velocity

8.2K
The escape velocity of an object is defined as the minimum initial velocity that it requires to escape the surface of another object to which it is gravitationally bound and never to return. For example, what would be the minimum velocity at which a satellite should be launched from the Earth's surface such that it just escapes the Earth's gravitational field?
To calculate the escape velocity, it is assumed that no energy is lost to any frictional forces. In practice, a satellite...
8.2K
Rocket Propulsion in Gravitational Field - II01:03

Rocket Propulsion in Gravitational Field - II

2.7K
A rocket's velocity in the presence of a gravitational field is decreased by the amount of force exerted by Earth's gravitational field, which opposes the motion of the rocket. If we consider thrust, that is, the force exerted on a rocket by the exhaust gases, then a rocket's thrust is greater in outer space than in the atmosphere or on a launch pad. In fact, gases are easier to expel in a vacuum.
A rocket's acceleration depends on three major factors, consistent with the...
2.7K
Rocket Propulsion in Gravitational Field - I01:20

Rocket Propulsion in Gravitational Field - I

3.2K
Rockets range in size from small fireworks that ordinary people use to the enormous Saturn V that once propelled massive payloads toward the Moon. The propulsion of all rockets, jet engines, deflating balloons, and even squids and octopuses are explained by the same physical principle: Newton's third law of motion. The matter is forcefully ejected from a system, producing an equal and opposite reaction on what remains.
The motion of a rocket in space changes its velocity (and hence its...
3.2K
Rocket Propulsion in Empty Space - I01:13

Rocket Propulsion in Empty Space - I

3.7K
The driving force for the motion of any vehicle is friction, but in the case of rocket propulsion in space, the friction force is not present. The motion of a rocket changes its velocity (and hence its momentum) by ejecting burned fuel gases, thus causing it to accelerate in the direction opposite to the velocity of the ejected fuel. In this situation, the mass and velocity of the rocket constantly change along with the total mass of ejected gases. Due to conservation of momentum, the...
3.7K
Escape Velocities of Gases01:19

Escape Velocities of Gases

1.3K
To escape the Earth's gravity, an object near the top of the atmosphere at an altitude of 100 km must travel away from Earth at 11.1 km/s. This speed is called the escape velocity. The temperature at which gas molecules attain the rms speed, which is equal to the escape velocity, can be estimated by using the equation for the average kinetic energy of the gas molecules. According to the kinetic theory of gas, the average kinetic energy of the gas molecules is proportional to its...
1.3K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk.

Science (New York, N.Y.)·2024
Same author

Light from cosmic dawn hints at how interstellar dust is made.

Nature·2023
Same author

Author Correction: Spectroscopic evidence for a large spot on the dimming Betelgeuse.

Nature communications·2021
Same author

Spectroscopic evidence for a large spot on the dimming Betelgeuse.

Nature communications·2021
Same author

[Research Progress on the Detection Method of DNA Methylation and Its Application in Forensic Science].

Fa yi xue za zhi·2017
Same author

Mapping the central effects of chronic ketamine administration in an adolescent primate model by functional magnetic resonance imaging (fMRI).

Neurotoxicology·2011

Related Experiment Video

Updated: Jan 3, 2026

Preparation of Carbon Nanosheets at Room Temperature
10:44

Preparation of Carbon Nanosheets at Room Temperature

Published on: March 8, 2016

12.4K

How much graphene in space?

Qi Li1,2, Aigen Li2, B W Jiang1

  • 1Department of Astronomy, Beijing Normal University, Beijing 100875, China.

Monthly Notices of the Royal Astronomical Society
|November 26, 2019
PubMed
Summary
This summary is machine-generated.

The interstellar medium likely contains very little graphene, with abundance limits significantly lower than previously estimated. Researchers also found no evidence for C24 molecules in interstellar dust, setting new upper limits on their presence.

Keywords:
ISM: lines and bandsISM: moleculesdust, extinctioninfrared: ISM

More Related Videos

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy
10:12

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy

Published on: September 21, 2020

7.5K
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
11:42

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Published on: July 24, 2015

15.9K

Related Experiment Videos

Last Updated: Jan 3, 2026

Preparation of Carbon Nanosheets at Room Temperature
10:44

Preparation of Carbon Nanosheets at Room Temperature

Published on: March 8, 2016

12.4K
Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy
10:12

Graphene Enclosure of Chemically Fixed Mammalian Cells for Liquid-Phase Electron Microscopy

Published on: September 21, 2020

7.5K
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
11:42

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Published on: July 24, 2015

15.9K

Area of Science:

  • Astrochemistry
  • Materials Science
  • Astrophysics

Background:

  • Graphene's potential presence in the interstellar medium (ISM) is debated.
  • Previous estimates of interstellar graphene abundance relied on spectroscopic ellipsometry (SE) data.

Purpose of the Study:

  • To investigate the abundance of graphene and C24 in the ISM.
  • To refine upper limits on interstellar graphene using electron energy loss spectroscopy (EELS).

Main Methods:

  • Comparing interstellar extinction curves with graphene's UV absorption calculated from EELS-derived dielectric functions.
  • Analyzing infrared emission spectra for characteristic C24 vibrational bands.

Main Results:

  • The interstellar extinction curve lacks graphene's characteristic π-π* electronic interband transition.
  • An upper limit of 10^-7 C/H was placed on interstellar graphene abundance, 3 times lower than SE-based estimates.
  • No characteristic vibrational bands of C24 were detected in observed infrared emission.

Conclusions:

  • The interstellar graphene abundance is significantly constrained, likely being very low.
  • The absence of C24 vibrational features sets a new upper limit on its interstellar abundance.
  • EELS provides more reliable dielectric functions for graphene than SE due to less surface contamination.